116946354 substation design

MINISTRY OF ELECTRICITY IRAQ SUPERGRID PROJECTS 400/132 kV SUBSTATIONS CONTRACT NO VOLUME 1 TECHNICAL SPECIFICATION SUBSTATION PLANT VOLUME 2 CIVIL AND BUILDING WORKS, AND BUILDING SERVICES VOLUME 3 SUBSTATION PLANT TECHNICAL SCHEDULES AUGUST 2005

MINISTRY OF ELECTRICITY IRAQ SUPERGRID PROJECTS 400/132 kV SUBSTATIONS CONTRACT NO VOLUME 1 TECHNICAL SPECIFICATION SUBSTATION PLANT AUGUST 2005

r List of Revisions

. Volume 1 - Technical Specification 400kV Substation Plant Issue 3 August 05

LIST OF REVISIONS

Current Rev.

Date Page affected

Prepared by

Checked by (technical)

Checked by (quality

assurance)

Approved by

1 2 3

19.11.04 07.03.05 Aug 05

ALL ALL

SSA SSA/JK JK/MH

JW JW JW

JW JW JW

JW JW JW

REVISION HISTORY

2 07.03.05 ALL Re-assessment following production of 132kV specification 3 Aug 05 ALL Updated with MOE comments and general alignment across

volumes.

r


CONTENT SHEET

VOLUME 1 TECHNICAL SPECIFICATION – PLANT VOLUME 2 TECHNICAL SPECIFICATION & SCHEDULES – CIVIL WORKS VOLUME 3 TECHNICAL SCHEDULES – PLANT

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CONTENTS

Page No. 1. SYSTEM PERFORMANCE..............................................................................1-1 1.1 Topographical and Meteorological Site Conditions ..........................................1-1 1.2 Electrical Design Criteria ..................................................................................1-2 1.3 Insulation levels (All equipment at site altitude)................................................1-2 1.4 Minimum Electrical Clearances in Air ...............................................................1-3 1.5 Structures .........................................................................................................1-3 1.5.1 Factors of Safety ..............................................................................................1-3 1.5.2 Switchgear Structure Stresses .........................................................................1-4 1.6 Switchgear Loadings ........................................................................................1-4 1.7 Electrical Station Services................................................................................1-4 2. GENERAL REQUIREMENTS ..........................................................................2-1 2.1 Intent and Nature of Work ................................................................................2-1 2.2 Standards and Codes.......................................................................................2-1 2.3 Abbreviations....................................................................................................2-2 2.4 Places of Manufacture......................................................................................2-3 2.5 Orders Issued to Subcontractors......................................................................2-3 2.6 Transport ..........................................................................................................2-3 2.7 Safety of personnel ..........................................................................................2-3 2.8 Compliance with regulations ............................................................................2-3 2.9 General particulars and guarantees .................................................................2-4 2.10 Planning and progress reports .........................................................................2-4 2.11 Quality assurance.............................................................................................2-5 2.11.1 Quality assurance requirements.......................................................................2-5 2.11.2 Quality assurance arrangements – quality plan ...............................................2-6 2.11.3 Monitoring by the Engineer ..............................................................................2-6 2.11.4 Contractor quality audits...................................................................................2-7 2.11.5 Control of subcontractors .................................................................................2-7 2.11.6 Inspection and tests .........................................................................................2-7 2.11.7 Construction/installation phase.........................................................................2-9 2.11.8 Non-conformances .........................................................................................2-10 2.11.9 Records ..........................................................................................................2-10 2.11.10 Method statements.........................................................................................2-11 2.12 Design and standardization............................................................................2-11 2.13 Quality of material ..........................................................................................2-12 2.14 Language, weights and measures .................................................................2-12 2.15 Erection, supervision and checking of work on site........................................2-12 2.16 Bolts and Nuts ................................................................................................2-13 2.17 Cleaning and Painting ....................................................................................2-13 2.17.1 Works Processes ...........................................................................................2-14

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2.17.2 Site Painting ...................................................................................................2-14 2.18 Galvanizing.....................................................................................................2-15 2.19 Labels and Plates...........................................................................................2-15 2.20 Erection Marks ...............................................................................................2-16 2.21 Tropicalization ................................................................................................2-17 2.22 Relays, Switches, Fuses and Ancillary Equipment.........................................2-19 2.23 Auxiliary Wiring and Panel Boards .................................................................2-20 2.24 Earth Connection............................................................................................2-22 2.25 Terminal Boards .............................................................................................2-22 2.26 Special tools ...................................................................................................2-23 2.27 Interchangeability ...........................................................................................2-23 2.28 Spares ............................................................................................................2-24 2.29 Packing, Shipping and Storage ......................................................................2-24 2.30 Integral Electric Motors...................................................................................2-25 3. SWITCHGEAR - GENERAL.............................................................................3-1 3.1 Extent of Supply ...............................................................................................3-1 3.2 Substation Design ............................................................................................3-1 3.3 Current Rating & Temperature Limitations .......................................................3-1 4. GAS INSULATED SWITCHGEAR (GIS)..........................................................4-1 4.1 General.............................................................................................................4-1 4.2 Gas Insulated Switchgear (GIS) Enclosures ....................................................4-1 4.3 Gas Insulated Switchgear - Busbars and Connection Chambers ....................4-1 4.4 Enclosure Gas Zones.......................................................................................4-1 4.5 Expansion Joints and Flexible Connections.....................................................4-1 4.6 Future Extensions ............................................................................................4-1 4.7 Gas Monitoring and Handling...........................................................................4-1 4.8 Local Control Cubicles .....................................................................................4-1 4.9 Gas Insulated Bus Duct and Bushings.............................................................4-1 4.10 GIS HV Circuit Breakers (72.5 kV and Above) .................................................4-1 4.10.1 General.............................................................................................................4-1 4.10.2 Circuit Breaker Operating Mechanisms............................................................4-1 4.11 GIS Disconnect Switches .................................................................................4-1 4.12 Earth Switches and Maintenance Earthing Devices.........................................4-1 4.12.1 GIS Earth Switches ..........................................................................................4-1 4.12.2 Portable Maintenance Earthing Devices ..........................................................4-1 4.13 Current Transformers .......................................................................................4-1 4.13.1 General.............................................................................................................4-1 4.13.2 GIS Current Transformers ................................................................................4-1 4.13.3 Current Transformer Primary Injection Tests ...................................................4-1 4.14 Voltage Transformers and Coupling Capacitors...............................................4-1 4.14.1 General.............................................................................................................4-1 4.14.2 GIS Voltage Transformers................................................................................4-1 4.15 Surge Arresters ................................................................................................4-1

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4.15.1 General.............................................................................................................4-1 4.15.2 Surge Counters ................................................................................................4-1 4.16 Sulphur Hexafluoride Gas (SF6) .......................................................................4-1 4.16.1 General.............................................................................................................4-1 4.16.2 Gas Handling Equipment .................................................................................4-1 4.16.3 Pipes and Couplings for the Connection of SF6 Gas.......................................4-1 4.17 Overhead Travelling Crane ..............................................................................4-1 4.17.1 General.............................................................................................................4-1 4.17.2 Construction Features ......................................................................................4-1 4.17.3 Structure...........................................................................................................4-1 4.17.4 Crane Rails.......................................................................................................4-1 4.17.5 Crane Bridge ....................................................................................................4-1 4.17.6 Electrical Parts .................................................................................................4-1 4.17.7 Motors ..............................................................................................................4-1 4.17.8 Push Button Control Station .............................................................................4-1 4.17.9 Overload Relays...............................................................................................4-1 4.17.10 Switchgear........................................................................................................4-1 4.17.11 Circuit Breaker Cabinets ..................................................................................4-1 4.17.12 Limit Switches ..................................................................................................4-1 4.17.13 Tools.................................................................................................................4-1 4.18 GIS Equipment Cable Facilities........................................................................4-1 4.18.1 Method of Termination of Cables .....................................................................4-1 4.18.2 Cable Test and Isolating Facilities....................................................................4-1 4.19 Interlocking Equipment .....................................................................................4-1 4.19.1 Extent of Supply ...............................................................................................4-1 4.19.2 General.............................................................................................................4-1 4.19.3 400 kV Area......................................................................................................4-1 4.19.4 Transformers 400/132/11 kV............................................................................4-1 4.19.5 132 kV Area......................................................................................................4-1 4.19.6 Tertiary Loads ..................................................................................................4-1 4.19.7 Site Supplies ....................................................................................................4-1 4.19.8 DC Station Service ...........................................................................................4-1 4.19.9 Miscellaneous Interlocks ..................................................................................4-1 4.19.10 Locking Arrangements .....................................................................................4-1 5. AIR INSULATED SWITCHGEAR (AIS)............................................................5-1 5.1 Clearances .......................................................................................................5-1 5.2 Method of Line Termination..............................................................................5-1 5.3 Circuit Breakers................................................................................................5-1 5.3.1 General.............................................................................................................5-1 5.3.2 Circuit Breaker Making and Breaking Capacity ................................................5-1 5.3.3 Circuit Breakers Operating Mechanism............................................................5-1 5.3.4 Circuit Breaker Handling and Maintenance Equipment....................................5-1 5.4 Disconnect Switches ........................................................................................5-1

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5.5 Current Transformers .......................................................................................5-1 5.5.1 General.............................................................................................................5-1 5.5.2 Air Insulated Current Transformers ..................................................................5-1 5.5.3 Current Transformer Primary Injection Tests ...................................................5-1 5.6 Voltage Transformers and Coupling Capacitors...............................................5-1 5.6.1 General.............................................................................................................5-1 5.6.2 Open Terminal Voltage Transformers and Coupling Capacitors......................5-1 5.7 Lightning (Surge) Arresters ..............................................................................5-1 5.8 Safety Screening of Equipment........................................................................5-1 5.9 Oil-Filled Chambers..........................................................................................5-1 5.10 Joints for Oil-Filled Chambers and Circuit Breakers.........................................5-1 5.11 Oil .....................................................................................................................5-1 5.12 Auxiliary Switches & Contactors.......................................................................5-1 5.13 Switchgear Busbars and Connections..............................................................5-1 5.14 Earthing Switches and Devices........................................................................5-1 5.14.1 400 kV System .................................................................................................5-1 5.14.2 132 kV System .................................................................................................5-1 5.14.3 Operating Mechanisms ....................................................................................5-1 5.14.4 Maintenance Earths .........................................................................................5-1 5.15 Busbars, Insulators and Hardware ...................................................................5-1 5.15.1 Extent of Supply ...............................................................................................5-1 5.15.2 Busbars and Connections ................................................................................5-1 5.15.3 Insulators..........................................................................................................5-1 5.15.4 Clamps and Fittings..........................................................................................5-1 5.15.5 Corona..............................................................................................................5-1 5.15.6 Guard Rings or Arcing Horns ...........................................................................5-1 5.16 Allowance for Damage, Breakage and Loss ....................................................5-1 5.17 Phase Identification ..........................................................................................5-1 5.18 Junction Boxes and Kiosks ..............................................................................5-1 5.19 Outdoor support structures and landing gantries .............................................5-1 5.20 Interlocking Equipment .....................................................................................5-1 6. TRANSFORMERS AND REACTORS..............................................................6-1 6.1 Extent of Supply ...............................................................................................6-1 6.2 Reference documents ......................................................................................6-1 6.3 Type .................................................................................................................6-1 6.4 General.............................................................................................................6-1 6.5 Tertiary windings ..............................................................................................6-1 6.6 Loss Evaluation ................................................................................................6-1 6.7 Penalties...........................................................................................................6-1 6.8 Magnetic circuits...............................................................................................6-1 6.9 Windings...........................................................................................................6-1 6.10 Internal earthing arrangements ........................................................................6-1 6.11 Tanks................................................................................................................6-1

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6.12 Bushings...........................................................................................................6-1 6.12.1 Oil/SF6 Bushings ..............................................................................................6-1 6.12.2 Oil/Air Bushings................................................................................................6-1 6.12.3 Terminations.....................................................................................................6-1 6.13 Conservator Vessels, Oil Level Gauges and Breathers ...................................6-1 6.14 Valves...............................................................................................................6-1 6.15 Cooling Plant ....................................................................................................6-1 6.16 Cooler Control ..................................................................................................6-1 6.17 On-load Tap Changing Equipment ...................................................................6-1 6.17.1 Automatic and Manual Voltage Control ............................................................6-1 6.18 Parallel operation .............................................................................................6-1 6.19 Disconnecting and sealing end chambers........................................................6-1 6.20 Temperature indicating devices, alarms and gas and oil actuated relays ........6-1 6.20.1 Temperature Indicating Devices and Alarms....................................................6-1 6.20.2 Gas and Oil Actuated Relays ...........................................................................6-1 6.21 Oil Flow Indicators ............................................................................................6-1 6.22 Current transformers ........................................................................................6-1 6.23 Surge protection ...............................................................................................6-1 6.24 Condition Monitoring System............................................................................6-1 6.25 Transformer Oil ................................................................................................6-1 6.26 Topping Up with Oil and Drying out on Site......................................................6-1 6.27 Oil Handling and Test Equipment.....................................................................6-1 6.28 Transformer Marshalling Kiosk.........................................................................6-1 6.29 400 kV Reactors ...............................................................................................6-1 7. 11 KV SYSTEM AND COMPENSATING EQUIPMENT...................................7-1 7.1 Extent of Supply ...............................................................................................7-1 7.2 11 kV Switchgear .............................................................................................7-1 7.3 Interconnecting Buswork ..................................................................................7-1 7.4 Station Service Transformers...........................................................................7-1 7.5 Earthing Transformers......................................................................................7-1 7.6 11 kV Capacitor and Series Reactor ................................................................7-1 7.6.1 General.............................................................................................................7-1 7.6.2 Capacitors ........................................................................................................7-1 7.6.3 Containers ........................................................................................................7-1 7.6.4 Fuses................................................................................................................7-1 7.6.5 Overvoltages and Overloads............................................................................7-1 7.6.6 Discharge and Earthing Devices ......................................................................7-1 7.6.7 Duty Under Fault Conditions ............................................................................7-1 7.6.8 Rating and Property Plates ..............................................................................7-1 7.6.9 Racks for Unit Capacitors.................................................................................7-1 7.6.10 Assumed Working Loads .................................................................................7-1 7.6.11 Construction .....................................................................................................7-1 7.6.12 Access and Interlocks ......................................................................................7-1

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7.6.13 Rack Insulation.................................................................................................7-1 7.6.14 Terminals..........................................................................................................7-1 7.6.15 Series Reactors................................................................................................7-1 7.6.16 Earthing Arrangements. ...................................................................................7-1 7.6.17 Surge Arresters ................................................................................................7-1 8. CONTROL, INDICATION, METERING AND ANNUNCIATION .......................8-1 8.1 General Requirements .....................................................................................8-1 8.1.1 Extent of Supply ...............................................................................................8-1 8.1.2 Plant Control Strategy ......................................................................................8-1 8.2 Station Metering ...............................................................................................8-1 8.2.1 System Voltage Local Indication (400 kV)........................................................8-1 8.2.2 System Voltage Local Indication (132 kV)........................................................8-1 8.2.3 400 kV System Frequency (Local Indication) ...................................................8-1 8.2.4 Voltage Recorder (Local Indication) .................................................................8-1 8.2.5 Station Totalising Metering (Local) ...................................................................8-1 8.2.6 Energy Meters ..................................................................................................8-1 8.2.7 Station Clocks ..................................................................................................8-1 8.2.8 Metering Transducers ......................................................................................8-1 8.3 SCS Specification.............................................................................................8-1 8.3.1 Introduction.......................................................................................................8-1 8.3.2 Design Principles..............................................................................................8-1 8.3.3 System Architecture .........................................................................................8-1 8.3.4 System Functions.............................................................................................8-1 8.3.5 System Capacity ..............................................................................................8-1 8.3.6 System Performance........................................................................................8-1 8.3.7 Software Requirements....................................................................................8-1 8.3.8 Hardware Requirements ..................................................................................8-1 8.3.9 Environmental Performance.............................................................................8-1 8.3.10 Uninterruptible Power Supply ...........................................................................8-1 8.3.11 Maintenance and Spares .................................................................................8-1 8.3.12 Documentation .................................................................................................8-1 8.3.13 Training ............................................................................................................8-1 8.3.14 Warranty and Support. .....................................................................................8-1 8.4 Facilities to be provided to the SCS for Substation and NCC ..........................8-1 8.4.1 General.............................................................................................................8-1 8.4.2 Facility List........................................................................................................8-1 9. PROTECTION REQUIREMENTS....................................................................9-1 9.1 General.............................................................................................................9-1 9.1.1 Background ......................................................................................................9-1 9.1.2 Extent of Supply ...............................................................................................9-1 9.1.3 Discrimination...................................................................................................9-1 9.1.4 Objective Fault Clearance Times .....................................................................9-1 9.1.5 Protection System Construction and Mounting ................................................9-1

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9.1.6 Indications ........................................................................................................9-1 9.1.7 Contacts ...........................................................................................................9-1 9.1.8 Numeric Relays ................................................................................................9-1 9.1.9 Trip Circuit Supplies .........................................................................................9-1 9.1.10 Trip Circuit Supervision and Auxiliary Supply Monitoring .................................9-1 9.1.11 Commissioning and Routine Testing Facilities.................................................9-1 9.1.12 Relay Settings ..................................................................................................9-1 9.2 Environmental Performance.............................................................................9-1 9.2.1 Atmospheric Environment ................................................................................9-1 9.2.2 Mechanical Environment ..................................................................................9-1 9.2.3 Electrical Environment......................................................................................9-1 9.2.4 Insulation ..........................................................................................................9-1 9.2.5 Electromagnetic Compatibility ..........................................................................9-1 9.2.6 Thermal Requirements.....................................................................................9-1 9.3 Protection/Relay Types ....................................................................................9-1 9.3.1 Distance Protection ..........................................................................................9-1 9.3.2 Inverse Time Overcurrent and Earth Fault Relays ...........................................9-1 9.3.3 High Set Overcurrent, Instantaneous Overcurrent and Earth Fault Protection .........................................................................................................9-1 9.3.4 Directional Relays ............................................................................................9-1 9.3.5 Overcurrent and Earth Fault Definite Time Lag Relays....................................9-1 9.3.6 Circulating Current Protection ..........................................................................9-1 9.3.7 Multi-Contact Tripping Relays ..........................................................................9-1 9.4 Protection Functions.........................................................................................9-1 9.4.1 400 kV Primary Line Protection Systems .........................................................9-1 9.4.2 400 kV Main Line Protection - Group A............................................................9-1 9.4.3 400 kV Main Line Protection Group B ..............................................................9-1 9.4.4 400 kV Line Protection Signalling Equipment...................................................9-1 9.4.5 Allocation of 400 kV Line Protection Signalling Channels ................................9-1 9.4.6 400 kV Line Reactor Protection........................................................................9-1 9.4.7 400 kV Tripping & Auto Reclose Logic .............................................................9-1 9.4.8 400 kV Substation and Back Up Protection......................................................9-1 9.4.9 400/132 kV Auto Transformer & Associated Equipment Protection .................9-1 9.4.10 132 kV Transformer Protection.........................................................................9-1 9.4.11 132 kV Line Protection .....................................................................................9-1 9.4.12 132 kV Busbars ................................................................................................9-1 9.4.13 132 kV Bus Section and Bus Couplers ............................................................9-1 9.5 General Protection Requirements ....................................................................9-1 9.5.1 Protection Relay Power Supplies .....................................................................9-1 9.5.2 General Protection Testing & Maintenance Facilities.......................................9-1 9.5.3 Fault Recording and Data Logging...................................................................9-1 9.5.4 400 kV Fault Location.......................................................................................9-1 9.6 Relay Panel Arrangement ................................................................................9-1 9.7 Direct Transfer Tripping and Teleprotection Signals ........................................9-1

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10. COMMUNICATION EQUIPMENT..................................................................10-1 10.1 Extent of Supply .............................................................................................10-1 10.2 Power Line Carrier .........................................................................................10-1 10.2.1 400 kV Line Traps ..........................................................................................10-1 10.2.2 132 kV Line Traps ..........................................................................................10-1 10.2.3 400 kV and 132 kV Line Coupling Capacitors ................................................10-1 10.3 Power Line Carrier Terminal Equipment, Line Matching Units and Co-axial Cable ..............................................................................................................10-1 10.4 Protection Signalling Equipment ....................................................................10-1 10.5 Microwave Radio Link Equipment ..................................................................10-1 10.6 Telephone Equipment (PABX) .......................................................................10-1 10.7 Optical Fibre Based PDH/SDH Equipment.....................................................10-1 11. ELECTRICAL STATION SERVICES..............................................................11-1 11.1 Extent of Supply .............................................................................................11-1 11.2 Main 110 Volt Station Batteries & Equipment.................................................11-1 11.3 Communication 48 V Batteries and Equipment..............................................11-1 11.4 LVAC Distribution Switchgear Panels, Cabling and Socket Outlets...............11-1 11.5 Diesel Generator ............................................................................................11-1 12. CABLES .........................................................................................................12-1 12.1 General...........................................................................................................12-1 12.2 Power Cables .................................................................................................12-1 12.3 Multicore Cables.............................................................................................12-1 12.4 Cable Terminations ........................................................................................12-1 12.5 Identification of Auxiliary Cables.....................................................................12-1 12.6 Terminal Colouring and Labelling...................................................................12-1 12.7 Termination of Auxiliary Cables......................................................................12-1 12.8 Laying and Installation of Cables ...................................................................12-1 12.9 Control Cables................................................................................................12-1 12.10 Metering Cables .............................................................................................12-1 12.11 Protection Cables ...........................................................................................12-1 12.12 Earthing ..........................................................................................................12-1 12.13 Communication Cables ..................................................................................12-1 12.14 SCS Cabling...................................................................................................12-1 12.15 Cable Functions .............................................................................................12-1 13. SUBSTATION EARTHING SYSTEMS...........................................................13-1 13.1 Earthing System Design.................................................................................13-1 13.2 Step and Touch Voltage.................................................................................13-1 13.3 Equipment Earthing........................................................................................13-1 13.4 Fence and Perimeter Earthing .......................................................................13-1 13.5 GIS Substation Earthing Systems ..................................................................13-1 13.6 Earthing of Neutrals........................................................................................13-1

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13.7 Surge (Lightning) Arrestors ............................................................................13-1 14. LIGHTNING PROTECTION ...........................................................................14-1 14.1 Extent of Supply .............................................................................................14-1 14.2 General...........................................................................................................14-1 14.3 General Design Data of Lightning Shielding System......................................14-1 14.4 Method of Design of Lightning Shielding System For AIS Equipment............14-1 15. INSPECTION AND TESTING ........................................................................15-1 15.1 General...........................................................................................................15-1 15.2 Inspection .......................................................................................................15-1 15.3 Testing............................................................................................................15-1 15.3.1 Approach to Testing .......................................................................................15-1 15.3.2 Responsibilities ..............................................................................................15-1 15.3.3 Test Equipment and Facilities ........................................................................15-1 15.3.4 Conduct of the Tests ......................................................................................15-1 15.3.5 Failures...........................................................................................................15-1 15.4 Tests During Commercial Operation ..............................................................15-1 15.5 Documentation ...............................................................................................15-1 15.6 Tests at Manufacturer’s Works.......................................................................15-1 15.7 Specific Equipment Tests ...............................................................................15-1 15.7.1 Transformers ..................................................................................................15-1 15.7.2 Reactors .........................................................................................................15-1 15.7.3 Reactor Site Tests (Minimum) ........................................................................15-1 15.7.4 Transformer & Reactor Related Equipment ...................................................15-1 15.7.5 GIS Switchgear ..............................................................................................15-1 15.7.6 Disconnectors and Earthing Switches............................................................15-1 15.7.7 Current Transformers (CT’s) ..........................................................................15-1 15.7.8 Voltage Transformers and Coupling Capacitors.............................................15-1 15.7.9 Insulating Oil, Sulphur Hexafluoride and Compound......................................15-1 15.7.10 Surge Diverters ..............................................................................................15-1 15.7.11 Line Traps ......................................................................................................15-1 15.7.12 AIS Busbar Conductor and Connections........................................................15-1 15.7.13 Post Insulators................................................................................................15-1 15.7.14 Insulator Strings .............................................................................................15-1 15.7.15 Tension and Suspension Clamps and Joints .................................................15-1 15.7.16 Large Hollow Porcelains.................................................................................15-1 15.7.17 Bushing Insulators ..........................................................................................15-1 15.7.18 Structures .......................................................................................................15-1 15.7.19 132, 33 and 11 kV Power Cables...................................................................15-1 15.7.20 LV Cables.......................................................................................................15-1 15.7.21 Motors and Motor Control Equipment.............................................................15-1 15.7.22 Material...........................................................................................................15-1 15.7.23 Galvanizing.....................................................................................................15-1 15.7.24 Line Traps ......................................................................................................15-1

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15.7.25 Control and Indicating Panels, Instruments and Secondary Wiring ...............15-1 15.7.26 Protection Equipment .....................................................................................15-1 15.7.27 Batteries and Associated Equipment..............................................................15-1 15.7.28 Low Voltage Switchboards .............................................................................15-1 15.7.29 33 kV Switchgear ...........................................................................................15-1 15.7.30 GIS Building Crane.........................................................................................15-1 15.7.31 Fire Protection Equipment ..............................................................................15-1 15.7.32 Substation Control System.............................................................................15-1 15.8 Site Testing and Commissioning....................................................................15-1 15.8.1 Extent of Supply .............................................................................................15-1

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VOLUME 1

TECHNICAL SPECIFICATION 400/132KV SUBSTATION PLANT

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PREAMBLE When this Specification is used for the supply of plant or materials or for construction or for the supply of services relating to Iraqi Power Sector Reconstruction, the capitalized terms that appear in this Specification shall have the following meaning: "Tenderer" and "Contractor" mean "Design Build Contractor" "Engineer" means "Construction Manager"

1-1 Volume 1 - Technical Specification 400kV Substation Plant Issue 3 August 05

1. SYSTEM PERFORMANCE

1.1 Topographical and Meteorological Site Conditions

Site Location

Altitude above sea level - maximum m 1000

Air pressure yearly average millibars 1010.8

Air Temperatures

-Maximum Peak °C (Design maximum ambient temperature)

50

-Highest maximum for 6 hours a day °C 55

- Maximum daily average °C 40

- Maximum yearly average °C 30

- Minimum °C -10

Highest one day variation °C 25

Sun temperature in direct sunlight °C 80

Maximum ground temp at depth of 100mm 35

Humidity

Maximum relative humidity at 40degrees % 92

Minimum relative humidity % 12

Yearly average % 38/44

Pollution level

HEAVY airborne contamination

Dust Storms days/annum 21.5

Isoceraunic level(All equipment) days/annum 15

Maximum wind velocity (for design purposes) m/sec 40.2

Ice loading, radial thickness mm 10

Total rainfall Maximum mm

500

Minimum mm 50

Maximum in one day mm 72

Average per year mm 150.8


1.2 Electrical Design Criteria

400 kV 132 kV

(in a 400kV substation)

11 kV Tertiary

(a) Maximum System Voltage (kV) 420 145 12

(b) Nominal System Voltage (kV) 400 132 11

(c) System Earthing Effective Effective Impedance

(d) System Frequency (Hz) 50 50 50

(e) Estimated X/R ratio 100 - -

(f) System Short Circuit Level (MVA) 28000 7200 950

(g) System Short Circuit Level (kA) 40 40 50

(h) Busbar Rated Current (A) 4000 3150 4000

(i) Sound level (NEMA TR-1) (dB) 88 88

1.3 Insulation levels (All equipment at site altitude)

The creepage distance for insulation shall be dependent on the environmental conditions. However, it shall be 31 mm per kV.

400 kV

132 kV (in a 400kV substation)

11 kV Tertiary

Lightning impulse voltage withstand level, positive and negative polarity kVp

1425

650

75

Lightning impulse voltage withstand level, (positive and negative polarity) -for windings kVp -for neutral kVp -for tertiary kVp

1300 110 110

550 350

-

75 -

Switching impulse voltage withstand level of insulation to ground, positive and negative polarity dry kVp wet kVp

--

Power frequency withstand voltage dry kV wet kV

630 275 275

45

Power frequency withstand voltage - for windings - for tertiary

570 38

220 140


Maximum radio influence voltage level measured at 1.1 times Us/√3 at 1 MHz µV

500

Minimum creepage to earth over insulation based on maximum system voltage (to IEC 815) mm/kV

31 31 31

Surface stress of overhead conductors at rated system voltage kV/mm

1.65

1.4 Minimum Electrical Clearances in Air

The dimensions apply in a substation where 400kV equipment is installed and are absolute minimums.

400 kV 132 kV

(in a 400kV substation)

11 kV

Phase to Phase (metres) 4.20 1.5 0.23

Phase to Earth (metres) 3.36 1.38 0.23 Safety clearance dimensions for open terminal equipment are shown on drawing number 1 IQ 18304.

1.5 Structures

1.5.1 Factors of Safety The minimum factors of safety for outdoor structures and associated equipment shall be as given below:

(a) Busbar or other connection, based on elastic limit of 0.1 percent (0.1%) proof stress

2.5

(b) Complete insulator units based on mechanical test

2.5

(c) Max. simultaneous short circuit current with max. wind speed

2

(d) Insulator metal fittings based on elastic limit

2.5

(e) Steel structures based on elastic limit of tension members and on buckling load; of compression members

2.5

(f) Foundations for structures against over turning and uplift under maximum simultaneous loads

2.5


1.5.2 Switchgear Structure Stresses The maximum allowable stress shall be in accordance with the Outdoor Steel Structures Section of these Specifications.

1.6 Switchgear Loadings

Loading conditions for design of outdoor switchgear and associated equipment shall be as given below:

(a) Minimum temperature of busbars and connections -100C

(b) Maximum temperature of busbars and connections 1000C plus load temp rise

(c) Wind loading As specified in Outdoor Steel Structure Section

(d) Seismic loading As specified in Outdoor Steel Structure Section

(e) Ice loading

(f) Tower structures shall be designed to withstand the loss of all conductors on one side of the structure.

(g) Structures shall be designed to withstand maximum loading due to short circuits.

(h) Tension load on substation terminal structure from incoming lines is 1600 kg. per phase.

1.7 Electrical Station Services

System Voltages

A.C. 380V ± 10% Three phase and Neutral 50 Hz. Effectively earthed.

D.C. (Control & Protection) 110 Volt nominal

D.C. (Communication & Interposing) 48 Volt nominal

Emergency diesel generator 380 Volt, Three phase and Neutral, 50 Hz. High resistance earthed.

Main station service transformers 11,000/380 Volts ± 10% ∆/Y complete with two load break make 380 Volt isolating switches each rated for Full Load Capacity.


2. GENERAL REQUIREMENTS

2.1 Intent and Nature of Work

This Specification provides for the design, manufacture, testing in factory, supply, delivery, off-loading on site, erection, testing on site, commissioning, setting to work and the remedy of all defects during the Defect Notification Period of the equipment detailed in the Schedules.

It shall be the responsibility of the Contractor to furnish equipment, which shall meet in all respects the performance specification and will have satisfactory durability for the prevailing site conditions.

The Contractor shall furnish all material and labour not herein specifically mentioned or included, but which may be necessary to complete any part of the work or work as a whole, in compliance with the requirements of this specification.

The detail design arrangement of the equipment shall be the responsibility of the Contractor subject to the approval of the Engineer.

The main system auto-transformers, 400 kV reactors, and 11 kV reactors may be supplied and erected by others. Where this is the case then it shall be the responsibility of the Contractor to provide all foundations for these units, together with all cabling requirements to the control cubicles.

2.2 Standards and Codes

Except where modified by this Specification all equipments and materials shall be in accordance with IEC (International Electrotechnical Commission) and ISO (International Standards Organisation) standards and recommendations. If relevant IEC and ISO standards and recommendations are not available in any case or cases then relevant British Standards or National Standards shall apply if available.

When IEC, ISO, BSI or National Standards are referred to the edition used shall be that current at the Date of Tender, together with and amendments issued to that date.

Further to that above additional standard order of preference is listed below,

IEC International Electrotechnical Commission ISO International Standards Organisation BSI British Standards Institute NS National Standards (where available) ANSI American National Standards Institute IEEE Institute of Electrical and Electronic Engineers NEMA National Electrical Manufacturers Association NEC National Electrical Code of USA NESC National Electrical Safety Code of USA UL Standards of the Underwriters Laboratories of USA IPCEA Insulated Power Cable Engineers Association of USA ASME American Society of Mechanical Engineers ASTM American Society for Testing and Materials AWS American Welding Society


Where the use of a standard other than IEC, ISO or BS is agreed then this standard shall be used, where applicable, throughout the work. Where other standards are proposed in place of IEC, ISO or BS standards, confirmation shall be provided that the provisions of the standards are equivalent to or exceed those of equivalent IEC, ISO or BS standards.

Copies of any standards proposed in substitution for IEC, ISO or BS standards must be submitted with the Tender accompanied where necessary by English translations of the appropriate sections.

Notwithstanding any descriptions, drawings or illustrations which may have been submitted with the Tender, all details other than those shown in Schedule F, ‘Deviations from the Technical Specification’ and approved by the Engineer shall be deemed to be in accordance with the Specification and the standard specifications and codes referred to therein.

No departures from the Specification except those shown in the Schedule F, ‘Deviations from the Technical Specification’ and approved by the Engineer are to be made without the written approval of the Engineer.

2.3 Abbreviations

The following abbreviations have been used in addition to those listed under Standards and Codes.

mm millimetre cm centimetre m metre km kilometre cm2 square centimetre cm3 cubic centimetre m3 cubic metre kg kilogram kfg/cm2 kilogram force per square centimetre sec second m/sec metre per second m3/sec cubic metres per second Amp ampere V volt kV kilovolt kA kiloampere kVA kilo volt-ampere MVA mega volt-ampere kW kilowatt MW megawatt kWh kilowatt hour MWh megawatt hour ºC degrees centigrade hp horsepower rpm revolutions per minute


Hz hertz (cycles per second) rms root mean square dB decibel µV micro volt

2.4 Places of Manufacture

The manufacturer and places of manufacture, testing, and inspection of the various portions of the Contract Works shall be stated in the Schedules.

2.5 Orders Issued to Subcontractors

The Contractor shall provide three copies of all sub-contracted orders and shall be submitted to the Engineer for approval at the time such order is placed. The Contractor shall ensure the sufficient information is to be given on each sub-order to identify the material or equipment to which the sub-order applies and to notify the sub-contractor that the conditions of the Specification apply. Prices are not required on the order copies. This clause shall not apply to sub-contracts given to regular suppliers of the Contractor for stock materials and minor components.

2.6 Transport

The Contractor shall inform himself fully as to all available transport facilities, road width, and axle load limitations, loading gauges and any other requirements and shall ensure that equipment as packed for transport shall conform to the relevant limitations. Any cost arising from the use of roads or tracks, including tolls, shall be borne by the Contractor.

The Contractor shall ensure by his own inquiries that the facilities available for unloading and bearing capacity of wharfs at the port of entry is adequate for his proposed plant and equipment.

The Contractor shall be responsible for obtaining from the relevant authorities all permissions necessary to use docking, off-loading, highway, and bridge facilities required for the transportation of contract materials and plant.

2.7 Safety of personnel

The Contractor and his representatives shall in all ways comply with the Ministry of Electricity’s Safety Rules regarding electrical apparatus and the safety of men working thereon.

No testing or other work on apparatus which has been delivered to Site and which is liable to be electrically charged from any source shall be permitted except under a “Permit to Work” which will be issued for the purpose by the Ministry of Electricity’s Operating Engineer.

2.8 Compliance with regulations

All apparatus and materials supplied and all work carried out shall comply in all respects with such of the requirements of the Regulations and Acts in force in Iraq as are applicable to the Contract Works and with other applicable Regulations to which the Ministry of Electricity is subject.


2.9 General particulars and guarantees

The Works shall comply with the general particulars and guarantees stated in the Schedules.

All working methods employed and all plant and apparatus supplied under this Contract shall be to approval.

The Contractor shall be responsible for any discrepancies, errors or omissions in the particulars and guarantees, whether such particulars and guarantees have been approved by the Engineer or not.

2.10 Planning and progress reports

The Contractor shall submit for review, within 4 weeks of the starting date of the Contract, an outline design, manufacture, delivery and construction and erection chart. Within a further period of 4 weeks the Contractor shall provide a detailed programme in a format to be agreed by the Engineer; this programme shall also include details of drawing submissions.

The Contractor shall submit to the Engineer at monthly intervals, not later than the seventh day of the following month, and in such formats as may be required by the Engineer, detailed progress reports of the status of design, material procurement, manufacture, works tests, delivery to Site, erection of all plant and materials included in the Contract, testing and commissioning with regard to the agreed contract programme.

Reports shall include a chart detailing plant manufacture, delivery and erection. The chart shall indicate all phases of the work with provision for modification if found necessary during execution of the Works.

The design aspect of the progress report shall include a comprehensive statement on drawings and calculations submitted for review.

The details on material procurement shall give the dates and details of orders placed, indicating delivery dates and expected inspection dates quoted by the manufacturer. If any delivery date has an adverse affect on the contract programme the Contractor shall state the remedial action taken to ensure that delays do not occur.

The section on manufacture shall indicate dates of arrival of material, the progress of manufacture and testing and shall state the date on which the material will be ready for transport. Any events which may adversely affect completion in the manufacturer’s works shall also be reported.

All works tests and the test results shall be listed and a commentary provided. Any test failures shall be explained and the Contractor shall state his proposed actions to prevent delay to the project completion.

The shipping or transport of each order shall be monitored in the progress report and shall give the date when equipment is available for transport, the expected time of delivery to site and the dates actually achieved.

The monthly report on the site works shall be subdivided into each of the activities included in the detailed construction programme and each activity shall be monitored giving work achieved, the percentage completion and estimated completion dates for each activity, in accordance with the


contract programme. The number of men working on site, both labour and supervisory staff, shall be reported together with any incidents or events that may affect the progress of site works. The progress reports shall include photographs of work items of interest and any unusual form of construction or foundation work.

A site weekly programme of work shall be provided each week during the previous week.

Any delays which may affect any milestone or completion date shall be detailed by the Contractor who shall state the action taken to effect contract completion in accordance with the contract programme.

The Contractor shall forward two copies of each progress report to the Engineer. If during the execution of the Contract the Engineer considers the progress position of any section of the work to be unsatisfactory the Engineer shall be at liberty to call progress meetings at site or in his office with a responsible representative of the Contractor.

2.11 Quality assurance

To ensure that the supply and services under the Scope of this Contract, whether manufactured or performed within the Contractor’s works or at his subcontractors’ premises or at Site or at any other place of work are in accordance with the Specification, with the Regulations and with relevant authorized standards, the Contractor shall adopt suitable quality assurance programmes and procedures to ensure that all activities are being controlled as necessary.

The quality assurance arrangements shall conform to the relevant requirements of ISO 9001.

The systems and procedures which the Contractor will use to ensure that the Works comply with the Contract requirements shall be defined in the Contractor’s Quality Plan for the Works.

The Contractor shall operate systems which implement the following:

Hold point - “A stage in material procurement or workmanship process beyond which work shall not proceed without the documented agreement of designated individuals or organizations.”

The Engineer’s written agreement is required to authorize work to progress beyond the hold points indicated in reviewed quality plans.

Notification point – “A stage in material procurement or workmanship process for which advance notice of the activity is required to facilitate witness.”

If the Engineer does not attend after receiving documented notification in accordance with the agreed procedures and with the correct period of notice then work may proceed.

2.11.1 Quality assurance requirements The Contractor and subcontractors, shall, for all phases of work to be performed under the Contract, establish and implement quality assurance arrangements which, as a minimum, meet the requirements of ISO 9001, “Model for quality assurance in design, development, production, installation and servicing”.


The Contractor shall ensure that all work carried out under the Contract is performed by suitably qualified and skilled personnel and that good quality materials, which meet relevant international standard specifications, where such exist, are used.

2.11.2 Quality assurance arrangements – quality plan The Contractor shall submit a comprehensive contract specific Quality Plan for review and comment, within two weeks of award of contract.

The Quality Plan shall identify as a minimum:

a. the Contractor’s organization and responsibilities of key management including quality assurance personnel;

b. the duties and responsibilities assigned to staff ensuring quality of work for the Contract;

c. the prime project documents, specifications, codes of practice, standards;

d. the correspondence and reporting interfaces, and liaison between the Engineer and the Contractor;

e. the procedures the Contractor intends to use to manage and control the Contract, including:

i. the duties and responsibilities assigned to staff ensuring quality of work for the Contract;

ii. hold and notification points;

iii. submission of engineering documents required by the Specification;

iv. the inspection of materials and components on receipt;

v. reference to the Contractor’s work procedures appropriate to each activity;

vi. inspection during fabrication/construction;

vii. final inspection and test.

It is recommended that separate Quality Plans be submitted for the design/manufacture and construction/installation phases.

The Contractor shall review, amend and re-submit quality plans as necessary during the Contract.

2.11.3 Monitoring by the Engineer During the course of the Contract the Engineer reserves the right to monitor the implementation of the Contractor’s quality assurance arrangements.


The Contractor’s compliance with equipment, documentation, drawing, delivery, construction, installation and commissioning schedules shall be monitored by the Engineer.

Monitoring may be by means of a programme of formal audits and/or surveillance of activities at the work locations. Where deficiencies requiring corrective actions are identified the Contractor shall implement an agreed corrective action programme. The Engineer shall be afforded unrestricted access at all reasonable times to review the implementation of such corrective actions.

For site work the Engineer may monitor all aspects of the Contractor’s daily work including that of subcontractors and assess the achievement of milestones as detailed by schedule deliverables.

The Engineer reserves the right to monitor the subcontractors and the Contractor shall ensure that all subcontracts include, and subcontractors are aware of, this requirement.

2.11.4 Contractor quality audits The Contractor shall carry out a formal programme of project quality audits. These shall include audits of the design, manufacture, assembly, erection, installation, test and commissioning functions of the Contractor’s organization and those of its subcontractors and suppliers. The Engineer reserves the right to accompany the Contractor on such audits.

The Contractor shall formulate a 6 month project specific audit programme, covering 6 month periods, which shall be submitted to the Engineer for review within 4 weeks of the commencement date of the Contract and thereafter every 6 months. Any revision to the audit programme shall be forwarded to the Engineer.

2.11.5 Control of subcontractors The Contractor shall be responsible for specifying the quality assurance requirements applicable to subcontractors and suppliers, for reviewing the implementation of subcontractors’ quality assurance arrangements and for ensuring compliance with the requirements.

The Contractor shall ensure that all appropriate technical information is provided to subcontractors and suppliers. The Contractor shall, for the supply of items, plant or equipment (including those subcontracted), arrange for suitable protection for the product at all stages including delivery and installation at the site.

The Contractor shall submit, for information, a detailed programme defining the basis of control to be applied to each subcontract or supply order.

2.11.6 Inspection and tests Inspection and test plans shall be prepared for all major items of equipment/plant, defining the quality control and inspection activities to be performed to ensure that the manufacture and completion of the plant complies with the specified requirements. Inspection and test plans shall be submitted for review.

The Contractor shall submit for review, within 30 days of the Contract Award, a schedule defining the plant/equipment/systems/services which are to be subcontracted, identifying all items for which inspection and test plans will be submitted.


The Contractor shall review all inspection and test plans and associated control documents, of any subcontractors and suppliers, to ensure their adequacy prior to submission.

The Contractor shall be responsible for identifying and arranging any statutory verification activities in the country of manufacture.

Inspection and test plans may be of any form to suit the Contractor’s system, but shall as a minimum:

a. Indicate each inspection and test point and its relative location in the production cycle including incoming goods, packing and site inspections.

b. Indicate where subcontract services will be employed (eg subcontractor NDT or heat treatment).

c. Identify the characteristics to be inspected, examined, and tested at each point and specify procedures, acceptance criteria to be used and the applicable verifying document.

d. Indicate mandatory hold points established by the Engineer, which require verification of selected characteristics of an item of process before this work can proceed.

e. Define or refer to sampling plans if proposed and where they will be used.

f. Where applicable, specify where lots or batches will be used.

The Contractor shall include in all orders to subcontractors, a note advising that all materials and equipment may be subject to inspection by the Engineer as determined by the inspection and test plan. Copies of such purchase orders shall be forwarded to the Engineer.

In order to verify compliance with engineering, procurement, manufacturing requirements and programmes, the Engineer shall have access, at all times, to all places where materials or equipment are being prepared or manufactured, including the works of the Contractor’s, subcontractors or supplies of raw materials.

The Contractor shall advise the Engineer of the readiness of inspection at least 3 weeks prior to a notification point or hold point. Work shall not proceed beyond a hold point without the written agreement of the Engineer or his nominated representative.

Inspection of the plant/equipment may be made by the Engineer and could include the following activities:

i. Periodic monitoring to confirm the effectiveness of, and the Contractor’s compliance with, the established quality plan, system procedures and inspection and test plan.

ii. Witnessing of inspections and tests and/or verification of inspection records to be carried out at the Engineer’s discretion covering:

• compliance of raw material with specified requirements


• compliance of manufactured parts, assemblies and final items with specifications, drawings, standards and good engineering practice

• witnessing of inspection and tests

• packing for shipment including check for completeness, handling requirements, and case markings and identification.

Raw materials, components, shop assemblies, and the installation thereof, shall be subject to inspection and test by the Engineer as required by the Specification and to the extent practicable at all times and places, during the period of manufacture.

The Contractor shall keep the Engineer informed in advance of the time of starting and of the progress of the work in its various stages so that arrangements can be made for inspection and for test. The Contractor shall also provide, without additional charge, all reasonable facilities and assistance for the safety and convenience of the Engineer in the performance of his duties. All of the required tests shall be made at the Contractor’s expense, including the cost of all samples used.

The Contractor shall not offer, unless otherwise agreed, any item of equipment or system for inspection to the Engineer until all planned inspections and tests to date have been completed to the satisfaction of the Contractor.

The Engineer shall endeavour to schedule the performance of inspection and tests so as to avoid undue risk of delaying the work. In the event of postponement, by the Contractor, of tests previously scheduled, or the necessity to make additional tests due to unsatisfactory results of the original tests, or other reasons attributable to the Contactor, the Contractor shall bear all costs for new tests and the costs incurred by the Engineer or his nominated representative in re-inspecting the non-conforming item or its replacement.

The inspection and tests by the Engineer of any equipment/component or lots thereof does not relieve the Contractor of any responsibility whatever regarding defects or other failures which may be found before the end of the defects liability period.

The Contractor shall provide a quality release certificate confirming compliance with the Contract requirements and a data book, comprising the inspection, test, qualification and material records required by the pertaining specifications.

No material shall be shipped to the Site or put to work until all tests, analysis and inspections have been made and certified copies of reports of test and analysis or Contractor’s certificates have been accepted and released by the Engineer or by a waiver in writing.

2.11.7 Construction/installation phase Within 30 days of mobilization of works, inspection and test plan(s), similar in form and content to that described in 2.11.6 above, shall be submitted defining relevant inspection and test points for all stages of construction/erection, installation and commissioning. The inspection and test plans shall identify activities for which method statements shall be prepared.

Method statements shall be submitted to the Engineer for review.


Programmes of site construction works shall be submitted to the Engineer, giving notification of forthcoming test/inspections on a weekly basis.

2.11.8 Non-conformances All items or services not in accordance with the Contract technical specification, or deviating from a previously reviewed document, shall be considered non-conforming.

All such items shall be clearly identified and isolated where practical, and reported to the Engineer via a non-conformance report. Information to be provided with non-conformance notifications shall include:

a. identification of the item(s);

b. reference to relevant specification/drawings, including applicable revisions;

c. reference to the application inspection and test plan stage;

d. description of the non-conformance, with sketch where appropriate;

e. method by which the non-conformance was detected;

f. cause;

g. proposed corrective action, with technical justification, where necessary;

h. for significant non-conformances, proposed action to prevent recurrence;

i. applicable procedures.

The Engineer shall have complete authority to accept or reject any equipment or part thereof considered not to be in accordance with the specified requirements.

Approval of any concession applications is the prerogative of the Engineer, and approval of a particular case shall not set a precedent.

Any non-conformances identified by the Engineer shall be notified by issue of the Engineer’s non-conformance report to the Contractor. Notification of re-inspection shall not be made until the completed non-conformance report, together with any applicable concession applications have been accepted by the Engineer.

Acceptance or rejection of the equipment and/or components will be made as promptly as practicable following any inspection or test involvement by the Engineer. However, failure to inspect and accept or reject equipment and/or components shall neither relieve the Contractor from responsibility for such items, which may not be in accordance with the specified requirements, nor impose liability for them on the Engineer.

2.11.9 Records Records packages to be delivered shall be agreed with the Engineer prior to setting-to-work of each phase, ie design, manufacture, construction, installation and commissioning.


2.11.10 Method statements Prior to commencing work, the Contractor shall submit method statements setting out full details of his methods of working. This is a hold point.

2.12 Design and standardization

Corresponding parts of all material shall be made to gauge and shall be interchangeable. When required by the Engineer the Contractor shall demonstrate this quality by actually interchanging parts. As far as possible all insulators, fittings and conductor joints and clamps should be interchangeable with the equivalent items of the existing transmission system, details of which are obtainable from the Engineer.

The Works shall be designed to facilitate inspection, cleaning and repairs, and for operation where continuity of supply is the first consideration. All apparatus shall also be designed to ensure satisfactory operation under the atmospheric conditions prevailing at the Site, and under such sudden variations of load and voltage as may be met with under working conditions on the system, including those due to faulty synchronizing and short circuit.

The design shall incorporate every reasonable precaution and provision for the safety of all those concerned in the operation and maintenance of the Works and of associated works supplied under other contracts.

All mechanisms shall, where necessary, be constructed of stainless steel, brass or gunmetal to prevent mal-operation due to rust or corrosion.

Means shall be provided for the easy lubrication of all bearings and where necessary, of any mechanism or moving parts that are not oil immersed. Grease lubricators shall be fitted with nipples complying with BSI 1486 - 2, and where necessary for accessibility, the nipples shall be placed at the end of suitable extension piping.

All electrical connections and contacts shall be of ample section and surface for carrying continuously the specified currents without undue heating. Fixed connections shall be secured by bolts or set screws of ample size, adequately locked. All apparatus shall be designed to operate without undue vibration and with the least amount of noise practicable.

All apparatus shall be designed so that water cannot collect at any point and if unavoidable, shall be properly drained.

All metal jointing surfaces shall be machined or ground and all moving, rubbing or wearing surfaces shall be machined or ground. Un-machined flat steel plate covers shall be used only where the corresponding joint flange is machined. The bolt spacing and packaging material employed with such covers shall be approved by the Engineer.

Any outdoor kiosks, cubicles and similar enclosed compartments containing secondary wiring forming part of the main equipment or auxiliary equipment shall be adequately ventilated to restrict condensation and provided with suitable low temperature heaters thermostatically controlled. All contactor or relay coils and other parts shall be suitably protected against corrosion. Where ventilation is provided, disposable filters shall be fitted to prevent dust infiltration. Doors and gaskets shall be weather and dustproof. Roofs shall be of double skin construction.


All apparatus shall be designed to obviate the risk of accidental short circuit due to animals, birds and vermin.

2.13 Quality of material

All material used under this Contract shall be new and of the best quality and of the class most suitable for working under the conditions specified and shall withstand the variations of temperature and atmospheric conditions arising under working conditions without distortion or deterioration or the setting up of undue stresses in any part and without affecting the strength and suitability of the various parts for the work which they have to perform. No repair of defective parts including welding, filling and plugging will be permitted without the sanction in writing of the Engineer.

2.14 Language, weights and measures

The English language shall be used in all written communications between the Engineer and the Contractor with respect to the services to be rendered and with respect to all documents and drawings procured or prepared by the Contractor pertaining to the work.

Whenever anything is required under the terms of the Contract to be marked, printed or engraved, the English language shall be used except where otherwise provided in the Specification.

The design features of all equipment, all quantities and values which are required to be stated in the Technical Schedules and all dimensions on drawings whether prepared by the Contractor or not shall be stated in the International System of Units (SI).

2.15 Erection, supervision and checking of work on site

The carrying out of all work on the Site included in this Contract shall be supervised throughout by a sufficient number of qualified representatives of the Contractor who have had thorough experience of the erection and commissioning of similar Works.

The Contractor shall ascertain from time to time what portions of the work on the Site the Engineer desires to check, but such checking shall not relieve the Contractor from the liability to complete the Works in accordance with the Contract or exonerate him from any of his guarantees.

If at any time it appears to the Engineer that the Contractor will be unable to complete any Section of the Works in the time stipulated, then the Contractor shall, if required by the Engineer, carry on such work outside normal working hours and shall not make any claims for any extra expense thereby incurred unless, in the opinion of the Engineer, the delay is due to causes for which the Contractor would be entitled to an extension of time under the Conditions of Contract.

The Contractor shall satisfy himself as to the correctness of all connections made between the apparatus supplied under the Works and apparatus supplied under any other contract before any of the former is put into operation.

If the Engineer shall certify that defects have shown themselves in the Works, the Contractor shall, for the purpose of the maintenance after the completion of the Works provided for by the Conditions of Contract, keep on Site supervisory staff of such numbers and for such periods as the Engineer may require.


The Contractor is to keep the site, on which he erects or stores plant, reasonably clean removing all waste material resulting from the Works as it accumulates and as reasonably directed. On completion of the Works the Site is to be left clean and tidy to the satisfaction of the Engineer. Any damage done to buildings, structures and plant or property belonging to the Ministry of Electricity is to be made good at the Contractor's expense.

2.16 Bolts and Nuts

Unless otherwise approved, the threads of all nuts, bolts and studs of 7mm diameter and above shall comply with the ISO Metric Coarse Thread Standards and the threads of all nuts, bolts and studs of less than 7 mm diameter shall comply with the ISO Metric Fine Thread Standards.

Terminal bolts or studs used for carrying currents of more than 100 amps, shall not be less than 16 mm in diameter. Brass terminal bolts or studs of less than 6mm size shall not be used for electrical connections. Where a lesser size is necessary, stainless steel or phosphor bronze may be used down to and including 5 mm provided the current carrying capacity is adequate.

All nuts and pins shall be adequately locked unless agreed with the Engineer. Wherever possible, bolts shall be fitted in such a manner that, in the event of failure of locking, resulting in the nuts working loose and falling off, the bolt will remain in position.

All bolts, nuts and washers, placed in outdoor positions, shall be of approved materials and treated to prevent corrosion of the threads and electrolytic action between dissimilar metals.

All exposed bolts, nuts and washers in contact with nonferrous metallic parts shall, unless otherwise approved, be of phosphor bronze.

Where bolts are used on external horizontal surfaces where water can collect, methods of preventing the ingress of moisture to the threads shall be provided.

Each bolt or stud shall project at least one thread but not more than three threads through its nut, except when otherwise approved for terminal board studs or relay stems. If bolts and nuts are placed so that they are inaccessible by means of ordinary spanners, special spanners shall be provided.

The length of the screwed portion of the bolts shall be such that no screw thread may form part of a shear plane between members.

Taper washers shall be provided where necessary.

2.17 Cleaning and Painting

Before painting, all un-galvanized ferrous parts shall be made completely clean and free from rust, scale or grease and all external rough surfaces shall be filled.

All paints shall be applied in strict accordance with the paint manufacturer's instructions.

All painting shall be carried out on dry and clean surfaces and under suitable atmospheric and other conditions in accordance with the paint manufacturer's recommendations.


2.17.1 Works Processes (a) All steelwork, plant supporting steelwork and metalwork, except galvanised surfaces or where

otherwise specified, shall be shot blasted to BS 4232 (second quality finish) or Swedish Standard Sa2½.

(b) All surfaces shall then be painted with one coat of epoxy zinc rich primer (two pack type) to a film thickness of 50 microns. This primer shall be applied preferably by airless spray and within twenty minutes but not exceeding one hour of shot blasting.

(c) All rough surfaces of coatings shall be filed with an approved two pack filler and rubbed down to a smooth surface.

(d) The interior surfaces of all steel tanks and oil filled chambers shall be shot blasted in accordance with BS 4232 (first quality finish) or SA3 and painted within a period of preferably twenty minutes but not exceeding one hour with an oil resisting coating of a type and make to the approval of the Engineer.

(e) The interior surfaces of mechanism chambers, boxes and kiosks, after preparation, cleaning and priming as required above, shall be painted with one coat zinc chromate primer, one coat phenolic based undercoating, followed by one coat phenolic based finishing paint to a light or white colour. For equipment for outdoor use this shall be followed by a final coat of anti-condensation paint of a type and make to the approval of the Engineer, to a light or white colour. A minimum overall paint film thickness of 150 microns shall be maintained throughout.

(f) All steelwork and metalwork, except where otherwise specified, after preparation and priming as required above shall be painted with one coat metallic zinc primer and two coats of micaceous iron oxide paint to an overall minimum paint film thickness of 150 microns.

(g) Galvanized surfaces shall not be painted in the works.

(h) All nuts, bolts, washers etc, which may be fitted after fabrication of the plant shall be painted as described above after fabrication.

2.17.2 Site Painting (j) After erection at site, the interior surfaces of mechanism chambers and kiosks shall be

thoroughly examined, and any deteriorated or mechanically damaged surfaces of such shall be made good to the full Specification described in paragraph e. above.

(k) All surfaces of steelwork and metalwork included in paragraph f. above shall be thoroughly washed down, any deteriorated or otherwise faulty paint-work removed down to bare metal and made good to the full Specification described in paragraph f. then painted one further coat of phenolic based undercoating and one coat phenolic based hard gloss finishing paint to provide an overall minimum paint film thickness of 200 microns.

(m) Any nuts, bolts, washers, etc, which have been removed during site erection, or which may be required to be removed for maintenance purposes shall be restored to their original condition.

(n) All paintwork shall be left clean and perfect on completion of the works.


Exposed ungalvanized nuts, bolts and washers that may have to be removed for maintenance purposes, shall have a minimum of one coat of paint after erection.

Sufficient quantity of touch-up paint shall be supplied. The touch-up work shall be done by the Contractor.

2.18 Galvanizing

All galvanizing shall be applied by the hot dip process and shall comply with BS EN ISO 1461 but shall not be less than 0.61 kg/m2.

All welds shall be descaled, all machining carried out and all parts shall be adequately cleaned prior to galvanizing. The preparation for galvanizing and the galvanizing itself shall not adversely affect the mechanical properties of the coated material. All drilling, punching, cutting and bending of parts shall be complete and all burrs shall be removed before the galvanizing process is applied.

The threads of all galvanized bolts and screwed rods shall be cleared of spelter by spinning or brushing. A die shall not be used for cleaning the threads unless specially approved by the Engineer. All nuts shall be galvanized with the exception of the threads, which shall be oiled.

Surfaces which are in contact with oil shall not be galvanized or cadmium plated.

Partial immersion of the work will not be permitted and the galvanizing tank must therefore be sufficiently large to permit galvanizing to be carried out by one immersion.

Galvanizing of wires shall be applied by the hot dip process and shall meet the requirements of BS 10244

Galvanizing of wires shall be applied by the hot dip process and shall meet the requirements of relevant ISO Standards or B.S. 10244. The zinc coating shall be smooth, clean and of uniform thickness and free fro defects. The preparation for galvanizing and the galvanizing itself shall not adversely affect the mechanical properties of the wire.

Tests shall be carried out in accordance with the requirements of B.S. EN ISO 1461 where applicable.

Alternative processes shall not be used without the approval of the Engineer.

2.19 Labels and Plates

Each main and auxiliary item of plant shall have permanently attached to it in a conspicuous position, a rating plate of indelible material upon which shall be engraved any identifying name, type or serial number, together with details of the loading conditions under which the item of plant has been designed to operate, and such diagram plates as may be required by the Engineer.

All items of plant shall be provided with a nameplate or label indicating, where necessary, its purpose and service position. The inscriptions shall be approved by the Engineer or be as detailed in the appropriate sections of this Specification. Each phase of alternating current and each pole of direct current equipment and connections shall be coloured in an approved manner to distinguish phase or polarity.

Phases of three phase alternating current systems shall be identified as follows: -


Phase Colour R Red S Yellow T Blue

Where applicable phases on outdoor equipment shall be identified by coloured discs attached to the structures at the following locations: -

(a) On tubular busbars midway between taps and at tapping points.

(b) On tensioned busbars or other tensioned connection spans, next to the anchor points at one end of every span.

(c) On line gantries, transformer gantries, next to the anchor points.

(d) On each transformer, reactor and circuit breaker.

Such nameplates or labels shall be of stainless steel or other approved incorruptible material and shall be fixed with stainless steel screws. Where the use of enamelled iron plates is approved, the whole surface, including the back and edges, shall be properly covered and resistant to corrosion. Protective washers of suitable material shall be provided front and back on the securing screws.

Where non-hygroscopic, non-transparent or translucent heat resisting material with engraved lettering of a contrasting colour or, alternatively, in the case of indoor circuit breaker, starters, etc, of transparent plastic material with suitably coloured lettering engraved on the back is proposed then this shall be first approved by the Engineer..

Size, colour and engravings shall be subject to acceptance by the Engineer.

All inscriptions shall be in English except for Danger and Warning signs, which shall be in both English and Arabic. Colour for Danger and Warning signs shall preferably in yellow on a black background and shall be approved by the Engineer.

Items of plant, such as valves, which are subject to handling, shall be provided with an engraved chromium plated brass nameplate or label not less than 3 mm thick with engraving filled with enamel.

The interior of each piece of equipment shall be clearly marked to show the phases and for this purpose either coloured plastic discs screwed to fixed components or identification by means of plastic sleeve or tape shall be used.

In addition, each item of switchgear shall have number plates bearing the switch number allocated by the Employer according to his standard operational switch numbering scheme.

2.20 Erection Marks

Before leaving the Contractor's Works all apparatus and fittings shall be painted or stamped in two places with a distinguishing number and/or letter corresponding to the distinguishing number and/or letter on an approved drawing and material list.

The erection marks on galvanized material shall be stamped before galvanizing and shall be clearly legible after galvanizing.


All markings shall be legible; weatherproofed tags, where used, shall be durable, securely attached and duplicated.

Prior to dispatch each separate box, crate or package of plant shall be clearly labelled in the English language and bear the markings shown on the appropriate tender drawing.

Marking shall be by means of block letters not less than 13 mm high, stencilled on the box, crate or package with black paint in an easily read location. When stencilling is not possible the information shall be marked on a durable metal tag that shall be securely wired to the box, crate or package.

2.21 Tropicalization

In choosing materials and their finishes, the Contractor shall be responsible for giving due regard shall be given to the humid tropical conditions under which equipment is to operate, and the recommendations of IEC 60721 should be observed unless otherwise approved by the Engineer. The Contractor shall submit details of his previous experiences, which have proven satisfactory and which he recommends for application on the parts of the works, which may be affected by the tropical conditions. The materials and finishes used shall be subject to approval by the Engineer. In particular all switchgear and control cubicles shall be vermin-proof and topical grade materials should be used wherever possible: -

(a) Metals. Iron and steel shall generally be painted or galvanised as appropriate. Indoor parts may alternatively have chromium or copper-nickel plated or other approved protective finish. Small iron and steel parts (other than rustless steel) of all instruments and electrical equipment, the cores of electromagnets and the metal parts of relays and mechanisms shall be treated in an approved manner to prevent rusting. Cores, etc., which are built up of laminations or cannot for any other reason be anti-rust treated, shall have all exposed parts thoroughly cleaned and heavily enamelled, lacquered or compounded.

When it is necessary to use dissimilar metals in contact, these should, if possible, so be selected that the potential difference between them in the electrochemical series is not greater than 0.5 volts. If this is not possible, the contact surfaces of one or both of the metals shall be electroplated or otherwise finished in such a manner that the potential difference is reduced to within the required limits, or if practicable, the two metals shall be insulated from each other by an approved insulating material or a coating of approved varnish compound.

(b) Screws, nuts, springs pivots, etc. The use of iron and steel is to be avoided in instruments and electrical relays wherever possible. Steel screws, when used, shall be zinc, cadmium or chromium plated, or when plating is not possible owing to tolerance limitations, shall be of corrosion-resisting steel.

All wood screws shall be of dull nickel plated brass or of other approved finish. Instrument screws (except those forming part of a magnetic circuit) shall be of brass or bronze. Springs shall be of non-rusting material, e.g. phosphor-bronze or nickel silver, as far as possible. Pivots and other parts for which non-ferrous material is unsuitable are to be of approved rustless steel where possible.

(c) Fabrics, cork, paper, etc. Fabrics, cork, paper and similar materials, which are not subsequently to be protected by impregnation, shall be adequately treated with an approved fungicide. Sleeving and fabrics treated with linseed oil or linseed oil varnishes shall not be used.


(d) Wood. The use of wood in equipment shall be avoided as far as possible. When used, woodwork shall be of thoroughly seasoned teak or other approved wood that is resistant to fungal decay and shall be free from shakes and warp, sap and wane, knots, faults and other blemishes. All woodwork shall be suitably treated to protect it against the ingress of moisture and from the growth of fungus and termite attack, unless it is naturally resistant to those causes of deterioration. All joints in woodwork shall be dovetailed or tongued and pinned as far as possible. Metal fittings where used shall be of non-ferrous material.

(e) Adhesives. Adhesives shall be specially selected to ensure the use of types which are impervious to moisture, resistant to mould growth, and not subject to the ravages of insects. Synthetic resin cement only shall be used for joining wood. Casein cement shall be used.

(f) Rubber. Neoprene and similar synthetic compounds, not subject to deterioration due to the climatic conditions, shall be used for gaskets, sealing rings, diaphragms, etc., instead of the standard rubber based materials.

Unless otherwise specified, varnish shall be applied thoroughly and completely to all moisture and fungus susceptible exposed surfaces inside equipment, such as circuit elements (resistors, capacitors, coils, etc), surfaces supporting circuit elements, interconnecting wiring and connections.

The varnish shall not be applied to any surface or part where the treatment will interfere with the operation or performance of the equipment. Such surfaces or parts shall be protected against the application of varnish. The following are examples of items and materials which shall be protected:

(i) Cable, wire, braids, and jackets flexed in operation and cable with plastic insulation.

(ii) Components and materials, such as:

• Capacitors, variable (air, ceramic or mica dielectric);

• Resistors (when wattage dissipation would be undesirably affected and when varnish may become carbonised);

• Wire-wound resistors;

• Ceramic insulators, subject to over 600 volts;

• Painted, lacquered or varnished surfaces;

• Rotating parts;

• Electron tubes;

• Tube clamps;

• Miniature tube shields;

• Plug-in relays;

• Pressure contact earths;


• Coaxial test points or receptacles;

• Windows, lenses, etc.;

• Transparent plastic parts;

• Plastic materials of the following types: polyethylene, polystyrene, polyamide, acrylic, silicone, epoxy (other than printed wiring boards), melamine-fibreglass, fluoro-carbon, vinyl and alkyd.

(iii) Organic materials that have otherwise been protected.

(iv) Electrical contacts, contact portions or mating surfaces of binding post, connectors, fuses, jacks, keys, plugs, relays, sockets (including tube sockets), switches and test points.

(v) Surfaces whose operating temperatures exceed 130 ºC or whose operating temperatures will cause carbonisation or smoking.

The varnish coating shall be applied in such a manner that the dried film will present a clear, smooth finish. The finish shall be free from air bubbles, wrinkles, filaments, spray, dust or entrapment of moisture (as indicated by blushing or darkening of film, poor adherence, etc.), running, lumping, droplets and other defects that will affect life, serviceability or appearance.

2.22 Relays, Switches, Fuses and Ancillary Equipment

All relays shall be of a type approved by the Engineer, and shall conform to IEC 60255. Relays associated with the three phases shall be marked with the appropriate phase colour and the fuses and links shall be suitable labelled. The relay elements, fuses or links associated with the R, S and T phases shall be mounted on the left, middle and right respectively, when viewed from the front of the panel. Three-pole relays of the vertical type shall have the R, S and T elements at the top, middle and bottom respectively.

All relays shall have sufficient thermal capacity for continuous energisation.

Control/selector switches for use other than on the control panel shall be of rotary type, having enclosed contacts that are accessible by the removal of covers. Switch escutcheon plates positions. “Close” or “Start” actions shall be clockwise (as seen from front); opposite actions shall be counter-clockwise.

Control switches shall be of adequate rating for the voltage and current to be carried. The required number of positions, maintained and momentary contract requirements shall be determined by the Contractor.

Control switches shall have pistol grip handles. Whilst, control, instrument and circuit selector switches shall be of a different type. Both shall be to the approval of the Engineer.

Heavy-duty oil-tight push buttons may be used as an alternative to control switches, provided they meet the voltage, continuous and interrupting current requirements.

Push buttons shall be selected to match the indicating lamps with which they will be associated. Wherever this requirement does not apply, heavy-duty oil-tight pushbuttons shall be used.


Fuses shall be of the cartridge type or of other approved type.

Fuse and link carriers and bases shall be of good quality moulded insulating materials.

Links and fuses shall be supplied with covers and located on the front of the respective cubicle. Fuses and links shall be grouped and spaced according to their function, in order to facilitate identification.

The labelling of relays, switches, pushbuttons, fuses and links shall be subject to the approval of the Engineer. Approved code symbols shall be used on diagrams and on relay, switch, pushbutton, fuse and link labels.

All panels and cubicles shall have a continuous earth bus of sectional area of not less than 15 sq. mm run along the bottom of the panels, each end being connected to the main earthing system. Metal cases of instruments, metal bases of relays and starters of the panels shall be connected to this bar by conductors of a sectional area of not less than 3 sq mm.

Current transformer and voltage transformer secondary circuits shall be complete in themselves and shall be earthed at one point only through links situated in an accessible position. Each separate circuit shall be earthed through a separate link, suitably labelled. The links shall be of the bolted type having 6mm nuts and provision for attaching test leads. Where CT’s are specified for protection, the earth connections will normally be made at panels in the Relay Building.

2.23 Auxiliary Wiring and Panel Boards

(a) Auxiliary Wiring

All panel and cubical wiring shall have approved 600 V stranded copper, with heat, moisture and flame resistant insulation, conforming to IEC 60227 or BSI 6004. The insulation shall have a glossy finish and shall be incapable of supporting combustion.

All wiring, other than that for light current (telephone type) apparatus, shall be of 3/1 mm or, preferably, of 7/0.75 mm tinned copper. Single strand copper wire, if proposed, shall be approved by the Engineer. Annealed copper having a circular cross-section of 2 mm minimum diameter shall be specified, if single-stranded wire is proposed.

All cubicle wiring shall conform to the following colour code:

Colour of Wire Circuit Particulars

Red Yellow Blue

Phase connection, whether earthed or unearthed, either directly connected to the primary circuit or connected to the secondary circuits of current and voltage transformers

Black AC neutral connections, whether earthed or unearthed, either directly connected to the primary circuit or connected to the secondary circuits of current and voltage transformers

Black AC connections other than those above

Green Connections to earth

Grey Connections to DC circuits


All cubicle wiring shall be neatly run and securely fixed in such a manner that, wherever practicable, wiring can be easily checked against diagrams. Wiring passing out of the cubicles shall be run in non-rustable flexible tubes or galvanized steel tubes.

Wherever practicable, wiring shall be accommodated on the sides of the cubicles and the wires for each circuit shall be separately grouped. Back-of-panel wiring shall be so arranged that access to the connecting stems of relays and other apparatus and to contacts of control and other switches is not impeded.

Where provision is made for addition of equipment not required initially, means shall be adopted for supporting and terminating wiring during the interim period.

All wiring shall be taken to terminal boards and the wires shall not be jointed or thread between terminal points. Conductors shall be terminated in terminals of design approved by the Engineer. The terminals shall clamp the wire by means of screws. Screw pressure shall be applied by a pressure plate.

Alternatively, conductors shall be terminated with crimped connections of a suitable type or with tinned claw washers, separate washers being used for each conductor. The size of washer shall be suited to the size of conductor terminated. No solder or “push-on” or “quick-fit” type connectors shall be used in connection with any wiring. Sample terminal blocks shall be submitted for approval.

Numbers ferrules shall be fitted to all wires on panels and to all multicore cable tails. Ferrules shall be of black or white insulating material with a glossy finish to prevent adhesion of dirt. They shall not be affected by moisture or oil and shall be clearly and permanently marked. Temporary marking is prohibited.

The same ferrule number shall not be used on wires forming connections not directly in series or parallel in the same panel.

All wires which, if interfered with, may cause tripping currents to flow shall be provided with red ferrules.

At those points of interconnection between wiring carried out by separate contractors, double ferrules shall be provided on each wire where a change of number cannot be avoided. The change of numbering shall be shown on the appropriate diagrams of the equipment.

Wiring diagrams for panels and cubicles shall be drawn as if viewed from the back. They shall show the terminal boards as arranged in service.

Bus wires shall be fully insulated and shall be run separately along the top or bottom of the cubicle. Fuses and links shall be provided to enable all circuits in a cubicle, except in the lighting circuit, to be isolated from the bus wires.

Wherever practicable, all power circuits shall be kept physically separated from the control wiring and low-level signal wiring. Separate raceways shall be provided for above systems. The working voltage of each circuit shall be marked on the associated terminal boards.


The DC trip and AC voltage supplies and the wiring to main protective gear shall be segregated from those for backup protection and also from protective apparatus for special purposes and also from protections of other bays. Each such group shall be fed through separate fuses either direct from the main supply fuses or the bus wires. There shall not be more than one set of supplies to the apparatus comprising each group.

Each alarm initiation point shall be connected to the SCS.

(b) Panelboards

This specification covers the construction of all control and relay panels.

The panels shall be of unit type construction forming a rigid, self-supporting, dustproof, free standing structure. The panels shall have lift-off hinged doors at the rear for internal access. The doors shall be provided with suitable locks. The panels shall be constructed of cold rolled steel 3 mm in thickness, welded and reinforced where necessary. The surface shall be flat and free from surface blemishes and suitable stiffened to prevent buckling.

All surfaces shall be thoroughly cleaned free from all rust and foreign material, painted with a rust resistant paint, primed, sealed (sealer required on exterior only) and finished with a quick drying paint. The interior shall be glossy white and the exterior shall be of approved grey colour. A suitable quantity of finish paint shall be supplied separately to “touch-up” any damage to the finish, which may occur during shipment or installation.

Panels shall be bolted together, not welded and individual panel fronts shall be removable without disturbing any adjacent panel. All panels shall be fitted with 220 Volt single-phase receptacle and an interior light controlled by a door-operated switch located inside the panel.

The panels shall be bolted to the floor.

Any cable entering to the panels shall be tight and dustproof through suitable cable glands.

2.24 Earth Connection

Each item of equipment shall be provided with all necessary terminals, of adequate size, for connection to the earthing system.

2.25 Terminal Boards

Terminal boards shall be spaced not less than 100 mm apart. They shall be mounted vertically at the sides of the cubicle and set obliquely toward the rear doors to give easy access to terminations and to enable ferrule numbers to be read without difficulty.

The bottom of terminal boards shall be spaced at least 200 mm above the cable crutch of incoming multicore cables.

Terminal boards shall have pairs of terminals for incoming and outgoing wires and not more than two wires shall be connected to any one terminal.


Insulating barriers shall be provided between adjacent pairs of terminals. The height of the barriers and the space of the terminals shall be such as to give adequate protection while still allowing easy access to terminals.

Terminal boards shall be provided for all power, controls, instruments, annunciators, meters and relays requiring external connection.

Panel wiring shall be connected to one side of the terminal board, whilst the other side shall be reserved for outgoing cable connections.

Adequate space shall be provided on both sides of the terminal blocks for connecting wires and for ferrule markers. Terminals for external connections shall be arranged for consecutive connection of conductors within one cable. One external wire will be connected to each outgoing terminal point. At least fifteen per cent (15%) spare terminals shall be provided on each terminal block.

Terminations shall be grouped according to function and labels shall be provided on the fixed portion of the terminal boards showing the function of the group.

Covers of insulating material, preferably transparent, shall be provided on terminal boards on which connections for circuits with a voltage greater than 125 Volts are terminated.

The use of terminal boards at junction points for wires, which are not required in the associated cubicle, shall be avoided wherever practicable.

2.26 Special tools

Complete sets of all special tools including jacks and slings required for the adjustment and maintenance of the equipment as recommended by the manufacturer, for each different item of equipment, shall be supplied for each sub-station. Each set shall be individually boxed and clearly marked as to the contents, and item of equipment for which they are to be used

A detailed list of tools, jacks, slings, etc. required for repairs for all the materials being supplied under this Contract shall be included in the tender for each sub-station.

The Contractor shall ensure that all items are new and are in good condition. Slings, jacks and tools used during installation and commissioning will not be accepted.

2.27 Interchangeability

Wherever possible, all similar parts shall be made interchangeable with those of other manufacturers so as to enable substitution or replacement from spare parts easily and quickly in case of seal or other failure. In particular this shall apply to apparatus bushings. The standard to which these bushing dimensions are established shall be given.

The Contractor shall co-ordinate through the Engineer his design with that of other manufacturers to ensure the required interchangeability.


2.28 Spares

The Contractor shall list details of recommended spare parts together with their individual prices. The Engineer or Employer may order all or any of the parts and those ordered within three months of placing the Contract shall be available at the time of completion of the plant.

A separate list of spares shall include consumable items sufficient for a plant operational period of three years after commissioning, as well as essential replacement parts to cover the event of a break-down which would affect the availability or safety of the plant. The Contractor shall provide five copies (5) of the recommended list of spare parts and each copy shall show quantities, unit price and other related information.

Any spare apparatus, parts and tools shall be subject to the same specification, tests and conditions as similar material supplied under the Definite Work section of the Contract. They shall be strictly interchangeable and suitable for use in place of the corresponding parts supplied with the plant and must be suitably marked and numbered for identification and prepared for storage by greasing or painting to prevent deterioration.

All spare apparatus or materials containing electrical insulation shall be packed and delivered in cases suitable for storing such parts or material over a period of years without deterioration. Such cases shall have affixed to both the underside and topside of the lid a list detailing its contents. The case will remain the property of the Employer. It is proposed that major apparatus will be stored outdoors and small items of equipment will be stored indoors.

2.29 Packing, Shipping and Storage

A comprehensive specification covering packaging, shipping, storage and marketing that shall be used by all manufacturers, suppliers and shippers shall be written and submitted to the Engineer for approval. The specification will include, but not be limited to, any methods or procedures described herein.

The Contractor shall ensure that all materials, plant and items forming part of the works, are adequately packed for transport by sea, rail and road, to provide protection against corrosion, physical damage, contamination and damage from water, dust, noxious gases, tropical and other climatic conditions or from any other source to which they may be subjected during handling, transport and storage. Approved precautions shall be taken to protect parts containing electrical insulation against the ingress of moisture. Packing cases and packing material shall remain the property of M.O.E.

All crates, boxes, bundles, etc., required for packaging shall be carefully handled at all times and shall not be tipped, dumped, thrown or pushed from, onto or in any form of transport, during storage or at any other time.

All bright parts, liable to rust, shall receive a coat of rust-resistant composition and shall be suitably protected.

The Contractor shall take special precautions to protect bearing journals where they rest on wooden or other supports likely to contain moisture. At such points, wrappings shall be used which are impregnated with rust-resistant composition and of sufficient strength to resist chafing through, when subject to the pressure and movement likely to occur in transit.


All arrangement shall be made for all forms of transport used, to ensure that all items are transported safely and on time to their destination.

Only reputable carriers, which have regular schedules to the required destination shall be used. All the facilities, reliability and record of carriers, ports and other depots shall be investigated and arrangements shall be made to supplement any deficiencies in handling equipment and other facilities. The number of carriers shall be kept to a minimum and double handling at ports and depots shall be avoided as far as possible. The contractor shall ensure that all warehouses used en route, are suitable and that all items can be stored without any deterioration or damage from water, sunlight dust or any other cause. Consignments shall be sent in complete units and sending partial consignments shall be avoided when possible.

The Contractor shall make all the necessary arrangements for customs clearance in Iraq, the country of origin, and any countries through which goods pass.

Law of Iraq No. 157 has been passed to facilitate the entry into and transit within Iraq of goods, plant, materials and equipment necessary for the construction of major projects, including this project.

The Contractor shall obtain all the necessary export and import permits and any other documents required for the transport of goods. Copies of all forms and documents relating to customs, permits, packing lists, bills of lading and insurance, etc. shall be forwarded to the Engineer.

All parts shall be clearly marked to facilitate easy sorting and erection.

All parts shall be boxed in substantial crates or containers to facilitate handling in a safe and secure manner. Drain holes shall be provided and secure manner. Drain holes shall be provided in crate bottoms where necessary. Each crate or container shall be marked clearly on the outside of the case to show where the weight is bearing and the correct position for the slings. Each crate or container shall also be marked with the contract number and port of destination. Material intended for different locations in Iraq shall be packed separately and packages shall clearly identify the destination.

It shall be ensured that all labels, markings and colour coding on crates, boxes or containers are clear, legible, waterproof, not affected by sunlight and are securely fixed or painted thereon. Standard markings, such as “Lift here”, “No hooks”, “Fragile”, etc., shall be applied as necessary. Oil, paint and other hazardous or inflammable materials shall be marked accordingly, including “flash point”, recommended storage temperatures and detailed instructions for use. Adequate storage areas in suitable locations in Iraq shall be prepared.

2.30 Integral Electric Motors

(a) Operating Conditions

Motors shall be designed for continuous service and to the requirements of IEC 60034. They shall also be adequate for withstanding long periods of inactivity, and environmental conditions existing at the site such as high humidity, storms, salt-laden air, insects, plant life, fungus and rodents.

Only a service-proved design shall be offered. When a design is offered that has not been proved in service for at least two years, the Engineer shall be advised which parts of the motor are affected and the extent of experience with these parts.


(b) Electrical Design Features - Horsepower and Voltage

Standard manufactured horsepower sizes shall be selected. If the required horsepower falls between two listed the motor having the larger rated horsepower shall be selected.

In general, motors shall be rated in accordance with the following:

HP Phases Frequency RPM Nominal System Voltage

Less than 1 HP

1 50 Hz 1500 220

1 - 500 HP 3 50 Hz 1500

380

Motors shall be squirrel cage induction type normal torque, unless otherwise required by the load, de-rated for continuous operation in a 50 ºC ambient, totally enclosed, fan-cooled guarded construction and suitable for full voltage starting. Specific approval may be obtained from the Engineer to provide open, drip proof motor construction in certain indoor clean locations.

Motors shall have non-hygroscopic insulation, at least equivalent to class B insulation system. The thermal rating of the coil connections shall be equivalent to that of the coil insulation.

Coils shall be secured tightly in the slots. The insulation system shall be impervious to all commonly encountered contaminants, and shall withstand moderately abrasive particles and conductive dust. Motors shall have a temperature rise corresponding to the next lower insulation system class. For example, class B insulation system shall have a class A insulation system temperature rise.

Motors shall be carefully selected to ensure their suitability and compatibility with the intended driven load with adequate regard given to the locked rotor pull-up and breakdown torque and inertia requirements of the load. Where high inertia long accelerating time loads or frequent starting duties are encountered, the design will have ample thermal capacity for the intended service.

Motors shall be capable or successive starts as required by the individual driven equipment and also by the overall substation operation. A schedule of all motors on the station will be supplied for approval and shall include in the data given the starting capabilities.

Motors shall be capable of a locked rotor time in the order of 20 seconds without injurious heating and the permissible accelerating time shall be in the order of at least 30 per cent greater than the permissible locked rotor type.

Motors shall operate successfully under all conditions at rated load with a variation in the voltage or the frequency up to the following:

Plus or minus 10 per cent of the rated voltage, (with the rated frequency)

Plus or minus 5 percent of the rated frequency, (with the rated voltage)


A combined variation in voltage and frequency of plus or minus 10 per cent (sum of the absolute values) of the rated values, provided the frequency variation does not exceed plus or minus 5 per cent of the rated values.

Motors shall be dynamically balanced. The use of solder or similar deposits shall not be accepted. Parent metal removed to achieve dynamic or static balance shall be drilled out in such a manner as not to affect the structural strength of the rotor; chiselling or sawing shall not be permitted.

Enclosure parts may be made of cast iron, cast steel, sheet steel, or steel plate.

Totally enclosed, non-ventilated and totally enclosed, fan-cooled, guarded motor enclosures shall completely enclose the motor. Designs in which the stator laminations form a part of the enclosure or in which the stator laminations are otherwise exposed to external cooling air are not acceptable.

Drip proof motors when approved shall have drip proof fully guarded enclosures. Ventilation openings shall be limited in size by design or by metal screens to prevent passage of a cylindrical rod 1.5 cm in diameter. These screens shall be made of corrosion-resistant material.

All internal parts of the motor exposed to the cooling air, such as air deflectors and fans, shall be made of corrosion-resistant material or have corrosion-resistant plating or treatment.

Nameplates shall be of non-corrosive metal construction and be securely fastened to the motor frame by means of metal screws. The following data shall be supplied on nameplates: horsepower, volts, phases, full load speed, full load amperes, frequency, locked rotor amperes, temperature rise, service factor, class of insulation system, type of enclosure, serial number, frame size and year of manufacture. If the motor has a preferred direction of rotation then this shall be indicated by a metal arrow in the preferred direction, secured to the motor frame by screws.

Antifriction bearing rating life shall be 40,000 hours minimum for direct-connected motors. Bearings shall be re-greasable with suitable fittings and shall be constructed and provided with seals so that dirt, moisture, or lubricant leakage around seals will not enter the motor.

Winding temperature detectors of the following types shall be provided for motor protection on motors of 50 H.P. and over:

Thermal temperature switch, hermetically sealed, and normally open or Three thermocouples or thermostats. Leads for thermal temperature switches and thermocouples shall be provided on motors for outdoor applications. The heaters shall have steel sheath construction, surface temperature not to exceed 200 degrees C, for 220 volt single-phase operation. They shall have sufficient capacity and be located as required to prevent condensation when the motor is not in operation. Space heaters shall be completely wired, with leads brought out to a separate terminal box.

Motor terminal boxes shall be of adequate size to permit terminating motor leads and other wiring at the motor.


The method of marking of terminal leads shall be permanent - suitable for the life of the motor. Leads shall have at least one identification marking within 150 mm of the stator frame.


3. SWITCHGEAR - GENERAL

3.1 Extent of Supply

This specification consists of design manufacture, testing, supply, delivery, installation, commissioning and guarantee of the following switchgear and the associated equipment:

Gas Insulated Switchgear Air Insulated Switchgear

(a) Circuit Breakers (a) Circuit Breakers

(b) Disconnect Switches (b) Disconnect Switches

(c) Current Transformers (c) Current Transformers

(d) Voltage Transformers (d) Voltage Transformers

(e) Lightning (Surge) Arresters (e) Lightning (Surge) Arresters

(f) Cable Terminations

(g) Bus Ducting

3.2 Substation Design

400 kV substations shall be designed and installed as a breaker and half arrangement. 132 kV substations shall be designed and installed as a double busbar arrangement unless otherwise specified in the Scope Of Works.

The 400 kV substation design shall be suitable for high-speed and delayed, single-phase and three-phase auto-reclose operations.

The substation design shall be of robust construction, designed to prevent accidental contact being made with any live part.

The substation design shall be such as to minimize the possibility of failure due to moisture and dirt being deposited on the insulation.

The Contractor shall investigate the requirement for pre-insertions resistors on the 400 kV circuit breakers to reduce over-voltages during high-speed auto-reclose. In previous installations the 400 kV circuit breakers had been provided with 600ohm pre-insertion closing resistors.

3.3 Current Rating & Temperature Limitations

Every current-carrying part of the switchgear equipment, including circuit breakers, SF6, oil or air-insulated isolating equipment, busbars, current transformer chambers, connections and joints shall be capable of carrying its specified rated current continuously under the atmospheric conditions existing at site, and in no part shall the temperature rise exceed the values specified in IEC 62271–100.


Every part of the switchgear equipment shall also withstand without mechanical or thermal damage the instantaneous peak currents and rated short-time currents pertaining to the rated breaking capacity of the circuit breaker. The short-time current rating of the current transformers shall not differ from that of the associated circuit breakers.


4. GAS INSULATED SWITCHGEAR (GIS)

4.1 General

The complete gas insulated switchgear shall be constructed in accordance with IEC 60517, unless otherwise stated in this Specification.

It shall be fully tested in accordance with IEC 62271-100, 62271-102 and 60694. All type tests shall be either, carried out by independent testing laboratories not associated with the manufacturers, or, witnessed by independent observers.

The contractor shall supply suitable test equipment, interface transducers and connections to fully test the equipment offered. All Capacitive Couplers for Partial Discharge monitoring and site testing of GIS installations prior to energisation, shall be left in position for later use by the Employer, to monitor periodically the levels of discharge.

Only the analyser shall be included in the list of spares.

The signature records taken by the manufacturer prior to energisation shall be made available to the Employer for future comparison purposes.

Continuous partial discharge monitoring on the installation is not required. However, an optional cost for a continuous partial discharge monitoring system should be provided.

4.2 Gas Insulated Switchgear (GIS) Enclosures

Enclosures shall be designed in accordance with the requirements of IEC 60517. The arrangement for bolting together and the method of ensuring electrical conductivity between enclosures shall be to approval of the Engineer. The live parts of the switchgear and busbars shall be supported on barriers of insulating material with proven long-term compatibility with SF6 gas and its arc degradation products. The insulating barriers shall be discharge free at all working voltages.

The design of the enclosure shall be such as to keep loss of SF6 gas to a minimum. It is expected that replenishment of gas shall not be necessary for at least 10 years. Therefore, the gas leakage rate of any gas zone must not exceed 1 per cent of its volume per year.

Gaskets and seals shall be designed for a life expectancy of at least 30 years and this shall be demonstrated by tests or otherwise.

The switchgear gas enclosures must be sectionalised into gas zones with gas tight barriers between sections or compartments. The sections shall be arranged to minimize the extent of plant rendered inoperative when gas pressure is reduced, either by excessive leakage or for maintenance purposes, and to minimize the quantity of gas that has to be evacuated and then recharged before and after maintaining any item of equipment.

In order to minimise the extent of equipment outage in the event of gas loss when gaining access inside equipment for maintenance or when an item of equipment needs to be removed, the overall equipment shall be divided into discrete gas zones isolated from each other by gas-tight bulkheads. Separate gas-zones shall be provided for busbars and isolators. The gas-tight support insulating barriers shall be capable of withstanding a pressure differential of a vacuum on one side and on the


other a pressure equal to the design gas pressure or the maximum gas pressure under conditions of an internal fault if this is greater.

The design of the enclosure assemblies shall be such that in the event of a fault, the damaged items can be replaced with minimum disturbance to the adjacent compartments.

Each gas-tight zone shall be provided with a device to relieve any pressure rise developed during internal flashover.

Overpressure created by arcing within an enclosure shall preferably be relieved by means of bursting discs venting into the atmosphere. The method of pressure release shall prevent permanent distortion of adjacent enclosures. Pressure relief by collapse of internal gas barriers is not acceptable.

The arrangement of any pressure relief device shall be such that any expulsion of disc debris or gas will be directed in a manner that will not endanger any personnel and relief vents shall be provided with deflectors or vent pipes as appropriate to satisfy this requirement.

The duration of the fault arc shall be determined by the operation of the main and back up protection equipment under all fault conditions as defined and specified in IEC 60517 and verified by relay setting calculations. During this fault period burn through of the enclosure by the fault arc is not permitted.

4.3 Gas Insulated Switchgear - Busbars and Connection Chambers

To minimise the extent of dismantling necessary to remove a part of a main busbar, it is required that discrete lengths of busbar shall be able to be withdrawn without disturbing adjacent busbar lengths; this may be achieved by the use of compressible bellows or other approved means.

The equipment shall be arranged to avoid excessive dismantling in the event of a main busbar fault. Information shall be provided with the tender to indicate the facilities incorporated in the equipment to allow removal of busbars and the consequential maximum extent of dismantling that may be involved in the event of such a fault.

All busbar connections and busbar chambers (where phase segregated busbars are employed) shall be colour coded to indicate the phase colour associated with the connection as defined elsewhere in this Specification.

All gas pipe work shall be colour coded and where more than one pipe follows a common route, each pipe shall be ring coded or labelled at regular intervals to identify the gas zone with which it is associated.

4.4 Enclosure Gas Zones

The switchgear gas enclosures must be sectionalised into gas zones with gas tight barriers between sections or compartments. The sections shall be arranged to minimize the extent of plant rendered inoperative when gas pressure is reduced, either by excessive leakage or for maintenance purposes, and to minimize the quantity of gas that has to be evacuated and then recharged before and after maintaining any item of equipment.


4.5 Expansion Joints and Flexible Connections

Expansion joints or flexible connections shall be provided in the busbars and metal enclosures to absorb the thermal expansion and contraction of the SF6 equipment. This shall include the switchgear supporting structures and shall accommodate differential settlement of the foundations and floors on which the equipment is mounted.

The method of compensating for temperature variation and differential settlement as well as the number and position of the compensating devices shall be stated in the Schedules.

4.6 Future Extensions

The design of the switchgear shall be such that it is possible to extend each end of the existing busbars without having to take more than one busbar out of service. Other circuits shall remain available for continuous uninterrupted service.

Where the distance between adjacent circuits is the width of a switchgear bay or greater, a removable straight through busbar section shall be included. It shall be possible to interchange this section with a future bay, if required, without having to take more than one bar out of service and without interruption of other connected circuits.

4.7 Gas Monitoring and Handling

All gas zones shall be filled to the design pressure with pure SF6 gas (to IEC 60376/BS 5207) and shall be monitored individually by temperature compensated pressure switches and pressure gauges.

A two-stage alarm system shall be provided for each gas section, including all relays, fascias, etc, these shall be accommodated adjacent to the switchgear. Additional repeat alarms to announce remotely each alarm stage for the group alarms of each switch bay shall be provided. The local control cubicle shall be adequately labelled to allow easy identification of signals from each gas section.

The low pressure/density alarm switches shall be arranged to provide an instruction for the operation, either automatically or manually of the circuit breakers and disconnectors adjacent to a faulted gas zone and to subsequently inhibit their further operation until suitable remedial action has been taken.

In view of the dependence of system security on the reliability of the gas density relays, and in view of the large number of relays involved in any regular relay checking procedure, the gas density relays shall have a high degree of reliability. Consideration shall be given in the design of the relay to allow easy checking of its proper operation.

Provision shall be made to enable routine measurement of the gas density in each gas-zone. The location of such measuring points shall be reasonably accessible.

Each gas density device shall be connected to the gas compartment via a self-sealing valve to facilitate easy removal of the device for maintenance. The use of stop valves for this purpose is not acceptable.

Facilities shall be provided to constantly monitor the gas density. A two-stage low gas pressure alarm and lock out system with local and remote indications shall be provided on each circuit breaker.


4.8 Local Control Cubicles

Local control cubicles shall be separate, floor mounted cubicles, provided adjacent to each switchgear section which shall contain all facilities for control, indication, local/remote control selection, protection and alarms associated with that switchgear section. A mimic diagram incorporating switches, contactors and relays necessary for local electrical control of circuit breakers, disconnectors and earth switches together with position indication shall be included.

Any plug and socket cable connections between switchgear sections and their associated local control cubicles shall be provided with a secure means of locking the connection to prevent inadvertent disconnection.

4.9 Gas Insulated Bus Duct and Bushings

SF6 insulated gas bus ducts and supporting structures and foundations shall be provided between circuits as specified in the schedules/drawings. The bus ducts shall preferably be of the phase isolated/phase segregated type. However, these shall suit the arrangement of the main GIS switchgear to which the bus duct is connected.

The SF6 enclosures shall be constructed from the same materials as the bus bar enclosures provided with the main GIS switchgear. The materials used shall prevent overheating at the specified rated currents. To reduce the effect of solar gain all SF6 insulated bus duct exposed to direct sunlight shall be covered with metallic sun shielding. The bus duct shall be complete with all components, enclosures, gas seals, gas monitors, gas compartments, gas filters, gas barrier and supporting insulators as defined in previous subsections.

The bus ducts shall be terminated at one end direct on to the GIS switchgear and at the other end on to either, outdoor porcelain-clad, or approved composite-material-clad bushings for OHL feeders, or direct onto cable sealing ends in suitable GIS enclosures.

The design of the bus ducts shall make full allowance of the thermal expansion associated with the switchgear, wall mounted bushings and any other equipments between which the bus ducts are connected. The Contractor shall fully co-ordinate the requirements of the SF6 insulated bus duct connections between the GIS switchgear feeders and the overhead line landing gantries, especially with regards to the differential settlement of the concrete floors of the switchgear room and the bus duct supporting structures.

The design and installation of the bus ducts shall as such be fully co-ordinated with the manufacturers of the equipments to be connected and shall also be co-ordinated with the civil design and works in relation to the building height, wall openings, wall/roof embedment, structural, etc, apart from the foundation requirements described herein.

The bus ducts and their supports shall be designed and tested for the specified rated normal and short time currents and for the maximum system voltage and specified test voltages. The ducts and their supports shall include any non-magnetic material or insulation necessary to prevent overheating or the induction of over-voltages in the secondary circuits.

Provision shall be allowed for access and disconnection links for equipment HV testing as may be required at site.


4.10 GIS HV Circuit Breakers (72.5 kV and Above)

4.10.1 General SF6 gas insulated (GIS) circuit breakers shall be single-pressure puffer or Self-blast or Self-blast/Rotating Arc type, suitable for indoor installations.

Circuit breakers shall be designed to IEC 60517 and fully tested in accordance with IEC 62271-100, 60694 and 61233 and with the requirements of this Specification and shall be suitable for minimum continuous current at an ambient temperature of +50º C.

All type tests shall be either carried out by independent testing laboratories or witnessed by independent observers.

The design of the circuit breaker shall be such that inspection and replacement of contacts, nozzles and any worn or damaged component can be carried out quickly and easily. The circuit breaker shall be fitted with the open/closed position indicators easily visible from ground level.

The inherent design of the circuit breakers shall be such that one set of contacts and nozzle (or nozzles as the case may be) shall be able to successfully interrupt at least twenty 100% fault currents without excessive erosion. When switching Capacitive (capacitor banks) and Inductive (including reactors) currents (IEC 61233), they produce very low over-voltages. The over-voltages produced on any switching duty must be considerably less (<<) than 2.5 pu.

The sound pressure levels of the breaker during the mechanical operations shall comply with the local and national health and safety regulations.

A suitably sized molecular sieve shall be used in the circuit breaker tank to absorb any moisture and contaminants for at least ten years in service.

The circuit breakers shall be suitable for at least 10,000 satisfactory open and close mechanical operations in accordance with IEC 62271-100.

A two-stage low gas pressure alarm and lockout system with local and remote indications shall be provided on each circuit breaker. The low pressure/density alarm switches shall instantly provide an instruction to the operator and subsequently inhibit their further operation until suitable remedial action has been taken.

The circuit breaker shall be fitted with the necessary transducers to allow regular monitoring of circuit breaker travel characteristics and all routine and site test records shall be made available to the Employer for ongoing comparison purposes. The provision of suitable test equipment for measurement of the circuit breaker timing cycle in included under this contract.

4.10.2 Circuit Breaker Operating Mechanisms 4.10.2.1 General The circuit breakers shall preferably be fitted with power-spring mechanism but other types of reliable mechanisms such as leak-free Hydraulic, Spring/Hydraulic, and Spring/SF6 gas will also be considered, provided they comply with the above circuit beaker mechanical operations requirement. A positively driven open/closed, mechanical indication device to show the position of the main


contacts and with local manual operated features for tripping, closing and spring charging, visible without the necessity to open the mechanism door, shall be provided. The drive for the device shall be positive in both directions. A Pneumatic mechanism is not acceptable.

The mechanism shall fully close the circuit breaker and sustain it in the closed position against the forces of the rated making current and shall fully open the circuit breaker without undue contact bounce at a speed commensurate with that shown by tests to be necessary to achieve the rated breaking capacity in accordance with IEC 62271-100. The mechanism shall be capable of being locked in the open position. When an auto-reclose facility is specified, the mechanism shall be capable of fully closing and opening again after the auto-reclose time interval specified i.e.: performing a complete O-0.3 sec-CO-3 min-CO duty.

Mechanical counters, to record the number of closing operations, shall be provided for each circuit breaker mechanism. Circuit breakers arranged for single-pole operation shall be provided with a counter for each pole.

The mechanism and the connected interrupters shall satisfy the mechanical endurance requirements of IEC 62271-100 and all additional requirements specified herein.

Means shall be provided to prevent the mechanism from responding to a close signal when the trip coil is energised or to reclosing from a sustained close signal either after opening due to a trip signal or failure to hold in the closed position. Any relays to accomplish these provisions shall be continuously rated and mounted at the circuit breaker. The mechanism shall also incorporate manual-trip facility fitted with a guard to preclude inadvertent operation.

Means shall be provided to detect phase discrepancy in the event of one or two phases failing to complete a close or trip operation and to trip all three phases after a time delay of 1 second.

Each mechanism shall be fitted with duplicate trip coils and phase discrepancy remote indication shall also be provided.

The following facilities shall be provided at each circuit breaker local control point: -

(a) LOCAL/REMOTE selector switch. The selection of `local' operation shall inhibit the operation of the breaker from any remote source with the exception of the protection scheme.

(b) OPEN/NEUTRAL/CLOSE control switch or open and close push buttons. Where push button controls are provided the selector switch shall have a neutral position.

(c) EMERGENCY TRIP DEVICE, suitable for manual operation in event of failure of electrical supplies. The device shall be accessible without opening any access doors and distinctively labelled and protected against inadvertent operation.

The selector switch shall be lockable in both positions and the control switch shall be lockable in the neutral position.

For maintenance purposes, means shall be provided for manual operation including the slow closing and opening of those circuit breakers whose moving contacts are mechanically coupled to the direct linkage mechanism. Such operation shall be possible without the necessity of gaining access to the interior of the power unit, and shall not require excessive physical effort.


4.10.2.2 Spring Mechanisms Spring operated mechanisms are the preferred type.

Provision should be made for remote indication of `Spring charged' and `Spring charge fail' conditions.

A spare normally open spring-drive limit switch shall be provided.

It shall be possible to hand charge the operating springs with the circuit breaker in either the open or closed positions. In normal operation, recharging of the operating springs shall commence immediately and automatically upon completion of the closing operation and shall be completed within 30 seconds. Closure whilst a spring charging operation is in progress shall be prevented, and release of the springs shall not be possible until they are fully charged.

The state of charge of the operating springs shall be indicated by a mechanical device which shows `SPRING CHARGED' when operation is permissible and `SPRING FREE' when operation is not possible. A local manual spring release device shall be provided and so arranged as to prevent inadvertent operations.

Means shall be provided for hand charging the operating springs.

4.10.2.3 Hydraulic and Hydraulic/Spring Mechanisms Operating pressure shall be maintained automatically, a gauge being provided to give indication of the pressure. The pressure gauge shall be suitably damped to ensure that it is not subject to transient pressure oscillations either during pumping or during operation of the circuit breaker.

A lockout device with provision for remote alarm indication shall be incorporated in each circuit breaker to prevent operation whenever the pressure of the operating medium is below that required for satisfactory subsequent operation at the specified rating. Such facilities shall be provided for the following conditions: -

(a) Trip lockout pressure.

(b) Close lockout pressure.

(c) Auto reclose lockout pressure.

Alarm contacts shall be provided to indicate conditions a, b and c. If two trip systems are specified, then trip lockout shall apply to both systems.

A sudden fall in pressure of the operating medium to a level below which a safe operation is not possible shall not result in slow opening or closing of the circuit breaker contacts. The mechanism shall be locked in position and electrical trip and close signals shall be isolated during this period.

Facilities shall be provided to enable the available operating energy stored by the mechanism to be determined prior to operating the circuit breaker, together with an alarm in the event of the potential energy falling below a minimum rated level. Facility for hand charging of hydraulic systems shall be provided.


Circuit breakers having independent operating mechanisms on each phase shall block tripping, closing, and auto-reclosing of all phases if the operating pressure is below a minimum rated level in one or more of the mechanisms.

A pump running time meter shall be fitted and an alarm shall be provided to indicate excessive running time.

4.10.2.4 Mechanism Housings Where heaters are provided, these shall be permanently connected. Where two-stage heaters are provided, one stage shall be permanently connected and the other switched.

Means for locking shall be provided for the doors of each mechanism housing.

Mechanism housings for use outdoors shall have an IP rating of 55, those for indoor shall be IP 30.

4.11 GIS Disconnect Switches

The GIS disconnect switches shall be constructed and fully tested in accordance with the requirements of IEC 62271-102, 60694, 61128, 60517, and 60265 and this Specification. The design shall incorporate features, which shall reduce or eliminate very high frequency voltage transients during disconnect switch operation.

The disconnecting function of disconnect switches shall still be effective when adjacent equipment components are dismantled. It is preferred that disconnect switch contacts are able to be maintained and replaced with the associated earthing switch closed.

Disconnect switches shall be fitted with position indicators visible from ground level. Viewing windows for confirming the positions of disconnect switches and earth switch contacts shall be provided unless prior agreement is reached with the Engineer.

The disconnect switches shall be provided with power and manually operated mechanisms. The power operation of the disconnect switches shall be capable of being controlled from a local or remote point.

Each power-operated disconnect switch shall be complete with a lockable LOCAL/REMOTE selector switch and OPEN/NEUTRAL/CLOSE control switch or push buttons. The function of all control and selector switches shall be clearly labelled.

Power operating mechanisms shall be capable of being locked in the open or closed positions.

The power operating mechanisms shall be suitable for the operation from voltages specified in the Schedules of this Specification.

Operating motors shall be provided with thermal overload protection and in the case of 3 phase motors, phase unbalanced protection.

The disconnect switches shall be suitable for slow closing operation. Manual operation of the disconnectors for maintenance purposes shall be provided.


The number of normally open and normally closed auxiliary switches required shall be as dictated by the particular scheme of application. Where any particular scheme requires special timing of auxiliary contacts, these shall be provided.

Electrical control circuits shall be so arranged that once initiated, an operation shall be completed unless prevented by loss of supply or operation of the motor protection. On restoration of supply the operation shall be completed.

Emergency hand operation shall be provided on power-operated disconnect switches and the power drive shall be mechanically disconnected during hand operation.

It is required that the manual effort to operate the disconnectors or earth switches shall not be greater than 150 N. There shall be adequate access for the manual operation.

In the case where the operating mechanism comprises an energy storage system followed by triggering for completion of the operation, the design shall exclude any possibility of operation by accidental triggering. Switch operation shall be effective only after full charging of the operating mechanism and after deliberate operator action.

The operating handles for manual operation of power-operated mechanisms may be detachable, in which case only two handles of each type are required per substation.

4.12 Earth Switches and Maintenance Earthing Devices

4.12.1 GIS Earth Switches Earth switches shall comply with IEC 62271-102 60694 and 60517 and the requirements of this Specification. They shall be provided with power and manually operated mechanisms and shall be provided on one or both sides of the disconnect switches dependent upon the locations. The electrical operation shall be performed from their control cubicles. The position indicators shall be clearly visible from the permanent working platform level.

Each separate section of switchgear that can be disconnected shall have provision for earthing in accordance with the following requirements: -

(a) All incoming and outgoing supply circuits shall be earthed by a device having a making current rating and short time rating equal to that of the associated circuit breaker.

When specified, the earth switch shall be fully insulated and the connection to earth brought out through the enclosure by means of an insulating bushing in order that the earth switch may be used for various test purposes. A removable bolted link shall be provided for connecting the insulated earth switch connection to the actual earthing terminal. The earth switch and connection bushing shall be capable of withstanding an applied power frequency voltage of 10 kV.

(b) Sections that can be established as having been disconnected shall be earthed by a device having a short time rating equal to that of the circuit breaker.


The earthing switch and the test injection point arrangement shall be suitable for a test current equal to the rated normal current of the connected busbars for a duration of 5 minutes minimum.

Earth switches on line circuits shall be capable of closing onto an energised circuit and of interrupting the current induced in the line by a parallel fully loaded line. The interrupting duty required is as specified in the schedules.

The earth switch operating mechanism shall be capable of being locked in the open or closed position.

4.12.2 Portable Maintenance Earthing Devices Where portable earthing is required, provision shall be made for applying fully rated portable maintenance earthing devices to the primary conductors of the equipment.

The design of the device shall be such that the chamber in which the device is applied can be refilled with SF6 gas when the device is in the closed position.

4.13 Current Transformers

4.13.1 General The current transformers shall comply with IEC 60044-1 & 6.

The current transformers shall have the following accuracies: -

Tariff metering Class 0.2

Instruments Class 1

Overcurrent and earth fault protection

Class 5P

Instruments and Overcurrent/earth fault protection combined

Class 1/5P

High impedance circulating current Protection

Class PX

For distance measuring protection, and current differential protection schemes the Contractor must state clearly the accuracy necessary for the correct functioning of the protection system offered and show that the secondary output of the current transformer is satisfactory for this purpose.

Current Transformers shall be of the ratios specified in Schedule D. The Contractor shall be responsible for the sizing, rating and other details pertaining to the current transformers.

The primary windings shall have a continuous and short circuit rating not less than that of the associated circuit breakers. The Contractor shall submit details of the precautions taken in the design of the primary of the transformer to prevent the mechanical and thermal stresses set up on short circuits from causing a breakdown.


Transformer circuits may be subjected to overload duties in accordance with IEC 60354; current transformers in transformer circuits shall have a rated continuous thermal current equivalent to at least the transformer long-time emergency cyclic loading capability.

Current transformers shall be of low reactance type and each core shall be electrically separated from the other windings.

The secondary windings of each set of current transformers shall be earthed at one point. Secondary terminals shall be located so that they are accessible while the equipment is alive.

Where adequate earth screens are fitted between the primary and secondary windings, earthing of the secondary winding shall be via a link mounted in the related protection or instrument cubicle. Where such earth screens are not fitted a separate earth system may be necessary.

Wherever possible the connection to earth shall be on the side of the S2 terminals.

Where multi-ratio transformer windings are specified, multi-ratio primary windings will only be considered where the protection arrangement makes these suitable for all aspects of the installation.

When multi-ratio tappings are specified, a label shall be provided indicating clearly the connections required for all ratios. These connections and the ratio in use shall also be shown on all connection diagrams.

Neutral current transformers shall be of the outdoor totally enclosed porcelain bushing type complete with mounting steelwork as required and terminal box for secondary connections.

Class PX CTs shall be specified in terms of the Turns Ratio (e.g. 1/2000) and have a secondary current rating (ISN) adequate for the primary rating (IPN) of the circuit to which it is connected; e.g. with a Turns Ratio of 1/2000, a primary rating of 2600A will require a continuous secondary rating of 1.3 A. The dimensioning factor (KX) shall be selected to ensure an adequate knee point voltage (EK), taking into account the other circuit elements and the protection function.

Line protection current transformers shall correctly transform during initial faults and following high speed three phase re-close onto faults without saturation at the system source X: R ratio (L: R) appropriate to the system voltage and shall be that used for the asymmetrical rating of the association circuit breakers.

The voltage produced at the cores by over current or during transients on the system shall be well below the saturation voltage to ensure good transient response. The Contractor should make calculations related to the C.T. burdens and transient response according to the relevant IEC standards and submit for approval.

Where current transformers are to be mounted on apparatus provided under another contract the contractor shall be responsible for making all the necessary arrangements directly with the other contractors and for keeping the Engineer informed.

Current transformers for balanced earth fault protection shall be tested to prove compliance with the requirements of IEC 60044-6.


4.13.2 GIS Current Transformers Gas insulated current transformers shall be of the bar primary type.

The pressure of the gas at normal temperature and pressure shall be such that it remains in its gaseous state when operating at the lowest temperature stated in the Schedules.

Facilities shall be provided for constant local monitoring of the current transformer gas pressure, and topping up or sampling the gas.

For safety reasons, a bursting disc shall be fitted to the current transformer housing.

4.13.3 Current Transformer Primary Injection Tests Facilities shall be provided which allow primary injection testing of the current transformers with the minimum disturbance to the switchgear.

4.14 Voltage Transformers and Coupling Capacitors

4.14.1 General Miniature circuit breakers (MCB) shall be provided on or adjacent to each voltage transformer, located such that they are accessible while the primary winding is alive. MCBs shall be identified by labels clearly indicating their function and phase colours.

The voltage transformer secondary circuits shall be complete in themselves and shall be earthed at one point only. A separate earth link shall be provided for each secondary winding and shall be situated at the transformer but earthing will be in the relay or control building. The primary winding shall be earthed at the transformer.

The secondary windings are to be kept electrically separated. For voltage transformers, consisting of single-phase units, separate earth links for secondary windings shall be provided and shall be located at the voltage transformer.

Where voltage transformers are supplied which are, or may be, connected to different sections of the busbar, it shall not be possible for the voltage transformer secondary circuits to be connected in parallel, unless the respective sections for the busbars are also connected in parallel.

An auxiliary switch or relay shall be provided in each phase of the secondary circuit of the synchronising and metering voltage supply connections to break the circuits automatically as soon as the circuit breaker is opened.

To prevent Ferroresonance, suitable damping devices shall be provided for connection to the transformer secondaries.


Voltage transformers shall have the following accuracies: -


Metering and instruments Class 1.0

Protection Class 3P.

4.14.2 GIS Voltage Transformers The inductive voltage transformer shall be housed in a metal tank, which complies with the internal arcing requirements of IEC 60517. The tank shall have a suitable lifting facility.

The high voltage cast resin insulators (barriers) shall be suitable for withstanding the differential pressure i.e. the normal working pressure on one side and the vacuum on the other side. They shall be compatible with SF

6 gas and its degradation products.

The pressure of the gas at normal temperature and pressure shall be such that it remains in its gaseous state when operating at the lowest temperatures stated in the Schedules.

Facilities shall be provided for constant local monitoring of the SF6 gas pressure inside the tank,

topping up or sampling the gas.

Facilities shall be provided for isolating the voltage transformer during the injection testing of GIS equipment.

For safety reasons, a bursting disc shall be fitted to the transformer housing.

4.15 Surge Arresters

4.15.1 General Surge arresters shall be of the metal-oxide, gapless type.

The design of equipment shall be in accordance with the requirements of IEC60099-1, IEC: 60099-4 and any additional requirements of this Specification. Each pressure vessel shall comply with the requirements of the appropriate CENELEC document and European standard. The testing of the equipment shall be in accordance with the requirements of IEC 60060, 60270 and 60099.

The surge arresters shall be designed to incorporate a pressure relief device to prevent shattering of the blocks/or housing, following prolonged current flow or internal flashover. They shall be designed to ensure satisfactory operation under the atmospheric conditions given in the Schedules, and under such sudden variation of voltage as may be met with under working conditions on the system.

Where surge arresters form part of an overall contract for the engineering of a station and the supply of equipment, the positioning of the arresters relative to other equipment shall provide protection to the other equipment according to the requirements of IEC 60099. Insulation coordination studies shall be carried out to demonstrate these requirements and issued to the Engineer for approval.


4.15.2 Surge Counters Surge counters shall be provided and shall be operated by the discharge current passed by the surge arrester. Surge counters shall be of the electro-mechanical type and designed for continuous service, they shall be provided with a facility for continuously monitoring the leakage current.

Internal parts shall be unaffected by atmospheric conditions on Site. Alternatively, a weatherproof housing to IP 55 shall be provided as part of the Contract and this shall be designed to allow the recording device to be read without exposing the internal parts to the atmosphere.

The surge counter shall be connected in the main earth lead from the diverter in such a manner that the direction of the earth lead is not changed or its surge impedance materially altered. A bolted link shall be provided so that the surge counter may be short circuited and removed without taking the arrester out of service.

4.16 Sulphur Hexafluoride Gas (SF6)

4.16.1 General The sulphur hexafluoride SF6 gas shall comply with the requirements of IEC 60376 and BS 5207. The SF6 gas shall be supplied in 45 kg cylinders. The dew point of the gas shall be lower than -45°C. Sufficient quantity shall be provided to fill all SF6 equipment supplied under this contract plus an additional 20 per cent.

The high-pressure cylinders in which the SF6 gas is transported to, and stored on site, shall comply with the requirements of local regulations and byelaws.

WARNING:

Under normal conditions the SF6 gas of temperature and pressure is colourless, odourless and non-toxic. It is however five-times heavier than air and the arced gas and degradation products are toxic and harmful. It is therefore important that all personnel working on GIS equipment are kept fully informed of the potential risks and appropriate health and safety regulations.

It is the responsibility of the GIS equipment supplier to provide:

- Adequate safety training to the Employer's staff regarding gas detection, the disposal of arced products and storage.

- Sufficient numbers of facemasks, goggles, hand gloves and respirators, protective clothing and gloves.

- First aid equipment including an eye wash bottle filled with distilled water.

4.16.2 Gas Handling Equipment The number of mobile gas handling plants for filling, evacuating, and processing the SF6 gas in the switchgear equipment, to be supplied as part of the Contract to enable any maintenance work to be carried out, shall be as specified in the schedules. These plants shall include all the necessary gas cylinders for temporarily storing the evacuated SF6 gas as well as any other gases that may be used in the maintenance process.


The capacity of the temporary storage facilities shall be at least sufficient for storing the maximum quantity of gas that could be removed when carrying out maintenance or repair work on the largest section of the switchgear and associated equipment.

The plant(s) provided shall be suitable for evacuating and treating the SF6 gas by the use of desiccants, driers, filters etc to remove impurities and degradation products from the gas. The capacity of the plant shall be such that the largest gas zone, with the exception of the circuit breaker, can be evacuated in less than one hour.

The plant shall also be capable of reducing the gas pressure within the circuit breaker to a value, not exceeding 8 millibars, within a time not greater than two hours.

It shall be capable of operating in the temperature range -27°C to +50°C.

4.16.3 Pipes and Couplings for the Connection of SF6 Gas All the necessary pipes, couplings, flexible tubes and valves for coupling to the switchgear equipment for filling or evacuating all the gases to be used, with all necessary instructions for the storage of this equipment, shall be provided.

4.17 Overhead Travelling Crane

4.17.1 General This contract includes the supply of all materials and works for a crane with all operating machinery, structural steel, control equipment including cables and all other parts and accessories required for proper and safe operation.

The travelling crane shall be used for erection work as well as for normal maintenance, repair and overhaul purposes.

The crane shall be complete, including, crab, hoisting machinery with motor and brakes, all lubricating devices, ropes, sheaves, hooks, flood lights, control apparatus including switchgear, runway rails, push-button controls, interlocks, limit switches, governors, protecting and alarm devices and all electric connections (cables and live rails including insulators) between all parts supplied.

4.17.2 Construction Features The design of the travelling crane has to guarantee fail-safe and satisfactory operation and has to be easy to access for service, inspection and repair.

A safety factor of 1.5 times of the maximum load is to be taken into account for all stress calculations to allow shock loading.

Adequate guards shall be provided to protect personnel from accidents caused by moving mechanism, live terminals, live conductors, etc.

The guards shall be removable for inspection and maintenance without disturbing any other part of the plant.


The Contractor shall supply suitable nameplates, giving details of the lifting capacity of the travelling crane. These nameplates shall be clearly visible to anyone who may use the cranes. The nameplates shall be inscribed in English Language.

Operating machinery and other exposed parts shall be suitably housed so that the exterior of the travelling crane will consist of smooth surface and pleasing lines.

4.17.3 Structure The minimum plate thickness for the steel construction shall be 7 mm, unless otherwise demonstrated suitable by the Contractor.

4.17.4 Crane Rails Travelling crane rails shall be provided by the Contractor. Joints between rails on opposite runway girders for the cranes shall be staggered with respect to each other and to the wheelbase of the cranes. All joints of rails shall be welded. Rail joints shall not be located over the runway girder splices. Provision for rail expansion shall be made at the end stop locations only.

Guiding of rails on the girders should be carried out with rail clamps to distance adjustment. Welded clips are not allowed.

End stops shall be designed and located to limit the maximum crane travel. The end stops shall be capable of stopping the travelling crane fully loaded and travelling at the rated speed.

4.17.5 Crane Bridge The travelling crane bridge shall consist of two girders rigidly attached to the end trucks. Gusset plates shall keep the crane in alignment.

Welded joints shall be used for the main structure of the crane, bolted joints shall be avoided whenever possible.

- In load bearing members, if a bolted joint is necessary, black bolts shall not be used.

- The strength of welded joints or joints made by friction grip bolts in structural members shall not be less than the net strength of the member. Friction grip bolts shall comply with BS 3139 and shall be fitted in accordance with the recommendations of BS 3294.

- The calculated strength of other bolted joints in structural members shall be not less than the net strength of the member plus 25 per cent. The calculated stress in screws, bolts and welds shall not exceed the appropriate permissible stress given in BS 2573.

The travelling crane girders shall be welded in structural steel box sections, with wide flange beams, standard "I" beams or reinforced beams. Girders must be symmetrical and line-of-sight must be considered along with girder design, as well as suspended crane supports. Trellis girder shall be prohibited.

The girders shall be designed to withstand all vertical loads and horizontal forces that may arise under service conditions. The vertical deflection of the girders, caused by the safe working load and the weight of the crab in the central position shall not exceed 1/1000 of the span.


The larger of the following load combinations shall control the design of the girders:

- The sum of the maximum stresses due the dead load, the weight of the trolley, the rated load, and the impact allowance.

- The sum of the maximum stresses due to the dead load, the weight of the trolley, the rated load, and an allowance for the lateral load due to acceleration and deceleration of the travelling crane.

The bridge girders shall be security braced to the end carriages to prevent cross racking. It must be impossible for the travelling crane to fall from the gantry in the event of derailment. The carriages shall be of the bogie type and shall be equipped on each end with spring buffers (bumpers).

4.17.6 Electrical Parts The travelling crane and hoists shall be so designed that adequate access for maintenance of the electrical control and operating gears is provided with suitable access facilities to enable removal of parts for maintenance and repair.

The power supply shall be provided via adequately protected contact wires along the crane track and a suspended cable on the crane girders.

The supply to the contact wires shall be via a manually operated load break isolating switch mounted at a convenient height above floor level, the switch being capable at being locked in the open position. Red indicating lights shall be arranged at collector level to show when the isolator is closed.

Motors shall be provided with quick action brakes; controllers, resistors, magnetic contractors and overload protection switches. Heavy dust and splash-proof limit switches shall be provided to prevent over hoisting, over transversal and over travelling motions.

4.17.7 Motors All motors shall be totally enclosed, wound rotor type specifically designed and built for crane service.

Motors shall be equipped with sealed antifriction, grease lubricated bearings, with provision for grease renewal.

Motors shall have tapered shaft extension on the brake end for easy removal of the brake wheel.

4.17.8 Push Button Control Station The push button control station shall be suspended by means of flexible galvanised wire rope and connected to the crane control panel by means of flexible multicore cable. The arrangement shall permit movement of the control station along the entire length of the bridge at all levels of operation.

The push button control station shall have a cost aluminium housing and shall have mechanical protection class of IP 44. The Control station shall contain besides all necessary individual push buttons for controlling operation of all crane motors, an emergency push button of the lockable type. This shall function as a master switch to cut off all power supply to the crane control panel, by switching off the master magnetic contactor.


4.17.9 Overload Relays Each motor shall be protected by overload relays adjustable for values between 150 and 300 per cent of the full load motor current.

4.17.10 Switchgear The power supply from the main collectors shall be controlled by means of a 3-phase, manually operated circuit breaker, and a 3-pole master magnetic contactor provided with under-voltage and phase reversal protection.

The operating coil of the contractor shall be wired in series with the auxiliary contacts of the adjustable, instantaneous relays in the circuit of each hoist and each travel motor, and in the circuits of all limit switches.

The circuits shall be so arranged that, on the functioning of an overload relay or the tripping of the limit switch, the flow of power to the crane will be interrupted.

4.17.11 Circuit Breaker Cabinets The main circuit breaker, lighting supply circuit breaker, master contractor, relays and protective devices shall be enclosed in a suitable steel cabinet with hinged doors. The main circuit breaker shall be so arranged that it can be operated without opening the cabinet door and that it can be locked in the open position.

4.17.12 Limit Switches Limit switches shall be provided to control the upper limits of travel of all hoist motors and at each end of travel for the bridge and trolley. Switches shall be of the totally enclosed safety type operated by the hooks or hook blocks.

4.17.13 Tools One steel toolbox shall be provided, containing complete set of ordinary and special tools needed for overhauling and repair of cranes furnished. General list of such tools shall be indicated in Tenderer's offer, and shall be detailed and submitted by the Contractor to the Engineer for checking and approval.

4.18 GIS Equipment Cable Facilities

4.18.1 Method of Termination of Cables The following requirements are applicable to switchgear equipment where the HV power cables are terminated directly in the SF

6 metal clad switchgear using cable sealing ends designed for use in SF

6

gas and shall comply with IEC 60517.

The cable connection to the switchgear shall be in accordance with IEC 60859. The switchgear contractor shall be responsible for the design, testing and supply of the insulating barrier, which provides sealing between SF

6 and air and also between SF

6 and the cable insulation. The Contractor

shall ensure that there will be no leakage of SF6 gas, oil or moisture across the sealing joint from one

chamber to the other throughout the service life of the equipment. This barrier is to be designed to


accept the cable sealing end provided by others. The switchgear contractor will also be responsible for providing the electrical connection between the cable sealing end and his equipment.

Suitable cover plates and seals shall be provided as part of the switchgear contract for sealing each aperture where a cable sealing end is to be fitted, to enable the switchgear to be completely filled with SF

6 gas and tested when a cable sealing end is not available or fitted.

4.18.2 Cable Test and Isolating Facilities Testing isolation facilities shall be provided as follows:

(a) High voltage, AC pressure tests. The cable circuits will be tested with a mobile AC test set at a test voltage in accordance with IEC 62067. GIS systems will be provided with access ports and an AC test bushing to permit testing of the cable system at the above voltage.

(b) Low voltage cable tests. The cable earth switches shall be fully insulated and connected to earth through a bolted link, as specified, so that the LV cable test equipment (of rated voltage less than 10 kV) may be connected to the cable without opening any of the metal clad gas enclosures.

The insulation level of all equipment from the cable sealing end up to and including the cable circuit earth switch and disconnector (open) shall be capable of withstanding without failure or reduction of general insulation levels, the HV power cable routine AC test voltage applied for 15 minutes between the conductor and earth at the minimum rated working SF

6 gas density or pressure. The AC test

voltage shall be in accordance with the recommendations of IEC 62067.

Where three phase enclosure designs are supplied, the test facilities provided shall be such that each phase can be tested individually without the need to evacuate and refill the enclosure between tests.

4.19 Interlocking Equipment

4.19.1 Extent of Supply The Contractor shall be responsible for the designing, supply and commissioning of all interlocking schemes to the satisfaction of the Engineer. Designs are to cover the 400 kV switchgear, 400/132 kV transformers, 132 kV switchgear, tertiary loads, ac station services, dc station services. Interlocking facilities are specified in the SCS section of this Specification and these shall be in addition to the facilities in this section.

4.19.2 General All disconnecting switches and earthing devices shall be provided with interlocking features of the mechanical sequential locking type or electromechanical bolt type, and the scheme of interlocking shall be subject to approval and shall include the hand operation of apparatus which is normally electrically operated.

All mechanical interlocks shall be applied at the point at which hand power is used, so that stress cannot be applied to parts remote from that point.


Where key interlocking is employed, tripping of the circuit breaker shall not occur if any attempt is made to remove the trapped key from the mechanism. Any local emergency tripping device shall be kept separate and distinct from the key interlocking.

All electrical interlocks shall so function as to interrupt the operating supply. Failure of supply or connections to any electrical interlock shall not produce or permit faulty operation.

Electromechanical bolt interlocks shall be energized only when the operating handle of the mechanism is brought into the working position. Visible indication shall be provided to show whether the mechanism is locked or free. Means shall be provided whereby the bolt can be operated in the emergency of a failure of interlock supplies.

The guarding and screen-work of all equipment, wherever provided, shall be interlocked with the associated circuit breaker and the isolating devices in such a manner that entrance to the guarded equipment cannot be obtained unless the circuit breaker and isolating devices are open and all equipment within the guarded area is de-energized and safe. It shall not be possible to make the apparatus alive while the guarding is open.

Earthing switches are to be interlocked with the appropriate disconnect switches such that the earth switch cannot be closed unless the disconnect switches are open. Conversely, the disconnect switch cannot be closed unless the earth switch is open.

When made of steel or malleable iron, operating boxes, handles, rods, tubes and other fittings for outdoor equipment shall be galvanized.

4.19.3 400 kV Area In general the following applies to line and breaker disconnect switches:

(a) Breaker disconnects can only open when the breaker is OPEN.

(b) Breaker disconnects can close only when the breaker is OPEN.

(c) With breaker disconnects switches OPEN, it must still be possible to operate the breaker by LOCAL control only.

(d) After using breaker local control a trip signal must be applies to the breaker when switching to remote control position.

(e) Line disconnect switches can only be OPENED when the associated breakers are OPEN.

(f) Line disconnect switches can only be CLOSED when the associated breakers are OPEN.

(g) Interlocks on line disconnects must permit single beaker per line operation from any associated breaker.

(h) Earth switches shall be interlocked with its associated disconnect switches.

(j) Line reactor disconnects can only be CLOSED or OPENED if the line earth switch is Closed.


4.19.4 Transformers 400/132/11 kV In general the following applies to transformers breakers and disconnect switches:

(a) Breaker disconnect switches same as (c) - (i), (ii), (iii) and (iv).

(b) Transformer disconnect switches (400 kV side) can only OPEN when associated transformer breakers on 400 and 132 kV voltage sides are OPEN.

(c) Transformer disconnect switches (400 kV side) can only be CLOSED when the associated transformer breakers on 400 and 132 kV sides are OPEN.

(d) Interlocks on transformer disconnect switches (400 kV side) must permit single beaker operation on the 400 kV side.

(e) Transformer disconnect switches (400 kV side) can only be CLOSED if the earthing blades on 400 kV & 132 kV side of the transformer is OPEN.

(f) Transformer disconnect switch (132 kV side) same as in (v).

4.19.5 132 kV Area Busbar disconnects shall be so interlocked with the appropriate busbar coupling and sectioning equipment so that sections of busbar cannot be paralleled by means of the busbar disconnect switches unless a parallel circuit is already closed through the equipment.

In all other circumstances the busbar disconnecting devices of equipment, other than busbar sectioning and coupling equipment, shall be so interlocked that their respective circuit breakers can only be coupled to one set of busbars at a time. It shall not be possible to parallel section of busbars except through the circuit breakers of the busbar coupling and sectioning equipment.

4.19.6 Tertiary Loads Individual interlocks shall be provided and maintenance requirements on each item of equipment connected to the tertiary system.

4.19.7 Site Supplies In accordance with the Electrical Station Services Section, the Contractor shall provide suitable interlocks to ensure that the Site Supply Transformers are not connected in parallel during normal operation.

The Contractor shall interlock the emergency diesel generator circuit breaker at the main secondary switchgear with the station service transformer circuit breaker such that the diesel generator can only be connected on complete loss of ac supplies.

At stations where an “Offsite” supply is available, interlocks are to be provided to prevent possible parallel operation unless agreed otherwise with the Engineer.


4.19.8 DC Station Service In accordance with the 110V DC Station Battery Section, the Contractor shall provide suitable interlocks to ensure that faults on one battery system do not endanger the other system. The interlock system proposed shall at all times prevent paralleling of the battery systems, unless one charger is supplying both batteries following the failure or maintenance of the other charger.

4.19.9 Miscellaneous Interlocks The Contractor shall bring to the Engineer’s attention any other circuitry, plant or equipment that he is designing or supplying, that may endanger the operator, maintenance staff or the system itself and provide the necessary interlocks to prevent such dangers to the satisfaction of the Engineer.

4.19.10 Locking Arrangements Locking arrangements shall be provided for:

(a) Locking each circuit breaker local manual operating handle in the “neutral” position.

(b) Locking each equipment cover, door, guard or screen in the “closed” position, as specified in this specification.

(c) Locking each isolator and earthing device handle in the “open” or “closed” positions.


5. AIR INSULATED SWITCHGEAR (AIS)

5.1 Clearances

The minimum spacing in air between conductors of different phases and clearances between conductors and earth shall be as specified in Section 1.0. The clearances and positions of apparatus including the access facilities, shall permit safe maintenance of any section of the apparatus, while the remaining sections are alive and the removal or temporary covering of circuit breakers, disconnect switches and transformers without reducing the clearance specified.

Where arcing horns or rings are provided, the minimum distance between live metal and earthed metal shall always be between the arcing rings or horns.

The minimum height from earth to the base of all post-type or bushing insulators that are not mounted vertically and the minimum height from the earth to any live part of the equipment, which is not in a screened enclosure, together with other minimum clearances shall be as specified on drawing 1 IQ 18304

5.2 Method of Line Termination

Where the connection to the station is by overhead line, all conductors will be terminated at the terminal structures. The line conductors and the tension insulators to be mounted for connection to the dead-end tower will be supplied by others, together with the necessary clamps (including bimetallic clamps). The fittings needed for the connections of the line and earth conductors to the station conductors, shall be supplied by others.

Where the connection to the station is by cable, the necessary sealing ends for the cable shall be by others. The supporting structures and connections from the sealing ends to the switchgear shall be supplied by the Contractor.

5.3 Circuit Breakers

5.3.1 General SF6 gas insulated circuit breakers shall be single-pressure puffer or Self-blast suitable for indoor installations.

Circuit breakers shall be designed to IEC 62271 and fully tested in accordance with IEC 62271-100, and with the requirements of this Specification and shall be suitable for minimum continuous current at an ambient temperature of +50º C.

All type tests shall be either carried out by independent testing laboratories or witnessed by independent observers.

The design of the circuit breaker shall be such that inspection and replacement of contacts, nozzles and any worn or damaged component can be carried out quickly and easily.

The inherent design of the circuit breakers shall be such that one set of contacts and nozzle (or nozzles as the case may be) shall be able to successfully interrupt at least twenty 100% fault currents without excessive erosion. When switching Capacitive (capacitor banks) and Inductive (including


reactors) currents (IEC 61233), they produce very low over-voltages. The over-voltages produced on any switching duty must be considerably less (<<) than 2.5 pu.

The sound pressure levels of the breaker during the mechanical operations shall comply with the local and national health and safety regulations.

The circuit breakers shall be suitable for at least 10,000 satisfactory open and close mechanical operations in accordance with IEC 62271-100.

A two-stage low gas pressure alarm and lockout system with local and remote indications shall be provided on each circuit breaker. The low pressure/density alarm switches shall instantly provide an instruction to the operator and subsequently inhibit their further operation until suitable remedial action has been taken.

The circuit breaker shall be fitted with the necessary transducers to allow regular monitoring of circuit breaker travel characteristics and all routine and site test records shall be made available to the Employer for ongoing comparison purposes. The provision of suitable test equipment for measurement of the circuit breaker timing cycle in included under this contract.

Circuit breakers shall be single-pole SF6 gas insulated design, suitable for high-speed single phase or three-pole auto-reclose operations. In the case of 400 kV circuit breakers these shall be supplied with a single-pole re-close facility. In the case of 132 kV circuit breakers, the re-close requirements shall, where applicable, be provided with a three-pole re-close facility.

400 kV circuit breakers will be equipped with duplicate trip coils and 132 kV circuit breakers shall have single trip coils. The circuit breakers shall be capable of parallel tripping, when installed in the breaker and a half configuration, without delaying the tripping of either breaker. Circuit breakers shall be electrically and mechanically trip free with either or both of the duplicate trip circuits connected.

The circuit breaker shall be fitted with the open/closed position indicators easily visible from ground level.

5.3.2 Circuit Breaker Making and Breaking Capacity Each circuit breaker shall be capable of making and breaking short circuit faults in accordance with the Specification and the requirements of service operation for the three-phase short circuit ratings. The circuit breakers making and breaking capacity shall comply with IEC 60517 in all respects.

No part of the switchgear or its supporting structure, circuit breaker, tank or chamber shall be permanently strained when breaking or making the rated short circuit currents.

The Contractor shall ensure that each circuit breaker provided shall be capable of making or breaking the magnetizing current of transformers and the charging current of overhead lines and cables without sustaining any damage or causing excessive over-voltages.

Each circuit breaker shall be capable of interrupting faults within 8 kilometres of the line termination, when supplied from busbars and providing the full-specified short circuit duty.

The particulars related to the rate of rise of re-striking voltage to which the circuit breakers will be subjected during short circuit tests shall be subject to Engineers’ approval.


Making and breaking tests on the circuit breakers shall be carried out by the Contractor to the satisfaction of the Engineer. The Engineer may, at his discretion, waive the requirement of testing, if the Contractor submits the details of independently witnessed tests on identical circuit breakers and these details conform to the requirement as specified in the Specification.

5.3.3 Circuit Breakers Operating Mechanism 5.3.3.1 General The circuit breakers shall preferably be fitted with power-spring mechanism but other types of reliable mechanisms such as leak-free Hydraulic, Spring/Hydraulic, and Spring/SF6 gas will also be considered, provided they comply with the above circuit beaker mechanical operations requirement. A positively driven open/closed, mechanical indication device to show the position of the main contacts and with local manual operated features for tripping, closing and spring charging, visible without the necessity to open the mechanism door, shall be provided. The drive for the device shall be positive in both directions. A Pneumatic mechanism is not acceptable.

The mechanism shall fully close the circuit breaker and sustain it in the closed position against the forces of the rated making current and shall fully open the circuit breaker without undue contact bounce at a speed commensurate with that shown by tests to be necessary to achieve the rated breaking capacity in accordance with IEC 62271-100. The mechanism shall be capable of being locked in the open position. When an auto-reclose facility is specified, the mechanism shall be capable of fully closing and opening again after the auto-reclose time interval specified i.e.: performing a complete O-0.3 sec-CO-3 min-CO duty.

Mechanical counters, to record the number of closing operations, shall be provided for each circuit breaker mechanism. Circuit breakers arranged for single-pole operation shall be provided with a counter for each pole.

The mechanism and the connected interrupters shall satisfy the mechanical endurance requirements of IEC 62271-100 and all additional requirements specified herein.

Means shall be provided to prevent the mechanism from responding to a close signal when the trip coil is energised or to reclosing from a sustained close signal either after opening due to a trip signal or failure to hold in the closed position. Any relays to accomplish these provisions shall be continuously rated and mounted at the circuit breaker. The mechanism shall also incorporate manual-trip facility fitted with a guard to preclude inadvertent operation.

Means shall be provided to detect phase discrepancy in the event of one or two phases failing to complete a close or trip operation and to trip all three phases after a time delay of 1 second.

Each mechanism shall be fitted with duplicate trip coils and phase discrepancy remote indication shall also be provided.

The following facilities shall be provided at each circuit breaker local control point: -

(a) LOCAL/REMOTE selector switch. The selection of `local' operation shall inhibit the operation of the breaker from any remote source with the exception of the protection scheme.

(b) OPEN/NEUTRAL/CLOSE control switch or open and close push buttons. Where push button controls are provided the selector switch shall have a neutral position.


(c) EMERGENCY TRIP DEVICE, suitable for manual operation in event of failure of electrical supplies. The device shall be accessible without opening any access doors and distinctively labelled and protected against inadvertent operation.

The selector switch shall be lockable in both positions and the control switch shall be lockable in the neutral position.

For maintenance purposes, means shall be provided for manual operation including the slow closing and opening of those circuit breakers whose moving contacts are mechanically coupled to the direct linkage mechanism. Such operation shall be possible without the necessity of gaining access to the interior of the power unit, and shall not require excessive physical effort.

5.3.3.2 Spring Mechanisms Spring operated mechanisms are the preferred type.

Provision should be made for remote indication of `Spring charged' and `Spring charge fail' conditions.

A spare normally open spring-drive limit switch shall be provided.

It shall be possible to hand charge the operating springs with the circuit breaker in either the open or closed positions. In normal operation, recharging of the operating springs shall commence immediately and automatically upon completion of the closing operation and shall be completed within 30 seconds. Closure whilst a spring charging operation is in progress shall be prevented, and release of the springs shall not be possible until they are fully charged.

The state of charge of the operating springs shall be indicated by a mechanical device which shows `SPRING CHARGED' when operation is permissible and `SPRING FREE' when operation is not possible. A local manual spring release device shall be provided and so arranged as to prevent inadvertent operations.

Means shall be provided for hand charging the operating springs.

5.3.3.3 Hydraulic and Hydraulic/Spring Mechanisms The operating pressure shall be maintained automatically, a gauge being provided to give indication of the pressure. The pressure gauge shall be suitably damped to ensure that it is not subject to transient pressure oscillations either during pumping or during operation of the circuit breaker.

A lockout device with provision for remote alarm indication shall be incorporated in each circuit breaker to prevent operation whenever the pressure of the operating medium is below that required for satisfactory subsequent operation at the specified rating. Such facilities shall be provided for the following conditions: -

(a) Trip lockout pressure.

(b) Close lockout pressure.

(c) Auto reclose lockout pressure.

Alarm contacts shall be provided to indicate conditions a, b and c. If two trip systems are specified, then trip lockout shall apply to both systems.


A sudden fall in pressure of the operating medium to a level below which a safe operation is not possible shall not result in slow opening or closing of the circuit breaker contacts. The mechanism shall be locked in position and electrical trip and close signals shall be isolated during this period.

Facilities shall be provided to enable the available operating energy stored by the mechanism to be determined prior to operating the circuit breaker, together with an alarm in the event of the potential energy falling below a minimum rated level. Facility for hand charging of hydraulic systems shall be provided.

Circuit breakers having independent operating mechanisms on each phase shall block tripping, closing, and auto re-close of all phases if the operating pressure is below a minimum rated level in one or more of the mechanisms.

A pump running time meter shall be fitted and an alarm shall be provided to indicate excessive running time.

5.3.3.4 Mechanism Housings Where heaters are provided, these shall be permanently connected. Where two-stage heaters are provided, one stage shall be permanently connected and the other switched.

Means for locking shall be provided for the doors of each mechanism housing.

Mechanism housings for use outdoors shall have an IP rating of 55, those for indoor shall be IP 30.

The power supply for controlling circuit breaker operation will be as stated in section 4.4. The electrical devises shall operate satisfactorily between the voltage limits of IEC 62271 with the coils at a temperature of 50 degrees C.

For 400kV circuit breakers separate operating mechanisms must be provided for each phase, to permit single-pole re-closing. Approved means shall be provided to ensure simultaneous operations of the three phases.

Where a circuit breaker consists of three separate single-phase units with a common operating mechanism, they shall be so coupled so that any unit can readily be replaced by a spare unit. It shall be possible to make independent adjustments on each unit. The operation of the three single-phase units shall be simultaneous.

Mechanisms shall be so designed as to minimize the possibility of inadvertently making or breaking one or two phases only, except during single-pole re-closing. Provisions shall be made for automotive tripping of the circuit breaker and for a remote alarm indication in the event of any phase failing to complete a closing operation.

The necessary equipment shall be provided to initiate and control single-pole and three-pole auto re-closures. Each shall be single shot re-close and lock-out, and also high speed or delayed re-close.

The circuit breaker mechanism shall include operating counters to record the number of closing strokes.

Unless otherwise specified, each circuit breaker shall be provided with a local control panel located in a position outside the circuit breaker enclosure. Means shall provided to avoid the local and remote


control apparatus from being in operation simultaneously. It shall be possible to mechanically trip the circuit breaker from the local control panel even though an electrical supply is not available, unless locked out.

5.3.4 Circuit Breaker Handling and Maintenance Equipment Portable equipment shall be provided, which will enable normal handling and maintenance of each circuit breaker to be carried out with a minimum of time and labour. Where one-piece circuit breaker parts of 35kg must be handled in normal maintenance, special tackle or lifting points shall be provided, which will enable normal tackle to be used.

Handling equipment shall comply with the applicable regulations for the design of such equipment.

5.4 Disconnect Switches

The disconnect switches shall be constructed and fully tested in accordance with the requirements of IEC 62271-102, and this Specification.

The disconnect switches shall be capable of carrying the full-load current of the circuit and shall be arranged for operation while the equipment is alive; they will not be required to break current other than the charging current of open busbars and connections or load current shared by parallel circuits.

The minimum total length of air gap between terminals of the same pole with the disconnect switch open, shall be designed to provide an impulse voltage withstand level not less than 15 percent in excess of that specified for the insulation of the substation to earth.

Disconnect switches shall be so designed that they shall not open by forces due to currents passing through it, and shall be self-locking in both the “open” and “closed” positions.

Unless otherwise specified, disconnect switches shall be provided with electrical operating mechanisms and shall be arranged for local and remote control. Electric motor operated mechanisms shall be provided with means for emergency manual operation. The mechanism shall normally open and close all three poles simultaneously.

Means shall be provided at the local control point to prevent the local and remote control apparatus from being in operation simultaneously.

The operating mechanism shall be located so that it can be maintained while the disconnect is alive.

Service conditions require that disconnect switches shall remain alive and in service without being operated and without maintenance for periods of up to 2 years. The contacts shall therefore remain capable of carrying their rated load and short-circuit currents without over heating or welding for this period under the atmospheric and climatic conditions existing at site. After such periods, the maximum torque required to open them at the manual operating handle shall be within the capabilities of one man, e.g. approximately 35 kg, m.

5.5 Current Transformers

5.5.1 General The current transformers shall comply with IEC 60044-1 & 6.


The current transformers shall have the following accuracies: -


Instruments Class 1

Overcurrent and earth fault protection

Class 5P

Instruments and Overcurrent/earth fault protection combined

Class 1/5P

High impedance circulating current protection

Class PX

For distance measuring protection, and current differential protection schemes the Contractor must state clearly the accuracy necessary for the correct functioning of the protection system offered and show that the secondary output of the current transformer is satisfactory for this purpose.

Current Transformers shall be of the ratios specified in Schedule D. The Contractor shall be responsible for the sizing, rating and other details pertaining to the current transformers. Details will be submitted with the tender.

The primary windings shall have a continuous and short circuit rating not less than that of the associated circuit breakers. The Contractor shall submit details of the precautions taken in the design of the primary of the transformer to prevent the mechanical and thermal stresses set up on short circuits from causing a breakdown.

Transformer circuits may be subjected to overload duties in accordance with IEC 60354; current transformers in transformer circuits shall have a rated continuous thermal current equivalent to at least the transformer long-time emergency cyclic loading capability.

Current transformers shall be of low reactance type and each core shall be electrically separated from the other windings.

The secondary windings of each set of current transformers shall be earthed at one point. Secondary terminals shall be located so that they are accessible while the equipment is alive.

Where adequate earth screens are fitted between the primary and secondary windings, earthing of the secondary winding shall be via a link mounted in the related protection or instrument cubicle. Where such earth screens are not fitted a separate earth system may be necessary.

Wherever possible the connection to earth shall be on the side of the S2 terminals.

Where multi-ratio transformer windings are specified, multi-ratio primary windings will only be considered where the protection arrangement makes these suitable for all aspects of the installation.

When multi-ratio tappings are specified, a label shall be provided indicating clearly the connections required for all ratios. These connections and the ratio in use shall also be shown on all connection diagrams.


Neutral current transformers shall be of the outdoor totally enclosed porcelain bushing type complete with mounting steelwork as required and terminal box for secondary connections.

Class PX CTs shall be specified in terms of the Turns Ratio (e.g. 1/2000) and have a secondary current rating (ISN) adequate for the primary rating (IPN) of the circuit to which it is connected; e.g. with a Turns Ratio of 1/2000, a primary rating of 2600A will require a continuous secondary rating of 1.3 A. The dimensioning factor (KX) shall be selected to ensure an adequate knee point voltage (EK), taking into account the other circuit elements and the protection function.

Line protection current transformers shall correctly transform during initial faults and following high speed three phase re-close onto faults without saturation at the system source X: R ratio (L: R) appropriate to the system voltage and shall be that used for the asymmetrical rating of the association circuit breakers.

The voltage produced at the cores by over current or during transients on the system shall be well below the saturation voltage to ensure good transient response. The Contractor should make calculations related to the C.T. burdens and transient response according to the relevant IEC standards and submit for approval.

Where current transformers are to be mounted on apparatus provided under another contract the contractor shall be responsible for making all the necessary arrangements directly with the other contractors and for keeping the Engineer informed.

Current transformers for balanced earth fault protection shall be tested to prove compliance with the requirements of IEC 60044-6.

5.5.2 Air Insulated Current Transformers Each current transformer shall be filled with oil as specified by IEC 60156 and BS 148.

The current transformers shall have fittings (d), (e), (h), (i) and (j) as specified for Voltage Transformers below.

5.5.3 Current Transformer Primary Injection Tests Facilities shall be provided which allow primary injection testing of the current transformers with the minimum disturbance to the switchgear.

5.6 Voltage Transformers and Coupling Capacitors

5.6.1 General Miniature circuit breakers (MCB) shall be provided on or adjacent to each voltage transformer, located such that they are accessible while the primary winding is alive. MCBs shall be identified by labels clearly indicating their function and phase colours.

The voltage transformer secondary circuits shall be complete in themselves and shall be earthed at one point only. A separate earth link shall be provided for each secondary winding and shall be situated at the transformer but earthing will be in the relay or control building. The primary winding shall be earthed at the transformer.


The secondary windings are to be kept electrically separated. For voltage transformers, consisting of single-phase units, separate earth links for secondary windings shall be provided and shall be located at the voltage transformer.

Where voltage transformers are supplied which are, or may be, connected to different sections of the busbar, it shall not be possible for the voltage transformer secondary circuits to be connected in parallel, unless the respective sections for the busbars are also connected in parallel.

An auxiliary switch or relay shall be provided in each phase of the secondary circuit of the synchronising and metering voltage supply connections to break the circuits automatically as soon as the circuit breaker is opened.

To prevent Ferroresonance, suitable damping devices shall be provided for connection to the transformer secondaries.

Voltage transformers shall have the following accuracies: -


Metering and instruments Class 1.0

Protection Class 3P.

5.6.2 Open Terminal Voltage Transformers and Coupling Capacitors Voltage transformers may be either the capacitor type or electromagnetic wound type. Voltage transformers shall comply with the requirements of IEC 60044-2 and IEC 60186. Coupling capacitors shall comply with IEC 60358.

The creepage and flashover distances of the high voltage insulator shall be suitable for the outdoor service conditions specified in the Schedules.

5.6.2.1 Wound Type (Electromagnetic) Voltage Transformers Wound type voltage transformers may be of the single or cascade winding type, sealed via an expansion diaphragm, and they shall comply with the requirements of IEC 60044-2.

The following facilities shall be provided: -

(a) Arrangement for terminating primary and secondary connections.

(b) Earth terminal of adequate dimensions so arranged that the earth connection cannot be inadvertently removed.

(c) Conservator tank fitted with sump and drain valve and having a capacity adequate to meet operating temperature conditions in Iraq.

(d) Single-float gas-actuated relay of an approved make with connections to terminal box.

(e) Oil level indicator of prismatic or other approved type.


(f) Earthing terminal of adequate dimensions so arranged that the earth connection cannot be inadvertently removed.

(g) Two valves, one at top and one at bottom of tank.

(h) Sampling device at bottom of tank.

(j) Lifting and jacking lugs solidly connected to tank.

(k) Approved arrangement for establishing primary and secondary connections.

(m) Secondary terminal and link box with cable gland.

Electromagnetic voltage transformers shall be filled with oil, as specified by IEC 60156 and BS 148.

5.6.2.2 Capacitor Type Voltage Transformers The design of capacitor voltage transformers shall be such that the accuracy shall not be affected by the presence of pollution on the external surface of the insulation, they shall comply with the requirements of IEC 60186.

They shall be suitable for simultaneous use as coupling and voltage measuring capacitors, and should, whenever possible, be capable of supporting the associated line trap unit. Where this is not possible the line trap may be mounted on post insulators or suspension mounting can be used, when approved by the Engineer.

These voltage transformers shall be designed to operate devices with require a potential source of approximately constant voltage ratio and negligible phase shift with respect to the high-voltage circuit.

The voltage transformers shall be high-capacitance type. The accuracy and rating shall be determined by the Contractor and shall be suitable for all devices connected thereto.

Secondary fuses shall be grouped in three-phase banks, where applicable, provided on or adjacent to each voltage transformer, located so that they are accessible while the primary is alive, and shall be provided with labels indicating their function and their phase colours. A link for each three or single-phase set of windings is to be supplied. MCBs may be offered as an alternative.

Where possible 400 kV capacitive type VTs should not be used to provide coupling for PLC equipment and 400 kV coupling capacitors should be provided separately. 132 kV capacitive type VTs will in some instances provide coupling for the PLC equipment in addition to the secondary winding.

The capacitor unit should normally be hermetically sealed.

A bushing shall be provided to enable a high frequency signal to be coupled to the capacitor unit. The bushing shall be fully protected against rain and vermin when in use, so as to avoid the possibility of being shorted to earth.

The capacitor voltage transformer mounting structure shall have provision for the following, which may be provided under a separate contract: -


(a) A line-matching unit contained in a weatherproof housing.

(b) An earthing switch capable of being operated from ground level. It shall preferably include a facility to enable the capacitor coupling unit to be earthed via the drain coil whilst simultaneously isolating the carrier equipment for test purposes.

(c) A surge diverter connected between the coupling capacitor and earth to protect the matching unit, drain coil, etc.

5.6.2.3 Oil-Filled Voltage Transformers The following facilities shall be provided:

(a) Oil level indicator of prismatic or other type, or a visual means of determining the position of the diaphragm or bellows seal from the ground level

(b) Oil sampling device located at the base of the tank where applicable.

5.6.2.4 SF6 Gas-Filled Voltage Transformers The normal gas pressure shall be such that it remains in its gaseous state when operating at temperatures down to those stated in the Schedules.

Facilities shall be provided for constant local monitoring of the voltage transformer gas pressure, and topping up or sampling the gas.

For safety reasons, a bursting disc shall be fitted to the transformer housing.

High voltage insulation may be either porcelain or a fully proven composite material.

The Contractor shall be responsible for sizing, rating and details pertaining to the voltage transformer.

Contractor should calculation about the voltage drops on the V.T. and the wires and submit for approval.

5.7 Lightning (Surge) Arresters

Surge arresters shall be of the metal-oxide, gapless type.

The design of lightning (surge) arresters shall generally be in accordance with the relevant sections of IEC 60099.

Porcelains and fittings shall be designed to comply with the applicable requirements of Section 1.0 of this specification.

(a) Construction:

The arresters shall be of robust construction and shall be designed to facilitate handling, erection and cleaning and to avoid pockets in which water can collect.

The method of assembly of the arrester shall be such that adequate contact pressure is at all times maintained between the faces of the series non-linear resistance blocks. The design of


the series gaps and voltage grading resistors, shall be such that the gap setting cannot be affected by vibration, mechanical shock or change in temperature.

All joints shall be made in an approved manner such that the diverter is hermetically sealed with material, which will not deteriorate under any service conditions.

The Contractor shall provide details of grading rings that are to be provided. This shall include details of all materials used and clearances required from grading rings to earth and to live parts of other equipment.

Where necessary by site specific requirements the arrester porcelain housing shall have increased creepage length to withstand local pollution conditions to the approval of the Engineer.

(b) Surge Counters

Surge counters shall be provided and shall be operated by the discharge current passes by the lightning arrester. Surge counters shall be of the electromechanical type and designed for continuous service. They shall be robust and capable of passing repeatedly, without damage the maximum discharge current of the diverter.

Internal parts shall be unaffected by atmospheric conditions on site. Alternatively a weatherproof housing shall be provided and this shall be designed to allow the recording device to be read without exposing the internal parts to the atmosphere.

The counter shall be connected in the main earth lead from the arrester in such a manner that the direction of the earth lead is not changed or its surge impedance materially altered. Bolted links shall be provided so that he surge counter may be short-circuited and removed without taking the arrester out of service.

5.8 Safety Screening of Equipment

The minimum height from the ground of any live part of the equipment, which is not in an earthed screen enclosure shall be as specified in Section 1.0. Where the clearances are not obtainable with an approved arrangement of the equipment, earthed screen enclosures or partitions shall be provided which shall prevent approach to any live parts. The screens and partitions necessary for each item of equipment shall be provided therewith and included in the cost thereof.

The means of access to the guarded or screened area shall be provided by interlocking with equipment.

5.9 Oil-Filled Chambers

Suitable provision shall be made for the expansion of the filling medium in all oil-filled chambers, and the chambers shall be so designed as to avoid the trapping of air or gases during the filling process.

All wiring in the vicinity of oil-filled chambers shall be insulated with oil-resistant insulation of approved quality and shall be run in rust-resistant flexible tubes or galvanized steel tubes from terminal boards conveniently situated.


5.10 Joints for Oil-Filled Chambers and Circuit Breakers

All joints other than those which have to be broken shall be welded and oil-tight. Defective welded joints shall not be caulked.

All joints which have to be broken shall be metal-to-metal machine faced. Packing, if employed, shall be of a suitable type and thickness.

5.11 Oil

Where applicable, sufficient oil shall be supplied to fill all the voltage and current transformer tanks and any other oil-filled portions of the switchgear. The oil shall comply with IEC 60156 and BS 148 and shall be suitable in all respects for use in the equipment when they are operated under the conditions laid down in the specification.

Facilities shall be provided on all oil filled equipment so that it shall be possible for an observer to ascertain, while the equipment is alive, that it contains the required quantity of oil. Means, other than an indication painted on the tanks, shall be provided to indicate the oil level in each item of oil filled equipment.

5.12 Auxiliary Switches & Contactors

With each circuit breaker, disconnecting device, and earthing device, all necessary auxiliary switches, contactors and mechanisms for indication, protections, control, interlocking, supervisory and other services shall be supplied as required. Not less than four spare auxiliary switches shall be provided with each circuit breaker. All auxiliary switches shall be wired to a suitable terminal board on the fixed portion of the switchgear, whether they are in use or not, in the first instance. Auxiliary switches shall be provided to interrupt the supply of current to the tripping mechanisms of the circuit breakers when the operation of the breakers has been completed. All such switches and mechanisms shall be mounted in accessible positions clear of the operating mechanisms and shall be adequately protected. The contacts of all auxiliary switches shall be heavy duty and shall have a positive wiring action when closing.

Discharge resistors shall be provided when required, to prevent undue arcing during the operation of contactors.

Each breaker, line disconnect and breaker disconnect shall be supplied with sufficient contacts for:

(a) Remote and supervisory indication of switch position.

(b) Electrical interlock circuits.

(c) Safety breaker trip circuits on breaker disconnects.

(d) Where necessary, current transformer bus protection secondary transfer circuits.

5.13 Switchgear Busbars and Connections

Each item of equipment shall be provided with all necessary terminals, of adequate size, for connection to the earthing system.


5.14 Earthing Switches and Devices

5.14.1 400 kV System Each section of busbar, feeder and transformer circuit shall be provided with an earthing switch for connecting the busbar to earth. These switches may be independent units or integral with the disconnecting switches. Each earthing switch will be interlocked with the relevant disconnect switches.

5.14.2 132 kV System Each feeder equipment shall be provided with an earthing switch for connecting the incoming overhead lines or cables to earth. Each bus section and bus coupler equipment shall be provided with an earthing switch on the busbar side of each set of associated isolators for connecting the busbars to earth. The earthing switch shall be interlocked with the line or cable isolating devices or all relevant isolating devices in the case of the bus section nor bus coupler switch as per Section 1.2.5.9.

5.14.3 Operating Mechanisms The operating mechanisms shall be arranged for manual operation from earth level.

5.14.4 Maintenance Earths The Contractor shall provide at each substation portable earth connections. Each set shall comprise three individual phase and earth connectors, detailed as follows:

400 kV Equipment 132 kV Equipment

Rating 40 kA for 1 second 40 kA for 1 second

Double conductors may be provided to assist in handling operations. If deemed necessary the Contractor shall provide suitable manual handling equipment to assist in the installation of the maintenance earths.

5.15 Busbars, Insulators and Hardware

5.15.1 Extent of Supply This Section covers: -

(a) Busbars and connections.

(b) Clamps and fittings.

(c) Insulators.

(d) Junction boxes and kiosks.

The specification for the steel structures is covered in the specification for the Civil Works.

Busbar Arrangements


Busbars will be constructed from suitably sized and rated aluminium conductor. Associated structures will be kept to the lowest possible height, whilst conforming to other sections of the specification.

5.15.2 Busbars and Connections The general construction of the busbars shall be kept as short and straight as possible and their insulated supports shall be of approved construction, mechanically strong and shall withstand all the stresses which may be imposed upon them in ordinary working due to the fixing, vibration, fluctuations in temperature, short circuit or other causes.

Safety factors shall be such that no material used for busbars, connections or for supporting the connections, where insulated or otherwise, shall be stressed to more than one-fourth of its breaking load or one-third of its elastic limit, whichever is the lesser. Provision shall be made for expansion and contraction of the busbars and connections with variations of temperature. The busbars shall be so arranged that they may be extended in length without difficulty. The design of the connectors from outdoor busbars and connections to the parts of the equipment shall be such as to permit easy dismantling for maintenance purposes.

The Contractor shall provide all necessary terminals on the switchgear for the connection to other apparatus and cables. The Contractor shall specify the busbars and connections to be provided for approval by the Engineer.

The busbars and connection shall be so arranged and supported that under no circumstances, including short circuit conditions, can the clearance from earthed metalwork or from other conductors be less than distances specified in Section 1.0.

Stranded conductors having hollow cores shall be stranded around non-ferrous metal spacers of approved type. The number and diameters of the individual wires, forming the finished conductor or the thickness of tubes, shall be defined by the Supplier to the approval of the Engineer.

Overhead conductors, carried by the substation structures, shall be erected with such sags and tensions that the maximum loading of the structures is not exceeded when the conductors at 65 degrees C, are subject to the transverse wind pressure as specified.

Means for adjusting the sags and tension of overhead conductors shall be provided and shall be preferably by means of sag adjusting plates. The method adopted and range of adjustment provided shall be approved by the Engineer.

All clamps and other fittings for attaching the connections to the busbars, switchgear, transmission lines and the bare copper terminals rods on the bushing insulators shall be provided. All fittings shall be in accordance with this Specification and joints shall be of approved design. Where dissimilar metals are connected, means shall be provided to prevent electro-chemical action and corrosion. Joint surfaces of copper or copper alloy fittings shall be tinned.

Stranded copper connections shall be tinned at clamping points and if of the hollow pattern shall be supported against crushing at such points by sweating solid or by insertion of a suitable plug. Scratches, burrs and projections on welds shall not exceed 3 mm in depth or projection.


5.15.3 Insulators 5.15.3.1 General Porcelain insulators shall be to IEC 60137 where applicable.

Porcelain shall be sound, free from defects and thoroughly vitrified so that the glaze is not dependent upon for insulation. The glaze shall be smooth, hard, and shall completely cover all parts of the insulator, which are exposed to contamination.

Outdoor insulators and fittings shall be designed to withstand all atmospheric conditions due to weather, ozone, acids, alkalis, dust, sandstorms or rapid changes of temperatures, under working conditions existing at site.

5.15.3.2 Electrical Design of Insulators The electrical characteristics of insulators shall be as specified in design criteria.

Where the use of extended creepage insulation is specified, the total creepage distance over the external porcelain surface of bushings or insulators, measured in millimetres, shall not be less numerically than the working voltage between phases in kilovolts divided by a factor of 31. The protected creepage distance shall also be not less than half the minimum total creepage and shall be that portion of the external surface lying in shadow when the insulator is illuminated at 90 degrees to its axis. For post insulators comprising standard units, the above requirements shall, unless otherwise specified, be met by the additional of an approved number of additional units to the normal assembly.

5.15.3.3 Mechanical Design of Insulators The strength of the insulators, as given by the electromechanical test load, shall be such that the factor of safety when the insulators are supporting the maximum working loads shall not be less than 2.5.

The design shall be such that stresses due to expansion and contraction in any part of the insulator and fittings shall not lead to the development of defects.

Porcelain shall not connect directly with hard metal and, where necessary, yielding material shall be interposed between the porcelain and the fitting. All joint faces of porcelain shall be accurately ground and free from glaze. All fixing material used shall be of approved quality and applied in an approved manner, and shall not enter into chemical action with the metals parts or cause fracture by expansion in service. Where cement is used as a fixing medium, cement thickness shall be as small and even as possible and proper care shall be taken correctly to centre and locate the individual parts during cementing.

The design of all insulators shall be such as to permit easy cleaning.

5.15.3.4 Marking of Insulators Each insulator and bushing shall have marked upon it the manufacturer’s identification name or trademark and such other mark as may be necessary to assist in the representative selection of batches for the purposes of the type tests stated in Section 4.6. Each porcelain insulator shall, in addition, be marked to indicate the date of firing. Each tension and suspension insulator shall also be marked with the guaranteed electromechanical strength. All marks shall be visible after assembly of


fittings and shall be imprinted and not impressed. For porcelain insulators the marks shall be imprinted before firing and for paper insulators before varnishing, in such a manner that the marks shall be permanent and clearly legible on the finished insulator.

When a batch of insulators, bearing a certain identification mark, has been rejected, no further insulators bearing this mark shall be submitted. The Contractor shall satisfy the Engineer that adequate steps will be taken to mark or segregate the insulators constituting the rejected batch in such a way that there shall be no possibility of the insulators subsequently being resubmitted for test or supplied for future use.

5.15.3.5 Suspension and Tension Insulators Suspension and tension insulators shall consist of porcelain units with ball and socket fittings. Insulators units and the balls and sockets of the units and of associated fittings shall be in accordance with BS EN 60137.

The individual units to both suspension and tension insulator sets shall be identical and interchangeable.

Retaining pins or locking devices for insulator units shall be of phosphor bronze or other approved material. They shall be so formed that, when set and under any conditions, nothing but extreme deformation of the retaining pin or locking device will allow separation of the insulator units or fittings or will permit accidental displacement for the retaining pins or locking devices. Their design shall be such as to allow easy removal or replacement of insulator units or fittings without removal of the insulator sets from the structures. Retaining pins or locking devices, when in position, shall be incapable of rotation.

5.15.3.6 Post-Type Insulators Post-type insulators, were required, shall be built up of strong interchangeable units and shall be designed to withstand all shocks which may be met in operation. Post-type insulators of uniform composition shall be designed so that they can be used either upright or inverted.

5.15.3.7 Bushing-Type Insulators Bushing insulators provided for connection to bare conductors shall be of an approved type and shall be provided with suitable connectors.

Bushing insulators shall be filled with oil of a suitable type. Means shall be provided to ensure maintenance of the correct oil level and level gauges shall be such as to give reliable indication to an observer at ground level with the equipment alive.

All condenser type bushings shall be provided with a tapping, brought out to a separate terminal for testing purposes on site.

5.15.4 Clamps and Fittings Conductor suspension and tension clamps shall be of suitable types and shall be as light as possible. Where applicable, clamps for steel cored aluminium conductors shall be lined with soft aluminium liners to prevent damage to the conductors. Suspension, compression fittings and tension clamps shall be designed to avoid any possibility of deforming the stranded conductor and separating the individual strands.


Clamps and fittings made of steel or malleable iron shall be galvanized in accordance with this specification. All bolts and nuts shall be as specified and shall be locked in an approved manner.

Conductor tension clamps or compression fittings shall not permit slipping of, or damage to, or failure of the complete conductor or any part thereof at a load less than 95 per cent of the ultimate strength of the conductor.

Suspension clamps shall be free to pivot in the vertical plane about a horizontal axis passing through and transverse to the centre line of the conductor. Suspension clamps shall permit the complete conductor to slip before failure to the latter occurs, but the conductor shall be clamped in an approved manner. All conductor grooves and bell-mouths shall, after galvanizing, be smooth and free from waves, ridges or other irregularities.

Bolted-type tension clamps shall be radiuses at the mouth as specified for suspension clamps and the above specified requirements for the conductor grooves shall be taken into account where applicable.

In tension clamps in which the conductor is necessarily cut, approved means shall be taken to treat the cut ends of the conductors to prevent ingress of air or moisture. The mechanical efficiency of such tension clamps shall not be affected by methods of erection involving the use of “come along” or similar erection clamps before, during or after assembly and erection of the tension clamp itself.

Tension insulator sets and clamps shall be arranged to give a minimum clearance of 150 mm between the jumper conductor and the rim of the live end of the insulator unit or string.

Except when erected with the extra insulator unit, each tension insulator set shall be provided with a link whose centre distance is equal to the centre distance of the tension insulator unit, so that the total length of the tension insulator set is equal to that of the set including the extra unit.

All split pins for securing the attachment of individual units of insulator sets shall be of phosphor bronze and those for securing fittings shall be stainless steel and shall be backed by washers of approve size and thickness.

The factor of safety of safety of the fittings, when supporting the maximum working load, shall not be less than 2 ½ based on the elastic limit of the material

5.15.5 Corona Conductors shall be designed so that the voltage stress at the conductor surface shall not exceed a value equivalent to 16.5 kV (rms)/cm at sea level.

All equipment shall be tested as specified in the Specification and shall be corona free at the specified test voltage.

5.15.6 Guard Rings or Arcing Horns Guard rings or arcing horns or rings of approved type, size and material shall be attached to bushing and post-type insulators and to the conductor clamp fittings of all suspension and tension insulator sets but not to the clamps themselves. The design of the arcing horns or rings shall be such as to reduce, as far as reasonably possible, cascading and damage to clamps, insulator units, bushing, insulators and to other fittings under all flashover conditions.


The guard rings or arcing horns shall be of substantial design in order to minimize the damage to them when flashover occurs and to bear the weight of a man during cleaning operations. The gap setting proposed by the Contractor shall be approved by the Engineer.

5.16 Allowance for Damage, Breakage and Loss

The Contractor shall supply not less than 5 per cent of the net requirements for insulators, hardware and fixing devices as an allowance for damage, breakage and loss during erection.

5.17 Phase Identification

Coloured discs shall be installed to identify phases. Black letters on the following background colours shall be used:

Phase R - Red

Phase S - Yellow

Phase T - Blue

Discs shall be installed on one set of structures at the following locations:

(a) On the main bus, midway between taps;

(b) On the bus, at line or transformer tapping;

(c) On the line entry gantry;

(d) On the transformer gantry;

(e) Each circuit breaker;

(f) Each transformer and reactor.

5.18 Junction Boxes and Kiosks

The Contractor shall supply for each circuit breaker and approved marshalling kiosk to which allow connections from the switchgear will be run.

All junction boxes, terminal boxes and marshalling kiosks shall be constructed of steel or cast iron.

All main equipment shall be arranged so that it is accessible from the front of the box or kiosk.

Outdoor boxes and kiosks shall have sloped double roofs and shall be of weatherproof, vermin-proof and termite-proof construction, with adequate ventilation and draining facilities. They shall be so designed so that condensation shall not affect the insulation of the internal apparatus, the terminal boards or the cables. Where necessary, heaters shall be provided and shall be controlled by means of a water-tight switch mounted on the outside of the box or kiosk.

Any internal divisions between compartments inside the boxes or kiosks shall be perforated to assist the natural air circulation.


Access shall be provided at both the front and back of kiosks and junction boxes, except for small terminal boxes of the type normally employed for wall mounting.

Doors and access covers shall be easily opened and shall not be secured by nuts and bolts. Doors and covers under 13-kg weight may be of the slide-on pattern; over this weight they shall be hinged.

Kiosk doors shall be fastened with integral handles rather than loose keys, and provision shall be made for padlocking each door.

Where 380, 220 or 110 volt connections are taken through a box or kiosk, they shall be adequately screened or insulated and labelled in accordance with the Specification.

All cables shall enter boxes and kiosks at the base through separate cable glands.

Plates for supporting cable glands shall be at least 450 mm above ground level. Cable glands and conduits will project at least 20mm above the gland plate to prevent any moisture on the plate draining into cables or conduits. Also, means shall be provided to drain water off the surface of the gland plate. The back, sides and front of the box or kiosk shall project at least 50mm below the gland plate to prevent moisture draining on to the plate and cable glands at any time.

5.19 Outdoor support structures and landing gantries

The requirements for lattice steel support structures for equipment and line landing gantries are provided in the Civil specification.

5.20 Interlocking Equipment

The interlocking requirements are specified in the Interlocking Equipment clause of the GIS section of this specification.


6. TRANSFORMERS AND REACTORS


The extent of supply of this specification shall consist of the design, manufacture, testing, supply, delivery to site, off loading, installation and oil filling, site testing, commissioning and placing in successful operation and warranty period of the works of 400/132kV auto transformers and associated earthing/auxiliary transformers and 400kV shunt reactors.

6.2 Reference documents

IEC 60076-1 Power transformers - General.

IEC 60076-2 Power transformers -Temperature rise.

IEC 60076-3 Power transformers - Insulation levels, dielectric tests and external clearances in air.

IEC 60076-5 Power transformers - Ability to withstand short circuit.

IEC 60076-10 Power transformers - Determination of sound levels.

IEC 60137 Insulated bushings for alternating voltages above 1000 V.

IEC 60214 On-load tap-changers.

IEC 60354 Loading guide for oil-immersed power transformers

IEC 60529 Degrees of protection provided by enclosures

IEC 61639 Direct connection between power transformers and gas-insulated metal-enclosed switchgear for rated voltages 72.5 kV and above.

IEC TS 60859 Cable connections for gas-insulated metal-enclosed switchgear for rated voltages 72.5 kV and above:

- Fluid-filled and extruded insulation cables

- Fluid-filled and dry type cable-terminations

NEMA TR1 Transformers, regulators and reactors [for audible sound levels]

The technical data schedules for the specified transformers are included in Schedule D

6.3 Type

The auto transformer shall be outdoor type single phase units with on-load tap-changer. The external cooling medium shall be air. The insulation shall be graded for operation with effectively earthed neutral. The transformers shall comply with the requirements of the schedules and standards listed above and other relevant IEC standards. Any ambiguity shall be referred for clarification at the time of tendering


6.4 General

The transformers shall be suitable for continuous operation on a three-phase 50 Hz high voltage transmission system as specified in the Technical Schedules.

All windings of the transformers shall be capable of withstanding short circuit for the periods of time specified in IEC 60076 when operating on any tapping position, including that corresponding to minimum effective impedance, with the fault current available at the terminals. It shall be assumed that the rated voltage will be maintained on one side of the transformer when there is a short circuit between phases or to earth on the other side. The Contractor shall demonstrate the transformer and reactor’s ability to withstand the specified short circuit conditions in accordance with IEC 60076-5.

Transformers and reactors shall meet the latest stage of development reached in design, construction and materials.

Irrespective of the direction of power flow, all transformers shall be capable of operating continuously without injurious heating when delivering the specified winding currents under conditions of continuous operation with voltages higher than tapping voltages.

Transformers shall be suitable for cyclic overloading and long-time emergency loading duties in accordance IEC 60354.

Ratings shall be based on the average winding temperature rise, as measured by resistance, of 55°C and the top oil temperature rise, as measured by thermometer, of 50°C with a cooling air maximum temperature of 50°C.

The transformers shall be designed to ensure that leakage flux does not cause overheating in any part of the transformer.

The design and manufacture of the transformers, reactors and auxiliary plant shall be such that the noise level is a minimum and that the level of vibration does not adversely affect any clamping or produce excessive stress in any material. Noise levels shall be measured in accordance with IEC 60551. The maximum acceptable level is 88 dB in conformity with NEMA standard TR-1.

The transformers and reactors shall be designed with particular attention to the suppression of harmonic currents, especially the third and fifth, so as to minimise interference with communications circuits.

The transformers shall be designed to operate satisfactorily in parallel when in the same tap position. The transformers and all associated facilities (e.g. tap-changer) shall have the ability to withstand the effects of short-circuit currents, defined as symmetrical short circuit current in the Technical Schedules, when operating on any tapping position according to requirements of IEC 60076-5. All metal parts of the transformer with the exception of the individual core laminations, core bolts and associated individual side plates shall be maintained at the same fixed potential. The earthing structure shall be designed to carry, without damage, the maximum possible earth fault current for a duration of at least equal to the short circuit withstand period of the main windings.


The design and manufacture of the transformers and auxiliary plant shall be such that the noise level is at a minimum and that the level of vibration does not adversely affect any clamping or produce excessive stress in any material. The transformer manufacturer shall supply sufficient information to the civil works contractor to ensure adequate design of the transformer mounting structure.

6.5 Tertiary windings

The tertiary winding of the transformer is required for the purpose of suppressing harmonics and of providing a connection for reactive (capacitive or inductive) compensation equipment and for a connection to an earthing transformer to provide an earth and an auxiliary supply as required by site and system conditions.

The 11 kV tertiary shall be designed to be capable to a rating of 75MVA.

The winding shall be capable of withstanding the forces to which it is subjected under all conditions, particularly the forces due to a short circuit between terminals or between any terminal and earth, with full voltage maintained on all other windings intended for connection to external sources of supply and allowing for any feed back through windings connected to rotating machines.

Suitable surge arresters are to be provided to protect the winding against overvoltage. If the winding is connected by cable the surge arresters shall be mounted in the disconnecting chamber.

6.6 Loss Evaluation

For the purposes of tender evaluation the transformer and reactor losses are capitalized in the following manner:

Transformers

No-load loss (NLL) [*] US$/kW at rated voltage

Load loss (LL) [*] US$/kW at rated MVA and voltage

Reactors

No-load loss [*] US$/kW at rated voltage

Capitalisation Price [*] x initial cost + NLL + LL

Note – $/kW and constant values [*] to be advised by MOE.

6.7 Penalties

The tolerance permitted is +10% of the total losses.

Any transformer or reactor with losses more than +10% will be rejected, unless otherwise agreed by the Engineer.

For transformers or reactors with total losses within +5% of the evaluated guaranteed losses no variation of the contract price will be made.


For transformers or reactors where the total evaluated losses are between +5% to +10% of the total guaranteed losses the contract price will be reduced by the total evaluated losses.

6.8 Magnetic circuits

Particular care shall be taken to secure even mechanical pressure over the whole of the core laminations. Each lamination shall be insulated with a material that will not deteriorate under pressure and the action of hot oil.

Where the magnetic circuit is divided into packets tinned copper strip bridging pieces shall be inserted to maintain electrical continuity between packets.

The transformer core shall be free from over fluxing liable to cause damage or to cause mal-operation of the protection equipment when operating under the continuous overvoltage condition specified in the Schedules. Under this steady overvoltage condition the maximum flux density must not exceed 1.9 tesla and the magnetising current must not exceed 5 per cent of the rated load current at normal rated voltage.

The core shall be manufactured of high grade, high permeability, grain orientated, non-aging sheet steel laminations having smooth surfaces. The core and all insulation associated with the core shall be designed so that no detrimental changes in physical or electrical properties will occur during the life cycle of the equipment.

The cores, framework, clamping arrangements and general structure of the transformers and reactors shall be capable of withstanding any shocks to which they may be subjected during transport, installation and service. Adequate provision shall be made to prevent movement of internal parts of the transformers and reactors relative to the tank, to support the core structure in the tank and to carry the weight of the core and windings when suspended.

6.9 Windings

Winding insulation and all non-metallic material used in winding stacks shall be so designed, installed and treated such that no further shrinkage shall take place after assembly.

The windings shall be formed using copper conductor. All permanent connections shall be brazed. All other connections shall be of a compression type with multi-bolt connections.

Coils shall be constructed to avoid abrasion of the insulation, (e.g. on transposed conductors), allowing for the expansion and contraction set up by changes of temperature or the vibration encountered during normal operation. The insulation on the conductors between turns shall be of paper.

The windings shall be designed to reduce to a minimum the out-of-balance forces inherent in the transformer. Tappings shall be arranged at such positions on the windings as will preserve, as far as possible, electro-magnetic balance at all voltage ratios.

Tappings shall not be brought out from the inside of a coil nor from intermediate turns.

The windings and connections shall be braced to withstand shocks, which may occur during transport or due to switching or other transient conditions during service.


Where the yoke supporting channels are adapted for taking up shrinkage in the windings, the arrangement shall be such as to throw a minimum amount of stress on any core bolt insulation.

If the winding is built up of sections or disc coils, separated by spacers, the clamping arrangements shall be such that equal pressure is applied to all columns of spacers. All such spacers shall be securely located and shall be of suitable material.

6.10 Internal earthing arrangements

All metal parts of the transformers and reactors with the exception of the individual core laminations, core bolts and associated individual side plates shall be maintained at some fixed potential.

The magnetic circuit shall be earthed to the clamping structure at one point only through a removable link with a captive bolt and nut accessibly placed beneath an inspection opening in the tank cover. The connection to the link shall be on the same side of the core as the main earth connection, and taken from the extreme edge of the top yoke in close proximity to the bridging pieces. Alternatively the core earth connection may be brought out through a bushing for earthing to the outside of the tank, in close proximity to the main yoke clamping structure earth point.

Where coil-clamping rings are of metal at earth potential each ring shall be connected to the adjacent core clamping structure on the same side of the transformer or reactor as the main earth connection.

The main yoke clamping structures shall be connected to the tank body by a copper strap located at the top of the tank. If there is no metal-to-metal contact between the top and bottom clamping structure, the latter shall be earthed.

Core clamping structures having an insulated sectional construction shall be provided with a separate link for each individual section.

All earthing connections with the exception of those from the individual coil clamping rings shall have a cross-sectional area of not less than 80 mm². Connections inserted between laminations shall have a cross-sectional area of not less than 20 mm².

6.11 Tanks

Transformer and reactor tanks shall be of welded steel and designed to allow the complete transformer or reactor, when arranged for transport, to be lifted by crane and transported without overstraining any joints and without causing subsequent leakage of oil. Each tank shall be provided with a minimum of four jacking lugs, to enable the transformer or reactor, complete with all tank mounted accessories and filled with oil, to be raised or lowered by jacks. The jacking points shall be not less than 300 mm above base level for transport masses up to 10 tonnes and not less than 700 mm for greater transport masses. Facilities shall also be provided to enable the transformer or reactor to be hauled or slewed in any direction.

The base of each tank shall be so designed that it will be possible to move the complete transformer or reactor in any direction without injury when using rollers, plates or rails. A design, which necessitates either slide, rails being placed in particular positions or detachable under bases shall not be used.


The base shall be designed to permit moving the assembled and oil-filled transformers on rollers. Length and spacing of each pair of reinforced parallel rolling areas shall be such that the fully assembled transformers, with or without oil, can be safely tilted 15 degrees. Internal reinforcing shall not prevent draining of all oil from the tank.

The transformers shall be fitted with jacking steps having a suitable clearance from the underside of step to bottom of base. The steps shall have a free surface for the head of the jack. Location of steps shall permit used of jacks without fouling any part of the transformer or shipping skids paralleling either axis. The arrangement of jacking steps and base members shall be such that the transformer can be safely jacked, using a pair of steps parallel to either axis. Each jacking step shall have capacity for lifting one half of the completely assembled transformer filled with oil.

The wheels must be suitable for a standard track (1.435 metre between inside of rail heads). The when the tank is jacked up clear of the rails or floor.

Means shall be provided for locking the swivel movement in positions parallel to and at right angles to the longitudinal axis of the tank.

The wheel loading shall not exceed 13,600 kg and the spacing between the wheels shall not exceed 1.7 metres, flanged wheels will be arranged so that they can be turned through an angle of 90 degrees

The transformers shall also be supplied with eyes for attaching hauling equipment, located in a position acceptable to the Engineer.

The main tank body, tap changing compartments, radiators and coolers, shall each be capable of withstanding, when empty of oil, one atmosphere vacuum filling with oil in the field. It shall also be capable of withstanding positive pressures of 0.35 kg/cm2 or, 125 per cent of maximum oil pressure whichever is greater vacuum test level. The plate thickness for the tank sides shall be a minimum of 6 mm.

Tank stiffeners and mounting brackets shall be continuously welded to the tank.

Wherever possible, the transformer or reactor tank and its accessories shall be designed without pockets wherein gas may collect. Where pockets cannot be avoided, pipes shall be provided to vent the gas into the main expansion pipe. The vent pipes shall have a minimum inside diameter of 20 mm and, if necessary, shall be protected against mechanical damage.

All joints other than those, which may have to be broken, shall be welded. Caulking of defective welded joints will not be permitted. Such defective joints may be re-welded subject to the written approval of the Engineer.

Gaskets of synthetic rubber or neoprene-bonded cork are not permitted. When installed in position, the outer edges shall be protected by metal-to-metal stops of fire-resistant stop gasket material.

Tank covers shall not permanently distort when lifted. Inspection openings of ample size shall be provided to give easy access to bushings, for changing ratio or winding connections, and for testing the earth connections. Inspection covers shall be provided with lifting handles. The tank cover shall be fitted with a thermometer pocket, with captive screwed cap, located in the position of maximum oil temperature at continuous maximum rating.


It must be possible to remove any bushing without removing the tank cover.

A pressure relief device of sufficient size capable of functioning without electrical power, shall be provided for the rapid release of any pressure that may be generated within the tank and which might result in damage to the equipment, but it shall be capable of maintaining the oil tightness of the transformer or reactor under all conditions of normal service. The device shall operate at a static pressure of less than the hydraulic test pressure for transformer or reactor tanks and shall be designed to prevent further oil flow from the transformer or reactor following its operation. In the event that the device is a spring operated valve type it shall be provided with one set of normally open contacts, which will be used for tripping purposes.

The relief device shall be mounted on the main tank and if mounted on the cover it shall be fitted with a skirt projecting inside the tank to prevent an accumulation of gas within the device.

Terminals shall be provided close to each corner at the base of the tank for earthing purposes.

The following plant information plates shall be fixed to the tank at an approximate height of 1.75 m above the ground level: -

(a) A rating plate bearing the data specified in IEC 60076 or IEC 60289.

(b) A diagram plate on which the transformer tapping voltages in kilovolts shall also be indicated for each tap, together with the transformer impedances at minimum and maximum voltage ratios and for the principal tapping.

(c) A property plate of approved design and wording.

(d) A title plate.

(e) A valve location plate showing the location and function of all valves, drain and air release plugs and oil sampling devices.

6.12 Bushings

6.12.1 Oil/SF6 Bushings Oil/SF6 bushings shall be designed in accordance with the requirements of IEC 61639, IEC 60137, IEC 60076 and IEC 62271.

Transformers may be subjected to overload duties in accordance with IEC 60354 and the bushings shall be suitably designed and rated to accommodate these overload duties.

To ensure satisfactory jointing of the flanges of the GIS trunking with the flanges of the HV and LV transformer bushings the maximum permitted tolerances on relevant dimensions of the transformer, taking the centre of the turret as the datum point, shall be as stated in the table below. These tolerances shall be applicable to the transformer in its on-site position after any necessary processing and when fully filled with oil.


Relevant Dimensions

(a) Between HV turrets and LV turrets ±20 mm

(b) From turrets to longitudinal centre line of tank ±15 mm

(c) From top of turrets to corresponding point on,

(i) The edge of the tank base ±20 mm

(ii) The plinth or floor ±25 mm

(d) Level of top of turrets ±1.0°

The bushing flange shall be insulated from the transformer tank to allow a test voltage of 5 kV rms for one minute to be applied between each bushing flange and transformer tank.

In service the bushing flange will be connected to the same substation earth mat as the transformer tank. The bushing flange should be earthed during all testing except for the flange insulation test described above.

The internal and external arrangements of the transformer shall be designed to permit the fitting of either oil/SF6 or oil/air bushings on-site without the need for factory modifications. If any additional parts are required to allow a change of bushing then these should be fully designed at the outset. However, these parts are not normally required to be supplied with the transformer but if needed will be requested by the Engineer.

The oil end of the oil/SF6 transformer bushing will be suitably dimensioned to accommodate current transformers, the number and dimensions of which will be specified by others

Oil/SF6 bushings of the oil impregnated design shall be fitted with a suitable pressure gauge and switch to give indication and alarm facilities in the event of,

(i) Leakage of SF6 gas from the GIS trunking into the self-contained bushing oil.

(ii) Loss of oil from the bushing

The switch(s) shall be capable of giving an alarm at abnormally low or abnormally high operating pressure of the internal bushing zone. The switches shall comply with the requirements of IEC 60255-13 category III. Alarm pressure settings shall be appropriate to the bushing design and its application.

Oil/SF6 bushings connected to GIS trunking shall comply with the temperature rise criteria of IEC 60157, operating at the GIS rated temperature limit as specified in IEC 60517.

6.12.2 Oil/Air Bushings Oil/air bushings shall be designed in accordance with the requirements of IEC 60137.


Transformer bushings for 132 kV and above shall be either of the oil impregnated paper or resin impregnated type. When filled with transformer oil there shall be no connection with the oil in the transformer and an oil gauge shall be provided. The visible oil levels in the gauge shall correspond to average oil temperatures from the minimum ambient stated in the Schedules to plus 90°C. The oil levels at 15°C and 35°C shall be marked. Connections from the main windings to bushings shall be flexible and shall be such that undue mechanical stresses are not imposed on them during assembly on site.

Bushings shall be mounted on the tank in such a manner that external connection can be made free of all obstacles. Neutral bushings shall be mounted in position from which a connection can be made to a neutral current transformer mounted on a bracket secured to the tank. The switchgear manufacturer will supply the current transformer but provision shall be made on the tank for mounting to the Engineer’s requirements.

6.12.3 Terminations The terminations shall be designed to suit the position and connection of the transformer as shown on the attached drawings listed in Schedule E.

MOE standardise on the size of cables used on connections between transformers and switchgear and typically the cables shall be of XLPE single core type and according to the following sizes:

132 kV side 800 sq. mm (A1) 33 kV side 400 sq. mm (Cu) 11 kV side 400 sq. mm (Cu)

In principle the full rating of the transformers is to be achieved and if the above cables are not sufficient then it is normal practice to increase the cable capacity by the addition of (3) of single core cable of the same size.

For transformers connected in a substation using AIS switchgear the 132kV bushing shall be supplied with a connector suitable for connection to an aluminium tube or stranded conductor

Neutral bushings will be suitable for connection to an external bus or conductor. There shall be no connection of the neutral to the inside of the tank.

The details of the connections to all terminals will be confirmed after award of contract.

6.13 Conservator Vessels, Oil Level Gauges and Breathers

Each conservator shall have a filling cap, an adequate sump and be so designed that it can be completely drained by means of a drain valve. One end of the conservator shall have a removable end cover, complete with integral lugs for lifting purposes and secured by nut and bolt fixings, to permit internal cleaning of the conservator.

Where conservator tanks are mounted on the separate coolers, a flexible stainless steel piece (expansion joint) shall be included in each oil pipe connection between the transformer or reactor and the conservator tank.


An oil level gauge shall be provided for each conservator. The indicated minimum oil level shall occur when the feed pipe to the main tank is covered with not less than 12 mm depth of oil. The indicated oil level range shall correspond to average oil temperatures from the minimum ambient to plus 90°C. The oil levels at 15°C and 35°C shall be marked on the gauge. The oil level gauge shall incorporate alarm contacts, which close when the oil level falls below a predetermined level.

Taps or valves shall not be fitted to oil gauges.

The main oil feed pipe from the conservator vessel to the transformer shall be connected to the highest point of the tank and shall be arranged at a rising angle towards the conservator of from 3 to 7 degrees to the horizontal. A valve shall be provided at the conservator to cut off the oil to the transformer.

Whether or not the oil is in direct contact with air or gas the air outlet from each conservator vessel shall be connected to a dehumidifying breather, which shall be mounted at approximately 1.4 m above ground level. This breather should be designed taking into account the ambient operating temperatures and should be at least one size larger than would be fitted for use in a temperate climate.

Where a conservator vessel contains two compartments, one for oil in the main tank and the other for the oil associated with the current making and breaking contacts of the tap change equipment, there shall be no communication between the two compartments in respect of the oil and air spaces. Each compartment shall be provided with the fittings detailed in the preceding paragraphs as if it were a separate conservator vessel.

6.14 Valves

Valves shall be of the fully sealing full-way type and shall be opened by turning counter-clockwise when facing the hand wheel. They shall be suitable for working between the minimum ambient and the maximum oil temperatures stated in the Schedules.

Padlocks shall be provided for locking all valves other than individual radiator valves in the "open" and "closed" positions. Valves shall be provided with an indicator readily visible from ground level, to show clearly the position of the valve.

All valve handwheels shall be fitted with nameplates, which shall be chromium plated brass not less than 3 mm thick with the engraving filed with enamel. All valves shall be fitted with spoked handwheels, the spokes and rims of which shall be smooth and where necessary, for appearance, shall be chromium plated.

All valves opening to atmosphere shall be fitted with blanking plates.

Each transformer and reactor tank shall be fitted with the following: -

(a) One 100 mm valve at the top and one 100 mm valve at the bottom of the tank mounted diagonally opposite each other, for connection to oil circulating and oil filtering equipment. The lower valve shall also function as a drain valve.

(b) An oil sampling device at the top and bottom of the main tank.


(c) All parts containing oil, and liable to trap air during filling, shall be fitted with a flanged type air release plug at their highest points.

6.15 Cooling Plant

Transformers shall have ONAN/ONAF/OFAF cooling options and facilities shall be provided at the marshalling kiosk or cubicle for the selection of AUTOMATIC or MANUAL control of the cooling plant motors.

Reactors shall be ONAN cooled.

Transformers shall be fitted with sectionalised cooling banks necessary to meet the continuous maximum rating (CMR). The Contractor shall be responsible for designing the optimum number of sections to meet the CMR and fit a spare section. CMR is to be available with the loss of one section of radiators and associated fans and pumps without depending on the overload capability of the transformer.

Transformers shall be capable of remaining in operation at full load for 20 minutes in event of failure of the cooling fans and for 10 minutes in the event of failure of the oil circulating pump without the calculated winding hot spot temperature exceeding 150°C. Failure of one fan in each group of fans shall not reduce the continuous maximum rating of the transformer.

Radiators and coolers shall be designed so that all painted surfaces can be readily cleaned and subsequently painted in position.

Detachable radiators and separate cooler assemblies connected to the main tank shall be provided with machined flanged inlet and outlet pipes.

Plugs shall be fitted at the top and bottom of each radiator for filling and draining.

Mal-operation of gas and oil actuated relays shall not occur on starting or stopping of forced-oil circulation.

The oil circuit of all coolers shall be provided with the following as appropriate to tank mounted or separate bank coolers: -

(a) A valve at each point of connection to the transformer or reactor tank.

(b) Isolating valves at the bottom of each individually detachable radiator. The valves shall be located on header side of the radiator attachment point.

(c) A valve in the main oil connection at the bottom of each cooler in addition to those mounted on the tank.

(d) Loose blanking plates to permit the blanking off of the main oil connection to the top of each cooler.

(e) A 100 mm oil filtering valve at the top and bottom of each cooler, the bottom valve shall also function as a drain valve.


(f) A thermometer pocket fitted with a captive screwed cap on the inlet and outlet oil branches of each cooler.

(g) Visual oil flow indicators in the pipework adjacent to the coolers. In the event that this will offer impedance to oil flow under ONAN conditions a differential pressure gauge of approved design and manufacture may be connected across the pumps, as an alternative.

The material of the tube plates and tubes shall be such that corrosion shall not take place due to galvanic action.

Where separately mounted cooling equipment is provided a flexible stainless steel piece (expansion joint) shall be included in each oil pipe connection between the transformer or reactor and the oil coolers.

Drain plugs shall be provided in order that each section of pipework can be drained independently.

Each forced oil cooler shall be provided with a fully weatherproof motor driven oil pump. The motor shall be of the submersible type. It shall be possible to remove the pump and motor from the oil circuit without having to lower the level of the oil in the transformer or coolers.

Where forced air cooling is provided it shall be possible to remove the fan, complete with its motor and supporting structure without disturbing or dismantling the cooler framework or pipework.

Wire mesh guards galvanized after manufacture shall be provided to prevent accidental contact with the fan blades. Metal guards shall also be provided over all other moving parts. The guards shall be designed such that neither the blades nor other moving parts can be touched by a Standard Test Finger to IEC 60529.

6.16 Cooler Control

Each motor or group of motors shall be provided with a three-pole electrically operated contactor and with control gear of approved design for starting and stopping manually.

Where forced cooling is used on transformers, provision shall be included under this contract for automatic starting and stopping from contacts on the winding temperature indicating devices. The control equipment shall be provided with a short time delay device to prevent the starting of more than one motor, or group of motors in the case of multiple cooling, at a time.

Where motors are operated in groups the group protection shall be arranged so that it will operate satisfactorily in the event of a fault occurring in a single motor.

The control arrangements are to be designed to prevent the starting of motors totalling more than 15 kW simultaneously either manually of automatically. Phase failure relays are to be provided in the main cooler supply circuit.

All contacts and other parts, which may require periodic renewal, adjustment or inspection, shall be readily accessible.


All wiring for the control gear accommodated in the marshalling kiosk together with all necessary cable boxes and terminations and all wiring between the marshalling kiosk and the motors shall be included in the contract.

Two independent sources of power shall be made available to ensure loss of cooling capacity for a single contingency is not greater than 50 per cent. 6.17 On-load Tap Changing Equipment

Each transformer shall be equipped with an on load tap changer suitable for the rated current (+20% overload) of modern design and robust construction of MR Type from Germany for varying the turns ratio without producing phase displacement. Tappings shall be brought out from the neutral end of the common part of the windings. The equipment shall vary the turns ratio without producing phase displacement.

All leads and connections to fixed and moving contact assemblies and between the transformer and the voltage control device shall be supported and adequately braced to withstand the short circuit current for which the associated transformer is designed.

Equipment for varying the effective turns ratio on-load shall consist of tap changing gear arranged for local hand and electrical operation and remote electrical operation. On load tap changers shall comply with IEC 60214, IEC 60542 and with the requirements of this specification. It shall also be so designed that it may be easily adapted to operate by automatic control.

The tap changing switches and mechanism shall be mounted in an accessible position in oil tanks or compartments and shall be supported in the main tank, from the main tank or from its base. It is preferable that examination and repair of both selector and diverter switches including their associated equipment should be carried out without lowering the oil level in the main tank. However, designs of tap-changer that involve lowering the oil level in the transformer tank may be accepted with the agreement of the Engineer.

It shall not be possible for the oil in those compartments of the tap change equipment which contain contacts used for making and breaking current, to mix with the oil in the main transformer or with the oil in the compartments containing contacts not used for making or breaking current. A drain valve shall be provided.

The oil in those compartments of the main tap-change apparatus that do not contain contacts used for making or breaking current shall be maintained under conservator head by means of a pipe connection from the highest point of the chamber to the conservator. This connection shall be controlled by a suitable valve and shall be arranged so that any gas leaving the chamber will pass into the gas and oil actuated relay.

Each compartment in which the oil is not maintained under conservator head shall be provided with an oil gauge.

Any enclosed compartment not oil filled shall be adequately ventilated and designed to prevent the ingress of vermin. All contactors relay coils or other parts shall be suitably protected against corrosion or deterioration due to condensation.


Tap changing shall be prevented when the transformer is carrying a load above a predetermined maximum or when on short circuit. Tap changing equipment however, shall be suitably rated for operation when transformers are subjected to overload duties in accordance with IEC 60354.

Limit switches shall be provided to prevent over-running of the mechanism and shall be directly connected in the circuit of the operating motor. Limit switches may be connected in the control circuit of the operating motor provided that a mechanical de-clutching mechanism is incorporated.

A mechanical stop or other approved device shall be provided to prevent over-running of the mechanism under any condition without resulting damage.

Thermal devices or other approved means shall be provided to protect the motor and control circuits. Switches for the initiation of a tap change shall bear the inscription "Raise Tap Number", as applicable.

Tripping contacts associated with any thermal device used for the protection of tap changing equipment shall be suitable for making and breaking 150 VA at 0.35 power factor, between the limits of 30 and 250 volts ac or breaking 150 VA and making 500 VA between the limits of 110 and 250 volts dc.

A hand crank for manual operation of the tap-changer driving mechanism shall be provided and shall include the necessary interlocking between manual and electrical operation. Suitable local storage for the hand crank shall be provided

A device shall be fitted to the tap changing mechanism to indicate the number of operations completed by the equipment.

A permanently legible lubrication chart shall be fitted within the driving mechanism chamber.

The terminals of the operating motor shall be clearly and permanently inscribed with numbers corresponding to those on the leads attached thereto.

Equipment for local and remote electrical and local hand operation shall comply with the following conditions: -

(a) It shall not be possible to operate the electric drive when the hand operating gear is in use.

(b) It shall not be possible for any two electrical control points to be in operation at the same time.

(c) Each step movement shall require separate initiation at the control point.

(d) All electrical control switches and the local operation gear shall be clearly labelled in an approved manner to indicate the direction of tap changing.

(e) The local control switches shall be housed in the tap changer drive mechanism cubicle or the transformer marshalling kiosk.

The equipment shall be arranged so as to ensure that when a step movement has been commenced it shall be completed independently of the operation of the control relays or switches. If a failure of the auxiliary supply during a tap change, or any other contingency, would result in that movement not being completed, means shall be provided to safeguard the transformer and its auxiliary equipment.


The equipment shall give indication mechanically at the transformer and electrically at the remote control points of the tapping in use. The indicator at the transformer shall show the number of the tap in use and the indicator at the remote control points shall show clearly the actual voltage ratio in kilovolts and the tap number representing this ratio. The numbers shall range from 1 upwards.

The equipment shall give indication at the remote control points that a tap change is in progress. This may be by means of an illuminated lamp and alarm buzzer if the Substation Control Point is a panel. If the tap change is not completed in its specified time the alarm shall remain permanent until the tap change is completed.

When operating in parallel with other transformers, an adequate interlocking device shall be provided for synchronous operation of the tap-changer. The equipment shall give an indication at the remote control points as described above when the units of a group of transformers arranged to operate in parallel are operating at different ratios. It shall not operate under any control arrangement other than parallel control.

On-load tap changing equipment shall be suitable for supervisory control and indication. Both a separate multi-way switch, having one fixed contact for each tap position and a 0 – 5 mA signal representing the tap position shall be provided for this purpose and wired to the marshalling kiosk or cabinet.

6.17.1 Automatic and Manual Voltage Control The on-load tap changing equipment shall be fully automatic, and an automatic voltage control relay (AVC) shall be provided. The relay shall be responsive to variation in the measured voltage and cause the necessary tap change to be made to restore the voltage to the desired level within pre-determined limits. The AVR shall operate the transformers connected to each electrically separate busbar in groups, on a busbar by busbar basis.

The recommended preset range for 400/132kV transformers is between 125.4-138.6kV and for 132/33/11kV transformers is between 10.5-11.5kv. Where 132kV transformers have dual voltage lv windings, the 11lV voltage shall be monitored. Where transformers may have their lv windings connected in parallel, the AVR will need to be able to control all such transformers as a co-ordinated function.

The voltage control equipment shall be suitable for control of up to a specified maximum number of transformers in parallel. Initially it may be required to control less than the maximum transformers, but it shall be possible to extend the facilities to cover up to the maximum transformers at a later date. For 400/132kV transformers, the maximum shall be four. For 132/33/11kV transformers, the maximum shall be three.


The following facilities shall be provided with the AVR:

Function Controlled from

Tap Raise and Lower National Control Centre or Substation Control Point for the transformers in each busbar group,

and the Transformer Tap Changer Mechanism/Marshalling Kiosk, for each transformer individually when in LOCAL

Tap Changer Auto/Manual National Control Centre or Substation Control Point, for each busbar group- Manual control shall be possible when the MANUAL/AUTO switch is in MANUAL position, and automatic facilities shall be inhibited

Tap changer Local/Remote The Transformer Tap Changer Mechanism/ Marshalling Kiosk

AVR point of control National Control Centre or Substation Control Point, for station AVR facilities

Target Voltage Set Point National Control Centre or Substation Control Point for each separate or interconnected busbar group

AVC relays equipped to accept electrical signals to control the actual set point shall be capable of set point adjustment in steps not exceeding 1 per cent.

Failure of the AVR should keep the tap-changer in position and give an alarm.

A full description of the AVR and its functions shall be submitted with the Tender.

The voltage control and parallel operation schemes and their complete analysis and design shall be the responsibility of the Contractor.

The AVR functionality may be embedded in the Substation Control System, if the Tenderer can provide satisfactory evidence of its successful implementation in a similar environment to Iraq. If the AVR functionality is provided by a separate AVR relay and controlled from the SCS, the Contractor shall be responsible for supplying all of the equipment and integrating these into a complete working system and shall comprise, in general, but not limited to the following:

(a) Control switches, pushbuttons, tap-position indicator, alarms and indications.

(b) AVR panels/cubicles complete with all the necessary interposing and auxiliary relays for voltage control.

(c) The AVR panel shall be located in the Control/ Relay Room.


The functionality of the AVR shall be subject to the approval of the Engineer.

Approved means, either by switch or links, shall be provided for each transformer to give complete isolation of all electrical supplies at the SCS, and/or the AVR Panel if fitted, without preventing the operation of tap-changers on the other transformers.

The measured voltages will be derived from voltage transformers, having secondary windings rated at 110 volts phase-to-phase and having an accuracy not inferior to Class 1. The relay shall have a nominal voltage rating equal to the VT secondary winding rating.

The relay setting voltage, expressed as a percentage of the relay nominal voltage shall be adjustable over a range of not less than 10 per cent of nominal.

The relay sensitivity band relative to the setting voltage shall be adjustable from not more than 1.5 times to not less than 2.5 times the percentage equivalent of one tap change step.

Settings for relay operating time shall be adjustable. For definite time relays, the setting range shall be from 10 s to 120 s and the timing device shall be of the "slow resetting" type. Relays having time dependent characteristics shall have a range of adjustments allowing a delay of up to at least 120 s for a voltage deviation 1 per cent greater than the sensitivity setting and not more than 10 s for a deviation of 5 times sensitivity or 10 per cent voltage, whichever is the greater.

The relay shall be insensitive to frequency variation between the limits of 47 Hz and 51 Hz and shall incorporate an undervoltage blocking facility to render the control inoperative if the reference voltage falls to 80 per cent of nominal value with automatic restoration of control when the reference voltage rises to 85 per cent of nominal value.

The relay setting voltage must be capable of adjustment from the remote and supervisory locations. When selected to either supervisory or remote and selected for automatic operation the control signal shall vary the set point of the AVR relay. When selected to manual the control signal shall operate the tap changers in a busbar group directly to raise or lower the tap position as required. It shall be possible to select auto/manual control from the remote and supervisory locations.

On-load tap change transformers provided with fully automatic control and required to operate in parallel as a group, shall be provided with means to ensure proportionate sharing of watts and VARs.

Control equipment supplied under this contract shall include all alarm, indication and repeat relays necessary to identity faulted equipment. Indication of faulted equipment shall be provided at the equipment itself, and to the remote control points. All equipment shall be suitable for operation within the limits 85 per cent - 110 per cent of the auxiliary voltage supply.

On each transformer the voltage transformer supply to the voltage regulating relay shall be monitored for partial or complete failure. If the circuit breaker controlling the lower voltage side of the transformer is open or when the tap changer is on other than automatic control then any alarm or indication should be made inoperative.


6.18 Parallel operation

The transformers shall be suitable for parallel operation with other transformers of the same type and comparable ratings at rated voltage and on taps of like turn ratio. Full details of these transformers shall be made available to the Contractor for design co-ordination.

6.19 Disconnecting and sealing end chambers

Where cables for 11 kV and above are terminated in a cable box, an oil filled disconnecting chamber with removable links shall be provided for testing purposes. The disconnecting chamber shall be capable of withstanding on site the cable high voltage test level in accordance with IEC 60055 and IEC 60141 as appropriate. During the test the links in the disconnecting chamber will be withdrawn and the transformer or reactor windings earthed. A barrier shall be provided on both sides of the disconnecting chamber to prevent ingress of the oil used for filling the chamber into the cable box or tank.

Where sealing end chambers are provided, the disconnecting chamber may be omitted and the facilities for testing shall be provided in the sealing end chamber itself; a barrier shall be provided between the sealing end chamber and the main tank.

Provision shall be made to allow for the expansion of the filling medium and drain plugs of ample size shall be provided for enabling the filling medium to be removed.

The disconnecting or sealing end chambers shall have a removable cover and the design of the chambers shall be such that ample clearances are provided to enable either the transformer or reactor or each cable to be subjected separately to high voltage tests. The disconnecting links shall be flexible or flexibly attached at one end.

The oil level in disconnecting or sealing end chambers shall be maintained from the main conservator tank by means of a connection to the highest point of the chamber and this connection shall be controlled by a valve.

An earthing terminal shall be provided in each disconnecting or sealing end chamber to which the connections from the transformer or reactor winding can be earthed during cable testing.

Terminals shall be marked in a clear and permanent manner.

6.20 Temperature indicating devices, alarms and gas and oil actuated relays

6.20.1 Temperature Indicating Devices and Alarms Oil temperature indicating devices shall be fitted with alarm and trip contacts.

Winding temperature indicating devices shall indicate the temperature of the hottest spot of the winding and shall have a load-temperature characteristic approximating to that of the main winding. Alarm and trip contracts shall be provided.

Alarm contacts of oil and winding temperature indicating devices shall be adjustable over a range of 60°C to 110°C and trip contacts adjustable over a range of 80°C to 150°C. Alarm and trip contacts


shall be suitable for making and breaking 150 VA at 0.35 power factor, between the limits of 30 and 250 volts ac or breaking 150 VA and making 500 VA between the limits of 110 and 250 volts dc.

For transformers having or being suitable for mixed or forced cooled ratings whether the forced cooling is to be supplied initially or at a later date, an additional contacts shall be provided to automatically control the forced cooling plant.

Temperature indicating devices shall incorporate a dial and a pointer indicator and a separate pointer to register the maximum temperature reached.

The capillary connected sensing bulbs of temperature indicators shall be positioned in separate oil-tight pockets arranged in the top oil.

Where winding temperature indicators are specified they shall be associated with one phase only. In the case of auto-transformers there shall be separate indicators for the series and common windings.

The winding temperature indicating devices shall be so designed that it shall be possible to move the pointers by hand for the purpose of checking the operation of the contacts and associated equipment. The working parts of the instruments shall be made visible by the provision of cut-away dials and glass fronted covers.

The characteristics of the winding temperature indicating devices shall be forwarded to the Engineer for approval prior to the delivery of the transformers and shall also be included in the operating and maintenance instructions.

All temperature indicators shall be housed in the marshalling kiosk or cabinet and shall be mounted so that they will not be affected by vibration.

6.20.2 Gas and Oil Actuated Relays Gas and oil actuated relays shall be fitted to each transformer and reactor and to each tap selector compartment. They shall have alarm contacts that close on collection of gas or at low oil level and tripping contacts, which close following an oil surge.

The surge float contacts shall close at a rate of steady oil flow between the following limits. As far as possible the limits shall also be met when the relay is subjected to oil surge conditions produced by rapid opening of a lever operated gate valve.

Oil Pipe Connection Internal Diameter

Operational Limits for Relay Rising Angles of 1º to 9º

mm Steady Oil Flow (mm/s)

25 700 – 1300

50 750 – 1400

75 900 - 1600


The normally open, electrically separate, alarm and tripping contacts shall not be exposed to oil.

The relays shall be fitted in the expansion pipe connecting the transformer or reactor tank to the conservator.

Each relay shall be provided with a test cock to take a flexible pipe connection for checking the operation of the relay.

A 5.0 mm inside diameter pipe shall be connected to the gas release cock of the relay and brought down to a point approximately 1.4 m above ground level where it shall be terminated by a cock.

6.21 Oil Flow Indicators

Forced oil cooled transformers shall be provided with a visual oil flow indicator in each outlet pipe connection from the coolers. These indicators shall incorporate contacts, which close under conditions of no oil flow.

6.22 Current transformers

If specified each transformer shall be equipped, with multi-ratio type current transformers, which shall conform to the requirements of IEC 60344-1

The current transformer shall be used in balanced-current protection schemes and will be suitable for this duty. Further information will be made available during the course of the contract.

6.23 Surge protection

The main transformers windings and neutral points are to be protected against incoming surges on both the HV and LV side by means of lightning arresters located as close as possible to the respective bushings. Generally the lightning protection arresters will be supplied in the Substation part of a contract.

6.24 Condition Monitoring System

When specified the Contractor shall provide as an optional cost for the transformer to be equipped with an on line monitoring system to provide condition assessment.

Typically measurements shall be used to derive the following data: -

Hot spot temperature in accordance with IEC 60354 Ageing rate in accordance with IEC 60354 Continuous overload current capacity of the transformer. Overvoltage detection including a lightning surge and overcurrent. Variation in the capacitance of bushings.

The monitoring system shall be capable of recording the following quantities: -

Measurement of current and voltage on the HV and tertiary winding. Top oil temperature. Moisture in the oil. Gas in the oil by means of a Hydran unit or similar.


Tap change position and number of tap change operations. Status of fans and pumps Tap changer motor power requirement.

The system may be used to control the operation of the pumps and coolers as required given the ambient temperature and transformer loading conditions.

All necessary sensors in addition to those already specified shall be supplied with the transformer.

The monitoring unit shall be mounted in the transformer marshalling kiosk and be suitable for outdoor operation.

The monitor shall be co-ordinated into the substation SCS system and be suitable for connection to a fibre optic LAN system and provide remote monitoring data to National Control Centre as required. Data shall be recorded locally and date stamped from the substation GPS time system.

6.25 Transformer Oil

The transformer oil shall comply with the requirements of IEC 60296. The oil shall be a highly refined oil suitable for use as an insulating and cooling medium in transformers and reactors. For information Shell Diala “B” and Nynas Nitro GBN10 oils have been used on the existing M.O.E. equipment.

The transformers shall be shipped filled with gas and sufficient gas bottles are to be connected during transit. The transformer shall be kept under a low positive pressure at all times during transportation.

Sufficient quantities of oil shall be supplied in drums with an additional 10% allowed provided. The oil shall have a dielectric strength, when shipped, of at least 30kV, as measured in accordance with IEC 60296. Test reports, stating the dielectric strength of the oil, shall be submitted to the Engineer prior to filling of the transformer on site.

6.26 Topping Up with Oil and Drying out on Site

If oil is to be added to a transformer or reactor at Site prior to commissioning, the oil in the transformer or reactor shall first be tested for dielectric strength and water content and each container of make up oil shall be similarly tested. The Resident Engineer or his representative shall witness all tests.

Should it be found necessary to resort to oil treatment before a transformer or reactor is commissioned, the Contractor shall submit to the Engineer, in writing, a full description of the process to be adopted, the equipment to be used and a statement of the precautions being taken to prevent fire or explosion.

Should a transformer or reactor arrive on Site without positive pressure of gas in the tank, it shall be dried out on Site at the Contractor's expense.

Clear instructions, in English shall be included in the Maintenance Instructions regarding any special precautionary measures, which must be taken before vacuum treatment can be carried out. Any special equipment necessary to enable the transformer or reactor to withstand vacuum treatment shall be provided with each transformer or reactor. The maximum vacuum which the complete transformer or reactor, filled with oil can safely withstand without any special precautionary measures being taken shall be stated in the Maintenance Instructions.


6.27 Oil Handling and Test Equipment

An oil processing plant is to be provided to remove solid matter, dissolved gases and moisture from the oil.

The oil treatment plant should be able to achieve a standard of oil purity similar to that specified by the transformer manufacturer for the first filling, and the rate of flow shall be suitable for filling the transformers in this specification but have a minimum value of 9000 litres/hour.

The flow rate shall be variable, but when adjusted it should be steady, continuous and automatic in operation. The degasifier and the filter shall be able to operate together or independently.

The pumps shall be rated suitably for the treatment of the required quantities of oil at ground level, and to deliver oil into the highest part of the oil system of the transformers specified herein.

The plant should be complete with vacuum pump, air cleaning set, cooling unit, suitable rubber hoses for use with oil and all other necessary accessories.

6.28 Transformer Marshalling Kiosk

A weatherproof and dustproof control housing of adequate size shall be located on the transformer near the base. It shall be mounted not less than 610 mm (2 feet) above the base and the space beneath it shall be free from obstruction, which could interfere with outgoing cable or conduit connections. It shall be equipped with the following: -

(a) Earth bus for individually earthing each set of current transformer leads and other circuits requiring earth points. The bus shall include one bolted type connectors of 10 mm 2 stranded copper cable size for each earthed circuit.

(b) Terminal blocks for the termination of all current transformer secondary leads, alarm, control, relay and thermocouple leads.

Terminal block for current transformer and thermocouple leads shall be through type with two clamping screws for each lead or designed for lapped joints with two clamping screws exerting pressure on each connection. Terminal blocks shall accommodate all sizes up to, and including, 16 mm 2 stranded conductor. All current transformer leads shall be kept separate from control leads.

(c) Two weatherproof convenience outlets outside the control cabinet as per latest B.S. 546 for single-phase, 220 volt, 20-ampere service.

(d) A suitable pocket or holder inside the control cabinet for one copy of the instruction manual.

(e) A plain, removable plate located in the bottom of the box of adequate size for terminating all conduits leaving the transformer. (The plate will be drilled in the field)

(f) Contactors for fan motors.

(g) Contactors for oil pump motors (if applicable).

(h) Necessary glands for power and control cables.


(i) Thermostatically controlled, anti-condensation heater for 220 volt, single-phase system.

6.29 400 kV Reactors

Where required by system conditions 400kV reactors will be connected directly to the outgoing overhead line circuits to compensate for their capacitive charging power.

The reactors shall be three phase, 50 Hz outdoor type either in a single tank or a three-phase bank of single phase units. The reactor shall either be solidly earthed at the neutral or have its insulation shall be graded for operation with the neutral earthed through a compensating reactor.

Ratings shall be based on the average winding temperature rise, as measured by resistance, of 55°C and the top oil temperature rise, as measured by thermometer, of 45°C with a cooling air maximum temperature of 50°C.

The basis of the cooling system is ONAN, but alternative systems can be proposed by the Contractor for approval by the Engineer.

Dependent on the site conditions the reactor can either be GIS connected or AIS connected and the reactor bushings will be designed accordingly.

The following transformer technical sections apply to the design of the 400kV reactors.

6.8 - Magnetic circuits 6.9 - Windings 6.10 - Internal earthing arrangements 6.11 - Tanks 6.12 - Bushings 6.13 - Conservators, oil level gauges and breathers 6.14 - Valves 6.15 - Cooling plant

6.20 - Temperature indicating devices and alarms


7. 11 KV SYSTEM AND COMPENSATING EQUIPMENT

The 11 kV system will be as shown on the relevant drawing and shall consist of transformers and compensating equipment connected to the delta tertiary windings of the system 400/132 kV auto transformers.


The work to be done under this Section consists of the design, manufacture, testing supply delivery to site, installation, commissioning and guarantee of the following equipment:

- 11 kV switchgear for the station and earthing transformers and compensation equipment

- Interconnection buswork cables and protection

- Station service transformers

- Earthing transformers.

- Capacitors

- Shunt reactors

7.2 11 kV Switchgear

(a) Circuit Breakers

The circuit breakers shall be three-pole, equipped with single trip coils. All circuit breakers shall comply with the requirements of IEC 62271. The type of breaker offered shall comply with the requirements of this Specification.

(b) Disconnect Switches

Disconnect switches shall comply with the requirements of this Specification.

(c) Fused Disconnect Switches

Station service transformers shall be connected to the 11 kV system by fused disconnect switches. The switch shall be designed to provide automatic opening of all poles if all or any of the fuses blow. The switches shall comply with the general requirements of this Specification.

(d) Enclosures

Enclosures required for any item of switch-gear shall be of double roof construction, weather-proof, dustproof, vermin-proof and with adequate ventilation to meet the climatic conditions.

7.3 Interconnecting Buswork

The Contractor shall provide all busbars, insulators, supports, clamps, fittings and the like necessary for the 11 kV system. This shall include interconnections between main single-phase auto-transformer tertiary windings and connections between the tertiary windings and all other 11 kV equipment.


7.4 Station Service Transformers

Each transformer shall be delta/star, with neutral earthed, supplied with on-load tap-changer on the HV winding (+ 10 percent taps). Windings and internal wiring must be copper. Aluminium is not acceptable.

Each transformer shall be rated to supply the total station auxiliary load plus an allowance for the future extension as per general layout and single-line drawing.

(a) Codes, Standards and References

Transformers shall comply with appropriate IEC or B.S. standards or Codes of Practice.

(b) Rating and Type

Transformers shall either be of outdoor type, oil-immersed, self-cooled or dry encapsulated design. Ratings shall be based on an average winding temperature rise, as measured by the resistance method of 55o C with the cooling air maximum temperature 50o C. Where applicable the top oil temperature shall be 50oC. The oil filled transformers shall have overload capabilities in accordance with the latest issue of IEC publication 60354.

Automatic on-load tap-changer is to be supplied with facilities for future remote control. Rating of transformers to be approved by the Engineer.

(c) Accessories

Where applicable, the following additional accessories shall be provided.

(i) Filter connections:

(ii) a 5 cm oil drain valve:

(iii) Handhole in cover to permit access to interior.

(iv) Oil level gauge, magnetic type with low level alarm contacts and wired to terminal box:

(v) Dial-type oil temperature indicators, one for the transformer and one for the tap-changer, each with two sets of alarm contacts plus maximum temperature indication:

(vi) Increase relief vent:

(vii) Engraved metal nameplate and connection diagram to indicate capacity, type, phase, tap voltage with related currents, frequency temperature rise, weights or core, coils, oil and complete unit, quantity of oil, manufacturer, serial number and date of manufacture.

(viii) Earthing terminal pads:

(ix) Combined pressure and vacuum gauge, if applicable.


7.5 Earthing Transformers

When specified each earthing transformer shall be of the oil immersed ONAN type suitable for outdoor installation and shall have an interconnected star winding which will be connected via cables to a circuit breaker connected to the busbars to be earthed.

The neutral point of the interconnected star winding of each earthing transformer shall be brought out of the tank through a bushing insulator similar to those on the phase terminals. This point may be isolated or may be connected to earth either directly or through an impedance (should that be necessary) in order to provide an earthing point for the neutral of the lower voltage system.

Rating shall be such that for any single-line-to-earth fault the reactance of the earthing unit Xo shall be such that the ratio Xo/X1, as viewed from the fault, will exceed three but be less than the value required for resonant earthing. The short time rating, based on the maximum value of current, which the earthing unit may be required to carry, shall be 30 seconds. Continuous current rating of the earthing unit must be stated in tender. Preference is given for realisation without separate earthing resistor.

Earthing transformers shall be capable of withstanding for a period of 3 seconds the application of normal three-phase line voltage to the line terminal and the neutral terminal connected solidly to earth.

The interconnected star winding of each earthing transformer, when at its maximum temperature due to continuous full load on the auxiliary winding, shall be designed to carry for thirty seconds without injurious heating an earth fault current not less than the value given in the Schedules.

Earthing transformers shall comply with the provisions of this Specification relating to the main transformers wherever these are applicable and shall be provided with the following fittings: -

(a) One thermometer pocket with captive cap.

(b) Dehumidifying breather.

(c) Filter valve and combined filter and drain valve.

(d) A sampling device at the bottom of the tank.

(e) Conservator vessel with removable end cover and prismatic oil gauge.

(f) Double float gas oil actuated relay.

(g) Pressure Relief Device

Shall generally conform with this Specification but with interconnected star "zigzag" winding, with the primary star point earthed through an impedance.

7.6 11 kV Capacitor and Series Reactor

7.6.1 General Where specified 11 kV capacitors together with a series reactor shall be provided as indicated on the single line diagrams and shall be connected to the 11 kV busbar. The switchgear shall be provided with control, protection, metering and signalling system.


The capacitor banks, associated reactors, surge arresters and 11kV switchgear shall be installed in an enclosure within the 400kV substation.

7.6.2 Capacitors Each capacitor bank shall consist of single-phase capacitor units connected to form an ungrounded double star 3-phase arrangement with an unbalance current transformer provided in the connection between the two neutrals of the double star.

The capacitor units shall be of the plastic film paper type, mounted on insulated racks and comply with the requirements of this specification and IEC 60871 with insulation material of Non-PCB type.

The arrangement shall include all necessary protective racks, insulation between racks, insulation to ground, discharge and damping devices and all other necessary equipment. The capacitor bank racks shall provide accommodation for at least 20 per cent more units than required for the specified duty.

Capacitor banks shall be designed to operate outdoors, continuously at the specified terminal voltage in an ambient temperature of 50°C. Sun shielding shall be provided.

Capacitors shall be capable of continuous operation at 130 per cent of fundamental sinusoidal current.

Capacitors shall be suitable for continuous operation at rated reactive power.

A capacitor unbalance current transformer shall be provided in the connection between the two neutrals of the double star.

Each battery shall comprise an assembly of capacitor units; each unit shall comprise an assembly of one or more capacitor elements in a single container with terminals brought out.

The arrangement shall include all necessary protective racks, insulation between racks, insulation to ground, discharge and damping devices and all other necessary equipment. The capacitor bank racks shall provide accommodation for at least 20 per cent more units than required for the specified duty.

7.6.3 Containers The containers shall be of stainless steel or other approved material. If the latter, then to ensure a long life between repainting, the following finish shall be applied. Acceptance of an alternative finish will be contingent upon an equivalent standard being obtained.

(a) Metallised zinc spray to BS 2569, Part I, 1964. (b) Degrease. (c) One coat of pre-treatment primer. (d) One coat of zinc chromate primer. (e) Two coats of phenolic resin based micaceous iron oxide paint.


(f) One coat of phenolic based hard glass paint to an overall film thickness of 150 microns.

7.6.4 Fuses Fuses shall be provided internally for protection of individual capacitor elements or groups of elements. The fuses shall not deteriorate when the unit capacitor is subjected to the discharge test specified in the Schedules nor the currents associated with the day-to-day operation of the capacitor bank.

The Contractor shall demonstrate or provide evidence to the satisfaction of the Engineer that each fuse is capable of breaking the fault current produced by the failure of the capacitor element or groups of elements or complete unit capacitor to which the fuse is applied without hazard from the fuse or the unit capacitor. The Contractor shall also demonstrate or provide evidence to the satisfaction of the engineer that the contamination of the impregnant is not such as to affect the reliability of the remaining sound elements.

Fuses shall be so constructed that when they operate due to a defective element(s), the blown fuse will withstand indefinitely the voltage imposed across it under working conditions.

Internal fuses shall be generally in accordance with IEC 60593.

Portable test equipment or other suitable means shall be provided to enable defective capacitors to be readily identified. The Contractor shall demonstrate to the satisfaction of the Engineer the use and performance of the apparatus provided under this clause.

7.6.5 Overvoltages and Overloads The capacitor bank must withstand all the transient currents and voltages inherent in the application.

In addition, the capacitor protection shall include equipment effective in limiting overvoltages arising from abnormal oscillatory conditions.

Each capacitor bank shall be capable of withstanding without damage, any overvoltages produced by excessive currents including inrush currents and short circuit currents for earth faults for a period of time not less than the maximum operating time of the associated protective equipment.

7.6.6 Discharge and Earthing Devices Each capacitor unit shall be fitted with a discharge device to reduce the residual voltage from the peak value of the rated voltage within 10 minutes after the capacitor is disconnected from the source of supply.

The Contractor shall ensure that it is not possible to switch on capacitor banks until the voltage at the terminals is less than 10 per cent of rated voltage.

Facilities shall be provided for short circuiting and earthing individual capacitor banks before access is allowed.


7.6.7 Duty Under Fault Conditions Unit capacitors and capacitor banks shall be capable of withstanding without damage, or deterioration of fuses, an external short circuit on the terminals of the live unit capacitor or of the live capacitor bank. Due consideration should also be given to the fact that external flashovers may occur as a result of transient overvoltages and that at the instant of the fault the unit capacitor may be charged up to a voltage considerably in excess of the normal peak voltage. The Contractor will be required to demonstrate compliance with these requirements in a manner to be approved by the Engineer.

7.6.8 Rating and Property Plates In addition to the rating plate, a property plate of approved design and wording shall also be provided.

Property plates may, subject to the approval of the engineer, be provided on each rack rather than on each capacitor unit. A capacitor bank rating plate shall be provided suitably mounted if possible at a height of 1.75 m from ground level and so attached as to be visible from the exterior of the housing or enclosure of the bank. This plate shall include the rating plate data specified in IEC 60871 as relevant to the rating of the assembled capacitor bank.

The above plates shall be of an approved material.

7.6.9 Racks for Unit Capacitors The racks shall be designed on a modular basis to carry all the required unit capacitors, conductors, insulators and other fittings and the rigid conductors comprising the necessary circuits under the loadings and factors of safety specified below and to give the specified clearances for the connections between the capacitors and associated circuits specified. The racks shall be designed to facilitate inspection and maintenance.

The number of devices specified to facilitate the easy removal and replacement of capacitor units shall be provided. They shall be designed with the minimum number of separate parts each of which shall not weigh more than 12 kilograms. Means shall be provided to ensure that the paintwork of the capacitor containers is not damaged by the use of the removal device.

7.6.10 Assumed Working Loads The assumed working maximum simultaneous loading of the platforms and racks shall be as follows: -

(a) Vertical loading. The dead weights of unit type capacitors, conductors, insulators and other apparatus carried on the racks.

(b) Deflection. The rigidity of the capacitor bank shall be such that the alignment and

satisfactory operation of the whole of the equipment shall not be affected by the loads to which the banks are subjected.

7.6.11 Construction Where members are stamped or marked for erection purposes the marking shall be legible, and where erection marks are stamped on galvanized material they shall be stamped before galvanizing and shall be clearly legible after galvanizing. All members, bolts and nuts and all fittings shall be galvanized except for racks constructed with aluminium.


7.6.12 Access and Interlocks The access doors in the capacitor bank enclosures shall be interlocked in a manner such that access cannot be obtained unless the bank is isolated from incoming supplies and the associated earth switch has been closed. All electrical interlocks shall function so as to interrupt the operating supply. An approved system of interlocks shall be provided which shall cover the emergency hand operation of apparatus that is normally power operated. Failure of supply connections to any electrical interlock shall not produce or permit faulty operation.

Where the specified clearances are not obtainable with an approved arrangement of the equipment, earthed screen enclosures or partitions shall be provided to prevent approach to any live part. The screens and partitions necessary for each equipment shall be included in this Contract.

In addition to the interlocking equipment, provision shall be made for accommodating padlocks, supplied under this Contract, on all access doors, earth switches etc.

7.6.13 Rack Insulation The insulation of the racks of capacitor units and the protection equipment shall comply with the relevant IEC recommendations for a three-phase system highest voltage of 12 kV. All clearances shall be to the approval of the Engineer. The insulation shall be of porcelain except where otherwise approved by the Engineer.

7.6.14 Terminals Suitable high voltage and neutral end terminals for connectors shall be provided on each phase of the capacitor bank.

7.6.15 Series Reactors 7.6.15.1 General Reactors shall be provided in series with each phase of the capacitor banks.

Reactors shall comply with, IEC 60289 and with the requirements of this specification.

The design and manufacture of the reactors shall be such that the noise level is a minimum and that the level of vibration does not adversely affect any clamping or produce excessive stress in any material.

The framework, clamping arrangements and general structure of the reactors shall be capable of withstanding any shocks to which they may be subjected during transport, installation and service. The entire assembly shall be mounted on post insulators of the appropriate insulation value.

The materials utilised in the construction of reactors should be selected to minimise any fire risk.

Each reactor shall be fitted with bolted terminal clamps. Means for lifting reactors shall be provided.

7.6.15.2 Windings Winding insulation and all non-metallic material used in winding stacks shall be so treated that no further shrinkage shall take place after assembly.


Coils shall be constructed to avoid abrasion of the insulation, (on transposed conductors), allowing for the expansion and contraction encountered during normal operation. The insulation on the conductors between turns shall be of paper.

The windings and connections shall be braced to withstand shocks that may occur during transport or due to switching or other transient conditions during service.

Where the yoke supporting channels are adapted for taking up shrinkage in the windings, the arrangement shall be such as to throw a minimum amount of stress on any core bolt insulation.

If the winding is built up of sections or disc coils, separated by spacers, the clamping arrangements shall be such that equal pressure is applied to all columns of spacers. All such spacers shall be securely located and shall be of suitable material.

Windings shall be designed with sufficient electrical clearance in air between adjacent layers of conductors. Where additional insulation is provided on conductors, this insulation shall be capable of withstanding temperatures of the class specified.

7.6.16 Earthing Arrangements. All metal parts other than those forming part of any electrical circuit shall be earthed in an approved manner. To facilitate this an earth terminal, of adequate size, shall be provided near to the reactor base to which the substation earth system can be connected.

7.6.17 Surge Arresters Surge arresters shall be provided to protect each phase of the capacitor banks.

The surge arresters shall comply with this specification as appropriate and shall be suitable for use with capacitor banks, in particular with respect to switching transient over-voltage and overcurrent and energy absorption capability.


8. CONTROL, INDICATION, METERING AND ANNUNCIATION

8.1 General Requirements

8.1.1 Extent of Supply This performance specification covers the design, supply of equipment, installation and commissioning of control, indication and annunciation equipment for 400/132 kV transformer substations. At newsubstations a Substation Control System (SCS) shall be provided for each 400/132kV substation. At existing substations the existing systems shall be augmented or replaced with a new SCS as specified in the Scope of Works or as otherwise indicated by MOE.

The Generic specification “Standard Specification for Telecommunication and SCADA Systems – December 2004” shall be referred to along with the performance requirements for the equipment contained in this specification. Quantities and configuration shall be determined by the specific site survey process, in agreement with the Employer’s Representative.

The SCS shall provide all the facilities for the safe and effective control of the substation plant and equipment as specified. Provision is to be made within the SCS to allow for extension and programming to include two additional 400kV “diameters” (two feeders and two transformers) and four 132kV bays. The extension hardware will not be required as part of this contract, but the SCS shall allow the future addition by connecting additional Bay Control Units into the existing LAN, adding to the existing Master Control Unit (if necessary) and modifying the existing site database.

The SCS shall be capable of serving as an RTU to the SCADA system master station located at the National Control Centre (NCC), acquiring and transmitting substation data to the NCC and executing commands sent from the NCC.

The communication equipment required at the substation for the connection between the SCS and the SCADA system at the NCC shall be as specified in the Communication Equipment section of this specification.

The confidence testing of the operation of the substation plant from the NCC SCADA system via the SCS and other control and monitoring from the Substation SCS and the NCC is included in the Works. The equipment shall be entirely compatible with the communications protocol as may be required by the NCC and with the communications media available. The Contractor shall undertake specific testing to demonstrate the compatibility of the SCS with the NCC.

8.1.2 Plant Control Strategy 8.1.2.1 Circuit Breaker Tripping Each 400 kV breaker phase shall be equipped with two trip coils. 132 kV breakers shall be equipped with a single trip coil. Each trip coil shall be individually protected. Fuses shall be provided on each appropriate relay panel. Breaker tripping shall be possible from:

(a) The SCS and NCC via the SCADA system.

(b) Protective relays energising the breaker “A” & “B” trip circuits via tripping logic.

(c) The Bay Control Unit, for maintenance. This is only to be operative when the circuit breaker is under test, with the Test/Normal switch in the Test position.


8.1.2.2 Circuit Breaker Closing The breaker shall be equipped with one closing coil per phase for 400 and 132 kV. The close coils and close circuits shall be protected by the same device which shall be separate from the trip circuits. Fuses shall be provided in the Relay Building on each appropriate relay panel. Breaker tripping shall be possible from:


(b) The Auto Reclose Scheme.

(c) The Bay Control Unit, for maintenance. This is only to be operative when the circuit breaker is under test, with the Test/Normal switch in the Test position.

8.1.2.3 Circuit Breaker Test/Normal Selection Each circuit breaker shall have a Test/Normal selector switch located in the Bay Control Unit. The switch is to perform the following functions:

(a) In the normal position, local control functions shall be disconnected, permitting operation of the breaker by remote (SCS) functions in both close and trip circuits of all poles.

(b) In the Test position all remote functions, including protection, are to be disconnected, permitting operation of the breaker from the Bay Control Unit in both trip and close circuits of all poles.

(c) A “Test Position” indication shall be provided at the SCS.

8.1.2.4 Trip Circuit Supervision Each trip circuit shall be continuously monitored, with the breaker in either the closed or the open position. The “A” & “B” trip circuit supervision relays for each 400 kV circuit breaker, shall initiate a common Trip Circuit Fail alarm at the SCS. The single supervision relay of each 132 kV circuit breaker shall have a similar facility.

8.1.2.5 Circuit Breaker Discrepancy Indication If the circuit breaker operates automatically, the SCS shall highlight the changed item of plant and operate the workstation audible sounder. A feature is to be provided to stop the highlighting and sounder, without affecting the annunciation of further changes.

8.1.2.6 Synchronising and Dead Line/Bar Check Interlocks 8.1.2.6.1 General A synchronising scheme shall be provided for all circuits to enable the safe interconnection of two sources of supply only when the phase difference, the rate of change of phase across the connecting circuit breaker and the respective voltages are within certain limits. When necessary, the scheme shall incorporate automatic voltage selection of the appropriate incoming and running voltages using circuit breaker and isolator auxiliary contacts or voltage selection relays. On the 132kV double busbar, the busbar side of the circuit breaker across which synchronising is to be effected is designated the running supply and the other side, usually the feeder side, is designated the incoming supply.

Large primary system earth fault currents may give rise to undesirable circulating earth fault currents in voltage transformer secondary circuits if these are earthed. Isolating interposing transformers shall


therefore be provided for synchronising purposes. Back energisation of voltage transformers on dead primary plant is not permitted and thus, where voltage selection is provided, the scheme shall be fail safe so that component failure cannot result in voltage transformer paralleling.

8.1.2.6.2 Check Synchronising Facilities (a) Equipment

The following equipment, plus any additional auxiliary equipment necessary to ensure correct functioning of the scheme, shall be provided: -

(i) Operation of the scheme shall be dependent upon the actuation of a synchronising selection, in such a way that only one circuit at a time can be selected for synchronising. This shall enable the appropriate incoming and running supplies to be applied to a check synchronising relay. Operation of the synchronising selection also prepares for closure of the circuit breaker via the control switch and a contact of the check synchronising relay.

(ii) A check synchronising relay. Check synchronising relays for manual synchronising provided, shall be utilised for auto-reclose requirements. A guard feature shall be provided to ensure that the check synchronising relay contact is closed before the closing switch is operated to close the circuit breaker. If the closing switch is operated before the check synchronising relay contact closes then circuit breaker closing should be prevented. A facility should also be included to detect welding or permanent closure of the synchronising relay contacts and prevent closing of the circuit breaker.

(iii) Interposing transformers for incoming and running voltage supplies. Phase to neutral voltages shall be used for synchronising purposes and the synchronising equipment shall operate satisfactorily over the range of 80 to 120 per cent of its rated value.

(iv) Voltage selection equipment, either auxiliary contacts from primary equipment or voltage selection relays, where specified.

8.1.2.6.3 DBC/DLC Interlocks Closure of a circuit breaker interconnecting two circuits may be required where the conditions for synchronising cannot be satisfied due to the absence of either running or incoming supply. In these cases, Dead Line Check (DLC), Dead Bar Check (DBC) and `Synchronising Override' interlocks shall be provided.

A DBC interlock permits reclosure only if the busbar is de-energized on all three phases. A DLC interlock permits reclosure if the associated line is de-energized on all three phases. In both cases the opposite supply to that which is de-energized must be energized. A busbar or line is considered to be de-energized when the voltage is less than 20 per cent of rated voltage and considered to be energized when at least 80 per cent of rated voltage.

An interlocked check synchronising override facility per circuit breaker shall be provided to enable the contact of the check synchronising relay in the closing circuit to be by-passed. Operation of this switch shall be interlocked with the voltage interlocks of DBC or DLC above, to prevent override of check synchronising unless one or both voltage supplies are absent.

8.1.2.6.4 Remote Supervisory Control The synchronising facilities available at the substation shall be repeated for the NCC, via the SCS.


8.1.2.6.5 Check Synchronising Relay Check synchronising relays shall measure the following parameters of incoming and running voltages:

(a) Phase angle difference. Adjustment of the phase angle between incoming and running voltages over which the relay contacts will close shall be provided over the range 20°to 45°. (Note - this results in a total angular segment over which circuit breaker closure is permitted of 40° minimum to 90° maximum).

(b) Rate of change of phase (slip). The maximum slip frequency at which closure is permitted is a function of circuit breaker closure time and adjustment shall be provided for this. The method of measurement of slip in which it is ensured that the true phase angle difference does not exceed the set phase angle difference for more than a given time, is preferred. A time range of 2 to 10 seconds is required. Alternative methods, e.g. direct instantaneous measurement of true slip frequency, are permitted and a range of settings of 0 to 0.125 Hz/sec is required. If the preferred measurement method is not used, a timer shall be provided so that at least 2 seconds must elapse between application of both ac supplies to the check synchronising relay and an output being given.

(c) Voltage difference. A voltage check feature shall be incorporated which shall inhibit operation of the check synchronising relay if either one or both of the synchronising voltages is less than a preset percentage of rated voltage. The voltage check feature shall be adjustable over the range 80 per cent to 90 per cent of the relay rated voltage.

8.1.2.7 Disconnect Switch Control The 400 and 132 kV disconnect switches are to be motor operated and controllable from:


(b) The Bay Control Unit, for maintenance. This is only to be operative when the circuit breaker is under test, with the Test/Normal switch in the Test position.

(c) Line disconnect switches shall not be operated automatically. Transformer disconnect switches may be opened automatically by the appropriate protection.

Circuit breaker auxiliary switches shall interlock the open and close circuits such that control is inoperative unless the related circuit breakers are open or other conditions allowed in the interlocking scheme are fulfilled.

8.1.2.8 Disconnect Switch Annunciation If the disconnect switch operates automatically, the SCS shall highlight the changed item of plant and operate the workstation audible sounder. A feature is to be provided to stop the highlighting and sounder, without affecting the annunciation of further changes.

A warning shall be provided to check for the three phases of single pole switches being out of step. One common alarm shall be provided separately for the disconnect switches of each feeder and transformer, where relevant

8.1.2.9 Earth Switches All earth switches shall have their status indications available at the SCS and NCC.


8.1.2.10 Transformer Tap Changer Control The 400/132 kV auto-transformers shall have on load tap changers controlled by an Automatic Voltage Control facility (AVC), as follows:

(a) Local Control from the Transformer Marshalling Kiosk, together with a Local/Remote selector switch, and tap raise and lower switches.

(b) Remote Control from the AVC and SCS. The following selections shall be provided to control the transformers:

(i) Auto/Manual – In Auto, the AVC voltage set point shall be adjustable from the SCS both at the substation and NCC

(ii) Group/Bank

(iii) Raise/Lower which shall only be available at the SCS in the substation when Auto/Manual is selected to Manual

The “R” phase phase-earth voltage signal from the transformer 132kV VT shall be provided for the Automatic Voltage Control scheme. A current signal for line drop compensation shall be provided from the transformer.

8.2 Station Metering

In addition to the facilities provided from the SCS workstation, the following station metering facilities shall be provided:

8.2.1 System Voltage Local Indication (400 kV) A large indicating voltmeter shall be provided for the 400 kV system voltage indication. The phase-earth voltage shall be obtained from each bus wound VT via an automatic changeover relay. The meter shall be calibrated to read phase to phase voltage and shall be mounted adjacent to the control workstation in a prominent location.

8.2.2 System Voltage Local Indication (132 kV) A large indicating voltmeter shall be provided for the 132 kV system voltage indication. The phase to earth voltages shall be from the 132 kV bus voltage transformers via an automatic changeover relay. The meter shall be calibrated to read phase to phase voltage and shall be mounted adjacent to the control workstation in a prominent location.

8.2.3 400 kV System Frequency (Local Indication) Frequency indication for the 400 kV system shall be provided. The frequency signal shall be obtained from the same source as the local 400kV indicating voltmeter voltage above. The frequency meter shall be an AC type indicating meter, mounted next to the 400 kV system voltmeter, above.

8.2.4 Voltage Recorder (Local Indication) Voltage recorders shall be provided for the 400 kV and 132 kV systems. The voltage signals shall be obtained from the bus VT's, via a manual changeover switch. Phase to earth voltages shall be recorded. The recorders shall be located on the station totalised metering panel.


8.2.5 Station Totalising Metering (Local) Station total metering shall be provided to record the kW, kVAr and kWh actually supplied through the power transformers from the 400 kV to the 132 kV level. Totalised MVAr supplied to the transformer tertiaries will also be recorded, where compensating plant is connected.

DC potentiometer recorders shall be utilised.

The inputs to the recorder shall be derived from the same sources as the indicating metering.

Total station kWh readings shall be recorded on a printometer type kWh meter.

8.2.6 Energy Meters The kWh meters shall be shipped to site as loose equipment, suitably packaged, The Contractor shall arrange to have all meters delivered to the MOE Meter Testing Station for calibration and certification.

After certification, the contractor shall collect the meters from the Testing Station and install them at the respective substations.

All costs incurred in calibration of the meters shall be paid by the contractor.

8.2.7 Station Clocks The contractor shall supply a station clock to match the station meters and supplied with an anti-reflection dial, suitable for dc operation from the station battery and be accurate to two seconds per month or better. The dial is to have "English" numerals, a sweep second hand and be mounted adjacent to the control workstation at a location agreed by the Engineer.

A second synchronous wall mounted clock, suitable for operation from 220V, single-phase 50 Hz supply, is to be mounted adjacent to the control workstation at a location agreed by the Engineer.


8.2.8 Metering Transducers Transducers in general shall be provided in accordance with BS EN 60688 and are to have the following characteristics:

Auxiliary power if necessary (A.C. is not accepted)

110 V D.C.

Nominal voltage input 120 Volts

Nominal current input 1 or 5 amps (to suit)

Full scale calibrating watts 200 watts

Output at full scale (d.c.) 0 - 5, -5 / 0 / +5 mA

Output load required 0-2 k ohms (max. 3 k ohm)

Accuracy / Linearity Class 1.68

Power Factor range Unity to lead or lag zero

Temperature range -100C to + 600C

Temperature effects on accuracy ±0.5% per 100C from 300C

Frequency range 45 - 55 Hz

A.C. component (Peak) 1 %

Response time to 99% of final value 200 ms

Voltage range 85 - 125 Volts

Input overload limit potential 150 Volts

Input overload limit current 2A cont. 20A for 1 second

Voltage burden (max. per element) 4 V.A.

Current burden (max. per element) 2 V.A.

Calibration adjustment 0 - 110 % ±10%

Zero adjustment ± 2% at least

Dielectric test-input to output to earth

For input insulation 2kV. 50Hz, 1 min

impulse 5kV, 1.2/50 ms

High frequency 2, 5kV, 1 MHz

For output insulation 2, 5kV, 1 MHz

8.3 SCS Specification

8.3.1 Introduction A distributed architecture Substation Control System (SCS) shall be provided to enable the substation plant to be monitored and controlled remotely from the substation control room. The SCS shall also


be capable of serving as a Remote Terminal Unit (RTU) to the Supervisory Control and Data Acquisition (SCADA) system master station located at the National Control Centre (NCC), acquiring and transmitting substation data to the NCC and executing commands sent from the NCC.

Where the Contractor can provide suitable numeric equipment that he can demonstrate has been implemented in a similar environment to Iraq, the SCS can be combined with the protection system, as an Integrated Protection and Control System. In this case, the following sections of the Specification can be treated as functional requirements that may be delivered in a different way. The Contractor shall provide full details of the previous implementation of the proposed equipment, together with its operational and maintenance history, to allow an informed decision to be made on its suitability for this project.

8.3.2 Design Principles The SCS shall be designed to achieve a high level of availability, reliability and safety in operation. The design shall be ‘fail safe’ such that failure of any component shall result in all functions affected by the failure defaulting to a defined ‘safe’ state. It shall be fault tolerant such that the failure of any single component within the overall system shall not affect the ability of the remaining healthy components in the system to continue to operate normally and for its functionality to remain available.

Essential functionality, i.e. that required for the continued overall operation of the SCS, shall be tolerant to single component failures. This may be achieved, for example, by using dual redundant hot/standby arrangements or by automatically re-distributing the functionality over the remaining operational components so that loss of any one component does not result in the loss of any functionality. The communications links between components within the overall SCS shall be regarded as essential functionality and the SCS must continue to operate with full functionality if any single communications link is out of service.

The system shall continuously monitor its own health and produce alarms for all detected failures. These alarms shall be presented in the alarms lists on the operator workstation and, as far as possible, by lighting ‘fault’ warning LEDs on the affected equipment itself, e.g. on individual circuit cards. There shall be no cases in which undetected failures could occur anywhere within the overall SCS, including within the communications links between the components of the system.

The equipment and the enclosures it is mounted in shall be designed to facilitate ease of maintenance, particularly fault-finding and replacement of components, e.g. replacement of rack mounted circuit cards. As far as possible, and consistent with safe operation, it shall be possible to ‘hot swap’ components such as I/O cards.

The equipment shall be robust, suitable for the operating environment in which it is installed and require minimal maintenance.

Each sub-system within the SCS shall be designed to meet an overall availability of at least 99.98 per cent based on a Mean Time To Repair (MTTR) of 8 hours.

The Contractor shall provide a Functional Design Specification that will allow the Employer to review and approve the facilities being provided in the SCS, and on which the testing documentation can be based.


8.3.3 System Architecture The SCS shall be based on a distributed architecture complying with the relevant IEC Standards. The proposed configuration of the equipment and the availability and security provided by the proposed architecture shall be described fully in the Tender.

The SCS shall typically comprise the following components:

• Master Control Unit (MCU) • Bay Control Units (BCU) • Operator Workstations • Local Area Network (LAN) • Communications Links to Off Site Control Systems

Bay Control Units shall normally be mounted adjacent to the Local Control Cubicle (LCC) or Marshalling Kiosk of each switchgear bay for 400 and 132kV and on the switchboards for 33 and 11kV. They shall be connected to the control and indication circuits of that cubicle to provide the interface between the substation plant and the SCS. The Bay Control Unit shall include facilities for the control, status indication (in mimic diagram format), analogue readings and alarms of the switchgear bay equipment.

The Master Control Unit typically provides overall supervision and management of the entire SCS. It may also provide communications ports supporting various data transfer protocols to enable the substation plant connected to the SCS to be monitored and controlled from remote points, e.g. from operator workstations in the substation control room and from remote SCADA systems at NCC. This communications interface function may also be provided by devices other than a Master Control Unit.

Since the substation is manned, and consistent with the single failure principle, duplicate Operator Workstations shall be provided comprising a graphical user interface for monitoring and control of the substation plant. Either workstation shall have full access to all of the SCS facilities. They shall be located in the substation control room and each shall be fed from an uninterruptible power supply source to ensure continued operation following loss of mains power supply.

A GPS receiver with antenna and cable, for time synchronisation of the SCS internal real-time clock, shall be provided in order to provide accurate time stamping of alarms and recorded events. The GPS shall be equipped to cater for the specified requirements and, in addition, be equipped with three spare ports.

8.3.4 System Functions 8.3.4.1 General The SCS shall provide, but not be limited to, the following functions that are generally intrinsic to SCS and SCADA systems. The Tenderer shall provide details of the full range of facilities provided by their system in their Tender submission.

(a) Display of the substation single line diagram and individual feeder mimic diagrams with status indication.

(b) Indicate in the mimic diagram plant status, voltages, currents, frequency, together with power factor, active and reactive power flows. High/Low limit excursions of measurands shall be alarmed and programmable.


(c) Acquire, display and printout substation events, individual feeder and substation equipment alarms with date and time stamp

(d) Acquire status, with plausibility checks, of the circuit breakers, disconnectors and earthing switches.

(e) Be capable of performing sequential control functions, such as auto-reclosing of breakers, taking feeders in/out of service, load shedding and load curtailment.

(f) Provide switch interlocking such that the operation of primary plant is prevented unless specified conditions are met. Interlocking functionality shall be available at bay and substation level. (The hard-wired interlocking scheme as specified shall also be provided and the SCS scheme shall provide an additional guard facility to ensure safe operation, based on the same logic).

(g) Perform supervised operations (Close/Open) on circuit breakers, busbar and line disconnectors.

(h) Perform check synchronisation functions. (The hard wired check synchronising relays and associated scheme as specified shall also be provided and the SCS scheme shall provide an additional guard facility to prevent closing out of synchronism).

(j) Perform reporting of acquired data in user-defined formats (numerical and graphical logging) including data from tariff metering. This data shall also be suitable for transmission in text format to another device for further data processing.

(k) Read relay settings, measured values and evaluate stored data.

(m) Storage of process data in managed files for future use.

(n) Resetting of electrical trip lockout relays.

(p) Record station external ambient temperature and humidity periodically.

(q) Receive and process commands from the NCC, process and transmit status, measurements and alarms to the NCC. It shall be possible to generate summary data to send to the NCC

(r) Provide access security to both operational and administrative functions, separately, by username and password.

(s) Be self-supervising, display its own system alarms and hardware status.

8.3.4.2 Commands All commands available at the substation in the SCS shall be capable of being operated at the National Control Centre, subject to the agreement of the SCS Overall Facility Schedule.

All command sequences shall be performed using a select then execute routine. The routine shall minimise the likelihood of accidentally performing the execute step as part of the selection step. Furthermore, there shall be a maximum time between the selection step and execution with the command sequence being cancelled if the execution is not performed within that time.


Prior to the execution of any command, the software shall perform a check to validate that the user has the authority to execute the command. Authority violations shall be indicated to the operator via a message on the VDU.

A ‘cancel’ key and/or poke point shall be provided to allow termination of any command sequence before it is executed.

8.3.4.3 Alarm and Indication Handling All alarms and indication changes annunciated in the SCS shall be treated in the same way i.e. as an Event. Each event shall be capable of being repeated to the National Control Centre, subject to the agreement of the SCS Overall Facility Schedule.

Two types of alarms shall be supported, these being fleeting and non-fleeting. The alarm type shall be configurable on a point-by-point basis.

Two types of indication shall be supported, these being single point and double point. Single point indications shall be used where no intermediate state needs to be identified. The indication type shall be configurable on a point-by-point basis.

All events shall be brought to the attention of the operator. The operator shall have the facility to accept events individually or as a page of events at a time. The name of the operator acknowledging an event shall be recorded and displayed in the event list.

When an event occurs, the workstation audible alarm shall sound and the appropriate entries shall be highlighted in the event list. Indications of changes of plant state shall flash the plant symbol on the SCS mimic diagram and alarms shall flash the “Alarm” symbol adjacent to the plant on the mimic.

Silencing events shall not inhibit the annunciation of further events or constitute an acknowledgement of the event.

Facilities shall be provided for the processing and display of events on the operator interface and shall include but not be limited to:

• Grouping on a bay basis.

• Grouping on the basis of type of event such as circuit breaker operation, protection operation, overloads, communication failures, etc.

The event list shall be displayed in chronological order.

Each event entry shall include the time and date of occurrence, location, device or other identifier, action, status, and value and normal status limits.

Navigation facilities shall be provided to enable the user to rapidly call up the display or area of a display on which the plant relating a to specific event selected in an event list appears.

8.3.4.4 Measured Value Lists Measured values comprising circuit loadings (Amps, MW, MVAr), voltages (kV), counter and integrated values (MWh, MVArh) and frequency (Hz) shall be available for display in the form of lists and tables in addition to being displayed on the single line diagrams. Where required, these shall be derived from transducers. Transducers shall be mounted to avoid long AC cable runs.


8.3.4.5 Supervisory Requirements (NCC) The SCS shall provide for control of the following from the National Control Centre:

Close/open of all circuit breakers. Close/open of all disconnectors. Resetting of all electrically reset trip relays. Control of transformers. Acceptance of all active alarms incoming from a substation.

The facilities actually made available at the NCC for each substation shall be as detailed in the SCS Overall Facility Schedule, and shall be agreed with the Employer’s Representative.

The “Local/Remote” switch, located at the Bay Control Unit shall allow control from the NCC only when in the “Remote” position. When the switch is selected to “Remote”, a further authority needs to be given from the SCS before control is transferred to the NCC.

The transfer of control from SCS to NCC shall be achieved through software, without affecting the safe operation and control of the substation.

On/off (open/close) and other position indication shall be provided to the NCC for the following items:

Circuit breaker. Disconnectors. AIS Line and GIS circuit earth switches and temporary earths. Local or remote control in service. All necessary indications to allow proper operation of the transformer Automatic Voltage Control facility.

These indications shall be transmitted to the SCS/NCC irrespective of the position of the “Local/Remote” selector switch.

Measurement signals shall generally be provided for the NCC as follows:

Feeder and transformer MW, MVAr, kV and A Busbar (phase to phase) voltage Busbar frequency. Feeder and transformer energy (MVAh, MWh and MVArh)

These signals shall be transmitted to the SCS/NCC irrespective of the position of the “Local/Remote” selector switch.

8.3.4.6 Trends The SCS system shall be capable of displaying any analogue value in graphical form to show the trend of the value over a selected time period. The trend display shall have adjustable x and y axis, indicate up to 10 values and operate either using real-time or historical data from the database.

8.3.4.7 Data Logging The SCS system shall incorporate long-term data logging facilities for all analogue, digital and other internally generated signals.


Any analogue or digital value defined on the SCS system shall be available for storage and subsequent re-call.

All signals shall be scanned periodically and updated values or digital status changes stored. Date and time tags shall be allocated to each signal.

Data shall be stored for up to three months on a suitable storage medium for subsequent re-call at a later date. An alarm shall be given to the operator when the storage of data approaches the capacity of the storage medium. All data shall be capable of being archived and retained for future reference.

The operator shall have the facility to recall data held in the data logger memory or from archives over a specified period of time. The information may also be restricted to specific SCS data points. The requested information may be presented on the operator’s workstations either in tabular form or as selected variables on a trend display. Information on print-outs may be either in tabular form or in a preformatted report form and may be produced automatically at specific times or on request.

It shall be possible to compare on the same display, trends, real-time data and historical data from the archives. This shall not affect the operation of the on-line data logging.

One printer shall be designated primarily as the operational “on demand” log. In the event of a printer failure facilities shall be provided, both automatic and manual to enable changeover to another similar printer which shall be provided by the Contractor.

The Operational log shall record and print on demand when required, the following information:

(a) Status changes.

(b) Onset and clearance of all alarms with facilities for distinguishing between the types of alarms, e.g. ‘urgent’, ‘non-urgent’, ‘group’, ‘individual’, etc.

(c) Control operations (both successful and unsuccessful).

(d) Operator actions such as alarm limit changes, tagging, hand-dressing, removal of parameters from scan, inclusion of new parameter into scan, alarm acknowledgement, log on, log off, etc.

This information shall be printed on the designated printer with each item consisting of the data and time of occurrence, together with a description of the operation, event or alarm, and sufficient information to enable full identification of the feeder/item of plant affected.

The operation log shall also be available as a VDU list of sufficient size to allow the display of information covering 5000 alarm/events.

In addition to the logging printers, a colour printer shall be provided to enable screen dumps and graphical displays etc to be printed.

8.3.4.8 Hand Dressing The single line diagram will contain variable elements, some of which are updated automatically by the application and some that are hand-dressed by the operators e.g. plant where remote indications are not available. Hand-dressed data shall be suitably indicated by a symbol or tag. The hand-dressed changes shall be inserted automatically in the database.


It shall be possible from the operator workstation to remove from scan any measurement, alarm or indication that comes within his area of responsibility. This shall be suitably indicated on the display and additionally a symbol or tag shall be used to indicate the removal from scan. It shall then be possible, from the workstation, to insert a new (hand-dressed) value for the element, with the hand-dressing also suitably indicated by a symbol or tag. The hand-dressed changes shall be inserted automatically in the database.

On manual restoration of the elements back into service, the readings shall again be recorded in the database, returned to their normal presentation and hence regularly updated on the displays.

Hand-dressing operations, as described above, shall be suitably tagged for logging purposes.

The system must recognise an attempt by the operator to make an invalid hand-dressing operation and this should be blocked, with a suitable error message being displayed on the screen.

8.3.4.9 Operator Interface The design of the operator interface shall be based on standard software packages and provide a Windows, Icons, Menus and Pointer (WIMP) style of presentation and use interaction with the system. All user actions shall be initiated using the pointer/keyboard and standard ‘windows’ methods.

The system shall provide facilities for the display of the entire substation single line diagram as a single display along with other displays for specific purposes, as required.

Pan, zoom, decluttering and windowing facilities shall be provided to allow the operator to navigate through the displays and adjust the level of displayed detail to that appropriate to the task they are performing.

To ensure the interpretation of information from displays is intuitive and not confusing to the operators all displays and lists shall be constructed following a consistent overall design philosophy. For example, all lists shall display in the same manner with new entries always being added to the top of the list or to the bottom of the list.

The software shall also guide the user, step-by-step, through each sequence by identifying, preferably via a visual technique on the workstation, the remaining valid entries.

Any invalid entry shall be detected by the software, ignored and an explanatory message displayed on the VDU. It shall then be possible to continue the sequence with a valid entry.

The system shall support context sensitive on-line help facilities. The help screens shall be easily customised to suit the owner’s needs.

8.3.4.10 System Operating Points There are three places from where any item of substation plant can be operated, as follows, although the substation will normally be manned, but also monitored/controlled from the National Control Centre via the SCS.

• locally at the plant (using hardwired controls and other facilities provided by the Bay Control Unit)

• remotely from the substation control room


• supervisory from the National Control Centre

The design of the SCS and substation plant shall be such that control of any item of plant is only possible from one control point at any particular time and the transfer of control between these points shall be achieved without affecting the safe operation, monitoring or control of the substation.

8.3.4.11 Modes of Operation As a minimum, the system software shall be capable of supporting five different levels of user, e.g. operator, engineer and system manager, etc. For example:

(a) Operators would be responsible to control and monitor the substation using the facilities of the SCS.

(b) Engineers would be responsible for any fundamental changes made to the SCS software or configuration.

(c) System managers would be responsible for the system security, back-up and database maintenance.

The availability of functions to each user shall be configurable, allowing the user’s area of responsibility to be defined.

The maximum number of different user levels supported and the degree of configuration available of each level shall be stated in the Tender.

8.3.5 System Capacity The design shall meet the following general requirements with regard to capacity and expandability.

The SCS shall be designed, delivered and commissioned with sufficient capacity for performing the requirements of this specification.

The SCS shall be equipped with control, indication and measurement functions required by the Scope of Work.

The maximum system capacity and system loading shall not be less than 200% of the specified system capacity, including the specified future expansion.

In addition to the facilities detailed in the Facility List section, approximately 10% spare input/output capacity shall be provided within the contract (this figure shall be confirmed at the specific site survey in agreement with the Employer’s Representative). These spare facilities shall be fully fitted and pre-wired to the Bay Control Units.

The design shall provide for future expansion, modification and testing with the minimum of disruption to existing facilities.

A minimum of 25% of the future expansion capacity shall be demonstrated during the FAT.


8.3.6 System Performance The SCS scanning and polling frequencies shall ensure the following overall performance. If better performance is necessary to ensure satisfactory operation of certain SCS functions, the Tenderer shall state this.

The SCS shall process, enter into the database and update all relevant displays currently on view within two seconds of a change occurring at a Bay Control Unit input. This time shall include for any calculation or other processing required to enter derived or compiled information into the files, logs, reports or displays.

The SCS shall also process all information required at the NCC (e.g. status, measurements and alarms) and have them available for transmitting to the NCC within two seconds of a change occurring at a Bay Control Unit input.

The elapsed time between selecting a display and the full display appearing on any screen shall be less than one second for 50% of requests, less than two seconds for 90% of requests and less than three seconds for 100% of requests.

The System shall give priority to commands such that commands issued from an operator’s workstation shall have confirmation of action (from the Bay Control Unit) displayed within four seconds of issue from the workstation (not including the time taken for plant to operate).

The SCS shall be capable of handling all alarms and status changes occurring during avalanche conditions without loss of any data. Avalanche conditions are defined as follows:

• A fault on a HV switchgear busbar (resulting in the generation of multiple alarms)

• Occurrence of 100 + 0.1N + √N changes is 5 seconds where N is the total number of data inputs (double signals count as two data inputs).

8.3.7 Software Requirements 8.3.7.1 General The software shall be of modular construction, developed using structured design techniques and written in a commonly used programming language. Where possible, standard library software shall be utilised. The contractor shall identify all standard proprietary software and any software specially developed for this project.

The application software shall ensure the secure execution of SCS functions.

The operator workstation software shall run under a well proven, widely used, industry standard and internationally supported operating system.

8.3.7.2 Real-time database A real-time database shall be maintained within the SCS system. A general check shall be initiated at intervals to retrieve all data points from the remote I/O to ensure validity of database entries. This interval shall be configurable between 30 minutes and 36 hours.

The real-time database shall be open and the data dictionary published.


The real-time database shall support the import/export of data via standard interfaces such as SQL, ODBC, etc.

8.3.7.3 Database management Engineering facilities shall be provided for database and graphic display creation and modification for the operator workstations.

Facilities shall be provided so that the operator workstations can be used as engineering consoles to modify and configure the overall SCS system. It shall be possible to prepare modifications in advance and implement them with minimal disruption to the running system.

8.3.7.4 Data processing In the event of detection of the failure of I/O components, indications and alarms from the previous successful scan of the failed I/O shall continue to be displayed on the operator workstation. However, facilities shall be incorporated to indicate to the operator that the relevant data is not presently being updated.

The system shall have the ability to differentiate between status changes resulting from operator actions and apparently spontaneously occurring actions, the latter drawing attention to the operator via an audible alarm and highlighting the status change on the workstation.

The processing of analogue signals shall include:

(a) Scaling for display in engineering units.

(b) Alarm supervision between adjustable limits, e.g. Low Alarm, Low Warning, High Warning & High Alarm.

(c) Devising values such as summated power flows.

8.3.8 Hardware Requirements 8.3.8.1 General The design of all SCS equipment shall be such as to ensure satisfactory operation in an electrically hostile environment typical of high voltage electrical installations.

Equipment located outdoors shall be suitable for operation in the local environmental conditions and shall be housed in weatherproof kiosk/cubicle protected in accordance with Class IP 55 of IEC 60144 and be dust, insect and rodent proof.

The equipment may be either of single board design or of rack mounted modular construction. All computer equipment shall be supplied with a real-time multi-tasking operating system which conforms to a recognised industry standard and not unique to one manufacturer. Interconnecting cables shall be made via substantial, secure plugs and sockets, which shall be mounted in accessible positions and clearly labelled.

A technical description of each item of equipment, together with evidence to show that the stated guaranteed reliability figures are supported by actual service conditions, shall be supplied with the Tender.


8.3.8.2 Master Control Units The Master Control Unit shall have an interface to a portable maintenance terminal through which it can be configured and operated locally. One portable maintenance terminal shall be provided with the SCS.

The power supply to the Master Control Unit shall either be derived from the plant 48V DC control supply battery or from the UPS specified below depending on its requirements.

8.3.8.3 Remote Communications Interface As a minimum, the SCS device providing the remote communications interface shall support the IEC 60870-5-101 and DNP3 protocols along with any other protocols specifically requested in the Scope of Work. The Tenderer shall provide details in their Tender of the SCADA communication protocols supported by their system.

The Contractor shall be responsible for the design, supply and installation, including the modification of existing plant that may be required for the correct interfacing of SCS equipment with the existing National Control Centre, including all protocols and communications as required. It is essential that the Contractor carries out tests to demonstrate that the full SCADA facilities are available over the communications interface and that the implementation of the standard protocols at the existing NCC Master End and the new SCS are the same.

The rights to access the SCS indications and controls from remote systems shall be programmable within the SCS for each communications link connected to the SCS.

The communication interface shall support dual redundant communication links to remote control sites (NCC) and have the ability to automatically change to a healthy link if one link should fail.

The power supply for this equipment shall provide a 8 hour standby capacity such that it is able to continue to communicate and exchange control and data with the NCC SCADA Master Station in the case of mains failure of the source of supply e.g. mains or charger failure.

8.3.8.4 Bay Control Units Each Bay Control Unit shall be individually programmable for integrated functions such as control, interlocking logic, metering without transducers and status/event/alarm acquisition.

Each Bay Control Unit shall have an interface to a portable maintenance terminal through which each Bay Control Unit can be configured and operated locally, This is in addition to integral facilities to allow operation from the Bay Control Unit itself.

Generally, one Bay Control Unit shall be provided per switchgear equipment bay. For Air Insulated Substation bays, the Bay Control Unit shall preferably be located in the circuit Marshalling Kiosk, subject to its environmental performance and the ability to provide a suitable sheltered working position, otherwise the Bay Control Unit shall be located in the Relay Room adjacent to the circuit relay panel. Additional Bay Control Units shall be used for substation general alarms and substation services, as necessary, and generally so that signals are connected to a Master Control Unit/ Bay Control Unit as close as is practically possible to where those signals are derived.

Power supply to the Bay Control Unit shall be derived from the plant DC control supply and shall provide for an 8 hour standby period in the event of failure of the source supply.


8.3.8.5 Digital Inputs Plant alarms and indications shall be derived from voltage free contacts with the wetting current supplied from the respective SCS input card. Equipment with two normal states e.g. circuit breakers and isolators, shall be represented by two source contacts to provide a positive indication of state, including illegitimate states.

Alarm signals may be derived from contacts that either close momentarily (fleeting) or remain closed for the duration of the alarm condition (sustained).

The change of state of a digital input shall be time tagged to a resolution of 1 ms for Sequence of Events (SOE) reporting.

8.3.8.6 Analogue Inputs Analogue inputs shall be capable of processing standard voltage and milliamp current inputs continuously. The inputs shall be digitised to a resolution of at least 11 bits plus sign bit.

8.3.8.7 Command Outputs Command outputs shall be designed to provide “select and execute” operation. The select output shall energise the interposing control relays allowing the open or close command to actuate the appropriate control relay.

The period of the command pulse shall be configurable between 2 seconds and 30 minutes to allow for circuits with synchronising facilities. The command pulse timer shall reset immediately the command is executed or the synchronising is cancelled.

8.3.8.8 Pulse Counting Inputs Pulse counting inputs shall acquire and count impulses produced by “volt free” contacts, which can be either normally open or normally closed. Pulse counting inputs shall be provided as either a separate input module or using digital inputs.

The accumulative values must be treated as instant analogue values for the purposes of the equipment at the NCC reading the data.

8.3.8.9 CT and VT Inputs Transducer-less inputs with direct connection to CTs or VTs for the measurement of frequency, voltage, current, phase angle, watts, VArs and VA for both single and three phase power circuits shall be provided.

8.3.8.10 Operator Workstations The operator workstations shall be rugged, industrial type units and shall be equipped with a high resolution colour visual display unit (VDU), alphanumeric keyboard and pointing device (mouse/trackball). It shall be possible to increase the number of VDUs per workstation to two or three, although one will be provided under this contract.

The visual display unit (VDU) shall be fitted with high quality Liquid Crystal Display (LCD) to ensure good resolution and clarity of information in all areas of the screen.


The VDU shall have power on/off switch and indicator along with brightness, contrast and any other necessary controls, all of which shall be readily accessible to the operator. It shall be possible to align the colours accurately once installed in its final position.

The pointing device shall enable quick and accurate movement of the cursor on the VDU to designate the selected points on the displays. On workstations with more than one VDU, it shall be possible to freely move the pointer over the contiguous screen area.

The workstations shall be provided with adequate memory for the required tasks with 25 per cent spare capacity.

A highly reliable mass storage device shall be provided in each workstation sized to satisfy the requirements of the operating system, applications software and anticipated stored data plus 40 per cent spare capacity.

Each workstation shall be supplied with a CDROM drive/writer/re-writer for loading software and backing-up/restoring software and data.

The operator workstation shall be equipped with a low level audible alarm.

The operator workstations shall be fully configured and set into operation by the Contractor. This shall include populating the I/O databases and preparing all graphical screen displays necessary to provide a user interface suitable for full operation and monitoring of the substation plant. The design and layout of the screen displays shall be approved by the Engineer.

The workstation shall be provided with an operator’s control desk as follows:

The control desk shall be 75 cm high, double pedestal type of reinforced and stiffened steel construction with flush panelling throughout the knee-hole, sides and front. Each pedestal shall contain one utility drawer with pencil tray and dividers, and one file drawer with two adjustable dividers. Utility drawers shall be mounted on silent-action nylon bearings. File drawers shall be mounted on telescoping tracks with ball bearing rollers. Drawer pulls shall be bright chromium plated. All steel panelling and drawers shall receive two coats of baked enamel finish throughout the exposed interior and exterior surfaces.

Desk tops shall be finished in plastic laminate, firmly bonded to the substrate. The tops shall have a 10 cm high plastic laminate edge banding finished flush with the side panels and drawers. A 20 cm high plastic laminate finished base shall extend all around the desk perimeter and pedestals also flush with side panels and drawers.

Enamel and plastic laminate colours shall be as selected by the Engineer.

8.3.8.11 Printers All printers shall be high performance and of robust construction, suitable for continuous duty.

The maximum noise level for the operation of any printer is 50 dB (A). The printers shall contain off-line self-test facilities that allow adjustment and maintenance without interfering with the remainder of the computer system.

Printer consumables shall be readily available locally in Iraq.


All printers shall be A4 size and print on single sheets. The printers shall hold at least 500 sheets of paper and a paper low alarm shall be provided at the SCS workstation. The on demand logging printers shall be black and white laser type. The colour printer shall be ink jet type.

8.3.8.12 Local Area Network The substation control system shall utilise a high speed optical fibre LAN that conforms to recognised industry standards for the interconnection of SCS equipment.

The LAN shall be complete with all necessary repeaters, bridges, routers, etc., required for the operation of the SCS equipment.

The Tenderer shall state in their tender submission the protocol used by their proposed LAN.

8.3.9 Environmental Performance 8.3.9.1 Atmospheric Environment 8.3.9.1.1 Temperature The standard nominal range of ambient temperature shall be -10°C to +55°C.

The protection system shall operate satisfactorily when tested to the following requirements:

IEC 60068-2-1 with severity class -10°C, 96 hours

IEC 60068-2-2 with severity class 55°C, 96 hours.

The protection system shall be able to withstand the temperature requirements for storage and transportation and shall be tested to the following requirements: -



8.3.9.1.2 Relative humidity: The protection system shall operate correctly with a relative humidity of 93 per cent and shall be tested to IEC Publication 6068-2-78 with severity class 56 days.

8.3.9.1.3 Enclosure: The protection relay shall meet the requirements of the tests detailed in IEC 60529 with classification IP50 (dust protected). If the individual enclosure of the relay is to a class less than IP50 then the Tenderer shall provide a cubicle to classification IP50 to accommodate the relay.

8.3.9.2 Mechanical Environment 8.3.9.2.1 Vibration: The protection system shall meet the requirements of the tests detailed in IEC 60255-21-1 with severity class 1.

8.3.9.2.2 Shock and Bump: The protection system shall meet the requirements of the tests detailed in IEC 60255-21-2 with severity class 1.


8.3.9.2.3 Seismic: The protection system shall meet the requirements of the tests detailed in IEC 60255-21-3 with severity class 1.

8.3.9.3 Electrical Environment 8.3.9.3.1 DC auxiliary energising quantity: The protection systems shall be capable of being energised from a dc auxiliary energising voltage of 110 V (nominal).

The protection system or its associated power supply for use in a 110 V (nominal) dc supply system shall operate correctly over a voltage range of 88 V to 132 V and shall withstand a maximum voltage of 143 V.

Numeric protection systems shall meet the requirements of IEC 60255-11 with interruptions to the dc auxiliary energising quantity of 10 mS.

8.3.9.3.2 Frequency: The standard rated frequency shall be 50 Hz.

The nominal range of frequency shall be -5 per cent to +5 per cent.

8.3.9.4 Insulation 8.3.9.4.1 Rated insulation voltage: The rated insulation voltage of circuits connected to current transformers of high impedance relays shall be 1000 V. All other circuits shall have an insulation voltage of 250 V.

All open contacts of the protection system shall withstand a voltage of 1000 V.

8.3.9.4.2 Dielectric tests: The protection system shall comply with the dielectric test requirements of IEC 60255-5. The test voltage shall be selected according to the rated insulation voltage of the circuits being tested form Series C of Table 1 of IEC 60255-5.

8.3.9.4.3 Impulse voltage: The protection system shall comply with the impulse test requirements of IEC 60255-5 with test voltage of 5 kV.

8.3.9.5 Electromagnetic Compatibility The requirements of this section of the specification are specifically applicable to numeric protection systems. The requirements may also be applied to some electro-mechanical relays that are very sensitive or of high speed, at the discretion of the Engineer.


8.3.9.5.1 1 MHz burst disturbance: The protection system shall comply with the requirements of IEC 60255-22-1 with severity Class III.

8.3.9.5.2 Electrostatic discharge: The protection system shall comply with the requirements of IEC Publication 60255-22-2 with severity Class III.

8.3.9.5.3 Radiated electromagnetic field disturbance: The protection system shall comply with the requirements of IEC 60255-22-3 with severity Class III. The test shall be carried out by using Test Method A and by sweeping through the entire frequency range 27 MHz to 500 MHz.

8.3.9.5.4 Fast transient disturbance: The protection system shall comply with the requirements of IEC 60255-22-4 with severity level IV.

8.3.9.5.5 Electromagnetic Emissions The protection system shall comply with IEC 60255-22-25.

8.3.10 Uninterruptible Power Supply An uninterruptible power supply (UPS) is required to power the SCS components in the substation control room such as the Master Control Unit and the operator workstations.

This shall either be from an Inverter fed from the station 50 volt battery system, and this is preferred, or from a stand alone UPS system. For the Inverter solution, the Tenderer shall state the increased battery capacity required to support the control room equipment such that an 8-hour standby capacity for the SCS is maintained.

The Inverter solution shall comprise an inverter, static by-pass switch and manual maintenance by-pass.

The UPS system shall comprise a rectifier/charger with maintenance-free sealed batteries, inverter, static by-pass switch and manual maintenance by-pass.

8.3.10.1 Modes of Operation The following requirements apply to both Inverter and UPS solutions except that the battery/charger comments will not apply to the Inverter solution.

• Normal

The inverter shall continuously supply the load. The UPS rectifier/battery charger or station 48v battery shall supply dc power to the inverter and the UPS batteries will simultaneously be maintained in a fully charged condition. The static by-pass switch shall be synchronised to the mains by-pass supply frequency so that an automatic change-over does not cause an interruption to the load.


• Overload

In the event of an overload, the static by-pass switch shall automatically switch the load to the raw mains by-pass supply. The static by-pass switch shall automatically switch the load back onto the inverter when the load current returns to a normal level, without interruption.

8.3.10.2 Mains Supply Failure In the event of mains supply failure to the UPS; the inverter shall draw its power from the UPS battery. For the inverter solution, the load will continue to be fed from the station 48v battery via the Inverter. There shall be no interruption to the load when mains power is restored. When power is restored, the UPS rectifier/charger shall recharge the UPS battery without any interruption to the load. The ampere-hour capacity of the UPS battery shall be adequate to support the equipment for a period of at least 8 hours in the event of a loss of supply.

8.3.10.3 Static By-Pass Switch In the event of a failure of the rectifier/charger, battery or inverter, the load shall be automatically switched to the raw mains by-pass supply using the static by-pass switch. This transfer shall not cause an interruption to the load. It shall also be possible to initiate a manual changeover to the by-pass if required, e.g. for maintenance.

8.3.10.4 Manual Maintenance By-Pass A manual by-pass facility shall be available to switch the load to the raw mains supply to facilitate maintenance and repair of the UPS system and batteries, or Inverter. Transfer to and from the manual by-pass shall not cause an interruption to the load.

8.3.10.5 Control and Instrumentation The UPS and Inverter shall have a local control panel to show the status of the key parameters and mode of operation of the system. The principle indications and alarms shall be:

(a) Mains input V and I

(b) inverter output V and I

(c) battery V

(d) rectifier alarms (UPS only)

(e) inverter alarms

(f) load alarms

Remote indication of the ‘general alarm’ status of the UPS/Inverter system shall be provided for annunciation in the substation control room and at the SCS.


8.3.11 Maintenance and Spares The intended maintenance strategy for the SCS is that the Employer will be able to:

(a) perform ‘first-line-maintenance’ of all subsystems, i.e. be able to locate faulty hardware components and replace them with spare parts with the faulty parts being returned to the original equipment supplier for repair or replacement

(b) analyse and define software faults and protocol interface problems with NCC

(c) re-configure and extend the SCS facilities with minimal assistance being necessary from the original equipment supplier, including updating databases, modifying and building new display screens and adding new equipment and devices to the SCS

Spare parts for the SCS shall be provided to support the maintenance strategy described above, particularly bearing in mind the ‘turn around time’ to repair/replace faulty components.

The Tenderer shall include an itemised and individually priced list of recommended spare parts in their offer. It is anticipated that this list would include at least one item of each hardware component used within the SCS for use in first-line-maintenance (or 10% of the components for components that occur in larger numbers within the system, e.g. I/O cards). Any special tools, including software and hardware (e.g. lap-top computers) maintenance tools shall also be itemised. The Employer shall be at liberty to purchase any numbers of those items at the tendered price until 3 months after contract placement.

8.3.12 Documentation Documentation for the SCS shall be provided in line with the general provisions specified in the Tender documentation. The documentation shall include the complete functional specification of all hardware and software and complete maintenance and user manuals for both hardware and software. In particular, the maintenance documentation shall include detailed fault finding flow charts to assist with first line maintenance of all subsystems and the user manuals shall provide detailed instructions on system configuration such that the Employer may re-configure and extend the SCS facilities without assistance being necessary from the original equipment supplier.

Complete and original copies of all software programmes, operating system, drivers, data bases, tools, and emulators etc shall be provided on CD.

8.3.13 Training Training of the Employer’s operations and maintenance personnel shall be provided to the levels required to enable them to safely and competently operate the SCS and to maintain the system to the levels described.

It is anticipated that 4 weeks of formal structured training courses will be provided locally on site (courses to cover both hardware and software). The operational “hands on” aspects of this may take place during the 500 hour Trial Period. In addition ‘on the job’ training shall be provided, whereby two of the Employer’s software engineers work alongside those of the equipment supplier at the equipment supplier’s factory for a period of 4 weeks during the configuration stages and continuing on site during the commissioning stages.


Details of the training shall be provided to identify the type or training, the training locations and the numbers of personnel to be trained, which in any case shall not be less than four for the on site training. All expenses associated with the training including international and local travel, hotel accommodation and meals and sundry expenses for all the trainees shall be included.

8.3.14 Warranty and Support. The Warranty Period shall be as stated in the contract conditions and ongoing support for the SCS shall be available for a minimum of five years after Taking over of the Works.

The Tenderer shall provide details of maintenance agreements, including prices, for the various levels of support that may be purchased after the completion of the Warranty Period.

8.4 Facilities to be provided to the SCS for Substation and NCC

8.4.1 General The following facilities are the minimum that shall be provided to the SCS. Where specific plant and equipment has facilities that are additional to these, they shall be included at no additional cost to the Employer. The facilities that shall be provided by the SCS at the substation, and those that are transmitted to/from the NCC, shall be agreed with the Employer using the Overall Facility Schedule and based on the NCC Standard Facility List, during the engineering phase of the Contract. The agreed Overall Facility Schedule shall then be used to configure the SCS and used as a basis for SCS testing.

8.4.2 Facility List

CONTROLS/COMMANDS 400 kV Circuit Breaker Trip Close 11 kV tertiary reactor capacitor bank circuit breaker Trip Close 400 kV Disconnect Switch Open Close 400 kV Auto Transformer On Load Tap Changer Raise tap Lower tap 132 kV Circuit Breaker Trip Close On test 132 kV disconnect switch Open Close 400 and 132 kV Feeder Auto Reclose In Service Out of Service INDICATIONS/STATUS 400 kV Circuit Breaker Open


Closed On test 11 kV tertiary reactor capacitor bank circuit breaker Open

Closed 400 kV Disconnect Switch Open Closed 400kV Earth Switch Open Closed 400 kV Auto Transformer On Load Tap Changer Tap position Auto (man) Master/Follower 132 kV Circuit Breaker Open Closed 132 kV disconnect switch Open Closed 132kV Earth Switch Open Closed 400 and 132 kV Feeder Auto Reclose In Service Out of Service ALARMS 400 kV Circuit Breaker Breaker trip Breaker fail protection operated CT stack protection operated Auto reclose operated Auto reclose successful SF6 pressure falling SF6 pressure low lock out Low operating oil pressure Gas heater fail (SF6) Trip circuit fail 400 kV Disconnect Switch Transformer disconnect switch opening automatically Transformer disconnect switch out of step Feeder disconnect switch opening automatically Feeder disconnect switch out of step 400 kV Feeder Distance trip - Group A Distance trip - Group B Overcurrent trip Back up protection Earth fault trip PLC channel fail Directional earth fault trip


Direct transfer trip received Permissive transfer trip received Block signal received SF6 pressure falling SF6 pressure low lock out Protection fail - Group A Protection fail - Group B 110 V DC fail PT voltage fail 400 kV Feeder Reactor Line reactor trip - Group A Line reactor trip - Group B Overcurrent trip Earth fault trip Differential trip Buchholz stage 1 – gas alarm Buchholz stage 2 – trip Oil temp stage 1 – alarm Oil temp stage 2 – trip Winding temp stage 1 - alarm Winding temp stage 2 - trip Low oil Neutral reactor O/C Neutral reactor Buchholz stage 1 – gas Neutral reactor Buchholz stage 2 – trip Neutral reactor temp stage 1 - alarm Neutral reactor temp stage 2 - trip Neutral reactor low oil SF6 pressure falling SF6 pressure low lock out 400/132 kV Auto Transformer Transformer Distance trip Overcurrent trip Earth fault trip 400 kV differential protection operated 132 kV differential protection operated SF6 pressure falling SF6 pressure low lock out Transformer Buchholz stage 1 – gas alarm Transformer Buchholz stage 2 - trip Tapchanger Buchholz stage 1 – gas alarm Tap changer Buchholz stage 2 - trip Transformer low oil stage 1 Transformer low oil stage 2 Tap changer low oil stage 1 Tap changer low oil stage 2


Tap changer gas pressure relay Transformer oil temp stage 1 400/132 – alarm Transformer oil temp stage 2 400/132 – trip Winding temp stage 1 400/132 - alarm Winding temp stage 2 400/132 - trip Transformer cooling fail On Load Tap Changer HI/LO limit On Load Tap Changer Out of step On load Tap Changer Protection trip Transformer protection fail - Group A Transformer protection fail - Group B Tap change incomplete Transformer 11kV winding/busbar protection trip Transformer 11kV winding/busbar differential trip Transformer 11kV winding/busbar overcurrent trip Transformer 11kV winding/busbar earth fault trip Tertiary reactor protection trip Tertiary reactor differential trip Tertiary reactor overcurrent trip Tertiary reactor Buchholz stage 1 - alarm Tertiary reactor Buchholz stage 2 - trip Tertiary reactor low oil Tertiary reactor oil temp stage 1 – alarm Tertiary reactor oil temp stage 2 – trip Tertiary capacitor bank protection trip Tertiary capacitor bank overcurrent trip Tertiary capacitor bank unbalance trip Earthing transformer protection trip Earthing transformer low oil Earthing transformer oil temp stage 1 - alarm Earthing transformer oil temp stage 2 - trip Services transformer protection trip Services transformer low oil Services transformer Buchholz stage 1 - alarm Services transformer Buchholz stage 2 - trip Services transformer oil temp stage 1 –alarm Services transformer oil temp stage 2 – trip 400 kV Busbar Differential trip Bus protection operated Bus protection fail SF6 pressure falling SF6 pressure low lock out Protection fail (CT secondary circuit fail)


110 V DC fail Communications PLC equipment fail Back up combs equipment fail PABX fail Fuse failure (composite) Communications equipment alarm (composite) 132 kV Feeder Line protection trip Back up protection trip Distance trip Overcurrent trip Earth fault trip Breaker fail protection operated Transformer trip received (if required) Auto reclose operated Auto reclose successful or definite tripping Permissive transfer trip received SF6 pressure falling SF6 pressure low lock out Gas heater fail (SF6) Trip circuit fail PT voltage fail PLC channel fail Pilot circuit fail 110V DC fail 132 kV Bus coupler Overcurrent trip Earth fault trip SF6 pressure falling SF6 pressure low lock out Breaker fail protection operated 132 kV Bus section Overcurrent trip Earth fault trip Breaker fail protection operated SF6 pressure falling SF6 pressure low lock out 132 kV Bus bar Busbar protection operated Differential trip Protection fail (CT secondary circuit fail) 110V DC fail SF6 pressure falling SF6 pressure low lock out 132 kV Transformer Transformer Distance trip Overcurrent trip Earth fault trip


Differential trip Breaker fail protection operated Winding temp stage 1 - alarm Winding temp stage 2 - trip Earthing transformer trip E/F SF6 pressure falling SF6 pressure low lock out Fire Alarm Fire alarm (each zone) Fire alarm faulty (each zone) Station General Station common fail Load shedding Stage 1 Load shedding Stage 2 Load shedding Stage 3 Fault recorder operated Fault recorder fail Station General Undervoltage alarm ac station service section No 1 Undervoltage alarm ac station service section No 2 Station Services Transformer No.1 trip Station Services Transformer No.2 trip Diesel generator protection operated Diesel generator running 110V charger fail (composite) 110V battery earth fault (composite) 110V battery alarms (composite) 110V DC station service section A undervoltage 110V DC station service section B undervoltage 48V charger fail (composite) 48V battery alarms (composite) 48V DC station service section A undervoltage 48V DC station service section B undervoltage Low frequency Substation Control System faulty Annunciator alarm fuse fail Domestic Water Tank Low water level Microwave tower lighting fail Packaged A.C. unit stopped (per unit) Switchgear/cable basement fan(s) stopped Battery Room extract fan failure A.C. filter assembly blocked A.C. fire/smoke detector energised A.C. return air temperature high Sandstorm monitor warning


ANALOGUE MEASUREMENTS 400 kV Feeder KV Amps MW MVAr 400 kV Busbar kV 400/132 kV Auto Transformer – 400 kV kV Amps MW MVAr OLTC position 400 kV Feeder Reactor MVAr 11 kV tertiary kV MVAr Amps Station voltage (400 kV) kV Station frequency Hz 132 kV Feeder kV MW MVAr Amps 132 kV Busbar kV 400/132 kV Auto Transformer – 132 kV kV MW MVAr Amps 132 kV Bus section Amps 132 kV Bus Coupler Amps Station voltage (132 kV) kV ENERGY IMPULSES 400 kV Feeder MWh export MWh import 400/132 kV Auto Transformer MWh export MWh import Station total MVAh MVAh export Station total MWh MWh export Station total MVArh MVArh export Station total MVAh MVAh import Station total MWh MWh import Station total MVArh MVArh import 11 kV tertiary MVArh MVArh export MVArh import


11 kV tertiary - Station MVArh Summated MVArh export MVArh import 132 kV Feeder MWh export MWh import 132 kV Transformer MWh export MWh import Auxiliary Transformer MWh


9. PROTECTION REQUIREMENTS

9.1 General

9.1.1 Background This section describes the functional performance requirements of the protection system to be supplied. Numeric protection relays are required and these may be in addition used to provide Integrated Protection and Control – see Clause 1.2.6 Control, Indications, Measurements and Annunciation, above.

The specification refers to specific discrete protection functions and it is accepted that with numeric relays these may be provided by common hardware.

The Contractor shall be fully responsible for all necessary coordination works regarding the protection equipment, with other contractors if necessary.

This section assumes the provision of conservator type main and tertiary transformer and reactors and the Tenderers ability to offer particular designs or protective system. If the Tenderer wishes to offer alternative schemes which perform equivalent duties then he shall provide complete details of the scheme proposed in accordance with the instructions to Tenderers.

Single line diagrams of a typical 400 kV substation diameter and a 132 kV double busbar showing ac connections and protection are included in the Specification. The diagrams are standard for all 400 and 132 kV substations.

A diameter is defined as the series of three circuit breakers connected between two busbars providing two circuit bays in the 1-1/2 breakers substation configuration. The typical diameter shows one line and one transformer. For diameters with two lines the transformer circuit is appropriately replaced with line protections.

Proven equipment shall be provided and evidence of site experience shall be provided by the Tenderer.

The primary network shall be considered as consisting of a number of elements, the limits of each element being its associated circuit breakers.

For the 400 kV network, each element shall be provided with two sets of high-speed discriminative protection, capable of detecting all "credible" faults and issuing tripping commands to the associated circuit breakers within the prescribed time. "Credible" faults shall include all faults whether phase/phase or phase/earth irrespective of whether maximum or minimum plant is connected, account being taken of the fault impedance. "Non-credible" faults are those involving a second order plant failure, for example, a broken conductor lying on high resistance ground and for which extended fault clearance time may be acceptable. Each set of discriminative protection (Group A and Group B) shall be physically and electrically separate with respect to dc supplies, current transformer cores, voltage transformer windings and multicore cables.

High-speed discriminative protection systems shall be engineered as complete schemes, due account being taken of CT and VT (or CVT) performance. The defined fault clearance time shall take account of the circuit breaker response and shall include the total time to elimination of the primary fault


current irrespective of the magnitude, fault location or fault current characteristic subject only to an upper limit of circuit breaker specified duty.

Attention shall be paid to the total performance including the behaviour pattern in the presence of system transients for faults "in zone", faults "out-of-zone", and during the period immediately following a switching operation irrespective of whether that operation is to eliminate a network short-circuit or is to energise or to de-energize any part of the network.

The protective equipment shall remain un-operated following the normal and correct discharge operation of one or more surge arresters.

9.1.2 Extent of Supply This section covers the minimum design requirements of the types of protective relay functions. The Contractor shall be responsible for co-ordinating the parameters of each device, circuit or system within the contract, and to arrive at a total compatible overall system. In addition, the work shall include manufacture, inspection and testing at makers works, packing for export, shipment, insurance, delivery to site, installation, electrical connections, testing commissioning and setting to work the equipment specified in this section.

9.1.3 Discrimination On the occurrence of a fault on the power system network high speed discriminating protection systems shall rapidly detect the fault and initiate the opening of only those circuit breakers which are necessary to disconnect the faulted electrical element from the network. Protection equipment associated with adjacent electrical elements may detect the fault, but must be able to discriminate between an external fault and a fault on the electrical element which it is designed to protect. Sequential time delayed tripping is not permitted except in the following specific circumstances.

(a) Operation of time graded back-up protection takes place as a result of either the complete failure of the communication links associated with the main protection systems, or the fault resistance is substantially greater than the value specified in section 1.2.8.1.12 of this specification.

(b) Operation of line back-up protection to disconnect primary system faults in the case of a circuit breaker failing to operate, (i.e. circuit breaker failure protection).

All back-up protection systems shall be able to discriminate with main protection systems, circuit breaker fail protection and with other back-up protection systems installed elsewhere on the transmission system.

9.1.4 Objective Fault Clearance Times The existing Iraq system objective maximum fault clearance times, based on a nominal circuit breaker trip time to arc extinction of three cycles – 60 mS, are as follows, however, it is expected that modern equipment will provide reduced timings and the figures in (brackets) should be aimed at:

400 kV

(a) Six cycles – 120 mS - Local end line faults and plant faults. (80 mS)

(b) Seven & Half cycles – 150 mS - Remote line faults using permissive trip. (100 mS)


(c) Nine cycles – 180 mS - Remote terminal faults using direct transfer trip.

(d) Sixteen cycles – 320 mS - Breaker fail protection with direct transfer trip.

132 kV (300 mS).

(a) Nine cycles – 180 mS - Local end line faults, plant faults, and bus faults

(new sites provided with bus zone protection)

(b) Twelve cycles – 240 mS - Remote line and remote plant faults requiring direct transfer trip

(c) Twenty-five cycles approximately – 500 mS - All other faults, including those busbar fault covered in Zone 2 of line distance protection.

The individual relay operating times should be as fast as possible and consistent with overall reliability. For both system voltages, the reduced overall fault clearance times will be preferred.

9.1.5 Protection System Construction and Mounting Protection systems shall preferably be accommodated in 19 inch rack or hinged rack cubicles and be of modular construction with factory assembled and tested wiring. The construction method shall offer the benefits of minimum site construction times and circuit outage requirements.

For modular protection systems, means shall be provided to lock positively each withdrawable module or unit in the "service" position. It shall not be possible to remove any module without first short-circuiting all associated current transformer circuits.

A portable colour printer and note-book type computer complete with all software required by each protection relay shall be provided.

Modular relays (e.g. rack mounted numeric relaying equipment) shall be tested as a complete assembly and details of such tests shall be agreed with the Engineer when details of the construction are known.

All relays which are accommodated in cubicles having a separate cubicle door shall be provided with individual relay covers. This requirement is to enable access to indication reset facilities without also allowing unauthorised access to relay setting adjustments.

For extension to existing installations, all new relay panels shall match the existing method of construction and installation as closely as possible.

9.1.6 Indications Each relay or protection scheme shall be provided with an adequate number of indications to ensure that the appropriate faulted phase, zone, etc can be easily identified after a fault condition. Each indicator shall be visible and capable of being reset without removing the relay cover. Unless otherwise approved, indications shall only be given by the protection(s) causing the fault to be cleared.

Where illuminated indicators are used (e.g. light-emitting diodes) the following shall apply:


(a) Long term storage of the indication must not be dependent upon an auxiliary supply

(b) A lamp test facility shall be provided.

9.1.7 Contacts Each protection relay or protection scheme shall be provided with an adequate number of output contacts of suitable rating to carry out the prescribed tripping functions, alarms, indication and fault recorder functions and such supplementary signalling functions as may be necessary for the initiation of automatic reclosing or automatic switching control, etc. In all cases, contacts intended for tripping duty shall be designed so that they cannot inadvertently interrupt trip coil current.

For contacts intended to be used to energise circuit breaker trip coils directly, information shall be provided to show that the contact rating is compatible with the trip coil parameters of the associated circuit breaker. Where appropriate, details shall also be given of the operating characteristics of any reinforcing contactor and, in particular, the pick-up and drop-off threshold levels of series connected (current dependent) contactors.

9.1.8 Numeric Relays Numeric protection relays shall utilise numerical techniques for both measurement and logic functions and in addition to the main protection functions, shall incorporate communication; fault, event and disturbance recording; instrumentation; configurable scheme logic; alternative setting groups and self-supervision facilities.

The communication facility should allow all information available locally at the relay front panel to be accessed remotely. It should also be possible to carry out bulk transfer of settings, fault record information etc using the appropriate PC based software.

All facilities necessary for the interconnection of the protection relays and for communication with the individual relays from a central location shall be provided e.g. fibre optic cables, coupling and interface devices etc.

All protection systems shall be provided with an integral local operator interface facility to enable communication with the relay without the use of external equipment. Any facilities provided for connection to an external computer shall be an additional feature to the local operator interface.

The protection relay shall also be supplied with the facilities identified below:

(a) Identification: Each protection system shall have a unique identifier which is clearly visible and the software reference and issue level shall be identified.

(b) Settings: Each protection system shall provide a means by which the user can easily access the protection system to apply the required settings, which shall be password protected and secure from inadvertent operation. A display of the selected settings shall be provided on the protection system.

(c) Indications: Each protection system shall provide indications appropriate to its facilities.

(d) Time Synchronisation: Each distance protection relay shall be capable of being synchronised to an external time source derived from a GPS receiver, shared with the SCS.


9.1.9 Trip Circuit Supplies Tripping supplies for Group A and Group B protection schemes for each 400kV circuit shall be derived from separate sections of the main dc distribution board such that under normal circumstances, each protection scheme is supplied from a different battery and each protection scheme utilises a separate trip coil on the circuit breaker.

9.1.10 Trip Circuit Supervision and Auxiliary Supply Monitoring Means shall be provided to continuously supervise the integrity of the circuit breaker tripping circuits and give an alarm in the event of the following fault conditions: -

(i) Loss of dc tripping supply, e.g. opening of trip supply MCB removal of dc trip link, etc.

(ii) An open circuit in the trip circuit including the trip coil, circuit breaker auxiliary switch and all associated connections (supervision to be effective with the circuit breaker in either the open or closed condition).

The alarm shall be time-delayed to prevent it operating during momentary dips in the dc. supply. The alarm shall also be inhibited when the circuit breaker auxiliary switch interrupts the trip coil circuit, on circuit breaker opening.

All auxiliary supplies, ac and dc, essential for the operation of the protection relay scheme shall be monitored and the loss of any supply shall be indicated on the relay panel and an alarm given.

9.1.11 Commissioning and Routine Testing Facilities Each functional relay scheme shall be so arranged that operational and calibration checks can be carried out with the associated primary circuit(s) in service.

Adequate test facilities shall be provided within the protection system to enable the protection and auto-reclosing equipment to be tested from the front of the protection equipment with the primary circuit(s) in service.

Adequate facilities shall be provided to isolate all dc. and a.c. incoming and outgoing circuits, together with ct shorting/disconnecting links, so that work may be carried out on the equipment with complete safety to personnel and without loss of security in the operation of the switching station.

All test equipment required for commissioning and routine testing of the offered protection equipment shall be listed in the tender documents. Where test equipment is specified, it shall include such injection transformers, test leads and plugs as are necessary to carry out secondary injection tests on each type of relay scheme and, for the more complex schemes, such special test equipment as may be necessary to verify the accuracy of timing and verify the effective operating characteristics of the equipment.

For numeric equipment, such test equipment as may be required to carry out on-site investigation into the performance of individual modules or printed circuit cards shall be listed in the tender documents. At least one complete set of any special test equipment shall be included within this Contract together with such additional connections, dummy extension boards, etc as may be necessary.


9.1.12 Relay Settings Not less than 6 months before commissioning, suitable settings shall be recommended for all relays and protection to be supplied. The recommended settings will ensure satisfactory operation in accordance with the intent of this Specification and the specified system operating conditions. The recommended setting shall not only include those normally available on the front of a relay but also the positions/settings of any internal links, plugs, etc not normally adjusted after installation. These settings shall be applied to the equipment prior to performing the commissioning tests. The settings for line protection shall be such as to permit correct operation of the protection for earth faults up to 100 ohms fault resistance. Any limitations imposed on the power system as a result of the settings proposed shall be explicitly stated.

9.2 Environmental Performance

9.2.1 Atmospheric Environment 9.2.1.1 Temperature The standard nominal range of ambient temperature shall be -10°C to +55°C.

The protection system shall operate satisfactorily when tested to the following requirements:



The protection system shall be able to withstand the temperature requirements for storage and transportation and shall be tested to the following requirements: -



9.2.1.2 Relative Humidity The protection system shall operate correctly with a relative humidity of 93 per cent and shall be tested to IEC Publication 6068-2-3 with severity class 56 days.

9.2.1.3 Enclosure The protection relay shall meet the requirements of the tests detailed in IEC 60529 with classification IP50 (dust protected). If the individual enclosure of the relay is to a class less than IP50 then the Tenderer shall provide a cubicle to classification IP50 to accommodate the relay.

9.2.2 Mechanical Environment 9.2.2.1 Vibration The protection system shall meet the requirements of the tests detailed in IEC 60255-21-1 with severity class 1.


9.2.2.2 Shock and Bump The protection system shall meet the requirements of the tests detailed in IEC 60255-21-2 with severity class 1.

9.2.2.3 Seismic The protection system shall meet the requirements of the tests detailed in IEC 60255-21-3 with severity class 1.

9.2.3 Electrical Environment 9.2.3.1 DC Auxiliary Energising Quantity The protection systems shall be capable of being energised from a dc auxiliary energising voltage of 110 V (nominal).

The protection system or its associated power supply for use in a 110 V (nominal) dc supply system shall operate correctly over a voltage range of 88 V to 132 V and shall withstand a maximum voltage of 143 V.

Numeric protection systems shall meet the requirements of IEC 60255-11 with interruptions to the dc auxiliary energising quantity of 10 mS.

9.2.3.2 Frequency The standard rated frequency shall be 50 Hz.

The nominal range of frequency shall be -5 per cent to +5 per cent.

9.2.4 Insulation 9.2.4.1 Rated Insulation Voltage The rated insulation voltage of circuits connected to current transformers of high impedance relays shall be 1000 V. All other circuits shall have an insulation voltage of 250 V.

All open contacts of the protection system shall withstand a voltage of 1000 V.

9.2.4.2 Dielectric tests The protection system shall comply with the dielectric test requirements of IEC 60255-5. The test voltage shall be selected according to the rated insulation voltage of the circuits being tested form Series C of Table 1 of IEC 60255-5.

9.2.4.3 Impulse voltage The protection system shall comply with the impulse test requirements of IEC 60255-5 with test voltage of 5 kV.

9.2.5 Electromagnetic Compatibility The requirements of this section of the specification are specifically applicable to numeric protection systems. The requirements may also be applied to some electro-mechanical relays that are very sensitive or of high speed, at the discretion of the Engineer.


9.2.5.1 1 MHz Burst Disturbance The protection system shall comply with the requirements of IEC 60255-22-1 with severity Class III.

9.2.5.2 Electrostatic Discharge The protection system shall comply with the requirements of IEC Publication 60255-22-2 with severity Class III.

9.2.5.3 Radiated Electromagnetic Field Disturbance The protection system shall comply with the requirements of IEC 60255-22-3 with severity Class III. The test shall be carried out by using Test Method A and by sweeping through the entire frequency range 27 MHz to 500 MHz.

9.2.5.4 Fast Transient Disturbance The protection system shall comply with the requirements of IEC 60255-22-4 with severity level IV.

9.2.5.5 Electromagnetic Emissions The protection system shall comply with IEC 60255-22-25.

9.2.6 Thermal Requirements The requirements of this section apply to protection systems rated at 1 A associated with line circuits where the load current is carried by current transformers which supply the protection system.

The protection systems shall have a minimum continuous thermal withstand of 2.4 A.

The thermal withstand currents for short duration overloads, after having reached a steady temperature with an input current of 2.0 A, shall not be less than given in the table shown below.

4.5A. Duration (mins) 20 10 5 3 2 5.5A. Current (amps) 3.10 3.5 4.0 5.0 6.0

9.3 Protection/Relay Types

9.3.1 Distance Protection 9.3.1.1 General Distance protection for 400 kV feeders shall comprise two sets of distance relays, each distance relay providing at least three forward and one reverse zone of protection; 400kV distance protection shall operate in conjunction with teleprotection channels operating over various communications media.

The 400 kV distance protection relays and teleprotection channels shall form:

- a permissive under reaching transfer tripping scheme

- an overreaching blocking scheme.

The 400 kV protection schemes shall be:

(i) Suitable for complete simultaneous multi-phase and earth fault three zone measurement. Phase selection and sequential measurement are not acceptable.


(ii) Suitable for single pole and three pole tripping and auto-reclose operation.

(iii) Suitable for application on a double circuit line, i.e. include mutual zero sequence compensation.

(iv) Provided with power swing blocking facilities suitable for blocking zones 1, 2, 3 as required.

(v) Provided with an integral distance to fault locator.

(vi) Provided with an integral directional earth fault protection function.

Overcurrent starting will not be accepted. However, schemes employing overcurrent elements that act as a check to prevent maloperation of the measuring elements during line de-energisation or resetting measuring elements during single-pole auto-reclose dead time are acceptable.

Only equipment having extensive field experience at 400 kV will be accepted. Tenderers shall provide a reference list of such projects for which the equipment has been used.

For the 400 kV feeder circuits, each set will be energized from separate current and voltage transformer secondary windings via separate multicore cables.

Both 400 kV distance protection relays shall have facilities for independently tripping duplicate circuit breakers and initiating auto-reclosing, breaker failure protection, intertripping, alarms, fault locators, fault recorders etc.

The Tenderer must guarantee that any distance relay offered will operate satisfactorily under the conditions described herein and with the distance relays at the remote substation.

Each distance relay shall operate for all types of phase and earth faults. Separate phase and earth fault distance measuring elements shall be provided; separate elements shall also be provided for each zone. Phase and earth fault compensation features shall be incorporated to ensure accurate distance measurement for all types of faults and to allow for the variation in the path of earth faults on the system.

Cross-polarized mho relays are preferred for zone 1 and 2 elements and these shall operate only for faults in the protected line direction. Under no circumstances shall the relay operate for reverse faults even when the voltage supplied to the relay falls to zero on all three phases, nor shall they operate due to the transient response of the line capacitive voltage transformers during or following the clearance of close-up faults behind the relay. Details of methods used for polarizing relays to deal with all types of faults close to the relaying point shall be provided. The relay characteristics shall ensure adequate fault resistance coverage under minimum plant and single outage conditions. Zone 3 shall be non-directional and shall be capable of being independently off-set in both directions. No measuring element shall operate during normal system switching or during de-energisation of the transmission line.

The relay characteristic of impedance measuring starting relays shall cover the protected line plus the longest line emanating from the remote station taking current in-feed into account. This requirement will be relaxed at the Engineer's discretion in the case of extremely long lines. The starting relays shall not operate during maximum power transfer. When single phase to earth faults coincide with maximum power transfer, only the starting or measuring relay associated with the faulted phase shall operate. The starting relays can be employed as zone 3.


On long lines the minimum load impedance presented to the relay during maximum power transfer may encroach an offset mho zone 3 characteristic. Zone 3, therefore, (and any associated power swing blocking characteristics, if applicable) shall be capable of being shaped to avoid load impedance.

The reach of each measuring zone and starting relay shall be individually adjustable. The characteristic angle shall be adjustable between approximately 60 and 85 degrees.

Zone 2 and zone 3 shall have time delay setting ranges of 0 – 1.5 seconds and 0 -3 seconds respectively.

The sensitivity of the protection shall be adequate for definite operation under minimum plant conditions and single outage conditions and shall not exceed 30 per cent rated current.

The operating time of each zone shall be substantially independent of fault current magnitude. Curves shall be provided showing the effect on operating time of line and source impedance, fault position and operating current and point on wave of fault application.

A switch on to fault feature shall be incorporated to ensure instantaneous tripping in the event that the circuit breaker is closed onto a fault on a previously de-energized line.

The switch onto fault feature in the relay proposed for use in the permissive under reach transfer tripping scheme shall also be capable of being enabled during the auto-reclose dead time. This is to ensure fast clearance of non-transient end zone faults where delayed zone 2 clearance would normally occur when the local end is reclosed before the remote end.

The distance protection shall include a voltage transformer supervision unit to prevent possible unwanted operation of the distance relay comparators in the event of a failure of one, two or three phases of voltage caused by open or short circuit faults in the voltage transformer secondary circuits or due to removal of VT fuses. In the event of loss of one, two or three phases the distance relay shall be blocked and a time delayed alarm initiated.

The VT supervision shall not operate during energisation of the line or of any power system transformers, during a single pole reclose cycle nor during any other power system primary disturbance. It shall also be inhibited during a single pole auto reclose cycle to ensure there is no delay in tripping remaining poles if a second fault occurs during the single pole dead time.

The VT supervision unit shall be faster than the distance relay measuring units under all circumstances.

Teleprotection channels over Power Line Carrier and other communications media will be used in conjunction with the distance relays to form:

- A permissive under reaching transfer trip scheme.

- An overreaching blocking scheme.

Supply and installation of cables from the protection relay panels to the main and standby teleprotection equipment included in the scope of work of this contract.


A separate fully adjustable timer, delayed on reset shall be provided to delay the resetting of the blocking signal received during fault current reversal conditions on a parallel circuit. The Tenderer shall recommend a minimum time setting for this timer.

A reverse looking, fast operating element shall be provided for initiating the transmission of the blocking signal. This element shall preferably have an offset mho characteristic to ensure that a blocking signal is definitely sent for any type of fault immediately behind the relay. As the relay will also respond to faults in the forward direction of the protected line, the blocking signal shall be interlocked with the forward looking zone 2 elements and shall not be sent if zone 2 elements operate. Under no circumstances shall a blocking signal be transmitted for faults in front of the relay. Since the reverse looking element must definitely operate for any type of fault behind the relay, its sensitivity must be at least equal to and preferably higher in all respects to the remote end zone 2 overreaching elements.

The distance relays shall incorporate indicators to show the zone in which the relay tripped and phase or phases faulted, whether the relay operation was due to aided trip, switch onto fault, power swing blocking, VT fuse fail or directional earth fault if appropriate. Indication must not be lost in the event of a supply failure.

In addition to sufficient tripping contacts, the protection shall have, where necessary, contacts for initiating single pole and three pole auto-reclosing, two sets of circuit breaker failure protection, fault locators, fault recorders, protection signalling and alarms.

Selection facilities are required to permit or inhibit auto-reclosing if the carrier is or is not in service.

Where appropriate the protection and associated auto-reclose equipment shall incorporate whatever means are necessary to ensure that all measuring and starting elements in the healthy phases of the faulted line and all measuring elements on the parallel circuit remain reset and are unaffected by the fault and load currents which flow in the healthy and parallel circuit during the single phase reclosure dead time. Additionally, the inter-phase fault measuring elements on the faulted circuit shall be stable in the presence of a heavy close-up earth fault. The methods used to ensure correct stability of healthy phase elements during single phase dead times and during fault conditions shall in no way prejudice the ability of the protection and auto-reclosing scheme to respond to faults during the dead time and reclaim time.

Distance relays shall be suitable for single phase reclosing schemes and the contractor shall demonstrate conclusively by conjunctive test and by calculation that phase selective tripping will be achieved under the various system and load conditions described in this section.

The necessary feature shall be incorporated in the relay to inhibit the zone 1 and zone 2 phase fault elements when necessary during single phase to earth faults and during the single pole auto-reclose dead time. Provision shall also be made to ensure the faulty phase earth fault elements definitely reset during the single pole auto-reclose dead time.

The effect of zero sequence mutual coupling between the double circuit lines on the protection shall be described together with any measures considered necessary to overcome this effect.

The 400 kV distance protection time delayed back-up zones shall be arranged to intertrip the remote station circuit breakers via direct transfer tripping channels. In this case auto-reclosing shall not be initiated.


Design calculations for current transformers for use with distance relays shall be submitted to the Engineer for approval within three months of contract award. CT design shall be based on a maximum fault level equivalent to the 400 kV switchgear rating as appropriate and the X/R ratios equated in this Specification.

9.3.1.2 Supplementary 400 kV Directional Earth Fault Protection To achieve fully discriminative clearance of high resistance earth faults at any point on the protected line, each 400 kV distance protection relay shall incorporate an integral directional earth fault (DEF) element operating in conjunction with teleprotection channels. The DEF protection shall operate either in a permissive overreach or an overreach blocking mode as necessary to match with DEF protection at the remote ends of the line. The DEF protection shall operate for phase to earth and two-phase to earth faults and the blocking scheme shall comprise forward and reverse looking directional earth fault elements. The same teleprotection channels may be used for the directional earth fault protection and the distance protection schemes.

Adjustable time delay units shall be provided for the following: -

(a) to allow the distance protection to operate before the DEF element for earth faults having values of fault resistance which lie within the zone 1 characteristic.

(b) to allow the DEF protection to operate as a back-up earth fault relay to provide remote back-up protection for high resistance faults independently of the carrier equipment. Auto reclosing shall be blocked in this case.

(c) to prevent maloperation during current reversal situations during fault clearance on the parallel line.

(d) to delay the DEF blocking scheme long enough to allow the receipt of a blocking signal for external earth faults.

Each timer shall be clearly labelled to identify its function.

A fixed timer (short delay on drop off) shall also be provided to delay resetting of the blocking signal by about 10 m secs.

DEF protection shall also trip the local circuit breaker three pole. Single pole tripping and single pole auto-reclosing from the DEF scheme is not required. Selection facilities in the form of links or switches shall be provided to either block or allow initiation of the delayed three pole auto-reclose scheme as desired.

The VT supervision unit associated with the distance protection shall also inhibit the DEF protection in the event of VT fuse failure.

It shall be possible to reset the DEF element by means of a signal from the auto reclose relay during the single pole dead time.

9.3.1.3 Power Swing Blocking The 400 kV distance relays shall incorporate power swing blocking elements.

Power swing blocking elements for distance relays having offset mho zone 3 characteristics or starters shall comprise an offset mho characteristic, which encompasses and is concentric with the


distance relay impedance starter or zone 3 characteristics. Similarly where it is possible to shape the zone 3 or starter characteristic the power swing-blocking characteristic shall also be capable of similar shaping.

Facilities shall be provided to block zones 1, 2 and 3 of the distance relay as required and an alarm signal to be initiated.

Blocking logic shall be derived by determining the time taken for the apparent impedance of the power swing locus to pass from the characteristic of the power swing element to the distance relay starter characteristic. Blocking shall not take place until the apparent impedance has passed through the two power swing characteristics and the timer has expired.

The associated time delay relay shall have a setting range of 50 - 250 m secs.

The setting range of the power swing characteristic angle shall at least be adjustable over the same range as the distance relay starting or zone 3 characteristic.

Reset times shall be fast enough to ensure that the distance protection reverts to its normal role as soon as possible following a power swing.

Where applicable, power swing blocking shall be inhibited during the single pole dead time of an auto-reclose cycle so that if a power swing develops during this period the distance protection can give an immediate three phase trip. The Tenderer shall advise whether it is possible to extend the inhibition of the power swing blocking to cover a period immediately following auto-reclosing so that if a power swing develops on reclosing onto a permanent fault a three-phase trip would be permitted. The Tenderer shall also advise whether power swing blocking can be inhibited if an earth fault occurs during a power swing.

If the associated VT supplies are lost due to VT fuse failure, the power swing blocking element shall not operate.

9.3.1.4 Fault Location Equipment Each 400 kV distance relay shall incorporate an integral fault location facility, which shall indicate the approximate distance between the line terminal and the fault. The fault locator shall preferably be of the reactance measuring type so that the loop impedance measurement is not affected by fault arc resistance. Measurement at each line terminal shall be independent of any measurement made at other terminals.

The fault locator element shall be fast in operation and shall have an accuracy such that the maximum error of any measurement will not exceed ±3 per cent of the total line length, irrespective of the total fault clearance time.

Determination of the fault position shall be as simple as possible. A direct reading digital display, calibrated in percentage distance of the total line length, is preferred.

If it is practicable to do so, automatic recording of the measurement shall be provided. If not, the measured information shall be capable of being stored, with no increase in error, for a period of not less than 100 hours.

The current and voltage transformer performance characteristics to adequately cover the performance of the fault location element during the worst "in service" conditions shall be specified.


The maximum required measuring time for the specified accuracy shall be smaller than the time available during the fastest anticipated fault clearance time.

9.3.1.5 Distance Protection Test Equipment To facilitate automatic testing of the feeder distance protection relays to be carried out regularly and rapidly and with a minimum of disturbance to relay equipment, the Tenderer shall include one set of programmable computer controlled automatic test equipment. This is to include computer unit, keyboard, monitor, general purpose software, software for testing operation in a single pole tripping scheme, etc.

9.3.2 Inverse Time Overcurrent and Earth Fault Relays Inverse time overcurrent and earth-fault relays shall be of the numeric type and shall have selectable characteristics, i.e. normal inverse, very inverse and extremely inverse.

The operating time characteristic shall be continuously variable over the minimum range 0.1 to 1.0 times the nominal time at any multiple of current setting.

The current settings shall be adjustable as a percentage of nominal relay rating over setting ranges which are at least:

overcurrent relays - 50 to 250%

earth-fault relays - 10 to 100%

The actual relay pick-up current shall not exceed 1.3 times the relay setting and the reset value shall not be less than 90 per cent of the pick-up current.

All relays shall comply with the accuracy requirements of Clause 7 of IEC 60255-4, the required class index of the reference limiting error being 5.

9.3.3 High Set Overcurrent, Instantaneous Overcurrent and Earth Fault Protection

High set overcurrent, instantaneous overcurrent and earth-fault protection shall be of the numeric high-speed type and shall have a current independent selectable time delay with a setting range from instantaneous (no intentional time delay) to 100secs in steps of 0.01secs.

High set overcurrent elements shall be of the low transient overreach type, i.e. the magnitudes of the current with and without the presence of a dc transient at which operation occurs shall be approximately the same. The value of the system reactance to resistance ratio at which the performance of the element is claimed should be stated. When applied to the protection of power transformers, high set overcurrent elements must be capable of being set to remain stable for maximum through fault currents associated with faults across the remote winding terminals.

The high impedance principle may be used to obtain stability of the instantaneous earth-fault protection.


9.3.4 Directional Relays Directional relays may either be provided as separate numeric relays or as part of an overcurrent or earth-fault inverse-time relay combination.

A range of characteristic angle settings shall be provided so that correct directional discrimination will be achieved for all credible system faults. Preference will be given to relays in which voltage polarising, current polarising or dual polarising can be achieved.

Where directional features are applied to overcurrent and earth-fault inverse-time relays, the following requirements apply:

(a) the operating time of the directional element shall have negligible influence on the total operating time of the composite relay

(b) The current setting of the directional element shall be low enough so as not to increase the overall setting of the composite relay for all faults in the operate direction.

9.3.5 Overcurrent and Earth Fault Definite Time Lag Relays Preference will be given to relay designs in which the current settings for phase to phase faults are the same as those for three phase faults and in which the current settings for single phase to earth faults are the same irrespective of the phase involved.

The current measuring elements shall be of the low transient overreach type and the value of the system reactance to resistance ratio at which the transient overreach performance claim is made shall be stated. Their operating time shall be less than 30 milliseconds at 5 times setting and their drop-off to pick-up ratio shall not be less than 90 per cent.

The associated timing relay shall have a timing range (or ranges) adjustable between 0.1 and 10 seconds minimum, the setting adjustment being either continuous or stepped, with a maximum of 20 milliseconds per step. The accuracy of setting shall be at least ± 5 per cent of setting or 20 milliseconds whichever is the greater.

9.3.6 Circulating Current Protection The protection shall remain unoperated for all out-of-zone fault currents ranging from 0 to 15 times full load rating of the protected circuit and all other system transient conditions, such as in-rush currents, which are not due to internal faults.

The protection shall remain stable for all out-of-zone faults with fault currents up to the short circuit rating of the switchgear, applied suddenly or gradually. The protection sensitivity shall be such as to ensure that definite operation of the protection occurs for all phase-to-phase and phase-to-earth faults under minimum plant conditions, irrespective of the number of circuits in service and the distribution of load and fault currents.

The operating time shall be 30 ms or less at 5 times setting.

Care shall be taken to ensure that the protection does not maloperate as a result of faults in the associated secondary wiring when the primary circuit is carrying load current. Continuous or automatic cyclic supervision shall be provided for this purpose. Where the operation of the


supervision device is dependent upon the load current in the primary circuit, operation shall occur at a current of 25 amperes or 10 per cent of the circuit rating whichever is the greater.

The Contractor shall submit all the necessary data required to prove the predicted performance of the protection.

9.3.7 Multi-Contact Tripping Relays All multi-contact tripping relays shall be suitable for panel mounting. The design of the operating coil shall be such as to permit operation in conjunction with series trip flag relays should these be specified. When provided on the relays, economy contacts used to reduce the level of energisation of the operating coil after operation shall be delayed in operation sufficiently long enough to ensure that series flag relays operate correctly.

All contacts shall operate within the prescribed time for the particular category which shall not, in any case, exceed 10 milliseconds from the time at which the operating coil is first energised to the time of complete contact closure.

Where lockout relays are specified, these must be of the mechanically latched type and shall be hand/electrically reset as specified.

9.4 Protection Functions

9.4.1 400 kV Primary Line Protection Systems Two primary line protection systems shall be provided based on multizone, multielement phase and earth fault distance protective relay schemes, to be operated independently and in parallel. Each system shall be supplied by separate CT and V.T. windings and fed by a separate DC supply system, and act on a separate trip coil per phase basis. Where “diameter” ct’s are summated to provide feeder current inputs to protection, the ct cores and lead burdens shall be matched.

9.4.2 400 kV Main Line Protection - Group A Provide main line protection - Group A with the following features:

- Three zone phase and earth fault mho or suitably shaped characteristic distance scheme utilising offset mho or equivalent elements for starting and backup purposes (depending on the requirements of the relays offered), and high speed tripping when closing on to a faulted line. Suitable contacts for use in a permissive underreach transfer trip (acceleration) scheme shall be provided.

- DC auxiliary supplies and tripping circuits on the “A” battery

- Four separate trip outputs: One per phase giving a single output on the faulted phase for zone 1 or accelerated single-phase to earth faults, and suitable for use with single pole auto reclosing. One three phase trip output for all multi phase faults and all timed clearance zone 2 or 3 faults, and suitable for three pole high speed or delayed auto reclosing.

- Complete reset of high speed trip measuring circuits, after arc extinction has occurred on the open phase of the faulted circuit following single pole tripping but high speed tripping should be provided if the fault develops to multi phase.


- A setting range for the zone 1 impedance measuring element of 50 per cent to 120 per cent of line length on all protected lines.

- A setting capability for zone 2 overreach protection to give typically 125 per cent of each line length with a time delay in the range 0-1.5 seconds.

- Zone 3 protection time delay range of 0-3.0 seconds with a setting range to cover at least 200 per cent of the protected line length.

- Blocking of relay tripping in the event of loss of V.T. supplies on one or more phases to the relays.

- Facilities for addition of power swing blocking.

- A sensitive directional comparison earth fault protection shall be provided using a separate protection signalling circuit and having additional logic to “echo” for returning the comparison signal if the remote end is open, or other wise to ensure fast tripping for high resistance earth faults over the whole feeder length, even if the remote end of the circuit is open.

- Timer for protection delaying of 0.1-0,6 range and for echo logic circuit to be alive of 0.2-1 second range shall be provided.

9.4.3 400 kV Main Line Protection Group B Provide main line protection - Group B with the following features:

DC auxiliary supplies and tripping circuits on the “B” battery supply.

Same basic features as Group A protection but of different design, thus allowing both systems to give complete coverage and reduce the possibility of protection failure due to any inherent weaknesses, and to provide full line protection if protection Group A is out of service.

The requirements for a different design may be met by provision of a blocked overreach distance protection rather than the combination of a permissive underreach and directional earth fault scheme system specified for Group A.

The system should provide fast tripping over the whole line length even when the remote end is open, and should also have underreach protection capability for fast clearance of local end line faults.

9.4.4 400 kV Line Protection Signalling Equipment Line protection signalling equipment shall provide facilities as follows:

- Provide separate permissive transfer trips using a fast simple logic code for the Group A earth fault distance and the directional comparison earth fault protections.

- The receipt of the appropriate protection signal shall operate through the respective protective system logic and phase selection facilities to provide fast phase and earth fault protection and to initiate single pole or three pole reclose.


- For maximum security provide a complex code for the direct transfer trip signal to trip the remote end circuit breaker. The receipt of the signal shall energise all three phases of both trip coils of the appropriate circuit breakers.

- Initiate the direct transfer trip signal from the line reactor protections and from the circuit breaker failure protections and from the CT stack protections.

- Provide a blocking signal for the overreach distance protection, where provided.

- Provide separate 110 V dc interposing relays, one for each sending and receiving signal for each of the duplicated signals in the “A” and “B” panels. The two contact system shall be used to provide most immunity to the relay interconnections from interference.

9.4.5 Allocation of 400 kV Line Protection Signalling Channels The direct transfer trip signals shall be given first priority in any priority coded signalling scheme and shall be duplicated on separate routes. The logic will be such that the receive output will be given continuously if a send condition is maintained at the remote end, and immediately cut off when the sending end condition is removed.

The blocking signal for any overreach distance scheme shall use the power line carrier channel over its own protected transmission line while the permissive transfer trip will use an alternatively routed channel. Both systems will have second priority (if appropriate) within their signalling systems.

Directional Comparison Earth Fault signals shall be duplicated over the two separate routes and shall be given third priority on both systems. The comparison signal will be sent after protection time delaying only.

If duplicate underreach distance schemes are provided then both A and B groups of line protection will initiate and receive in parallel permissive direct transfer trip signals using both signalling routes.

9.4.6 400 kV Line Reactor Protection Provide two groups of line reactor protection allocated to the appropriate groups as follows:

Group A

Phase and earth differential protection as appropriate to match with the current transformers on the reactor, and overcurrent protection.

Gas surge (Buchholz) protection, oil level low and oil over temperature protection for the main phase and neutral reactors operating into “B” battery circuits.

Group B

A neutral current instantaneous alarm and about 10 second delayed trip in the neutral reactor earth connection operating into “A” battery circuits.


9.4.7 400 kV Tripping & Auto Reclose Logic Provide tripping and auto reclose logic according to the following principles:

All circuit breaker and protection signalling operation devices shall seal in to ensure that complete breaker operation occurs and that the protection signalling equipment remote receive relays operate, but then release to allow auto reclose to proceed. The use of time delayed reset latching relays in those parts of the circuit not applicable to high speed single pole reclose would be acceptable.

Provide a high speed single pole auto reclosing scheme having no current or voltage check, other than a cancel signal provided from the associated protection three pole trip circuits which will reset any reclose that is in the process of timing out. Provide a time setting range from 0.5 to 3 seconds.

Provide three pole auto reclose scheme giving high speed reclose with about 0.2, to 1 second dead time and without synchro-check facilities and delayed reclose with about 1 to 6 second dead time. For delayed reclose only, voltage check and duty selection facilities to be provided to enable dead line charging and/or dead bus charging and/or synchronism check for live line reclosing. The delayed auto reclose equipment shall work in conjunction with the voltage selection and synchronising equipment specified.

Reclosure shall only take place on overhead line circuits and shall be initiated following tripping by the distance relay zone 1 equipment or following an aided trip in the permissive under reach transfer trip scheme or in the blocking scheme. Reclosure shall not be initiated in the event of a three-phase fault, any type of fault in the second or third back-up zones or when the circuit breaker is closed onto a fault on a previously de-energized line.

For 400kV overhead line circuits, three pole delayed auto-reclosing may also be initiated by the supplemental directional earth fault protection.

Provide both single pole high speed and three pole reclose logic separately for each 400 kV circuit breaker. Separate time sittings for single reclose, for three phase high speed reclose and for three phase delayed reclose to be provided in each breaker.

Single and three pole reclosure is prevented on circuit breakers that were open prior to the fault.

All single pole trip outputs initiate single pole reclosing following tripping of the appropriate phase.

All three pole trips prevent single pole reclosing on the affected circuit breakers.

If more than one pole trip output occurs, this shall initiate a three pole trip and inhibit single pole reclosing.

Three pole trips initiated at any stage during any reclose operation cause immediate trip of any closed phases and achieve three phase trip.

Three pole trips initiate three pole reclose where selected unless cancelled by a local circuit breaker fail, trip on energising, phase disagreement, backup overcurrent, direct transfer trip receipt or a local line reactor trip. Reclosing onto a fault shall lock out further reclosure, during the reclaim time.

Three pole reclose will be interlocked to prevent it from operating if a local trip relay has not reset or if the appropriate circuit breaker is not able to reclose.


Line reactor protection, circuit breaker fail protection or CT stack protection operation on line circuit breakers will initiate direct transfer trip signal to the remote end of the line.

Provide two selector switches on the appropriate relay panel to select from the following duties as required.

First : Selector Switch

(i) high speed single pole reclose

(ii) high speed three pole reclose

For single phase faults or three phase reclose for multi phase faults respectively dependent on the type of fault.

(iii) Three phase reclosure for all type of faults.

(iv) Reclose off.

Second: Selector switch (effective only in (ii) and (iii) position of the first selector switch).

(i) High speed three phase reclose

(ii) Delayed three phase reclose.

The circuit breaker tripping circuits to be connected to three pole trip for selections (iii) and (iv) of the first selector switch.

Provide an operation counter to record separately the number of operations for single pole and three pole trips and to lock out after a pre-selected number of protection trips has been recorded.

Tentative ranges of the high speed and delayed reclosing dead times are, as follows and equipment offered should cover these ranges.

High speed single pole reclose dead time: 0.3 to 3.0 seconds.

Delayed three-pole reclose dead time: 3 to 30 seconds.

The Tenderer shall state the available ranges.

The reclaim time shall be chosen to match the duty cycle of the circuit breakers, assuming the shortest available dead time is chosen. The reclaim time shall not, however, be less than 10 seconds, and the reclaim timer range shall extend to 180 seconds. The duration of the closing command shall be limited to two seconds, after which time the reclosing equipment shall be automatically reset without resetting the reclaim timer. The reclosing equipment shall also reset if dead line check, dead busbar check or synchronism check conditions are not satisfied within five seconds of the check relays being energised.

A signal shall be provided from the dead line check relays for interlocking of the line earth switches to prevent the switches being closed on a live line.


Facilities shall be provided for switching the auto reclose equipment out of service from both the relay panel and the SCS.

9.4.8 400 kV Substation and Back Up Protection 9.4.8.1 400 kV Overcurrent Back-up Protection In Group A protection IDMT overcurrent back-up protection operating into “A” battery circuits shall be provided using inverse time overcurrent relays connected in each line and transformer circuit. This protection shall trip all three poles of the associated circuit breakers by trip coil “A” and prevent all auto reclose equipment on those circuit breakers from operating.

Three phase over current relays and one residual overcurrent relay shall be provided. The phase over current relays are to be over-loading protection having a setting range of 1 –2.5 times of nominal current of the line or transformer. The neutral overcurrent relay shall give back up for faults and it shall be very sensitive (0,1 to 1 times of the nominal current).

Each inverse definite minimum time (IDMT) relay shall have an instantaneous element which shall be brought out to a separate trip output which shall be disconnectable.

The provision of definite time overcurrent relays will be considered if the Contractor can show that suitable settings and coordination can be achieved.

9.4.8.2 400 kV Circuit Breaker Fail and Malfunction Protection Circuit breaker fail protection shall be provided which shall clear a fault which has been correctly detected by the appropriate protection but for which the associated circuit breaker(s) has (have) failed to open, as follows:

(a) It shall operate for initiation by a trip signal on any phase of either trip coil of each circuit breaker on a breaker by breaker basis.

(b) Provide a timer with a range 50 to 200 ms and a fast resetting current check relay adjustable to minimum fault current infeed for faults, on either side of transmission circuit breakers, but thermally rated to meet the full breaker thermal rating.

(c) Provide circuits in Group B to three pole trip the next in line circuit breakers by trip coil “B” from “B” battery DC supply and to initiate both direct transfer trip channels to any appropriate remote circuit breakers following the detection of a breaker failing to trip on fault.

(d) Provide interconnection into the busbar differential protection B group trip circuit bus to trip all circuit breakers connected to the busbar on which the stuck circuit breaker is located

(e) Provide a mechanical phase disagreement trip, either as part of or external to the circuit breaker control circuits, to effect a three pole trip if one pole has been open for more than a given time. Time delay setting range shall be 1 to 5 seconds.

(f) The protection must be effective during single pole tripping cycles and must not operate during the single pole open conditions prior to single pole reclose.

(g) For software embedded circuit breaker fail protection, one detector function shall be utilised. For discrete relay (e.g. non-software embedded) circuit breaker fail protection system shall comprise two independent circuit breaker fail relays. Each circuit breaker fail relay comprising a


current detecting and time delay element. Coincident operation of both circuit breaker fail relays shall be arranged to initiate tripping of the appropriate busbar section.

(h) Two basic criteria shall be satisfied before each circuit breaker fail relay can initiate a trip output. Fault current must be flowing and the appropriate protection must have failed to reset within a preset time. Initiation of a circuit breaker fail trip condition should therefore be dependent on both the preset time elapsing and the current detecting elements being operated, outputs from both these functions being effectively connected in series.

(j) The scheme shall be fast reset and shall provide an acceptable safety margin for current circuit breaker operation taking into account any pre-insertion resistor switching provided.

(k) The settings of the current detecting elements shall be equal to or lower than the settings of the associated protection.

(m) The continuous current rating of the current detecting elements shall be at least twice their nominal current rating, the current settings selected being the lowest available.

(n) The resetting time of the current detecting elements on cessation of fault current shall not be greater than 20 ms. The current detecting circuits must be arranged so that, when single pole tripping is specified, correct operation of the scheme occurs during the dead time, i.e. the presence of load current in the healthy phases should not cause maloperation-operation of the scheme.

9.4.8.3 400 kV Busbar Protection Duplicated phase by phase circulating current differential protection relays (low impedance preferred) shall be provided, one for Group “ A” and one for Group “B”, as follows:

(a) Facilities shall be provided for disconnecting and shorting manually the CT circuit of any feeders from the bus protection CT ring Busbars.

(b) Supervision shall be provided to monitor low level CT unbalance and, after a time delay of about 2 to 3 seconds, it shall provide an alarm and block the busbar differential protection.

(c) The protection must remain stable for external fault currents equal to the breaking capacity of the circuit breakers with an adequate safety factor. System X/R ratio should be considered for the performance of the protection scheme. The relay circuit must have adequate thermal rating. Protection isolation facilities should be provided. Where a high impedance scheme is chosen, means shall be provided to limit over voltages.

(d) The busbar protection shall operate for both phase-to-phase and phase-to-earth faults. The principle of operation shall be based on the simple circulating current system. The operating time of the measuring relays shall not exceed 30 m secs at five times the relay current setting. The sensitivity shall be such that definite operation occurs for phase-to-phase and phase-to-earth short circuits during minimum plant conditions, irrespective of the number of circuits in service and the distribution of load and fault currents. The sensitivity level shall not exceed 30 per cent of the minimum fault level for all types of faults.

(e) The equipment shall be stable for all out-of-zone phase-to-phase and phase-to-earth fault currents up to the short circuit current rating of the switchgear, applied gradually or suddenly and irrespective of the distribution of current between the individual circuits.


(f) All circuit breakers connected to a faulty busbar shall be tripped simultaneously, whether they feed fault current or not.

(g) Care shall be taken to ensure that the protection does not maloperate as a result of faults in the associated secondary wiring when the primary circuit is carrying load current. Continuous or automatic cyclic supervision shall be provided for this purpose. Arrangements shall be provided to make the zone containing the faulty circuit inoperative. Where the operation of the supervision device is dependent upon the load current in the primary circuit, operation shall occur at a current of 25 amperes or 10 per cent of the circuit rating whichever is the greater.

(h) The following test and isolation facilities shall be provided on the front of the protection panel.

(i) Short circuiting and isolation of current transformers.

(ii) isolation of individual tripping and inter-tripping circuits.

(iii) Isolation of tripping and individual zones.

(j) Direct transfer tripping, where required, shall be affected by means of electrically separate outputs. The inter-tripping scheme shall be to the approval of the Engineer.

(k) Any Isolator auxiliary switches employed in current transformer circuits shall be of the heavy duty; silver plated type and two switches in parallel shall be used per current transformer connection. The Contractor shall clearly specify the number of secondary circuits which must be switched, the duty of the switches and the timing between individual switches; the Contractor shall be responsible for selecting switches which are adequate for the intended duty.

(m) Similar protection zones shall be provided to overlap areas between plant, bus and feeder protection systems, particularly during temporary stages of substation development.

9.4.8.4 400 kV Current Transformer Stack Protection Where current transformer stacks are fitted, frame leakage earth fault protection shall be fitted in the single earthing connection of each stack to give protection against insulator failure within the stack. Note that all cables between the CT terminal box and note plant must also be routed through the CT providing earth leakage protection.

A setting range as high as consistent with minimum fault levels shall be provided such that the risk of mal-operation is minimised.

9.4.9 400/132 kV Auto Transformer & Associated Equipment Protection 9.4.9.1 400 kV Transformer Main Windings The transformers may be supplied as a single unit or as a bank of three phase units. If single phase units are used, the neutral end and tertiary connections shall be connected such that the protection scheme works in the same way as single units. Multiple initiating devices e.g. Buchholz etc shall provide a common trip function, but the individual phase initiations shall be alarmed.

Phase by phase circulating current differential protection shall be provided for the auto transformer and the 400 kV bus connection using identical ratio current transformers on the 400 kV, 132 kV and individual phase neutral connections. Numerical low impedance relays are preferred. Two sets of relays shall be provided. One set shall be connected to Group B fed by the “B” battery supply and the


other set of relays shall be connected to Group “A” and operating into the “A” battery supply. When the 400 kV disconnect switch is open this protection scheme will be split into zones. Due consideration shall be given to the performance of the protection scheme under both primary operating conditions. Consideration shall be given to providing two identical relays fed from the all of the relevant ct’s. Their tripping functionality shall then be adjusted by the state of the disconnector to meet the objectives above and to provide ”stub end” protection to the transformer hv connections when the transformer is disconnected.

On the 400 kV side a low transient overreach instantaneous overcurrent protection and an IDMT phase by phase backup overcurrent protection shall be provided on Group “A” operating into the “A” battery supply. This may be provided as part of the 400kV Substation Protection – Overcurrent Back Up Protection specified above.

On the 400 kV side instantaneous and IDMT residual overcurrent protection shall be provided for Group “A”.

A minimum of two step distance protection for Group “A” fed by the 400 kV side CT and P.T. facility shall be provided to catch faults to the transformer direction, without to both direction sensing. The first step reach shall be about 70% of the transformer impedance, the second step about 125%.

Early make late break silvered contact auxiliary switches shall be provided specifically designed and approved to switch current transformer circuits or suitably monitored disconnected position relay (Mirror relays) on the transformer 400 kV disconnect to split the high impedance circulating current transformer protection into two zones when the disconnect switch is open.

Additional contacts shall be provided to interrupt the tripping between 400 kV to 132 (and vice-versa) when this disconnect switch is open. Provide tripping circuits trip the 400 kV, 132 kV, tertiary 11 kV and both 380 V circuit breakers when the 400 kV disconnect switch is closed and only those on the appropriate side of the disconnect switch when it is open. This functionality may be provided within the numerical relay.

Group B transformer Buchholz protection and the two stages of the 400 kV and 132 kV winding temperature (hot spot simulator) instrument connected to warning and urgent alarms but with the urgent stage reconnectable to trip the lv only, if required, shall be provided.

. Where “diameter” ct’s are summated to provide transformer current inputs to protection, the ct cores and lead burdens shall be matched.

9.4.10 132 kV Transformer Protection Group B circuit breaker fail protection shall be provided to trip the 400 kV circuit breakers and the appropriate 132 kV bus protection trip circuit if the 132 kV circuit breaker fails to operate on fault. The protective equipment to be similar to that provided for the 400 kV circuit breakers but needs to be suitable for single trip coil three phase trip breakers only.

L.V. IDMT phase and residual over current relays shall be provided on the transformer Group “A” protection to trip the 132 kV circuit breaker only.

A minimum of two step distance protection shall be provided as specified in Clause (a) above, but fed by 132 kV side C.V. and P.T.


9.4.10.1 11 kV Tertiary Winding The tertiary winding of the 400/132 kV auto transformers is connected to an interconnected star (zigzag) earthing transformer having primary star point earthed, or alternatively for unloaded tertiaries, one corner of the tertiary may be earthed via the main winding protected earth connections. These connections shall be easily accessible on site.

Group “A” individual phase by phase and separately residual high impedance circulating current differential protection shall be provided for the 11 kV Busbar fed by the 11 kV bushing CT of the Main Transformer (only the phase protection), the tertiary Reactor CT and the capacitor bank CT, if provided. Care shall be taken when setting the protection, to take account of the large current imbalance possible when subjected to external earth faults (e.g. from the capacitor or reactor).

If neither tertiary reactor nor capacitor bank is supplied, provide instantaneous overcurrent protection for Group “A” fed by the 11 kV bushing CT.

Group “B” IDMT overcurrent protection relays shall be provided on the main tertiary phase connections and earth fault IDMT protection in the earthing transformer neutral connection to earth using the “B” battery supply.

Group “B” transformer Buchholz protection shall be provided for the Station Supplies and Earthing Transformers, and an oil temperature and oil level stage 2 trips if it is available.

Circuits to make the above protections trip into the appropriate transformer trip circuits shall be provided.

Overcurrent and neutral overcurrent protection shall be provided on the 380-volt side of station service transformers to trip the 380-volt circuit breakers, settings to be coordinated with fuse settings. The 380-volt circuit breakers to also be tripped from transformer protections.

9.4.10.2 Tertiary Compensation Plant Group “A” individual phase by phase high impedance circulating current differential protection shall be provided together with IDMT and instantaneous overcurrent protection for the tertiary reactor and if oil filled reactor are provided Buchholz relay, oil temperature and oil level protection on Group “B”

Group “A” IDMT and instantaneous overcurrent protection and Group “B” capacitor unbalance protection for the capacitor bank shall be provided.

Trip circuits shall be provided from the main transformer protections to both tertiary circuit breakers, optionally switchable.

9.4.11 132 kV Line Protection The following types of system, based on the circuit types to be protected, shall be provided. The specific format of the feeder to be protected shall be set out in the Contract Scope of Work. The actual equipment used will be chosen according to the design and setting ranges of the equipment offered.

9.4.11.1 132 kV Overhead Line Feeders For overhead line feeders, phase-fault and earth-fault distance protection using permissive underreach transfer trip shall be provided. Facilities required for three pole auto reclose shall be provided. The relay shall be designed not to trip for the high zero sequence circulating currents which


occur during single pole open conditions on the overlying 400 kV supergrid (duration not to exceed 2 seconds). Facilities for fast tripping if a circuit breaker is closed onto a three phase solid fault when a line is energised shall be provided.

Time delayed (zone 2) tripping shall be provided for a fault occurring at the remote end of a line when (1) the signalling channel is out of service or (2) the remove end of the circuit is open and initiation of permissive signalling is not possible. Zone 2 should be capable of providing protection for any remote end busbar faults.

Zone 3 or starting offset mho elements (depending on the requirements of the relay offered) with an additional time delayed tripping output adjustable between 1 and 3 seconds shall be provided. This trip output shall not initiate auto reclosing. Zone measuring elements setting ranges to be as per 400 kV distance protection, but with extended Zone 3 reach where long lines follow short lines.

For overhead line feeders less than 10km in length, the Tenderer shall confirm that the Distance Protection offered will operate correctly for the length of feeder specified, based on the System Impedance Ratio and fault level, otherwise a pilot wire differential protection shall be offered.

Where the feeder is a mix of overhead line and cable, the Scope of Work will detail this to allow the Tenderer to offer a a suitable solution.

9.4.11.2 132 kV Cable Feeders Cable circuits shall be provided with pilot wire differential protection. Auto reclose on cable circuits wil not be required.

The protection may operate over optical fibre or twisted pair route pilot wires and this will be set out in the Scope of Work.

9.4.11.3 132 kV Transformer Feeders “Transformer Feeders” relates to substations where the line is terminated directly onto a transformer without a 132kV coupling circuit breaker between it and another circuit, i.e. no other line starts from the transformer substation.

Overhead line and cable transformer feeder circuits shall be protected as for standard feeders above, except that duplicated station to station direct transfer trip shal be provided. The distance protection shall be set to measure part way into the transformer.

If no remote 132 kV transformer circuit breaker is specified, duplicated direct transfer trips shall be provided for the remote transformer protections. A fault throwing switch shall be provided if no independent and reliable duplicated DTT can be constructed.

9.4.11.4 132 kV Backup Protection Circuit breaker fail protection shall be provided to trip the appropriate 132 kV bus protection trip circuit if the 132 kV circuit breaker fails to operate on fault. The protective equipment to be similar to that provided for the 400 kV circuit breakers but needs to be suitable for single trip coil three phase trip breakers only.

Three pole phase and one residual IDMT overcurrent relays shall be provided. Each relay shall be provided with an instantaneous element which shall be brought out to a separate output terminal.


These relays shall not initiate auto reclose when they operate with IDMT elements although the instantaneous elements should be connectable to initiate reclosing.

These relays shall be connected to the same current transformer core as used for instrumentation provided the burden limits are not exceeded.

Additional remote backup facilities may be specified for pilot protected circuits which feed busbars having no fast bus protection.

9.4.11.5 132 kV Auto Reclose This equipment should work in conjunction with automatic voltage selection and synchronising equipment specified.

Three pole high speed and delayed auto reclose facilities shall be provided, optionally switchable by a two position selector switch located on the relay panel. The high speed auto reclose shall be provided with a dead time range of about 0.2 to1 second, without synchro check facilities. The relayed auto reclose shall be provided with voltage and synchro check and with a dead time range of 1 to 6 seconds. Auto reclose shall be initiated by line protection only.

Facilities shall be provided for switching the reclose equipment out of service on local relay panels and the SCS.

Auto reclose operated, auto reclose successful and final trip indications shall be provided.

9.4.12 132 kV Busbars 9.4.12.1 132 kV Busbar Protection A selectable, phase by phase, busbar discriminating, bus protection with check facilities shall be provided (numeric, low impedance is preferred) so that both the discriminative and check feature must operate to give a trip output, as follows:

(a) The busbar protection shall operate for both phase-to-phase and phase-to-earth faults. The principle of operation shall be based on the simple circulating current system. The operating time of the measuring relays shall not exceed 30 msecs at five times the relay current setting.

(b) Duplicated functionality shall be provided either by separate algorithms within one numerical relay (preferred) or by separate Discriminating and Check facilities for each busbar section. Each system shall be capable of detecting all types of faults under all system generation conditions.

(c) This scheme shall only require one set of three phase CT’s per circuit, but with separate cores if required.

(d) There shall be fully discriminative clearance of busbar faults on any section of busbar and without introducing sequential tripping of coupler or section circuit breakers on the 132kV double busbar. All circuit breakers connected to a faulty busbar shall be tripped simultaneously, whether they feed fault current or not.

(e) Facilities shall be provided to prevent incorrect tripping should the CT selection circuits fail to transfer correctly during On-Load changeover.


(f) Care shall be taken to ensure that the protection does not maloperate as a result of faults in the associated secondary wiring when the primary circuit is carrying load current. Continuous or automatic cyclic supervision shall be provided for this purpose. Arrangements shall be provided to make the zone containing the faulty circuit inoperative. Where the operation of the supervision device is dependent upon the load current in the primary circuit, operation shall occur at a current of 25 amperes or 10 per cent of the circuit rating whichever is the greater.

(g) The following test and isolation facilities shall be provided on the front of the protection panel.

(i) Short circuiting and isolation of current transformers.

(ii) Isolation of individual tripping and inter-tripping circuits.

(iii) Isolation of tripping and individual zones.

(h) Direct transfer tripping, where required, shall be affected by means of electrically separate outputs. The inter-tripping scheme shall be to the approval of the Engineer.

(j) The sensitivity shall be such that definite operation occurs for phase-to-phase and phase-to-earth short circuits during minimum plant conditions, irrespective of the number of circuits in service and the distribution of load and fault currents. The sensitivity level shall not exceed 30 per cent of the minimum fault level for all types of faults.

If a high impedance scheme is offered, it must operate as follows:

(a) If required, the Discriminating system associated with each busbar section is unique, however the Check system is common to all busbar sections.

(b) This scheme shall only require one set of three phase CT’s per circuit, but separate cores for discriminative and check circuits (if required), and be capable of correcting for circuit CT’s of different ratios. With such a scheme, primary tapped 132 KV current transformers would be acceptable. If a scheme using the high impedance principle is proposed, the circuit CT’s must have secondary taps with bus protection cores having identical ratios and suitable characteristics.

(c) Each system shall comprise relays connected in parallel across busbar protection CT bus wiring.

(d) The Check system shall be connected in parallel across the busbar protection CT bus wiring associated with all incomers and feeders. Each Discriminating system shall be connected in parallel across the busbar protection CT bus wiring associated with feeders, incomers, bus coupler and bus section circuits connected to a particular busbar-section.

(e) Coincident operation of the Check system relay and the Discriminating system relay shall be arranged to initiate tripping of the appropriate busbar-section.

(f) Supervision relays shall be provided to monitor low level CT unbalance and to give time delayed alarm and protection block.

(g) Silvered contact bus disconnect auxiliary switches shall be provided, specifically designed and approved for switching CT circuits with the respective circuits alive (On load changeover) or


appropriately supervised disconnect position relays for CT selection. The switches or relays being set so that the auxiliary switch closes prior to main disconnect contacts pre-arcing on closing, and similarly opens after contact arcing ceases on opening. When both bus disconnects are open the CT's disconnected from the bus wires must be shorted and earthed.

(h) The Contractor shall clearly specify the number of secondary circuits which must be switched, the duty of the switches and the timing between individual switches; the Contractor shall be responsible for selecting switches which are adequate for the intended duty.

(i) For multi-section busbars, one check zone per double busbar section shall be provided.

9.4.13 132 kV Bus Section and Bus Couplers Three-pole phase and one residually connected (earth fault) IDMT overcurrent relays shall be provided on each bus section and bus coupler breaker, each with separately connected instantaneous elements.

A distance relay in line with that specified for feeder protection shall be provided for emergency purposes.

9.5 General Protection Requirements

9.5.1 Protection Relay Power Supplies All protective relay operating supplies shall be provided such that power for operation is either self-derived from the CT or VT circuit or obtained from the relevant 110V DC protection supply. These relay operating supplies to be suitable for successful non-delayed tripping when closing or reclosing onto all faults. The use of small rechargeable cells within the relay unit or system is not acceptable unless the charge cycle and duty can give a maintenance free life of over five years, and the Tenderer shall draw attention to any such proposal.

Supply all equipment (electromechanical or static) suitably barriered and protected so that any surges on the CT, VT or 110V DC supply system does not cause damage or relay malfunction, according to the relevant IEC Standard and the relay manufacturer prescription.

9.5.2 General Protection Testing & Maintenance Facilities Test facilities shall be provided on each relay or relay group to:

(a) isolate and short circuit, on the CT side, the associated CT circuits,

(b) allow insertion of a test device to break into each CT circuit in turn,

(c) isolate voltage supplies, if used,

(d) isolate all trip outputs,

(e) attach portable test equipment to secondary inject the relay group.

These test facilities may be part of the withdrawal facilities for withdrawal relays or separate for non-withdrawable or complex systems.


Because of the nature of the CT and trip circuit interconnections within each diameter of a 1-1/2 switch station the following additional facilities are required at 400 kV:

- Provide separate test blocks to isolate and short circuit, on the CT side, individual circuit breaker CT's where two or more sets feed into one protective scheme.

- Provide separate multi-element protection isolation changeover switches for each group in the protection of any one plant item, the other group to be kept in service. Provide switches to interrupt all interfaces with tripping, auto-reclose and protection signalling systems.

- Provide similar multi-element isolation switches, one for each protection signalling system (leased or PLC) on each circuit, to isolate all facilities on the 110 Volt side of the interface equipment.

- Provide, within the protection signalling equipment, sufficient isolation and test facilities to test each channel and signal.

9.5.3 Fault Recording and Data Logging Facilities shall be provided to measure and record for each 400 kV line circuit individually and for each 132 kV section, a general record for the following:

(a) Fault duration,

(b) Identity of faulted phase (in case of 400 kV lines and connected plant),

(c) magnitude of voltage variation fault,

(d) magnitude of the phase and neutral currents for 400 kV lines and for 132 kV lines and transformers within the affected station,

(e) operational times for all main 400 kV trip outputs,

(f) phase on which single-pole reclose equipment operated (e.g. signal from the distance protection starting),

(g) main stages within the single-pole reclose cycle,

(h) monitor the protection signalling signals,

(j) at least 500 ms of prefault recording of the voltage and current signals.

Resolution of events should be better than 5ms.

Time and date (month, day, hour, minute) shall be automatically recorded.

The storing, recording and presenting of operational data as it occurs shall not be over-written by further fault-trips or reclosures that are within the design operating cycles of the current breakers and primary relaying. The final allocation of monitor points is to be approved by the Engineer, agreed based on the type of recorder offered. For each 132 kV section, the monitor it is only required to monitor items I (a)-(d) and (i). If a multiple recorder is used for 400kV circuits, items I (a)-(d) and (i)


must be available on a common recorder initiated by rate of change of voltage starting. Individual or group recorders should be started by the trip of any directly associated circuit.

9.5.4 400 kV Fault Location Facilities shall be provided to monitor currents and voltages available at a line terminal during a fault and such equipment as necessary to compute and record line fault location.

Equipment shall be so designed as to protect the stored data from erasure caused by high speed reclosure onto a persistent fault.

9.6 Relay Panel Arrangement

Relay panel layouts shall be divided with regard to function and DC power supply so that the two DC supplies do not appear on the same panel except as specifically approved.

Panels shall be arranged so that protection circuit isolating, fusing and relay equipment is accessible from the front of the panel. Power supply fuses or switches and isolation devices to be accessible with the panel door closed.

9.7 Direct Transfer Tripping and Teleprotection Signals

The Tenderer shall identify the communications requirements for the protection during his specific site surveys and in discussion with the Employer’s representative. The contract includes the complete provision of communications equipment, including the substation end of the telecommunications link, and the relevant interconnections, whatever the medium used.

400 kV overhead line circuits shall be provided with direct transfer tripping between line feeders ends via two direct transfer tripping channels. Blocking and Permissive Underreach signals shall also be provided for the respective distance protections. Send/receive relays are to be provided for each signalling channel.

A channel shall also be provided for the Directional Comparison Earth Fault protection.

Separate cables are to be used for each teleprotection channel.

At the protection relay panels, the cables for the teleprotection signals are to be terminated on terminals, which are wired directly to isolating links. This is to enable the teleprotection equipment to be readily isolated from the protective relays and the 110 V dc tripping and control supplies. Disconnecting links incorporated in the terminal blocks will not be accepted for this purpose.

For each discrete teleprotection channel, a two-position test switch ("test/service") is to be installed on the front of the relay panel to enable the functioning of the teleprotection channel to be tested. The switch is to be lockable and provided with a lock and duplicate keys. An indication lamp is to be provided for indicating that the test switch is in the "test" position. A push-button is to be provided to initiate a test signal to the teleprotection equipment. A second indicating lamp shall be provided to indicate that a test signal has been received from the remote station.


10. COMMUNICATION EQUIPMENT


The contract includes the provision of all communication link equipment at the substation for whatever medium is required. This will normally involve Power Line Carrier, but the actual substation communication requirements shall be as set out in the Contract Scope of Work. The generic specification “Standard Specification for Telecommunication and SCADA Systems” shall be used to provide the performance requirements for the equipment. The remote ends of the communications links will be provided by others. Work under this section of the Specifications shall include:

(a) Design of communications equipment terminal ends as part of a total link.

(b) Design, manufacture, delivery to site, installation, testing and guarantee of items of equipment as detailed below.

The Contractor shall co-ordinate all aspects of the work with the suppliers of the remote end communications link equipment to ensure that the complete installation operates correctly and complies in every respect with the communications design specifications.

10.2 Power Line Carrier

10.2.1 400 kV Line Traps (a) Extent of Supply

Provide, deliver to site, and install 400kV line traps at 400/132kV substations as part of the overall requirements for Power Line Carrier circuits. The quantities shall be determined by the Tenderer from the Single Line Diagram of Substation Protection available with the solicitation documents. In general, for 400 kV single circuit lines, power line coupling is required on the R and S phases. For double circuit lines on the same towers, the S phase on each circuit will be used. The requirements for lines with mixed configuration etc will be provided in the contract Scope of Work.

(b) General Electrical Characteristics

These shall be in accordance with the general plant requirements of this specification.

(c) General Mechanical Characteristics

The equipment should be of modern lightweight design. All parts should be fully protected against deterioration due to the environmental conditions. If the design of line trap requires them, barriers should be provided to prevent the entry of birds.

(d) Mounting

The line trap should be suitable for pedestal or suspension mounting.

(e) Blocking Impedance

The blocking impedance shall be a minimum of 400 ohms over the required band of frequencies.


(f) Bandwidth Requirements

Precise frequencies have not yet been allocated. The expected bandwidth requirement will be 36 kHz. The geometric mean frequency approximately 100 kHz. Two 4 kHz full duplex power line carrier terminals may be required on each 400 kV line.

(g) Rated Inductance

The inductance of the line trap should be chosen to optimise the design of the coupling equipment with due consideration being given to cost, overall dimensions and the use of standard, proven, designs and inductance values.

(h) Surge Diverters and Protective Devices

Line traps and tuning units shall be provided with suitable surge diverters and protective spark gaps to protect the equipment against transient overvoltages. The power line carrier equipment will be used for protection signalling purposes. The operation of any protective device associated with the line trap should not affect the protection signalling system.

(j) Accessories and Mounting Hardware

The line traps shall be provided complete with all necessary accessories and mounting hardware required for their installation and operation in the overall power and communications systems.

10.2.2 132 kV Line Traps (a) Extent of Supply

Provide, deliver to site, test and install 132 kV line traps at 400/132 kV substations as part of the overall requirements for Power Line Carrier circuits. The quantities shall be determined by the Tenderer from the Single Line Diagram of Substation Protection available with the solicitation documents. In general, for 132kV single circuit lines, power line coupling is required on the R and S phases. For double circuit lines on the same towers, the S phase on each circuit will be used. The requirements for lines with mixed configuration etc will be provided in the contract Scope of Work.

(b) General Electrical Characteristics


(c) General Mechanical Characteristics

The equipment shall be of modern lightweight design. All parts shall be fully protected against deterioration due to the environmental conditions. If the design of the line trap requires them, barriers should be provided to prevent the entry of birds.

(d) Mounting

The line trap should be suitable for pedestal or suspension mounting.

(e) Blocking Impedance


The blocking impedance shall be a minimum of 800 ohms over the required band of frequencies.

(f) Bandwidth Requirements

The line trap shall be suitable for wide band application in the frequency range 40-500 kHz by fitting the appropriate tuning part.

(g) Rated Inductance

The inductance of the line trap should be chosen to optimise the design of the coupling equipment with due consideration being given to cost, overall dimensions and the use of standard, proven, designs and inductance values.

(h) Surge Diverters and Protective Devices

The line trap and associated tuning units shall be provided with suitable surge diverters and protective spark gaps. The power line carrier equipment will be used for protection signalling purposes. The operation of any protective device associated with the line trap should not affect the protection signalling system.

(j) Accessories and Mounting Hardware

The line trap shall be provided complete with all necessary accessories and mounting hardware required for its installation and operation in the overall power and communications system.

10.2.3 400 kV and 132 kV Line Coupling Capacitors (a) Extent of Supply

In general, power line carrier will be coupled using the primary system capacitor voltage transformers, covered elsewhere in this specification. Where required by the Contract Scope of Work, the Tenderer shall provide, deliver to site, test and install 400 kV line coupling capacitors at 400 kV/132 kV substations in Iraq as part of the overall requirements for Power Line Carrier circuits.

(b) Coupling Capacitors

Electrical characteristics of 400 kV and 132 kV systems:


System surge impedance 308 ohms

(c) Capacitance

The value of capacitance shall be decided by the power line carrier system design requirements.

(d) Mechanical Characteristics


The coupling capacitors shall be suitable for reliable operation outdoors under the specified climatic conditions. Drawings shall be provided with the tender documents clearly showing the available methods of mounting, principal dimensions, etc.

(e) Drain Coil, Earth Switch and Tuning Components

A suitable drain coil and earth switch, protected by suitable protective spark gaps shall be provided in the capacitor base housing. Provision shall also be made for mounting tuning components. A heater shall be provided if required by the design. The heater shall be suitable for operation from 200 Volt, 50 Hz, single-phase supplies.

(f) Earthing

An adequate means of earthing shall be provided.

(g) High Voltage Connection

Details of high voltage connections shall be given in the tender documents.

(h) Materials and Manufacturing Standards

The materials used and manufacturing methods employed must conform to the standards laid down for substation equipment.

The minimum creepage distance shall be in accordance with the substation design requirements.

(j) Nameplates

The following minimum information shall appear on the nameplates of all coupling capacitors:

1. Manufacturer's name.

2. Type and form designation.

3. Instruction book number.

4. Operating voltage rating.

5. BIL rating.

6. Capacitance.

7. Weight.

10.3 Power Line Carrier Terminal Equipment, Line Matching Units and Co-axial Cable

The Generic specification “Standard Specification for Telecommunication and SCADA Systems” shall be used to provide the performance requirements for the equipment. The normal communication medium will be Power Line Carrier and this will generally require one set of terminal equipment etc for each primary feeder end, as shown on the Single Line Diagram of Substation Protection available with the solicitation documents. In general, for 400 and 132kV single circuit lines, power line coupling is


required on the R and S phases. For double circuit lines on the same towers, the S phase on each circuit will be used. The requirements for lines with mixed configuration etc will be provided in the contract Scope of Work. Any other site specific requirements will be set out in the Contract Scope of Work.

10.4 Protection Signalling Equipment

The Generic specification “Standard Specification for Telecommunication and SCADA Systems” shall be used to provide the performance requirements for the equipment. Protection Signalling Equipment will be required on most Primary System Feeders and the quantities shall be determined by the Tenderer from the Single Line Diagram of Substation Protection available with the solicitation documents.

10.5 Microwave Radio Link Equipment

The Generic specification “Standard Specification for Telecommunication and SCADA Systems” shall be used to provide the performance requirements for the equipment The quantities and configuration shall be as set out in the Contract Scope of Works.

10.6 Telephone Equipment (PABX)

The Generic specification “Standard Specification for Telecommunication and SCADA Systems” shall be used to provide the performance requirements for the equipment.with a PABX wil berequired at each substation and the quantities and configuration shall be as set out in the Contract Scope of Work. In general, a small PABX equipped with two trunk lines and 20 extensions, including three weatherproof outdoor handsets, will be required.

10.7 Optical Fibre Based PDH/SDH Equipment

The Generic specification “Standard Specification for Telecommunication and SCADA Systems” shall be used to provide the performance requirements for the equipment. Where this equipment is required, quantities and configuration shall be set out in the Contract Scope of Work.


11. ELECTRICAL STATION SERVICES


The work to be done under this Section of the Specification consists of the design, manufacture, testing, supply, delivery, installation, commissioning and guarantee of the following equipment:

(a) Main 110volt DC and communications 48volt DC battery systems.

(b) DC distribution switchgear and panels.

(c) AC distribution switchgear and panels.

(d) Standby / Emergency Diesel Generating Set.

(e) Commissioning power supply.

11.2 Main 110 Volt Station Batteries & Equipment

(a) General

The Contractor shall provide a duplicate 2-wire, 110 V DC (nominal voltage) DC supply system, fed from two independent battery banks, each having separate charging systems. Separate main and subsidiary distribution panels and minimal manual/automatic changeover interconnection between systems so that the loss of one battery bank, charger or main distribution board does not jeopardise the second system. Each battery/charger shall be capable of feeding the entire station load continuously for the rated duration of 8 hours.

The DC voltage shall be 110V + 10%. The Contractor shall submit calculations related to the voltage drops, with a list of the maximum and minimum allowable voltages for all the DC devices and relays.

The battery systems shall be referred to as "A" battery and "B" battery and the protective equipment divided between the two battery banks as indicated in the specifications, so as to maximise the reliability of the protective system in the event of failure of one of the battery banks or related equipment.

(b) Batteries

Batteries shall be of nickel-cadmium, pocket or sintered plate, open or semi-sealed design, housed in suitable translucent plastic containers to BS 6290. Each cell shall be provided with a vent cap and/or filler plug and a pressure operated gas release valve.

Sufficient electrolyte reserve shall be provided to give six monthly maintenance periods.

The plates shall be designed and constructed so that the plates are rigidly held so as to avoid distortion and short-circuiting of the plates.

The battery shall be suitable for float and boost charging and capable of providing the required output throughout the specified ambient conditions.


The battery cells shall be arranged in tiers on suitable racks and spaced so to allow sufficient access for maintenance. The racks shall be of a design to withstand corrosion by battery electrolyte.

All cells shall be consecutively numbered and terminal cells marked to indicate polarity.

Each battery shall be designed to provide sufficient capacity for operation at full load for eight (8) hours in the event of charger failure.

(c) Battery Chargers

The battery chargers shall be a solid-state type, suitable with respect to size and design for the defined operating conditions. The mode of charging shall be by the constant voltage method and the charging voltage shall be variable to compensate for internal losses in the cells and constant loads, etc. Voltage selection shall be such as to avoid overcharging.

Each battery charger shall be suitably sized so as to be capable of charging both batteries at the same time should one of the chargers fail or be out of service for maintenance.

The system shall be designed for the selection of float and equalising voltage levels most appropriate to the system conditions and co-ordinate this with the rating.

Voltage regulation shall be designed to ensure that the voltage is within ± 1 per cent of the output over the load range zero to full load with an output voltage ripple of less than 2 per cent rms.

The charger shall have an incoming supply voltage monitor to detect loss of supply.

(d) DC Main Distribution Panel

The main DC distribution panels shall be connected to the batteries by a 4 breaker automatic change-over system with a manual resetting scheme, interlocked to prevent paralleling of the batteries. A manual interconnection MCB shall be provided for emergency purposes to allow one charger to charge both batteries.

."A" and "B" battery supplies shall be maintained on separate distribution boards. Provision of sub-distribution from these boards by MCBs or HRC fuses to the various load centres.

Supply each row of panels by two ring circuits from each of the two DC supplies. One for the protection supply and the other for breaker control.

Protect each protective system and circuit breaker control system with either an MCB or HRC fuse. Provide one DC under-voltage check relay per ring circuit.

The Contractor shall submit a plan that proves selectivity of the fuses and/or circuit breakers.

(e) DC Bus and Battery Instrumentation and Alarms

Provide DC ammeter and voltmeter accurate to within 2 per cent, for each battery, charger and DC Distribution board.


The battery will be high resistance earthed from the mid-point of a potentiometer. MCBs/fuses will be on the positive side of the battery.

Provide earth leakage alarm when any leakage to earth exceeds 2 mA. The detection level of this alarm should be adjustable.

No relay connected to the system should operate due to discharge current of the capacitance of the negative side wiring if an earth fault occurs on the positive side of the relay coil, without any other operation.

Provide DC high voltage and low voltage alarms that give a signal when exceeding the set levels. All alarms to have independent contacts suitable for the alarm equipment and be independent of the 110 volt supply for operation.

(f) Separation of Protection Relay Groups

Provide the following relays groups on the "A" battery:

(i) All protections Group "A".

(ii) All breaker controls, including closing coils and "A" trip coils.

(iii) Alarms, interposing relays etc.

Provide the following protection equipment on the "B" battery:

(i) All of protection group "B".

(ii) Breaker "B" trip coils.

11.3 Communication 48 V Batteries and Equipment

(a) General

The Contractor shall provide a duplicate 2-wire, 48 V DC (nominal voltage) DC supply system, fed from two independent battery banks, each having separate charging systems. Separate main and subsidiary distribution panels and minimal manual/automatic changeover interconnection between systems so that the loss of one battery bank, charger or main distribution board does not jeopardise the second system. Each supply shall be capable of feeding the entire station load continuously for the rated duration of 8 hours.

(b) Batteries

(i) Battery Voltage:

The battery voltage shall be 48 volts nominal with a 48V ± 10% maximum in operation. The Contractor shall submit calculations about the voltage drops and provide a list of the maximum and minimum allowable voltage on all the 48V DC devices and relays.

(ii) Batteries

The Contractor shall provide a design suitable for communications equipment use.


Provide batteries of nickel-cadmium of the pocket or sintered plate, open or semi-sealed design housed in suitable translucent plastic containers to BS 6290. Each cell shall be provided with a vent cap and/or filler plug and a pressure operated gas release valve.

Sufficient electrolyte reserve shall be provided to give six monthly maintenance periods.

The plates shall be designed and constructed so that the plates are rigidly held so as to avoid distortion and short-circuiting of the plates.

The battery shall be suitable for float and boost charging and capable of providing the required output throughout the specified ambient conditions.

The battery cells shall be arranged in tiers on suitable racks and spaced so to allow sufficient access for maintenance. The racks shall be of a design to withstand corrosion by battery electrolyte.

All cells shall be consecutively numbered and terminal cells marked to indicate polarity.

Each battery shall be designed to provide sufficient capacity for operation at full load for eight (8) hours in the event of charger failure.

Reference shall be made to the general section of the specification for information on environmental and climatic conditions.

The main battery and charger fuses shall be mounted as close to the battery terminals as possible. Battery and charger cables shall be separately fused and linked.

(c) Battery Chargers

The Contractor shall provide for each battery bank a solid-state battery charger, suitable with respect to size and design for the defined operating conditions. The mode of charging shall be by the constant voltage method and the charging voltage shall be variable to compensate for internal losses in the cells and constant loads, etc. Voltage selection shall be such as to avoid overcharging.

Each battery charger shall be suitably sized so as to be capable of charging both batteries at the same time should one of the chargers fail or be out of service for maintenance.

The system shall be designed for the selection of float and equalising voltage levels most appropriate to the system conditions and co-ordinate this with the rating.

Voltage regulation shall be designed to ensure that the voltage is within ± 1 per cent of the output over the load range zero to full load with an output voltage ripple of less than 2 per cent rms.

The charger output shall be sufficient to return the battery to full charge in twelve hours, after an eight-hour discharge at full load, while maintaining normal service.

The equalising and float voltage levels shall be adjustable and suitable for the range of operating conditions recommended by the battery manufacturer.


The output voltage shall be maintained within ± 1 per cent of its set value for combined input and load variations of:

Load 0 - 100%

Nominal line voltage ± 10%

Frequency ± 2Hz

The regulation response time shall be better than 50 milliseconds.

A suitable DC ammeter and a DC voltmeter shall be provided for each battery, charger and DC main output.

An under-voltage alarm shall be provided at the charger or its associated distribution board. A contact shall be provided to extend the alarm to an external annunciator.

The charger shall have an incoming supply voltage monitor to detect loss of supply.

(d) DC Distribution Panels

Suitably designed DC distribution panels shall be connected to each battery by a 4 breaker automatic change-over system with a manual resetting scheme, interlocked to prevent paralleling of the batteries. A manual interconnection MCB shall be provided for emergency purposes to allow one charger to charge both batteries.

The distribution boards shall serve as the main distribution points to the communications equipment cubicles and racks.

(i) Design Features:

The distribution board shall have as a minimum requirement:

- MCBs or fuses and links for up to twelve sub-circuits.

- Provision for the fitting of a second group of MCBs or fuses and links for twelve additional sub-circuits.

- DC ammeter and voltmeter accurate to within 2 per cent, for each battery, charger and DC Distribution Board.

- Earth link for earthing one side of the battery, if required.

- DC high voltage and low voltage alarms that give a signal when exceeding the set levels. All alarms to have independent contacts suitable for the alarm equipment and be independent of the 48 volt supply for operation.


(ii) Cabling:

Suitable arrangements shall be made for the glanding and termination of all cables entering and leaving the distribution panel in a manner that allows easy addition of future cables as required.

All distribution cabling shall be radial. All fuses and links shall be fed from suitable low impedance busbars that shall in turn be connected to the battery terminals via the main battery cable.

11.4 LVAC Distribution Switchgear Panels, Cabling and Socket Outlets

A 380/220 volt, 3 phase 4 wire, earthed neutral system shall be provided for the AC station services. The supplies will be taken from the station service transformers via load breaking, fault making disconnect switches. Each supply shall be capable of carrying the full rating of the transformer.

Arrangement and connection details of the AC systems for both substations are as shown in the Tender drawings..

(a) Main Switchgear

The distribution panel shall be equipped with a single busbar , 380 volt, ac board with a bus tie breaker, each busbar section is to be fed from an auxiliary transformers (or other in-feed) together with all necessary switch fuses required to supply all the substation switchgear, transformers,d.c.batteries and chargers, and the buiding services, including air conditioning, lighting and power circuits.

The bus tie - breaker shall run normally open and be interlocked with the incoming breakers to automatically close when one of the supplies is lost. Manual control shall be provided for maintenance requirements and restoring equipment to normal operating mode. Sub-distribution from these assemblies shall be from HRC fused switches to distribution panels. Units are to be supplied with suitable locks and keys. The main switchgear assembly is to be metalclad Form 4 type and is to be termite and vermin proof (IP 50).

The switchboards shall be built up of circuit-breaker units, isolating fuse-switches, isolators, contactors, moulded case and miniature circuit-breakers. All units, when built up into a complete switchboard, shall be such that the completed switchboard is of flush fronted design having a neat and clean appearance and is readily extensible.

The units are to house all protection equipment, include lighting, heating and socket outlets as required. Heavy-duty filters, replaceable without tools, shall be provided if forced ventilation system is used.

(b) Distribution Panels

Distribution panels as required are to be 380 V AC, three-phase and neutral fitted with miniature circuit breakers or equivalent. Type and manufacturer of equipment is to be approved by the Engineer. Panels are to be supplied with locks and keys. Each building is to have its own distribution panel(s) for building services requirements.


Contractor is to size the panels and the number required to meet the requirements as detailed in the Plant and Civil specifications.

(c) Power Plugs and Convenience Outlets

In addition to those provided under Building Services, the following sockets shall be provided, complete with plugs and adequate switchgear on the LVAC switchboard, with the switchgear/transformers:-

(i) Power plugs for portable welding equipment shall conform with BS EN 60309. These units are to be 380 volts, 63 amps, 4-wire (3 phase, neutral and earth), metal-clad to IP 65, weatherproof and incorporate spring-return flap cover., incorporate an on-load disconnector, MCB rated to suit the switch and a residual current circuit device rated at 30 mA.

. No aluminium is to be used in their construction. Power plugs are to be supplied on the following basis:

1 - in each 400 kV Switch and a Half Diameter in AIS stations and one per two Switch and a Half Diameters in GIS stations

1 - for each transformer/reactor bank

1 - for every third 132 kV switch bay in AIS stations and two per switchroom in GIS stations

1 – workshop, if applicable

(ii) Convenience outlets are to conform with the relevant BS standards Outlets are to be 220 volt, 13 amp AC (2-pole and earth). Convenience outlets are to be supplied on the following basis:

1 - each breaker marshalling cubicle/Bay Control Unit

1 - each transformer marshalling kiosk

1 - each line termination gantry

1 - each 380/220V station service main switchboard

1 - each reactor marshalling kiosk

2 - control desk

1 - each row of control metering panels

1 - each row relay panels

(iii) Outlets with capacity of 20A AC and with voltage of 110V/63V, four wires and earth shall also be provided on each row of relay panels, complete with supply transformer.


(iv) Socket Outlet for Oil-Filled Transformer Bays

One Oil filtration Plant socket shall be provided on the wall adjacent to each transformer bank, and for each line reactor and tertiary reactor bank. The sockets shall be suitably rated for the oil treatment plant, but no less than 150A. The plug and socket shall be of 5 pole type (3ph + E + N) of the metal-clad type complete with a switch-fuse unit, IP 65 rated, for outdoor use and incorporating a spring return flap cover over the plug socket. A sunshade should be provided over the box. These should be directly fed from the 380V LV AC switchboard.

The plug and socket shall be interlocked such as that the socket cannot be switched on until the matching plug is fully inserted, nor can the plug be withdrawn with the switch closed.

The socket unit shall be provided with the following:

• Facility for incoming supply cable looping, and

• Provision for padlocking the switch in the off position.

11.5 Diesel Generator

The diesel generator shall comprise but not be limited to the following items:

Diesel engine with governor and accessories; synchronous generator, 380 volt, 50 Hz, 3-phase 4-wire, high resistance earthed, exciter and voltage regulator;

Fuel tank and stand;

Mounting hardware;

Control panel;

Battery supply for control alkaline type complete with automatic battery charger;

Generator circuit breaker;

Tools, sufficient for routine maintenance;

Two sets of “Start-up” spares

Interconnecting wiring of engine controls;

Exhaust system, complete with silencer;

One(1) suitable walk-in housing for all components, excepting fuel tank, and complete with necessary foundations.


(a) Service Conditions

(i) The fuel tank shall be installed at a safe and convenient adjacent location. The tank shall contain sufficient fuel for three days continuous operation. The ambient air temperature may range from 5°c to 50°c.

(ii) The engine may be required to run for extended periods of time during maintenance, without benefit of its assigned generator loads.

(iii) Equipment will be exposed to wind-borne sand and dust, and therefore shall be equipped with appropriate fuel, oil and air filters.

(iv) Site altitudes are approximately 50 metres above sea level. Site air humidities shall be considered by the Contractor to ensure correct cooling system design.

(v) The M-G set will not be used for parallel operation.

(vi) Although the M-G set is intended for stand-by / emergency duty, all ratings must be based on full load 24 hour continuous service, without benefit of interruption or load cycling, in order to allow for power outage of indefinite duration.

(b) Starting System

The engine shall be started automatically on failure of normal power supply.

The generator will be connected manually to the load.

(c) Engine Instruments

A panel on the engine shall contain:

Tachometer with hour-meter

Lubricating oil pressure gauge

Lubricating oil temperature gauge

Jacket water temperature gauge (if water-cooled)

(d) Engine Protection

The engine shall be equipped with switches and local alarms for shut-down due to operation of the mechanical overspeed governor.

Shut-down, followed by alarm in event of high jacket water temperature or low lubricating oil pressure.

A mechanical lubricating trip shall operate in the event that the engine fails to shut down on low oil pressure due to an electrical malfunction. The electrical controls shall stop the engine through a "fail safe", de-energised to shut down, 24V solenoid on the governor.


(e) Diesel Generator and Control Panel

The Contractor shall size the generator for each substation to suit the sum (plus 25%) of the maximum individual demand kVA of each of the following loads:

- Battery chargers

- All 400 kV relay room air conditioning units

- Control room lighting

- Relay building lighting

- Communications room (in Control Building) air conditioning

- One switchyard distribution panel

The generator shall be a synchronous type alternator, brushless, direct driven with revolving field. Anti-condensation heating shall be included for the stator winding for connection to a 220 V 50 hertz supply.

A relay assembly shall be mounted in the control panel to provide dry alarm contacts for remote indication of engine safety device operation.

(f) Radio-Frequency Suppression

RFI suppression by means of adequate shielding and filtering, shall be included to minimise radio interference in standard broadcast bands.

(g) Site Testing

The Contractor shall propose and perform sufficient tests to satisfy the Engineer that the engine generator and all auxiliaries are in satisfactory working order.


12. CABLES

12.1 General

All cables provided under this Contract shall be of type and finish approved by the Engineer and shall be provided with a termite and vermin resistant covering. Many instances of rats eating away the outer PVC insulation cover are reported therefore, a suitable non-corrosive wire armour to make the cable vermin-proof shall be provided for all LV auxiliary and control and protection cables.

Wherever any part of an LV cable circuit is installed within a room or enclosure containing electrical control or protection equipment, in the proximity of oil filled equipment or where personnel are normally present cables employing insulation and sheathing which minimises the production of smoke and toxic fumes to IEC 60331 and/or 60332 shall be used. Cable installed wholly outdoors may be of a PVC insulated type.

Where cables pass through holes in floors immediately beneath oil filled switchgear or other oil filled equipment, the Contractor shall be responsible for plugging the holes with approved silicon foam fire seals or other approved materials after the cables have been installed and the cost thereof is deemed to be included in the contract price quoted for the cables.

Cables for power supplies at voltages up to 600/1000 V and for all 220 V ac and dc protection, control, alarm and indication shall have copper conductor with XLPE or PVC insulation and overall oversheath, together with galvanized steel wire armour. They shall comply with IEC 60227 and IEC 60228 and the colours for PVC insulation shall comply with IEC 60304.

Cables for circuits between 250 and 600V shall be 1,100 V grade. All other voltage levels shall be approved by the Engineer. Control, Protection and indication cables shall be installed with a minimum of 15 per cent (15%) spare conductors.

The conductors shall be plain annealed copper wire complying with IEC 60228 (BS 6360) as applicable or equivalent and all cores shall be clearly identified by printed numbers at regular intervals.

The minimum conductor size shall be not less than seven strands of 0.67 mm diameter wire, or in the case of single wire conductors the minimum cross-sectional area shall be not less than 2.5 mm2. In special cases for light current Control installations single strand, annealed copper conductors with a cross-section of 1.5 mm2 may be used.

All sheaths shall be free from defects and impervious to water.

Multicore and control cables shall be terminated in accordance with the manufacturers recommendations and the cable cores shall be left long enough to be terminated without the addition of separate tails.

The Contractor is responsible for checking all cable routes for burden on CT's and VT's for voltage drop on DC control and trip circuits and for satisfactory service with the equipment supplied. It is also the Contractor's responsibility to route cable to minimise "pick-up" within the station and where necessary to take precautions to prevent damage to cable sheaths from system earth fault current.

The Contractor shall submit full details of all loadings on cables and in the case of interposing current transformer connections, the loop resistance of each circuit.


The Contractor shall provide fully detailed wiring diagrams covering all parts of the plant. Detail diagrams shall be cross referenced and shall show multicore cable schedule reference numbers to facilitate cable identification.

12.2 Power Cables

The power cables covered by this section are to be thermally independent circuits laid in trenches and ducts generally as shown in the layout drawings as follows:

- 132 kV single core cables from SF6 switchgear to overhead lines

- 11 kV single core cables from 11 kV from the auto transformer to the 11kV switchgear.

The installed cable system shall be designed for a reliable service life of at least 40 years.

All cables, joints, terminations and ancillary equipment will be fully type tested in accordance with the most current BS, IEC specifications and the latest recommendations from CIGRE.

Continuous rating calculations are to be performed in accordance with IEC 60287.

Short circuit ratings must be calculated using the adiabatic methods described in IEC 60949.

Cyclic and emergency ratings should be calculated in accordance with IEC 60853.

The Contractor is required to provide calculations to demonstrate that the cables meet the required cable cyclic loadings as specified for the Transformers at the site conditions.

132 kV cables and accessories shall, as a minimum, meet all the requirements of IEC standard 60840 plus any additional requirements specified within this specification.

The 132kV single core cables shall comprise a water-blocked circular stranded conductor, insulated by a continuous vulcanisation triple extrusion process simultaneously applying a thermosetting semi-conducting conductor screen, a thermosetting XLPE insulating dielectric and a thermosetting semi-conducting core screen. All three materials should be extruded in one operation and fully bonded. The extruded core shall be cured using a dry curing process and the byproducts of cross-linking removed prior to the application of the metallic sheath. The core shall be sheathed overall with an extruded seamless lead sheath, if deemed necessary by the cable supplier, copper wires may be included to augment the short circuit carrying capacity of the metallic sheath. The cable shall be longitudinally water-blocked under the lead sheath. The oversheath shall be continuously extruded MDPE or HDPE and have anti-termite additive and shall be coloured BLACK. A thin layer of graphite or other conductive layer shall be applied overall to permit testing of the cable oversheath.

The oversheath should be legibly embossed along its length with the following information:

132000V Electric Cable, (Manufacturer), (Year of Manufacture) MOE as appropriate to the rating.

The embossed letters and figures shall be raised and consist of upright block characters along two or more lines, approximately equally spaced around the circumference of the cable. The maximum size of the characters shall be 13 mm and the minimum size not less than 15 per cent of the nominal or specified external diameter of the cable or 3 mm, whichever is the greater. The spacing between the end of one set of embossed characters and the beginning of the next on the legend shall not exceed


150 mm. Any additional information embossed on the sheath (e.g. the Manufacturer’s name) shall not affect the spacing between repetitions of the legend.

Both ends of the cable shall be rendered fully watertight by fitting a metallic end cap and a pulling eye that are plumbed to the cable metallic sheath. The pulling eye shall be directly connected to the conductor and be capable of withstanding a tensile load of 100N/mm² of conductor area up to a maximum of 6 tonnes. When requested by the user, pulling eyes shall be fitted to both ends of the cable.

The cable shall be despatched on a drum of suitable construction of minimum hub diameter 20D (where D is the overall diameter of the cable). The drum shall be fully enclosed by either adjacent fitting wooden battens or continuous metallic cladding.

Gas Immersed cable terminations into 132kV SF6 switchgear shall comply with the requirements of the latest version of IEC 60859. The Supplier shall demonstrate that terminations meet the mechanical loading of IEC 60859. The terminations may be of "dry type" or “wet type” construction, containing an epoxy resin insulator and an elastomeric stress cone. The insulator shall be constructed with a ‘blind end’, i.e. in such a way that the final seal between the cable insulation and the SF6 is made and tested at the factory and not at site, ideally this will take the form of an un-perforated metallic electrode cast into the epoxy resin insulator. The cable glands of the sealing ends shall be insulated from the SF6 switchgear.

Outdoor Termination insulators must be manufactured from Porcelain materials, all materials shall be fully factory tested during production. The pollution severity shall be ‘very heavy’ as defined in IEC 60815. Corona shields and arcing rings or horns shall be provided at the top of each open type termination and a horn or ring at the base. The base itself shall be insulated from supporting steelwork by mounting upon porcelain pedestal type insulators.

Cable joints may be of the one-piece premoulded type or prefabricated type. Taped joints are not acceptable. The joint shall be provided with a copper joint shell suitable for a metallic seal to the extruded metallic sheath of the cable. Cable joints buried in the ground shall be enclosed in a fibreglass or equivalent casing and the space between the joint and casing shall be completely filled with a bituminous or thermosetting resin compound. Bitumen filled boxes shall not be used for cable joints installed in tunnels; such joints may be wrapped in a suitable insulating tape or heat shrink layer.

The 132kV cable circuits shall be installed as insulated sheath systems. Single point or cross bonding may be employed to reduce sheath losses. In such systems, sheaths of different phases shall be bonded together only at the positions where they are earthed. The design of all specially bonded systems shall be such as to ensure that there is a continuous metallic return path of adequate cross-section for the specified fault current. All required direct inter-sheath and sheath-to-earth connections shall be made via disconnecting links enclosed in link boxes. Inter-sheath and sheath-to-earth connections through sheath voltage limiters shall be disconnectable within link boxes. Designs of bonding leads and link boxes shall be submitted to the Engineer for approval prior to installation. For system design purposes, the magnitude of sheath voltages induced under balanced maximum full load conditions and also under prospective short-circuit fault conditions shall be calculated by the methods and formulae recommended by CIGRE. Details of all such calculations shall be submitted to the Engineer for approval. At terminations, the base metal work of the cable sealing end shall be shrouded against accidental contact if the sheath voltage exceeds 10V. In order to minimise transient over-voltages on sheath insulation, sheath voltage limiters (SVLs) shall be installed at unearthed ends


of single point bonded sections. Under certain circumstances, SVLs may be necessary at earthed terminations into SF6 switchgear. SVLs shall be of zinc oxide type and shall consist of three non-linear resistors housed in the link box, the star point being earthed normally to local earth points. SVLs installed at metalclad terminations shall be encapsulated. The SVLs shall be capable of withstanding the voltages and currents impressed upon them and of limiting transient voltages to acceptable levels. Designs of SVLs shall be submitted to the Engineer for approval prior to installation.

All links and SVLs, other than those directly connected across sectionalising insulation at metalclad equipment terminations shall be enclosed in stainless steel or cast iron boxes that shall be earthed. SVLs and associated links shall be accommodated in a common housing unless otherwise approved by the Engineer. The boxes shall be provided with a means of preventing incorrect link positioning and shall also be provided with a label showing the normal link arrangement. The terminal posts and links shall be suitable for the specified short circuit requirements. The link housing shall be designed to confine the effects of the failure of SVLs and link insulation to withstand the duty imposed upon them by an internal cable fault due to the high system fault levels. All link boxes shall be of horizontal type with bolted-on lids suitable for installation in shallow pits below ground surface unless otherwise agreed by the Engineer. Pits shall be provided with removable cast iron covers.

The link box shall have a label fitted externally bearing the legend:

DANGER - ELECTRICITY

The label shall also give circuit identification details. Appropriate warning labels shall also be affixed inside the box. A phase identification label shall be provided adjacent to each terminal.

Bonding leads shall have PVC or polyethylene insulated stranded plain copper conductors and shall be of concentric construction. The type of PVC or polythene used shall be suitable for a short-circuit temperature of 160ºC.

Bonding leads shall comply with BS 6346 as far as applicable.

The outer insulation of the bonding lead shall be embossed with the legend:

ELECTRIC CABLE-BONDING LEAD

Joints in bonding leads are not acceptable in new installations, but may be used in subsequent alterations e.g. diversions, subject to the approval of the Engineer. All connecting leads shall be as short as possible and of the concentric type. Except for connections to the SVLs at unearthed sheath positions, bonding and earthing leads shall be of sufficient cross section to meet the prospective system fault and transient duties.

11 kV cables shall, as a minimum, meet all the requirements of IEC standard IEC 60502-2 and BS 6622. Cables laid within buildings shall have a low emission of smoke and corrosive gasses and shall also meet the Flame Propagation, smoke emission and corrosive and acid gas test requirements of BS7835.

11 kV accessories shall, as a minimum, meet all the requirements of the latest editions of IEC standard IEC 60502-4 and BS 7888.


The 11 kV single core cables* shall comprise circular stranded copper conductor, insulated by a continuous vulcanisation triple extrusion process simultaneously applying a thermosetting semi-conducting conductor screen, a thermosetting XLPE insulating dielectric and a strippable thermosetting semi-conducting core screen. All three materials should be extruded in one operation. The core shall be copper tape screened with aluminium wire armour. The oversheath shall be continuously extruded and contain anti-termite additive, 11kV cables shall be coloured RED.

*The conductors of11kV cable need not be water blocked

Where single point bonding of 11kV cable is required to meet the current rating requirement the cables shall be bonded at the switchgear end of each circuit.

12.3 Multicore Cables

Multicore cables shall be either solid or stranded copper conductor with cross section of conductor not less than 2.5 square millimetres. Each core shall be numbered individually and uniquely. Conductors larger than 4.0 square millimetres shall be stranded.

12.4 Cable Terminations

Cable terminations shall provide reliable, and rigid connection and shall be non-self loosening type of design approved by the Engineer.

Modern cable core terminals shall be used for stranded copper conductors, of a design approved by the Engineer.

Where crimp type terminals are used, adequate procedures shall be in place to manage the crimping tool to ensure consistency of the crimp.

12.5 Identification of Auxiliary Cables

All auxiliary cables shall be identified at both ends by bands on which shall be engraved the cable number, the number and size of cores, the type of cable and the destination. The bands shall be made of material proofed against corrosion, damp and mechanical wear.

The cable installation; laying, entering to a box or panel and termination shall be made to ensure easy identification of all the cable wires, cable numbers and marks for following the wiring.

12.6 Terminal Colouring and Labelling

Phase colours shall be marked in an approved manner on cable boxes, tail ends and single-core cables at all connecting points and/or any positions the Engineer may determine.

12.7 Termination of Auxiliary Cables

Auxiliary cables shall be terminated in a manner approved by the Engineer with clamps or armour clamps as may be required.

Where tails are liable to be in contact with oil or oil vapour, the insulation shall be unaffected by oil and subject to special approval by the Engineer.


12.8 Laying and Installation of Cables

Direct buried cable shall not be accepted. Cables shall be installed in concrete trenches with removable slab covers, or rigid conduits. The routing shall be generally as shown on the drawing.

All cables laid in concrete trenches shall be the armoured water-proof type.

Where cables enter or pass through ducts or trenches, adequate space shall be provided for the later installation of a further 15 per cent (15%) of new cables. Openings to floors and foundation pads shall be large enough to allow free movement of the cable during installation. Trenches and ducts shall be sealed where they enter a building to prevent the entry of moisture, gases and vermin into the building.

Where cables enter a marshalling box, kiosk or panel, cable glands shall be provided.

Manufacturer's restrictions on the bending radius or the cable shall be strictly adhered to and sharp bends which might damage the cable or cause difficulty in pulling shall be avoided.

12.9 Control Cables

All 110 volt DC cabling between outdoor equipment and the Relay Building shall be by multi-conductor cable shielded overall, routed via marshalling kiosks as required. Interconnections between outdoor equipment (interlocks, etc) shall be made at the marshalling kiosks.

12.10 Metering Cables

Where transducers are required to drive indications, they shall be located in the Relay Building to keep the ac connections as short as possible. AC current and potential cables shall be multi-conductor shielded overall. These cables shall run direct between outdoor equipment and the Relay Building.

12.11 Protection Cables

All AC current and potential cables for protective relaying functions shall run directly from outdoor equipment to the Relay Building. Connections shall be made with multi-conductor cables, shielded overall.

Current and voltage transformer circuits shall have their star point earthed at one point only per metallic circuit. The earth point shall be in the Relay Building, to reduce interference in the connection.

DC power supplies to relay panels shall be shielded overall.

12.12 Earthing

Cable sheaths and armouring will normally be earthed at both ends. Single point earthing shall be provided on specific cable sheaths to reduce induction. The teleprotection and 48 volt control cables shall be designed, in co-ordination with the terminal relays, to be immune to pick up levels associated with earth faults in the station and normal operation of station equipment.


12.13 Communication Cables

Twisted pair cable with overall cable shield shall be used for communication cables. To minimise exposure to interference, the communication cables shall be isolated from power cables wherever practicable.

Twisted pair cable shall conform to BS 7870. Twisted pair cables shall be used for interconnection between protection signalling equipment and protection equipment and shall be suitable for carrying signals without any weakening effect over distances of about 300 metres.

Only armoured cable shall be used in the switchyard.

Cables used for telephony shall be twisted pair and shall not be more than 0.6mm diameter solid copper conductor, suitable for Insulation Displacement Connections (IDC).

Cables entering the substation from outside shall be of paired construction and the entry conduits shall be non-metallic, and non-corrosive.

Coaxial cables where required shall be suitable for installation in cable trenches and shall be suitable for carrying signals without any weakening effect over distances of about 600 metres.

12.14 SCS Cabling

All cables for SCS transducer measurements are to be multi-conductor twisted pairs, individually screened and shielded overall. Direct input current and voltage shall be via multi conductor Control Cables. All cables for SCS status indications are to be multi-conductor twisted pairs and shielded overall.

The Contractor shall supply and install all necessary cables between substation equipment and the SCS BCU/RTU’s.

12.15 Cable Functions

The Contractor shall provide separate cables for the following functions and for the "A" and "B" systems. Multi-function cables shall not be used.

AC direct CT secondary circuits for metering and protection.

AC direct VT secondary circuits for metering and protection.

DC 110 volt protection control and indication circuits.

DC 48 volt protection signalling interface pilots.

DC 48 volt control and indication circuits.

Transducer output-metering information circuits.

AC 380/220 volt main service cables.

Supervisory control circuits.


13. SUBSTATION EARTHING SYSTEMS

13.1 Earthing System Design

The earthing system shall be designed to meet the requirements of this specification and shall be in accordance with "The Guide for Safety in Alternating Current Substation Grounding" as published by the Institute of Electrical and Electronic Engineers Incorporated, Publication No. IEEE 80. The Contractor shall present calculations to show the earthing system meets these requirements and can be shown to be safe in terms of touch, step and transferred potentials.

The design of the earthing for the 400 kV, 132 kV, 33 kV and 11 kV systems shall each be considered independently. Each system shall be adequately bonded together during normal system operation.

Electrical measurements of the subsoil at various depths, up to 20 metres shall be made at the Site of each substation in order to determine the layered effects of the ground from which the effective ground resistivity and hence the expected resistance of the proposed earth grid system may be predicted.

Soil composition may be highly corrosive and special consideration shall be given to this problem. The earthing grid shall be effectively protected against corrosion. Cathodic protection, if considered, may adversely affect other equipment and shall be subject to approval by the Engineer.

In actual design, the earthing system shall take the form of a combination of grids of buried conductors and earth rods driven vertically into the ground. Within the grid, conductors shall be laid in parallel lines at reasonably uniform spacing. They shall be located along rows of structures or equipment to facilitate the making of earth connections, where practical.

The main earth and each subsidiary earth shall have a sectional area, as required by fault currents of not more than 0.5 second duration but in any case not less than 120 mm2 in any part of its length. Each branch connection shall have a sectional area of not less than 70 mm2 .

Connections to the grid of all non-current carrying metallic parts, which might become energised by chance, such as metal structures, building earth, equipment, earth rods, water pipes, etc. shall not be less than 70 mm2 and shall be of adequate size, current-carrying capacity and mechanical ruggedness.

The spacing between conductors forming the mesh system shall be such as to limit the grid potential rise to a value that limits the touch voltage to a value not greater than the maximum tolerable touch potential assuming a fault clearance time equal to that of the main protection equipment being provided.

Each group of earth electrodes shall be connected to the main earth grid through connections having a sectional area of not less than 120 mm which shall be protected from corrosion.

The grid shall be subdivided into a number of sections, interconnected with test links. These links shall be accessible from above-ground.

Areas of grid, where high concentrations of fault currents can appear as at neutral earthing connections, shall have reinforced conductor sizes where necessary, to handle adequately the highest fault current and its duration.


In case the equipment is widely spaced in the station, individual local grids may be established at the various equipment locations and the local grids shall be interconnected and connected to earthing grid. Interconnecting conductors shall not be less than the size of the conductor for main grid.

Metal parts of all equipment, other than those forming part of an electrical circuit shall be connected directly to the main earth system via a single conductor. The arrangement of the mesh earth system shall be such as to minimise the length of these single connections.

Earth bars installed directly into the ground should normally be laid bare and the trench back-filled with fine topsoil. Where the soil is of a hostile nature, precautions must be taken to protect the earth bar.

Copper to copper joints on strip conductor shall be brazed, using zinc-free brazing material with a melting point of not less than 600°C, or by approved exothermic welding.

All exposed joints shall be at a minimum height of 150 mm above floor or ground level.

Earth conductor joints that are required to be broken for testing or maintenance shall have mating surfaces tinned.

The grid voltage rise under fault conditions shall not exceed 15 kV. If the calculated grid voltage rise exceeds 430 V (or 650 V if fault clearance time is less than or equal to 200 ms) the Telephone Authority shall be advised of the grid voltage rise, by the Engineer, and of the distance of the 650 V contour from the substation grid periphery.

The measured earth resistance shall not exceed 0.5 ohm. In the event of a higher value being considered, precaution shall be taken it does not affect the minimum pick-up currents of earth relays. A value higher than 0.5 ohm. shall be subject to the approval of the Engineer.

The resistance shall be measured with all transmission line earth wires connected to the earthing grid.

In the event of the substation resistance obtained with the foregoing installation being of a magnitude unacceptable to the Engineer, then where practicable, the ground area enclosed by the earth system should be increased by installing directly in the ground a copper conductor in the form of a ring around the site at a significant distance from the boundary fence. Alternatively earth conductors can be directly buried radially outside the substation perimeter fence. The use of earth plates as current carrying electrodes is not acceptable.

From the point of view of the possible damage to apparatus, the earthing system shall be such as to limit voltage appearing between the substation equipment and the main body of earth, so that insulation breakdown or burning does not occur on apparatus. For the same reason, voltage rise between earthed points in the substation shall be kept to a minimum. In addition, the effectiveness of any surge protection devices shall be fully realised by providing an adequate earth path. In this case, the earthing system shall not only be of low resistance, but of as low reactance as practicable.

After installation of the earth system the Contractor shall measure the resistance of the substation. The method used shall preferably be the "fall of potential" method, requiring the availability of a local low voltage supply but other methods using an earth resistance megger will be acceptable in the event of a local supply being unavailable.


13.2 Step and Touch Voltage

The earthing systems shall be so designed as to keep the "step" and "touch" potentials within acceptable limits, thereby ensuring safety to the personnel. The aim shall be to ensure that under both normal or abnormal conditions no dangerous voltages can appear on the equipment or accessories to which a person has legitimate access.

13.3 Equipment Earthing

Circuit breakers, power transformers, voltage transformers, earthing and auxiliary transformers, earthing switches and other electrical apparatus shall each, be connected to the main earth bus by means of a separate subsidiary connection.

Gradient control mats shall be installed adjacent to each circuit breaker and disconnect switch mechanism box. Each mat will be connected directly to the earthing grid and the equipment.

Isolating supports, busbar supports and cable sheaths may be earthed in groups by a separate branch connection from each item of equipment in the group the branch connections being connected by a single subsidiary connection to the main earth. Isolating and earth switch mechanism boxes shall be earthed by a connection separate from that effecting the earthing of the associated switch.

The main members of the steel structures shall be earthed by continuous copper connections bonded to the steelwork and these connections shall be connected separately at each column to the main or subsidiary earth.

Connections to apparatus and structures shall be made clear of ground level, preferably to a vertical face and protected against electrolytic corrosion.

Current transformer and voltage transformer secondary circuits shall be complete in themselves and shall be earthed at one point only (at the Relay Building) through links situated in an accessible position. Each separate circuit shall be earthed through a separate link, suitably labelled. The links shall be of the bolted type, having necessary provision for attaching test leads.

The earth links for protective and instrument current transformer secondary circuits shall be mounted at the Relay Building; earth links for metering current transformer secondary circuits shall be mounted at the Relay Building.

The earth system shall be designed so as to include all overhead line terminal towers, which shall be earthed by extending the system so as to envelope all towers within the earth system. Each tower shall be bonded directly to the earth system from at least two locations. Structures and masts for lighting and security surveillance equipment shall also be within the perimeter of the earth grid. No fixed low voltage equipment, with the exception of a warning or alarm button and intruder alarms, which shall be of the double insulation type, shall be erected outside the perimeter of the earth grid.

All control and relay panels shall have a continuous earth bus run of sectional area approved by the Engineer along the bottom of the panels, each end being connected to the main earthing system. Metal cases of instruments and metal bases of relays on the panels shall be connected to this bar by conductors of sectional area approved by the Engineer.

Loops shall be provided on the earthing system in positions approved by the Engineer, for the attachment of portable earth connectors during maintenance. These will normally be in the earth bar


run between the equipment and the base of the structure. They shall be formed separately from the bar and soldered or thermo-welded thereto. Where necessary, rods shall be provided at the tops of bushings or insulators for the attachment of portable earth clips.

Earthing for high frequency coupling equipment and surge diverters shall be via a copper rod driven directly into the ground at a position immediately adjacent to the equipment being earthed in addition to the normal earth connection.

13.4 Fence and Perimeter Earthing

The fence surrounding the substation shall be earthed to its own earth grid and the fence earth grid shall be connected to the main station earthing grid at frequent intervals as approved by the Engineer.

A continuous conductor shall be laid outside the periphery of the substation site at a distance of 1.5 to 2.0 metres from the boundary fence and at a depth of between 0.6 metres below the surface. This shall be welded to earth rods installed at adequate intervals and at points adjacent to each corner and immediately below any overhead line entering or leaving the Site. The location of the mesh conductors shall be such as to enable all items of equipment to be connected to the earth system via the shortest possible route. All corner fence posts and posts adjacent to earth rods shall be effectively connected to the earth conductor.

Gateposts forming part of the substation fence shall be bonded together with below ground connections and the gates themselves shall be electrically bonded to the posts.

The alternative approach of independently earthing the fence and placing it outside the earth grid area shall only be adopted if the above mentioned procedures prove insufficient or impracticable. The Contractor shall provide calculations to show that this approach produces safe touch voltages at the fence and shall ensure that the fence is isolated from all other buried metalwork.

13.5 GIS Substation Earthing Systems

The earthing system shall comprise a mesh grid formed by copper strip or flexible conductor buried directly in the ground outside the GIS building and arranged so as to utilise fully the available site area. The earthing system inside the GIS building shall be connected to the external system at a minimum of two locations. The reinforced concrete floor slab of the GIS building shall be maintained at earth potential by connecting the reinforcing bars to the earth grid at intervals of 5 m. The reinforcing bar shall be provided with a connection brought out to a vertical face for connection to the main earth bar.

Where the area of the site is restricted to that of the GIS building it may be necessary to lay an earth mesh formed of copper strip or flexible conductor under the concrete floor slab before building work commences; this shall be determined by calculation and will depend upon the characteristics of the site.

13.6 Earthing of Neutrals

400 kV and 132 kV systems shall be effectively earthed.

400 V ac system shall be solidly earthed.

33 and 11 kV systems shall be earthed through a grounding transformer.


13.7 Surge (Lightning) Arrestors

In the case of surge (lightning) arrestors a local earthing connection shall be made by driving electrodes into the earth near the arrestors and the lightning arrester earthing conductor shall be connected to both the rod and to the common earthing grid of the station. The connection from arrester to earth shall be as short and as straight as possible. The conductor shall not be less than 120 mm 2.


14. LIGHTNING PROTECTION


The work to be done under this section shall consist of the design, supply, delivery to site, erection, commissioning and guarantee of the lightning protection system for each substation.

The system shall be designed in accordance with the following requirements. However, the Contractor may submit as an alternative, other shielding systems giving equal protection.

14.2 General

For the GIS substation the building shall be designed to provide adequate shielding of the high voltage equipment from direct lightning strikes.

For AIS equipment protection shall be provided to effectively shield the station structures and equipment against direct lightning strikes. Where applicable horizontal skywire conductors supported by the main structures, and lightning masts will be used to shield the AIS equipment.

Downlead conductors connecting the overhead system to earth shall be installed at even intervals with a view to offering low impedance to the passage of stroke current to the earthing grid and shall provide a direct path. No sharp bends or narrow loops in conductors to the earthing grid shall be acceptable.

The downlead conductor system shall be of copper or copper clad steel of low impedance, and durable and highly rugged construction. It shall require no maintenance and both conductor and clamps shall be corrosion-resistant. In particular, allowance shall be made for corrosive atmosphere and salt-laden air where applicable. Steps shall be taken to prevent galvanic corrosion.

Where any part of the downlead conductor system is exposed to mechanical injury it shall be protected by covering it with moulding or tubing, preferably of wood or other non-conductive material. If metal pipe or tubing is used around the conductor the conductor shall be electrically connected to the pipe or tubing at both ends.

Joints in downlead conductors shall be as few in number as practicable. Where they are necessary they shall be thermal-well types, mechanically strong, well made and shall provide adequate electrical conductivity.

14.3 General Design Data of Lightning Shielding System

The substation lightning protection design shall be in accordance with up to date techniques and will follow the general procedure described below:

- The design ISOKERAUNIC level shall be not less than 25 thunder-days per year. This is equivalent to a ground flash density (GFD) of not less than 3.84 strokes per km2 per year.

- The design shielding failure risk shall be not greater than one failure per 100 years.


14.4 Method of Design of Lightning Shielding System For AIS Equipment

The method shall be based on the use of Fig. 1 and Fig 2 to establish the protected distance and hence the shielding angle given by a skywire. The Contractor shall be responsible for the selection of skywire effective height, which shall be approved by the Engineer.

In making use of Fig. 1, which gives the protected distance for a 30.5 metre length of skywire, the following methods should be used based on IEEE paper T75-060-9.

A = Total area, L x W

n = Number of equal areas A1 totalling A.

Y1 = Shielding failure risk for A1 - nY years.

XP = Protected distance Ey skywire.

H = Effective height of skywire. The difference in height between the lightning conductors and highest equipment.

Method:

(1) Select A1 to be protected by one lightning conductor 30.5 metre in length.

(2) Determine protected distance XP from XP = A1/.60 metres.

(3) From Y1 and XP obtain effective H from Fig. 1.

(4) Total number of parallel skywires = 30.5 n/L or 30.5 n/W.


15. INSPECTION AND TESTING

15.1 General

The material shall be subject to inspection and tests by the Engineers representatives at any time during manufacture in order to establish compliance with the specified requirements. All testing and inspection shall be made at the place of manufacture.

The dates for readiness for inspection and testing, access to site(s), delivery and completion of the various sections of the Contract Works shall be stated in the Schedules.

The Employer will provide any on site electrical energy for the purpose of approved preliminary tests and for the official tests. Where applicable, this supply will be metered and charged for.

15.2 Inspection

The manufacturers shall provide all inspection facilities for the said inspection and testing. The inspector shall have the right of rejecting any portion of the material at any time during manufacture if it does not meet with the requirements of this specification in all particulars. The Inspector may oversee the packing and shipping of all materials to be supplied.

Inspection of incoming goods and components, and subassembly testing, shall be undertaken by the Contractor in accordance with the procedures set out in the Contractor's own Quality Plan.

No inspection or lack of inspection or passing by the Engineer of work, plant or materials, whether carried out or supplied by the Contractor or sub-contractor, shall relieve the Contractor from his liability to complete the Contract Works in accordance with the Contract or exonerate him from any of his guarantees.

15.3 Testing

15.3.1 Approach to Testing The Contractor shall carry out the tests stated in accordance with the conditions of this Specification and, without extra charge, such additional tests as may be reasonably required to confirm that the Contract Works comply with this Specification under either test whether in manufacturer's works, on the Site or elsewhere. Type tests may be omitted at the discretion of the Engineer if satisfactory evidence is given of such tests already made on identical equipment.

The principle of testing shall be that, at stages throughout the work, formal tests shall be performed and recorded against written test specifications, to provide a high level of confidence to the Contractor and the Engineer that subsequent stages can proceed.

The degree to which the Engineer intervenes in the process will depend upon the level of confidence built up during the project.

Tests shall be arranged to represent working conditions as closely as possible.

15.3.2 Responsibilities Not less than 3 weeks notice of all tests shall be given to the Engineer in order that he may be represented if he so desires. Failure of the Contractor to give such notice which results in a delay in


the completion of the tests cannot be used by the Contractor as a reason for failure to meet the overall completion date and any extra costs incurred by the Contractor are not recoverable. As many tests as possible shall be arranged together. Two copies of the Contractor's record of tests shall be supplied to the Engineer.

The Contractor's responsibilities shall include but not be limited to requirements to:

(a) Produce written test plans, schedules, procedures, method statements, test record sheets and procedures for fault reporting, for all tests.

All test documentation associated with a subsystem or system test shall be submitted for approval by the Engineer at least 12 weeks prior to the commencement of the associated test.

(b) Ensure that all test documentation associated with any testing has been approved by the Engineer prior to the commencement of the corresponding testing.

(c) Provide the equipment, test equipment, test software, personnel and facilities to conduct the tests.

(d) Successfully carry out all tests according to the approved test procedures and correct any errors, with subsequent re-testing of functions that may be affected by the correction, prior to the witnessed acceptance tests.

(e) Provide facilities for the Engineer to witness any Factory tests.

(f) Produce permanent records of all test progress and results in a formal systematic manner.

(g) Carry out all remedial work and re-testing found to be necessary in order that the equipment should pass the tests.

Each of the above responsibilities shall be discharged to the satisfaction of the Engineer, but approval by the Engineer shall not imply any diminution of the Contractor's responsibilities.

The Contractor shall supply suitable test pieces of all materials as required by the Engineer. If required by the Engineer test specimens shall be prepared for check testing and forwarded at the expense of the Contractor to an independent testing authority selected by the Engineer.

It is expressly the responsibility of the Contractor to satisfy himself that items ‘supplied by others' are in a satisfactory condition for the Contractor's tests to be conducted.

The Contractor shall be responsible for the proper testing of the work completed or plant or materials supplied by a sub-contractor to the same extent as if the work, plant or materials were completed or supplied by the Contractor himself.


15.3.3 Test Equipment and Facilities The Contractor shall provide all equipment and services required for testing, including, but not limited to:

(a) Laboratory test instruments

(b) Special test equipment, emulators, simulators and test software, to permit full testing of System functions and performance (in particular a means of connecting to or emulating the NCC Master Station)

(c) Other items of the System, specified elsewhere as being part of the Contractor's supply, even if not part of the Subsystem under test

(d) Consumables.

All test instruments shall be subject to routine inspection, testing and calibration by the Contractor. All test instruments shall be subject to approval by the Engineer and, if required by the Engineer, shall be calibrated at the expense of the Contractor by an approved standards laboratory prior to being used during the testing.

15.3.4 Conduct of the Tests The Contractor shall conduct the tests in accordance with the approved test procedures and shall enter the results in the result sheets.

For each test, the Engineer will determine whether the test has passed or failed. In general, the test will be considered to have failed if either:

(a) the result of the test is not in accordance with the expected result described in the test procedure, or

(b) the result of the test is in accordance with the expected result described in the test procedure but some other unexpected or unexplained event occurred which the Engineer considers to be a fault.

Full use shall be made during the tests of operator manuals and other documentation provided by the Contractor to provide a series of tests of their accuracy. The Engineer may refuse to allow the commencement of the testing if this documentation is not available at the test site.

15.3.5 Failures The Contractor shall correct all faults found during testing, and shall arrange for the test to be repeated. The test shall only be repeated when the fault has been remedied and the equipment demonstrated to functioning correctly.

Where remedial measures involve significant modifications that might, in the Engineer's opinion, affect the validity of earlier tests, then the Contractor shall repeat the earlier tests and obtain satisfactory results before repeating the test in which the fault was first identified.


The Engineer shall have the right to order the repeat or abandonment of any test in the event that results demonstrate that the equipment is significantly non-compliant with the Contract requirements, without in any way prejudicing his rights.

The Engineer shall have the right to suspend any test in the event that errors or failures have become unacceptable. The Engineer shall also have the right to suspend any test in the event of a fault being detected by the Contractor but not reported to the Engineer within 24 hours. In this event, the suspension shall remain in effect until reporting has been brought up to date to the satisfaction of the Engineer.

Any costs incurred by the Employer or the Engineer in connection with inspection and re-testing as a result of a failure of the subject under test, or damage during transport, or erection on site before take-over by the Employer, shall be to the account of the Contractor.

15.4 Tests During Commercial Operation

After the plant has passed the site tests required under this Contract, and has become available for commercial operation, certain additional tests may be carried out in order to investigate the response and recovery of the system during events such as the switching of various items of plant, system faults and load rejection.

15.5 Documentation

The Contractor or his sub-Contractors shall supply to the Engineer, as soon as practicable after works tests, commissioning and site tests have been witnessed, the original plus five copies of the relevant test certificates. These shall contain details of each test performed as required by the Engineer; records, results and calculations of all electrical tests.

15.6 Tests at Manufacturer’s Works

Test at manufacture's work shall comprise type tests and routine tests.

(a) Type test:

These tests are in general those detailed in the IEC, which pertain to the equipment being tested. Type tests are to prove the general design of the equipment and the manufacturer may submit test certificates of tests, which have been carried out on identical equipment. Not withstanding any provision in an IEC the inspector shall have the right to accept such certificate in lieu of the specified type test or to reject them.

The type test prescribed shall be carried out in all cases where such certificates are not available or are rejected.

Unless otherwise stated, type tests when called for shall be made on equipment which has previously passed its routine tests.

(b) Routine Tests Routine tests should be carried out on the following specific equipment and in accordance to the latest issue of IEC specifications.

All materials used shall be subjected to and shall withstand satisfactorily such routine tests as are customary in the manufacture of the types of plant included in the Contract Works.


15.7 Specific Equipment Tests

This section of this schedule lists inspections, works and site tests which the Engineer requires for specific equipment, but this shall not preclude the Engineer's right to call for further tests if he considers these necessary.

15.7.1 Transformers Routine, type and special tests shall be carried out in accordance with IEC 60076. The following additional tests shall be made.

15.7.1.1 Tests in the Manufacturer's Works The tests shall be arranged to represent working conditions as closely as possible.

Unless otherwise stated, type tests when called for shall be made on equipment which has previously passed its routine tests.

15.7.1.2 Routine tests (a) The winding resistance and impedance voltage tests should also be carried out at all tapping

positions.

(b) Magnetic circuit insulation.

(i) A power frequency voltage of 2 kV for 1 minute applied as follows:-

Core bolts to core, to yoke clamps and to core leg side plates.

Core to yoke clamps and to core leg side plates.

(ii) Immediately prior to despatch, 2 kV for 1 minute applied between core and earth. A megger may be used for this test.

(c) No load current at:-

(i) 90 per cent rated voltage.

(ii) 100 per cent rated voltage.

(iii) 110 per cent rated voltage.

(iv) The maximum voltage equivalent to the value quoted in the Schedules.

(d) Lightning impulse test on all terminals including neutral.

(e) Dissolved gas analysis: A dissolved gas analysis test shall be carried out before and after a temperature rise test and before and after the series of dielectric tests. The tests shall be in accordance with IEC 60567 and IEC 60599.

(f) Voltage ratio, polarity and phase relationship tests: The voltage ratio shall be measured at each tapping. The polarity and phase relationship (vector group) of each transformer shall be checked.


15.7.1.3 Type Tests (a) The lightning impulse chopped wave test: Tests shall be carried out on all windings of 300 kV

and above in accordance with IEC 60076-3 Clause 13.

(b) Transferred surge: The transformer shall be tested so that with the test voltage, applied to the other windings, the maximum surge that can be transferred to the unloaded winding(s) does not exceed its specified insulation lever. Compliance with this requirement may be achieved by the use of external equipment connected to the unloaded winding and shall be proved by recurrent surge oscillograph measurements, by comparison with the transferred voltage on open circuit.

(c) Noise level: The level of noise shall be measured in accordance with IEC 60551.

(d) The measurement of zero sequence impedance shall be carried out in accordance with IEC 60076-1 sub clause 8.7.

(e) During the temperature rise test the accuracy of oil and/or winding temperature indicating devices shall be determined.

(f) The following transformer “footprint” test shall be carried out prior to leaving the works,

Capacitance and power factor measurements (Doble tests) Transformer winding frequency response analysis (FRA) Recovery voltage measurements (RVM) or equivalent

15.7.1.4 Transformer Site Tests The site tests, full details of which are to be submitted by the Contractor after the Contract has been placed, shall include those tests described in outline below.

(a) Insulation resistance of core and windings.

(b) Dielectric strength of oil samples.

(c) Ratio and no-load current at low voltage (e.g. 380 V) on all tappings.

(d) Vector relation check.

(e) Calibration check of temperature instruments, including secondary current injection and proving contact settings.

(f) Air injection tests of gas/oil-actuated relays.

(g) Setting check of oil-level and oil-flow devices.

(h) Complete functional tests of cooling equipment and tap-change equipment, including manual/automatic sequences, indications, alarms and interlocks, measurement of motor currents, adoption of suitable motor protection settings and proof of protection for stalled or single-phasing conditions.

(j) Operational tests of "freeze-drier" type breathers.

(k) Insulation resistance of all secondary circuits.


(m) Repeat “footprint” tests to confirm that no damage to the windings has taken place during transit and installation.

(n) Final checks before energising:-

(p) Venting, position and locking of valves, earthing of star-point(s) and of tank, state of breathers and of pressure-relief devices, oil levels, absence of oil leakage, operation of kiosk heaters, tap-change counter readings, resetting of maximum temperature indicators, final proving of alarms and trips.

(q) Dissolved Gas Analysis of transformer oil after final processing

(r) Tests when energised:-

On-load tap-changer operation throughout range (subject to not exceeding 1.1 pu volts on any windings).

Maintenance of 1.1 pu volts on untapped windings for 15 minutes (but not exceeding this value on tapped winding).

(s) Tests on load:-

Temperature instrument readings.

Measurement of WTI CT secondary currents.

Repeat Dissolved Gas Analysis of transformer oil after energisation tests completed

15.7.2 Reactors Routine and type tests shall be carried out in accordance with IEC 60289. The following additional tests shall be made.

15.7.2.1 Routine Tests (a) Magnetic circuit insulation (where appropriate).

(i) A power frequency voltage of 2 kV for 1 minute applied as follows:-

Core bolts to core, to yoke clamps and to core leg side plates.

Core to yoke clamps and to core leg side plates.

Clamping bolts to screens and screens to earthed metal paths from which the screens are isolated.

(ii) Immediately prior to despatch, 2 kV for 1 minute applied between core and earth. A megger may be used for this test.

(b) Noise level: The level of noise shall be measured in accordance with IEC 60551.


(c) Vibration: Vibration measurements shall be taken and the level recorded shall be subject to approval. This test shall be carried out unless it can be shown to the satisfaction of the Engineer that the level of vibration in the reactor and its auxiliaries is harmless.

(d) Voltage/reactance characteristics shall be recorded from 50 per cent to 100 per cent in steps of 10 per cent rated voltage. Reactance values up to 130 per cent rated voltage shall be determined by test or calculation.

(e) DIssolved gas analysis: A dissolved gas analysis test shall be carried out before and after a temperature rise test and before and after the series of dielectric tests. The tests shall be in accordance with IEC 60567 and IEC 60599

(f) The following “footprint” test shall be carried out prior to leaving the works,

Capacitance and power factor measurements (Doble tests)

Transformer winding frequency response analysis (FRA)

Recovery voltage measurements (RVM) or equival

15.7.2.2 Type Test (a) Switching surge: In accordance with IEC 60076-3.

15.7.3 Reactor Site Tests (Minimum) (a) Insulation resistance of core and windings.


(c) Dissolved Gas Analysis of transformer oil after final processing

(d) Calibration check of temperature instruments and proving contact settings.

(e) Air injection tests of gas/oil-actuated relays.

(f) Setting check of oil-level and oil-flow and water-flow devices.

(g) Operational tests of "freeze-drier" type breathers.

(h) Insulation resistance of all secondary circuits.

(j) Repeat “footprint” tests to confirm that no damage to the windings has taken place during transit and installation.

(k) Final checks before energising:-

(m) Venting, position and locking of valves, earthing of star-point(s) and of tank, state of breathers and of pressure-relief devices, oil levels, absence of oil leakage, operation of kiosk heaters, resetting of maximum temperature indicators, final proving of alarms and trips.

(n) Tests when energised:-


Maintenance of 1.1 pu volts on untapped windings for 15 minutes.

Temperature instrument readings.

Repeat Dissolved Gas Analysis of reactor oil after final processing

15.7.4 Transformer & Reactor Related Equipment 15.7.4.1 Voltage Control Equipment Routine and type tests shall be carried out in accordance with IEC 60214.

15.7.4.2 Cable Boxes and Disconnecting Chambers (a) Routine test

Oil tightness - All cable boxes and disconnecting chambers shall be tested with oil, having a viscosity not greater than that of IEC 60296 insulating oil when at a temperature of 15°C, at a pressure of 70 kN/m2 for 12 hours; during this time no leakage shall occur nor shall there be any permanent set when the pressure is released.

15.7.4.3 Bushings Routine, type, sample and special tests shall be carried out in accordance with IEC 60137 and IEC 60233.

15.7.4.4 Tanks and ONAN Coolers (a) Routine tests

(i) Oil leakage - All tanks and oil filled compartments including all forms of radiator but excluding separate coolers using forced oil circulation, (for which see Section 8 below) shall be tested for oil tightness by being completely filled with oil of a viscosity not greater than that of IEC 60296 insulating oil at a temperature of 15°C and subjected to a pressure equal to the normal pressure plus 35 kN/m2. This pressure shall be maintained for a period of not less than 24 hours, during which time no leakage shall occur.

(ii) The tap-changer barrier shall be subjected to normal oil pressure head for 24 hours,

during which time there shall be no leakage from the panel or bushings.

(iii) Detachable radiators may be tested as separate units.

(b) Type tests

(i) Vacuum:

(1) One transformer tank, one raectot tank, tap-changing compartment, radiator and cooler of each type shall be subjected when empty of oil to that vacuum test level specified in the Schedules. There shall be no permanent deflection of the stiffeners, nor shall the permanent deflection of the panels exceed the value specified in the following table.


Major dimension of panel between stiffeners (metres) vertical or horizontal

Maximum permanent deflection

Up to 1.5 m 3 mm

1.5 m – 3 m 8 mm

Above 3 m 13 mm

(2) A further test a vacuum equivalent to 3 m bar absolute pressure for a period of

8 hours shall be made for the purpose of checking the mechanical withstand capability of the tank; during this test no damage or fractures shall occur. This test may be combined with other tests or made during the processing of the unit.

(ii) Pressure:

(1) One transformer tank and one reactor shall be subjected to a pressure corresponding to the normal pressure plus 35 kN/m2. After the release of the excess pressure there shall be no permanent deflection of the stiffeners nor shall the permanent deflection of panels between stiffeners exceed the value specified in the above table. This test may be combined with a routine oil leakage test.

(2) The tap-changer barrier shall be shown to withstand an over pressure test of normal pressure plus 35 kN/m2 for 12 hours.

(c) Pressure relief device

When required by the Engineer one pressure relief device of each size shall be subjected to increasing oil pressure and shall operate before reaching normal pressure plus 35 kN/m2.

The operating pressure shall be recorded on the test certificate.

15.7.4.5 Cooling Plant with Forced Oil Circulation (a) Routine tests

(i) Air/oil coolers - All coolers using forced oil circulation shall be filled with oil of a viscosity not greater than that of IEC 60296 insulating oil at a temperature of 15°C and subjected to a pressure equal to twice the maximum working pressure at the inlet to the cooler under service conditions which shall be maintained for a period of not less than 24 hours; during this time no leakage shall occur.

(b) Type tests

(i) One forced-oil cooler of each type shall be subjected, when empty of oil, to that vacuum test level specified in the Schedules. There shall be no permanent deformation or distortion of any part of the cooler.


15.7.4.6 Pressure relief device When required by the Engineer one pressure relief device of each size shall be subjected to increasing oil pressure and shall operate before reaching normal pressure plus 35 kN/m2.

The operating pressure shall be recorded on the test certificate.

15.7.4.7 Fans, Pumps, Motors, Pipework, Oil Sampling Devices and Valves (a) Routine tests

(i) Oil filled equipment - The bodies of all oil pumps complete with submerged motors, if any, and the oil pipework, oil sampling devices and valves shall withstand an hydraulic pressure of 140 kN/m2 for 15 minutes.

(ii) Fans - Static and dynamic balance shall be checked on all fan impellers.

(iii) Control gear - All control gear shall be subjected to the tests specified in the appropriate IEC.

(iv) Motors - Each machine shall be subjected to the following tests where applicable:-

(1) Measurement of winding resistance (cold).

(2) No load test at rated voltage for determination of fixed losses.

(3) An overvoltage test at 1.5 times rated voltage applied with the machine running at no load, for a period of 3 minutes, to test interturn insulation.

(4) High voltage in accordance with IEC 60034-1.

(b) Type tests

(i) Motors - Performance tests shall be in accordance with IEC 60034-1 however, certificates of type tests in accordance with IEC will be accepted.

(ii) Except for non-return valves, all valves and oil sampling devices which are subject in service or during maintenance to oil pressure shall withstand, when empty of oil, absolute pressure not exceeding 350 m bars. In the case of valves this test is to be applied to the body only. This type test shall subsequently be followed by a repeat oil leakage test.

15.7.4.8 Oil (a) Sample tests

Samples of oil from each consignment shall be tested in accordance with IEC 60296 before despatch.

Subject to the agreement of the Engineer a test certificate, confirming that the oil from which the consignment was drawn has been tested in accordance with IEC 60296, may be accepted. Before commissioning any transformer, the electric strength of its oil shall be check-tested and a Dissolved Gas Analysis shall be taken and the results approved by the Engineer.


15.7.4.9 Gas and Oil Actuated Relays (a) Routine tests

The following tests shall be made on relays when completely assembled. Where oil is referred to it shall have a viscosity not greater than that of IEC 60296 insulating oil at 15°C.

(i) Oil leakage - The relay, when filled with oil shall be subjected to an internal pressure of 140 kN/m2 for 15 minutes. No leakage shall occur either from the casing or into normally oil free spaces, such as floats, within the casing.

(ii) Gas collection:

(1) With the relay mounted as in service and at a rising angle of 5 degrees (tank to conservator) and full of oil, gas shall be introduced into the relay until the gas collection contacts close. The oil level contacts shall not close when gas is escaping freely from the relay on the conservator side. These contacts shall, however, close when the pipework is empty of oil.

(2) the empty relay shall be tilted, as if mounted in pipework rising from tank to conservator, at an increasing angle until the gas collection contacts open. The angle of tilt shall then be reduced and the gas collection contacts shall close before the angle is reduced to less than 13 degrees to the horizontal.

(3) With the relay mounted at a falling angle of 16 degrees to the horizontal and full of oil, the gas collection contacts shall be open.

(iii) Oil surge - With the relay mounted as in service and full of oil at approximately 15°C the surge contacts shall close within the steady oil flow limits specified in the Schedules. This option shall not be adversely affected when the gas collection contacts have already closed and gas is escaping freely.

(iv) Voltage - With the relay empty of oil, a voltage of 2 kV shall be applied in turn between each of the electrical circuits and the casing for one minute, the remaining circuits being connected to the casing.

(v) Operation - With the transformer assembled with its cooling plant as in service, tests shall be made to demonstrate that the relay does not operate whilst the oil pump motors are being started or stopped.

(b) Sample test

At the discretion of the Engineer, the following test shall be made: -

(i) Variation of performance with mounting angle with the mounting conditions as in service, the mounting angle shall be varied within the rising angle limits 1 and 9 and tests repeated in the manner prescribed for the routine tests.


15.7.4.10 Secondary Wiring All secondary wiring, including panel wiring and control circuits and all apparatus connected thereto shall be subjected to the following tests:

(a) Routine tests

(i) Voltage - 2 kV applied for one minute except where this requirement is modified by a British Standard, to which item the appropriate test shall be applied.

(ii) Insulation resistance - By megger of not less than 500 volts.

15.7.4.11 Galvanizing (a) Sample tests

Samples selected by the Engineers of all galvanized material shall be subjected to the galvanizing tests set out in either BS 443 or BS 729, whichever is applicable.

15.7.4.12 Oil Filtering Equipment Such tests as are considered necessary by the Engineer to show that the guaranteed particulars in the Schedules are met.

15.7.4.13 Minimum Acceptable Transformer Site Tests The site tests, full details of which are to be submitted by the Contractor after the Contract has been placed, shall include those tests described in outline below:

(a) Insulation resistance of core and windings.


(c) Ratio and no-load current at low voltage (e.g. 380 V) on all tappings.

(d) Vector relation check.

Calibration check of temperature instruments, including secondary current injection and proving contact settings.

(e) Air injection tests of gas/oil-actuated relays.

(f) Setting check of oil-level and oil-flow devices.

(g) Complete functional tests of cooling equipment and tap-change equipment, including manual/automatic sequences, indications, alarms and interlocks, measurement of motor currents, adoption of suitable motor protection settings and proof of protection for stalled or single-phasing conditions.

(h) Operational tests of "freeze-drier" type breathers.

(i) Insulation resistance of all secondary circuits.

(j) Repeat “footprint” tests to confirm that no damage to the windings has taken place during transit and installation.


(k) Final checks before energising:-

(i) Venting, position and locking of valves, earthing of star-point(s) and of tank, state of breathers and of pressure-relief devices, oil levels, absence of oil leakage, operation of kiosk heaters, tap-change counter readings, resetting of maximum temperature indicators, final proving of alarms and trips.

(ii) Dissolved Gas Analysis of transformer oil after final processing

(l) Tests when energised:-

(i) On-load tap-changer operation throughout range (subject to not exceeding 1.1 pu volts on any windings).

(ii) Maintenance of 1.1 pu volts on untapped windings for 15 minutes (but not exceeding this value on tapped winding).

(m) Tests on load:-

(i) Temperature instrument readings.

(ii) Measurement of WTI CT secondary currents.

(iii) Noise measurement tests

(iv) Repeat Dissolved Gas Analysis of transformer oil after energisation tests completed

15.7.5 GIS Switchgear 15.7.5.1 Circuit Breaker Inspection & Testing Type and routine tests shall be carried out strictly in accordance with IEC 62271-200, IEC 60694, IEC 62271-100, IEC 60427, IEC 60060, IEC 60270, IEC 61233 and any other relevant standards and requirements of this Specification where appropriate.

15.7.5.2 Circuit Breaker Type Tests The following type tests shall be performed:

(a) Dielectric test on main circuit - Lightning impulse, Power frequency voltage withstand tests, Partial discharge and Radio interference voltage (r.i.v) tests

(b) Dielectric test on auxiliary and control circuit

(c) Temperature rise test

(d) Measurement of the resistance of the main circuit

(e) Short-time and peak withstand current tests

(f) Short-circuit making and breaking, out-of-phase making and breaking, critical current and capacitive and inductive (reactor) current switching tests

(g) Internal arcing test


(h) Mechanical endurance, environmental operation tests

(j) Electromagnetic compatibility (EMC) tests

(k) Verification of the degree of protection and tightness tests

(m) Any other tests in accordance with the above standard

15.7.5.3 Circuit Breaker Capacitive Current Switching Tests The capacitive current switching duty specified in the Schedules for the circuit breaker shall be tested in accordance with IEC 62271-100. Test evidence shall be submitted to confirm that the highest over voltage during any switching duty does not exceed 2.5 p.u. by either performing the relevant tests or by submitting the relevant type test reports to the satisfaction of the Ministry of Electricity.

15.7.5.4 Circuit Breaker Low Inductive Current Switching Tests A series of switching tests shall be made to IEC 61233 on each type of circuit breaker being supplied in order to demonstrate its performance when switching transformer magnetising currents and reactor currents. Test evidence shall be submitted to confirm that the highest over voltage during any switching duty does not exceed 2.5 p.u. by either performing the relevant tests or by submitting the relevant type test reports to the satisfaction of the Ministry of Electricity.

In addition to the above, additional, low inductive current switching test evidence of 10, 50, 100 amp currents, in accordance with IEC 61233 under site conditions, to confirm that the highest over voltage during any switching duty does not exceed 2.5 p.u.

15.7.5.5 Circuit Breaker Internal Arcing Tests Internal arcing tests shall be carried out in accordance with IEC 60298 - Annex AA. The test evidence for each compartment shall confirm that the equipment satisfies the IEC test criteria that the internal arcing fault in one compartment does not affect the adjacent compartments and in particular the relay compartment.

15.7.5.6 Circuit Breaker Routine Tests The following routine tests shall be performed:

(a) Dielectric test on the main circuit - Dry power frequency voltage withstand, Partial discharge and Radio interference voltage (r.i.v) tests

(b) Voltage withstand tests on auxiliary and control circuits

(c) Measurement of the resistance of the main circuits

(d) Mechanical operating tests

(e) Pressure and Gas tightness tests

(f) Design and visual checks

(g) Inspection of the general condition

(h) Timing tests of the main contacts and auxiliary switches


(j) Complete electrical functioning tests

(k) Closing and opening check at reduced voltage and other necessary tests and verifications

15.7.5.7 Circuit Breaker Site Tests As a minimum, the following tests after installation on site shall be performed:

(a) Power frequency voltage tests on the main circuits

(b) Dielectric tests on auxiliary circuits


(d) Gas tightness tests

(e) Design and visual checks

(f) Measurement of gas condition

(g) Mechanical operation tests

(h) Secondary injection tests on all protection relays

(j) Primary inject tests on all protection relays and associated current transformer circuits

(k) Complete electrical functioning tests including the function of all interlocks

15.7.6 Disconnectors and Earthing Switches All tests shall be performed in accordance with IEC 62271-100, IEC 60427, IEC 60694, IEC 60060, IEC 60270, IEC 61233 and other relevant IEC standards.

15.7.6.1 Type Tests The following type tests shall be performed:

(a) Lightning impulse tests

(b) Power frequency voltage withstand wet and dry tests

(c) Partial discharge tests

(d) Dielectric test on auxiliary and control circuit

(e) Temperature rise test

(f) Measurement of the resistance on the main circuit

(g) Short-time and peak withstand current tests

(h) Tests to prove the short-circuit making and breaking, performance of earthing switches (as applicable)

(j) Operating and mechanical endurance tests


(k) High temperature operation tests

(m) Artificial pollution tests

(n) Radio interference voltage test.

15.7.6.2 Routine Tests The following routine tests shall be performed:

(a) Power frequency voltage withstand dry tests on the main circuit.

(b) Voltage withstand tests on auxiliary and control circuits


(d) Mechanical operating tests

15.7.6.3 Site Tests The following tests shall be performed :

(a) Inspection of the general condition

(b) Manual and electro/mechanical closing and opening tests

(c) Closing and opening tests at the reduced voltage

(d) Checking of operating time

(e) Control and interlock checks.

and other necessary checks and verifications.

15.7.7 Current Transformers (CT’s) Testing shall be in accordance with IEC 60044-1 plus any additional tests indicated in this section and the schedules.

15.7.7.1 Type Tests (a) Short-time current test: Test data for similar units supported by calculation and equivalent

static load tests may be acceptable.

(b) Temperature rise test

(c) Lightning impulse test

Um < 300 kV: 15 positive plus 15 negative

Um ≥ 300 kV: 3 positive plus 3 negative

(d) Switching impulse test: 15 positive impulses applied wet for outdoor equipment, (applies to transformers with Um ≥ 300 kV).


(e) Wet dielectric tests:

Um < 300 kV: Power frequency test

Um ≥ 300 kV: Switching impulse test

(f) Determination of errors

(g) Radio interference test (RIV):

(h) Proof of Class PX low reactance

15.7.7.2 Routine Tests (a) Verification of terminal markings.

(b) Power-frequency withstand on primary.

(c) Partial discharge measurement

(d) Power-frequency withstand on secondary winding

(e) Determination of errors

(f) Class PX magnetising curves

15.7.7.3 Special Tests The following special category tests are required:

(a) Chopped lightning impulse

(b) Measurement of capacitance and dielectric dissipation factor

(c) Mechanical tests

15.7.7.4 Site Tests (a) Inspection of the general condition

(b) Secondary winding resistance measurement and burden checks.

(c) Ratio checks

(d) Magnetisation curves

(e) Insulation resistance measurements to earth and between windings.

15.7.8 Voltage Transformers and Coupling Capacitors Inductive voltage transformers (IVTs) shall be tested in accordance with IEC 60044-2. Capacitor voltage transformers shall be tested in accordance with IEC 60186 and any additional tests identified in the Publicly Available Standard PAS/IEC 60044-5. For coupling capacitors IEC 60358 shall apply.


15.7.8.1 Type Tests (a) Short-time current test

(b) Temperature rise test

(c) Lightning impulse test

Um < 300 kV: 15 positive plus 15 negative

Um ≥ 300 kV: 3 positive plus 3 negative

(d) Switching impulse test: 15 positive impulses applied wet for outdoor equipment, (applies to transformers with Um ≥ 300 kV).

(e) Wet dielectric tests:

Um < 300 kV: Power frequency test

Um ≥ 300 kV: Switching impulse test

(f) Determination of errors

(g) Radio interference test (RIV)

(h) Transient response test (CVTs only)

(j) Ferro-resonance test (CVTs only)

(k) Tightness of electromagnetic unit (CVTs only)

15.7.8.2 Routine Tests (a) Verification of terminal markings.

(b) Power-frequency withstand on primary (IVT only).

(c) Partial discharge measurement

(d) Power-frequency withstand on secondary winding and between sections

(e) Determination of errors

The following additional tests are required for CVTs:

(i) Tightness of capacitor voltage divider

(ii) Power-frequency test on the electromagnetic unit

(iii) Power frequency test on low voltage terminal

(iv) Ferro-resonance check


15.7.8.3 Special Tests The following special category tests are required:

(a) Chopped lightning impulse

(b) Measurement of capacitance and dielectric dissipation factor

(c) Mechanical tests

(d) Tightness of capacitor units (CVTs only)

15.7.8.4 Site Tests (a) Inspection of general condition

(b) Insulation resistance measurements to earth and between windings.

(c) No-load test with normal applied voltage on secondary terminals for a minimum of 30 minutes (IVTs only).

(d) Ratio checks

(e) Burden checks

15.7.9 Insulating Oil, Sulphur Hexafluoride and Compound 15.7.9.1 Insulating oil Samples of oil from each consignment shall be tested and shall comply with the tests specified in IEC 60296 for insulating oils, before any oil is despatched.

15.7.9.2 Sulphur Hexafluoride Samples of SF6 from each consignment shall be tested and shall comply with the tests specified in IEC 60376 and 60480, before any SF6 gas is despatched.

15.7.9.3 Compound Samples of compound selected by the Engineer from the bulk shall be tested to prove compliance with the requirements of BS 1858 for the appropriate grade of compound.

15.7.10 Surge Diverters 15.7.10.1 Tests on Surge Diverters (a) Zinc oxide, gapless type

Type, routine and standard acceptance tests shall be carried out in accordance with the IEC 60060, 60270 and 60099 metal oxide surge arresters.

Type test certificates will be accepted subject to their approval.

15.7.10.2 Tests on surge counters (a) Minimum Current Operation Tests


The rated minimum operating current of the counter, stated in the schedules, shall be passed ten times and the counter shall correctly register these operations.

(b) Maximum Current Withstand Tests

The maximum rated current stated in the schedules with a 8/20 µsec wave shape shall be applied to the counter ten times without any cooling periods and the counter shall register and withstand without distress.

15.7.11 Line Traps Each design of line trap being supplied shall indicate the class of insulation used and shall be subjected to the type and routine tests specified in IEC 60353 and the additional requirements as follows:-

The current used for the temperature rise test shall be not less than the rated current of line trap.

The current duration for the short time current test shall be not less than that stated in the schedules.

15.7.12 AIS Busbar Conductor and Connections The tests shall be in accordance with IEC 61089.

15.7.13 Post Insulators Each type of post insulator being provided shall be type, sample and routine tested in accordance with IEC 60168, 60660 and the following supplementary tests:-

15.7.13.1 Radio Influence Voltage Type Test Each type of post insulator being provided shall be assembled as in service and subjected to radio influence voltage test in accordance with NEMA Publication 107, IEC 60060 and IEC 60437.

15.7.14 Insulator Strings Type, sample and routine tests on insulators of the string type, porcelain or glass, shall be made in accordance with the requirements of IEC 60383 and 60815 and the supplementary type tests stated below.

15.7.14.1 Dielectric Tests The 50 per cent flashover level as well as withstand shall be determined during the impulse and power frequency tests.

15.7.14.2 Radio Influence Voltage Test Each type of string insulator shall be assembled as in service and subjected to radio influence voltage tests in accordance with NEMA 107, IEC 60060, 60437 and this Specification.

15.7.15 Tension and Suspension Clamps and Joints 15.7.15.1 Type Tests All joints and clamps shall be submitted for examination before test and all assembly, cutting off of conductor, compound filling (where applicable), and any work whatsoever necessary for the assembly


of the clamps and joints in the field shall be carried out in the presence of the Engineer with the erection methods and tools proposed for field use. Approval of such methods and tools will be subject to inspection at the time of the tests. The Contractor shall ensure that a reasonable number of his supervising staff shall be present at the type tests.

(a) Mechanical type test

The following tests shall be carried out on the conductor clamps and joints:-

(i) Two tension clamps shall be fitted to the end of a length of conductor not less than 6 metres long.

(ii) A tension joint shall be fitted in the centre of a 6 metre length of conductor, each end of which shall be held in a half joint.

For both tests (i) and (ii) a tensile load of about 50 per cent of the breaking load of the conductor shall be applied and the conductor shall be marked in such a way that movement relative to the fitting can easily be detected. Without any subsequent adjustment of the fitting, the load shall be steadily increased to 95 per cent of the breaking load and then reduced to 90 per cent of the breaking load and maintained for one minute. There shall be no movement of the conductor relative to the fitting due to slip during this one minute periods and no failure of the fitting.

A slip test shall be carried out on suspension clamps to demonstrate compliance with this Specification and to establish the torque to be applied to the clamp bolt nuts.

Non-tension joints and clamps, and non-tension parts of tension clamps shall be similarly tested to show compliance with this Specification.

(b) Electrical Type Tests

The following test shall be carried out on a sample each of tension joints, tension clamps in which the conductor has necessarily to be cut, and non-tension joints. The test shall be carried out on an assembly consisting, where applicable, of a tension clamp, tension joint and non-tension joint, together with a length of the line conductors, the whole being connected in series. The lengths of intermediate conductor shall be cut so that the distance between the mouths of the test fittings shall not be less than 1 metre. The assumed maximum full load current specified in the Schedules at 50 Hz shall be passed continuously through the assembly for a period of 8 hours, followed by approximately 16 hours shutdown, followed by a further 8 hours heat run. At approved intervals throughout this period measurements of temperature rise shall be recorded on the fittings and on the intermediate conductors. Immediately at the ends of the heat-runs accurate voltage drop measurements shall be made on standard lengths, including fittings and conductor. If possible a.c. voltage drop measurements shall also be made during the heat runs. The temperature rise and resistance per unit length of any fitting shall at no time exceed those of the conductors. Temperature measurements on fittings and conductors shall be made in an approved manner. No tightening up or adjustment of fittings in any way shall be permissible during the progress of the test.

At the conclusion of the test all fittings shall be completely dismantled and there shall be no signs of local heating, burning or fusing on any part of the fittings or on the conductor itself.


All conductor fittings shall be shown to comply with the visible corona and RIV levels specified.

15.7.15.2 Sample Tests Sample clamps and joints shall be submitted to such tests as the Engineer may require in order to demonstrate compliance with this Specification.

15.7.16 Large Hollow Porcelains Each type of large hollow porcelain being supplied shall be subjected to the routine and sample tests specified in IEC 60233, modified and supplemented as follows:-

15.7.16.1 Routine Pressure Test Each hollow porcelain being provided shall be subjected to the appropriate routine hydraulic pressure tests in accordance with the requirements of this Specification. The test shall be made on the porcelain complete with irremovable metallic flanges.

15.7.16.2 Temperature Cycle Test These tests shall be made on the porcelain complete with all irremovable fittings.

15.7.16.3 Routine Bending Test If the stress expected on the porcelain in service exceeds 20% of the minimum failing load then the following routine test shall be made:-

Each porcelain shall be subjected to a cantilever bending test such that the insulator is fully stressed in all directions, but in the event of a point loading procedure being adopted and the number of points at which the load is applied shall be a minimum of four. The applied bending moment, arrangement for test, and test procedure shall be to the approval of the Engineer.

15.7.16.4 Sample Bending Test When the porcelain service stress is less than 20 per cent of the minimum failing load then sample bending tests shall be made as specified. Samples shall be selected as specified in IEC 60233.

15.7.16.5 Ultrasonic Tests Routine tests shall be made on each porcelain insulator being supplied using ultrasonic crack detection techniques. These tests shall be made on the insulator prior to fitting of metallic flanges.

15.7.17 Bushing Insulators Type and routine tests on bushing type insulators shall be made in accordance with the requirements of IEC 60137 modified and supplemented as stated below.

The test voltages shall be as specified in the Schedules.

15.7.17.1 Type Tests (a) Short time current test

Each type of bushing being provided shall be subjected to a short time current test at the rating specified in the Schedules, the test procedure being in accordance with that of IEC 56. The


following measurements shall be made after this test to demonstrate that the bushing is in a sound condition.

(i) Power Factor (Loss Angle) - Voltage characteristic up to 120 per cent of normal working voltage.

(ii) Internal Discharge Test and Applied Voltage of 0.67 E - The results of these tests shall not differ significantly from those obtained during routine tests on the same design of bushing.

(b) Internal discharge and power factor tests

These tests shall be made on each bushing being type tested in the manner specified. The internal discharge test shall be made before and after the power frequency impulse and switching impulse voltage type tests, but the power factor measurements need only be made after these tests.

15.7.17.2 Routine Tests (a) Sequence of routine tests

The routine dielectric tests shall be made in the following order: -

(i) Internal discharge test as specified.

(ii) Dielectric loss angle measurement as specified.

(iii) Power frequency dry voltage test.

(iv) Dielectric loss angle measurement as specified.

(v) Internal discharge test as specified.

(b) Internal discharge test

Each bushing shall be assembled complete as in service, and subjected to an internal discharge test as specified in IEC 60137.

(c) Dielectric loss angle measurements

Measurement shall be made of the dielectric loss angle and capacitance of the primary insulation between line terminal and test tapping or metallic flange of each complete bushing using a Schering Bridge.

The loss angle voltage characteristic shall be determined over a voltage range of up to 1.2 times phase to neutral voltage.

The loss angle measured shall not change with voltage and shall not exceed the value guaranteed in the Schedules.


15.7.18 Structures A representative sample of each type of support structure being provided shall be assembled prior to dispatch to site and loads simulating the specified design parameters shall be applied.

Such loads shall be withstood without deformation of any structure member.

15.7.19 132, 33 and 11 kV Power Cables 132/33/11kV cable and cable accessories should be tested together as a complete system for type test purposes. Commissioning tests will inherently test these components as a complete system.

15.7.19.1 Type Tests The appropriate type tests in full accordance with IEC 60840 and IEC 60502 and shall be made available in order to demonstrate satisfactory performance requirements.

These tests excepting those which are also required as additional regular tests need not be repeated once they have been performed successfully, unless alterations are made to cable design or materials which might affect the performance.

The accessory manufacturer must demonstrate by type test approval tests on the specific cable that any joint or termination that it is intended for use with the cable supplied for a specific contract is compatible with that cable.

Designs suitably tested may be used for applications where the electrical design stresses are the same or lower than those tested.

The tests are based upon a maximum continuous design conductor temperature of 90°C. Where enhanced or emergency conductor temperatures are to be offered modification of these tests may be required.

15.7.19.2 Routine Tests Routine tests shall be conducted in accordance with IEC 60840 and IEC 60502 as appropriate.

General

The following routine tests shall be carried out on each drum length of cable to be supplied:

(a) Dimensional Checks.

(b) Measurement of Conductor D.C. Resistance.

(c) Measurement of Capacitance.

(d) D.C. Voltage Test on Oversheath.

(e) Partial Discharge Test.

(f) Insulation A.C. Voltage Withstand Test.

The test methods and requirements for items (a), (e) and (f) are as follows: -.


(a) Dimensional Checks

A measurement of the thickness of the insulation, metallic sheath and oversheath shall be carried out on every drum length of cable. The checks of cable construction are specified in IEC 60840 Clause 11.4.1.

The thickness of the semi conducting screen shall be measured as specified in IEC 60811-1-1. The minimum thickness shall not be less than 60% of the declared nominal value.

(e) Partial Discharge Test

The cable shall be tested for partial discharge as specified in IEC 60840 Clause 11.3.5.

All production cable is expected to be discharge-free and any partial discharge detected will require evidence of investigation and explanation.

(f) Insulation A.C. Voltage Withstand Test

The test shall be carried out on all cables as prescribed in IEC 60840 and IEC 60502 as shown below. No breakdown of the insulation shall occur.

System Voltage (kV) Power Frequency Test Voltage (kV) Duration (min)

132 2.5.U0] 30

33 3.5.U0 5

11 3.5.U0 5

(g) Pre-moulded Accessory Tests

Every pre-moulded accessory shall be assembled on a suitable former and shall be subject to a routine test at 2 U0 for 1 h. It shall not breakdown. During the test the assembled accessory shall be monitored for partial discharge with a background noise level no greater than 2 pC. After testing every component shall be inspected for signs of electrical discharge. Any evidence of partial discharge or visible damage shall be brought to the attention of NGC and included in the test report. Only sound and visually inspected components shall be packed for delivery to site.

15.7.19.3 Tests on a Dispatch Drum of Cable The following tests shall be carried out on dispatch drum of cable, to check that the whole of each length complies with the requirements.

(a) Voltage test: Each drum length of completed cable shall withstand a voltage of 25kV DC for one minute between the metal sheath and the external conducting surface.

(b) Partial discharge test

(c) Dielectric loss angle

(d) Conductor examination


(e) Measurement of electrical resistance of conductor

(f) Oversheath voltage withstand test

15.7.19.4 Site Test Requirements (a) D.C. Conductor Resistance Measurement

The ambient temperature and d.c conductor resistance of each completed circuit shall be measured to at least three significant figures and recorded.

(b) Sheath Insulation D.C. Voltage Withstand Test

The fully insulated sheath system including cable oversheath, terminal base insulation, joint external and sectionalising insulation if present, together with the insulation of bonding leads and link boxes or pillars, shall withstand a voltage of 10 kV d.c applied between sheath and earth for a period of one minute.

The maximum leakage current shall not exceed 10 mA. Current above this level is indicative of an oversheath fault.

(c) Single Point Bonded Systems

The metallic sheath of a single point bonded system must only be connected to earth at one point. This will normally be at the termination but some systems may have the earth connection at the mid point.

Prior to commissioning the sheath connection to earth shall be verified either visually or by the use of a suitable megger.

If the sheath is inadvertently earthed at more than one point any load current in the circuit will establish circulating currents in the sheath. To ensure that this is not the case, when the circuit is first placed on load a tong ammeter shall be used to ensure that there is no current in the sheath earth strap.

(d) Contact Resistances

The contact resistance of all earthing and sheath bonding connections shall be measured using a calibrated digital micro-ohmmeter.

The contact resistance between each lug attached to the joint sleeve of a sectionalised joint and the corresponding bonding lead connector shall be measured prior to the fitting of the outer protective cover.


The contact resistance shall not exceed the following:-

Contact Maximum Contact Resistance (µΩ)

Link Contact 20

SVL Terminal Connection 50

Join Lug and Bonding Connector 20

Earth Connection 50

(e) Insulation A.C. Voltage Withstand Test

The cable shall withstand an a.c. test voltage applied between the conductor and sheath, with the sheath earthed. The test voltage will normally be provided by a resonant test set operating close to power frequency. The requirements of the test are summarised below. No breakdown of the insulation shall occur.

System Voltage (kV) Site Test Voltage (kV) Frequency (Hz) Duration (h)

132 2.0.U0 30-300 1

33 2.0.U0 30-300 1

11 2.0 U0 1

(f) Oversheath D.C. Voltage Withstand Test

The cable oversheath shall be subject to a D.C. voltage test as specified in IEC 60229 This requires a direct voltage of 4 kV/mm of specified thickness up to a maximum of 10 kV with the sheath as the negative electrode. For 132 kV cables the oversheath thickness will be taken as the nominal value.

15.7.19.5 Cable Sealing Ends Type, routine, sample and special tests shall be carried out in accordance with IEC 60137, where applicable, and the Schedules. Type tests shall be made on an external insulator which has passed its routine tests.

15.7.20 LV Cables 15.7.20.1 Type Tests Type tests shall be shown to have been performed on each type and rating of the specified equipment with purpose of proving its properties.

The following type tests shall be performed:

(a) Partial discharge test at room temperature.

(b) Bending test followed by partial discharge test.

(c) Measurement of power factor depending on temperature.


(d) Measurement of insulation resistance at room temperature and service temperature.

(e) Impulse voltage withstand test.

(a) Dielectric test by DC voltage preferably.

15.7.20.2 Routine Tests Routine test shall be performed at each item of equipment to be supplied for the purpose of revealing faults in material or construction. They shall not impair the properties and reliability of a test object or reduce its lifetime.

The following routine tests shall be performed on all lengths of cables and all accessories to be supplied:

(a) Conductor resistance

The dc resistance of the conductors shall be measured by an approved method and shall not be greater than the figure stated in the Schedules when adjusted for temperature.

(b) Voltage test

The voltage test shall be made with alternating current of approximately sine wave form at any frequency between 40-62 Hz inclusive. The voltage shall be increased gradually and maintained continuously for one minute at 5 kV ac rms between each conductor and the remaining conductors connected to the armour and earthed. No breakdown of the insulation shall occur.

(c) Insulation resistance

The insulation resistance shall be measured between each conductor and the other conductors connected to the armour. After the application of 500 V dc for one minute, the measured value shall not be less than the figure stated in the Schedules when adjusted for temperature.

(d) Electrical tests on extruded PVC oversheath

Extruded PVC oversheaths shall be spark tested in the manner described in Clause 16.2 of BS 6346.

(e) Mutual capacitance

The mutual capacitance of multipair cable shall be measured between the two conductors of each pair with the other conductors and armour earthed. The measurements shall be made using alternating current and a suitable bridge and the mean value obtained shall be recorded.

(f) Bending test

A sample of each completed cable shall be subjected to a bending test as specified in Clause 31 of BS 6480, the test cylinder diameter being not less than eight times the overall diameter of the cable. After test a 300 mm length cut from the middle of the sample shall be stripped and examined.

15.7.20.3 Site Tests On arrival at site, during installation and after complete installation, all items of equipment shall be inspected and tested in order to check quality, correct operation and correct installation of the equipment.


The following tests shall be performed:

(a) General inspection of the cable routes, verification of proper installation, fixing to the racks, bending radius, etc

(b) Verification of proper earthing of the screen and armouring

(c) Measurement of cables insulation resistance

(d) Verification of proper condition of external surfaces

(e) High voltage test

Each completed circuit shall be tested for 15 minutes at a dc voltage of 4 Uo or an ac voltage of U applied between the conductor and the sheath or metallic screen without failure.

(f) Conductor resistance test

The dc conductor resistance of each completed circuit shall be measured and recorded. When corrected to 20°C by means of the temperature correction factors in Appendix 2 it shall not be greater than the figure stated in the Schedules.

(g) Cable covering protection units (CCPU).

The CCPU shall be voltage tested on site and the current/voltage characteristics shall be recorded and shall be within the values given in the Schedules.

On completion of the above test the CCPU shall be isolated from each and the resistance between the CCPU and earthed metal shall not be less than 10 megohms when measured with a 1000 V Meggar.

(h) Testing of link boxes and links

Link connections shall be capable of withstanding an impulse of 35 kV peak between links and 17.5 kV peak between links and earth.

(j) Voltage test on outer covering

(i) After laying each drum length, the cable shall withstand a voltage of 10 kV dc or 5 kV ac applied for one minute between the screen or metallic sheath and the external conducting surface.

(ii) After completion of the installation of each circuit the cable shall withstand a voltage of 5 kV dc applied for one minute between the screen or metallic sheath and the external conducting surface.

(k) Capacitance test

Each complete cable shall be listed for capacitance to earth of each core which shall not be greater than the figure stated in the Schedules.


15.7.21 Motors and Motor Control Equipment Motor performance tests shall be in accordance with IEC 60034-1. Motor control equipment type and routine tests shall be carried out in accordance with IEC 60947-4-1.

15.7.22 Material Where required, selected Type tests shall be performed on samples from metals used in the contract works. They shall be tested to prove compliance with the specification including the stated guarantees.

15.7.23 Galvanizing Selected samples of all galvanized material shall be subjected to the galvanizing tests set out in BS EN 10244-2 (Testing of Zinc Coating on Galvanized Wires) or BS EN ISO 1461 (Testing of Zinc Coating on Galvanized Articles other than Wire) whichever is applicable.

15.7.24 Line Traps 15.7.24.1 Type Tests Line traps shall be subject to type tests in accordance with IEC 60353.

The power line carrier equipment cubicles shall be subject to type tests to verify the performance parameters and characteristics required by the specifications. In particular reference is made to the following:-

(a) Where the carrier is specified for use with protection signalling, it shall be proved that the system will be substantially free from mal-operation under power system disturbance conditions.

(b) Where the carrier system is specified for use with supervisory control and telemetering, its suitability for this purpose at the signalling speeds concerned shall be verified. Measurements of differential delay distortion may be required.

15.7.24.2 Routine Tests Line traps shall be subject to routine tests in accordance with IEC 60353, together with verification of the tuning device and protective characteristics.

The capacitance and power factor of the coupling capacitor shall be measured, and the dielectric tests shall be carried out on the coupling capacitor.

The characteristics of the line matching units and coupling filters shall be verified, and dielectric tests shall be carried out on these items.

The power line carrier equipment cubicles shall be subject to routine tests in accordance with the manufacturers works programme of tests. The following shall be included in the range of tests to be applied: -

(a) Insulation tests on output relays and circuits connected with the low voltage a.c. and d.c. auxiliary supply systems.

(b) Tests on power supply stability over the permitted range of input supply voltage variation.


(c) Nominal level of signals throughout the equipment.

(d) Range of audio input and output levels.

(e) Response characteristics audio/audio, audio/sideband and sideband/audio.

(f) Inherent signal/noise ratio and distortion factor.

(g) Functioning of automatic gain control.

(h) Functioning of emergency telephone

15.7.25 Control and Indicating Panels, Instruments and Secondary Wiring 15.7.25.1 Type Tests (a) Mimic diagram panel operation tests.

One typical indicating panel shall be erected as in service and the indicating devices operated to the satisfaction of the Engineer.

15.7.25.2 Routine Tests All panels and instruments shall comply with the tests specified in the appropriate standard Specifications.

The wiring on each panel, cubicle, rack and each removable panel or plate of apparatus shall be subjected for one minute to an alternating voltage equal to the test pressure specified for the apparatus to which it is connected. This test shall take place after the complete assembly of the apparatus and wiring on or in the panels, cubicles and racks.

All wiring and apparatus which is, or may become, connected to voltage sources other than the supply for the very low voltage (50 volts and below) apparatus shall be subjected for one minute to an alternating test pressure of 2 000 volts rms to the frame of the panels on which they are accommodated, immediately after which the insultion measured at 6 500 volts dc shall not be less than 20 megohms. Included in these requirements is apparatus and wiring which become connected to voltage or current transformers.

The windings and electrical connections of indicating and recording meters shall be subjected for one minute to a test voltage of 2 000 volts rms to the case or any other metal which is not intended to be insulated from the case when the instrument or meter is in use.

15.7.26 Protection Equipment 15.7.26.1 Routine Tests All relays shall be subjected to routine tests at the manufacturers works to confirm that they comply with the claimed performance and design limits.

For measuring relays (ie relays which have a defined setting of the input and/or characteristic quantity subjected to accuracy requirements, eg current, time, etc) these routine tests shall include as a minimum the following:


(a) Measurement of the assigned error(s) under reference conditions, ie measuring accuracy and operating time characteristics.

(b) Measurement of the resetting ratios.

(c) Dielectric tests as specified in Clause 6 of IEC Publication 60255-5, the test voltage being 2 kV rms. All normally open output contacts of all relays shall withstand a test voltage of 1 kV rms.

For all-or-nothing relays, the routine tests shall include a check of relay operation and resetting, together with the dielectric tests described above.

Unless otherwise agreed with the Engineer, all unit protection schemes using either biased differential, current balance or voltage balance principles shall be subjected to heavy current conjunctive tests using the actual current transformer windings which will be used in service. Tests shall be made to prove operating sensitivity, time of operation and to demonstrate stability of the protection under the worst transient external fault conditions. Tests will only be waived if the manufacturer is able to produce type test results for an identical scheme. In this case it will be sufficient to prove that individual component characteristics are identical, eg current transformers are of the same design, have the same magnetisation characteristics, knee-point voltage and secondary resistance.

For protection schemes including distance protection, phase comparison protection, auto reclosing and automatic switching sequence schemes, etc routine tests shall be performed on each complete scheme to ensure that all possible operational sequences and features are fully functional. Where necessary, this shall be done using simulation of any ancillary equipment normally used in conjunction with the scheme, e.g. circuit breakers. These routine tests will be performed in addition to the tests normally applied to individual elements of the scheme and details of the proposed test programme shall be submitted to the Engineer for approval not less than one month before they are to be performed.

If such routine tests are not practicable due to the complexity of the scheme, a scheme type test will be accepted on representative production equipment. The test shall be performed so as to simulate, as nearly as possible, the conditions which will be experienced in service and details of the proposed test programme shall be submitted to the Engineer for approval not less than one month before they are performed. In those cases where correct operation of the scheme is dependent on measured quantities associated with primary system plant (eg circuit breaker gas pressure), such quantities shall be measured directly during the tests.

Each circulating current protection scheme designed in accordance with Appendix 4 must fulfil the following routine testing requirements:

(a) Each current transformer, which must be of the low reactance type, shall be individually tested for turns ratio, secondary winding resistance and excitation characteristic up to a secondary voltage equal to 120 per cent of the "knee-point" voltage.

(b) The VA consumption at operation of current operated relays shall be measured and shall not exceed the maximum value declared by the manufacturer.

(c) The operating current of voltage relays shall be measured and shall not exceed the maximum value declared by the manufacturer.


15.7.26.2 Type Tests Approved type tests shall be carried out in the manufacturers works on each type of protection system. During the tests, ancillary equipment shall be erected and connected so as to reproduce service conditions as closely as possible. The main purpose of these tests shall be to determine the performance of the protection for the range of system conditions which will be encountered by the protection in practice, and to determine all the appropriate application parameters. The test condition shall be as agreed by the Engineer.

Where type tests have been carried out under previous contracts on protective equipment similar in all essential respects to the equipment included in the Contract, the Engineer may waive the type tests on production of complete test records which he approves, relating to the equipment concerned. Each set of test records shall include a full statement of the performance claims, eg performance under reference conditions, effect of influencing the quantities, steady state and dynamic stability for unit protection schemes, current and voltage transformer requirements, etc and full details of tests performed on representative samples of production equipment to demonstrate that the performance claims have been met.

15.7.27 Batteries and Associated Equipment 15.7.27.1 Battery Charger (a) Constant voltage chargers

Tests shall be carried out to show that the output voltage remains constant with any combination of the input voltage, frequency and load variations stated in the Schedules and the output voltage on each voltage tap shall be measured at rated load and frequency.

The efficiency shall be measured at normal output voltage and current and normal input voltage and frequency.

Tests shall be made to prove that the insulation resistance of the transformer complies with this Specification.

The output terminals of the charger shall be short circuited and the output current measured. This shall not be greater than the value given in the Schedules.

In the case of 50 volt battery chargers only, tests shall be made to show that the psophometric noise level specified is not exceeded and for this purpose the following notes shall be observed:-

(i) For floated battery systems, it is necessary to keep any noise introduced by the charging device to an acceptable level for communication purposes. The maximum permitted noise level from all sources for commercial telephone circuits in cable is the equivalent of 2 mV at 800 Hz (rms value). Neither the average human ear nor telephone receivers in common use respond equally at all frequencies, the response being less above and below a narrow band of frequencies, around 800 Hz. A given disturbing voltage at frequencies outside this band therefore represents a lower noise level than such a voltage at 800 Hz. A correction factor is applied to obtain the equivalent in terms of 800 Hz noise. This correction factor is the "weighting" assigned to each frequency in the CCIF table, a copy of which is included as Appendix 5. By definition the psophometric noise is


1/800 * Pf2 * Vf2 where Pf is the weighting factor

and Vf is the voltage at different frequencies.

(ii) To obtain a result with one measurement only a psophometer must be used incorporating a weighting network. It is not possible to state the noise level from a measurement at one frequency only even if this is the fundamental ripple frequency, nor is it possible to measure the aggregate noise level without a suitable weighting network. Statements of ripple voltage in the form of a percentage are valueless. It will be noted that the maximum acceptable noise level for the battery and charger is that recommended for commercial telephone circuits in cable and apparently leaves no margin for other sources of noise. Battery potentials are not applied directly to telephone circuits, however, and in practice the adoption of the same standard for the battery and charger as for a telephone line provides an adequate margin and permits the charger smoothing equipment to be to commercial standards.

(iii) The maximum permissible noise level is specified with the battery connected in circuit. The battery provides a low impedance path for the ac currents involved. When acceptance tests are made on a charger otherwise in situ with its associated battery, the resistance of the test battery may be measured and a correction factor applied. The tests should always be made with a fully charged battery. There is, however, variation of battery resistance with temperature and state of charge, even though the battery appears to be fully charged. In order to obtain a uniform standard the noise measurements should be corrected by the percentage by which the battery resistance differs from the following figures: -

Normal Size Battery DC Resistance AC Resistance of charger Capacity in ohms in ohms 5 A 40 Ah 0.11 0.05 5 A 50 Ah 0.11 0.05 10 A 75 Ah 0.06 0.03 15 A 100 Ah 0.06 0.03 15 A 150 Ah 0.04 0.02 20 A 200 Ah 0.03 0.02 25 A 250 Ah 0.03 0.02 50 A 300 Ah 0.02 0.01

As it is unreasonable to expect a full range of batteries at a Contractor's works, chargers may be tested with a battery within this range, the necessary correction factor being applied in accordance with the table above, it being assumed that the charger is to work with a battery for which it is the normal size. The battery used must be in good condition and comply with BS 6290. Connections between charger and battery and load and battery must be taken back separately to the test battery and the connections must be adequate.

(b) Boost chargers

Tests shall be carried out to prove compliance with the particulars given in the Schedules.

Tests shall be made to prove that the insulation resistance of the transformer complies with this Specification.


15.7.28 Low Voltage Switchboards Type and routine tests shall be performed in accordance with IEC 60439. All individual components contained in the switchboard shall be tested in accordance with the relevant part of this Specification.

15.7.29 33 kV Switchgear Type and routine tests shall be carried out in accordance with IEC 62271-200, IEC 6227-100, IEC 60694 and IEC 61233 in independent testing laboratories not associated with the manufacturers or witnessed by an independent observer.

15.7.30 GIS Building Crane All parts of the GIS building crane shall be tested in accordance with the appropriate IEC or other standards to the approval of the Engineer.

15.7.31 Fire Protection Equipment All parts of the fire alarm system, fire extinguishers and transformer fire protection system shall be tested in accordance with the appropriate IEC or other standards to the approval of the Engineer.

15.7.32 Substation Control System 15.7.32.1 Approach to Testing The testing philosophy for the SCS shall ensure that the equipment functionality and site specific facilities are thoroughly exercised and validated at the Contractor's premises before delivery, and that the site specific facilities are confirmed during commissioning. The test methodology shall complement the design methodology and the two shall be developed in parallel.

This document does not constitute a Test Specification or Test Procedure for any part of the system, rather it sets out the stages at which tests are required and the subjects, location and purpose of each stage. All Test Documentation for all tests shall be written by the Contractor and submitted to the Engineer for approval at least 12 weeks before they are first used.

Where any equipment is not connected to the SCS, but has its facilities marshalled in the marshalling cabinet, these connections shall be included in the testing regime.

The confidence testing of the operation of the substation plant from the NCC SCADA system via the SCS and other control and monitoring from the Substation SCS and the NCC is included in the Works. The equipment shall be entirely compatible with the communications protocols as may be required by the NCC and with the communications media available. The Contractor shall undertake specific testing to demonstrate the compatibility of the SCS with the NCC.

15.7.32.2 Testing Stages The SCS shall be subject to acceptance testing as specified in this document. The stages of testing to be performed at higher levels shall be based on the following:


(a) Factory Acceptance Testing (FAT)

To check that the totality of the equipment supplied under the Contract performs in accordance with the Contract requirements.

Factory Acceptance Testing (FAT) shall be performed with the SCS assembled at the factory as a complete system. The FAT shall exercise and prove the correct operation of all functions of the supplied SCS whether used in this project (as supplied) or not, and the site specific facilities, using simulation where necessary, including the interface for connection to the National Control Centre SCADA system. The Tenderer shall state how they would undertake the FAT of the SCS in their offer.

(b) Site Acceptance Testing (SAT)

To check that the totality of the equipment supplied under the Contract performs in accordance with the Contract requirements and interacts correctly with equipment supplied by others and interfaces correctly to the Works.

Site Acceptance Testing (SAT) shall be performed with the complete SCS installed on site with all interfaces to the substation plant connected and functional and be conducted after the successful completion of the Contractor’s own testing of the system. The SAT shall exercise and prove the correct operation of the functions of the supplied SCS used in this project, including all the testing of all facilities between the National Control Centre and SCS. The Tenderer shall state how they would undertake the SAT of the SCS in their offer.

(c) 500 Hour Trial Period (following System SAT)

'Hands on' test period to demonstrate the reliability, stability and robustness of the SCS.

15.7.32.3 Notice & Witnessing of Tests The Contractor shall provide, as part of the Programme of Work documentation, a master plan showing the scheduled dates of testing and shall provide updates to this plan, when any changes are known, at least 6 weeks in advance of the tests.

The Contractor shall advise the Engineer in writing of the actual date of commencement of every test at least 10 working days before the commencement.

The Engineer shall have the right to witness any tests whether conducted at the Contractor's premises or elsewhere. Records of every test, whether witnessed or not, shall be taken by the Contractor and copies sent to the Engineer within 3 weeks of completion of the tests.

15.7.32.4 Test Procedures and Result Sheets The Contractor shall prepare test procedures and result sheets for all tests. The Contractor shall also prepare a cross reference listing to show that all of the requirements of the Functional Design Specification have been included in the tests.

Separate test procedures and result sheets shall be provided for factory and site acceptance tests. All test procedures and result sheets will be subject to review and approval by the Engineer.

Test result sheets will be retained as part of the permanent QA record for the SCS.


15.7.32.5 Contractor’s Prior Tests The Contractor shall successfully complete a prior run of all tests, using the test procedures and result sheets described above, before the commencement of the formal tests.

Any revisions to the test documents found necessary as a result of the prior tests shall be made before the commencement of formal tests.

Test results from the prior tests shall be made available to the Engineer, on request, to indicate the readiness of the equipment for testing to commence.

15.7.32.6 Fault Categories The Engineer will allocate a category to each fault, which shall determine the future tests required. Test categories shall be as defined in the Table at the end of this section.

15.7.32.7 Repeat Tests The Contractor shall correct and re-test every fault detected during the tests.

15.7.32.8 Fault Log The Contractor shall maintain a fault log throughout each series of tests. Every fault detected during the tests will be entered in the log, together with the actions taken to clear and re-test the fault.

The fault log will be retained as part of the permanent QA record for the SCS.

15.7.32.9 Hardware Failure Reports For each hardware failure that occurs at any stage of testing, the Contractor shall investigate the failure and prepare a report on its cause(s) and design implications. The report shall clearly show:

(a) the most likely cause of the failure

(b) an analysis of any stress that may have been caused to other components of the equipment being tested as a result of the failure

(c) whether the failure is a result of any component operating outside its design range

(d) whether any design changes should be made to avoid further failures.

All such reports will be retained as part of the permanent QA record for the SCS.

15.7.32.10 Software Failure Reports For each software failure that occurs, once the software has been approved for inclusion into the system and is subject to configuration control, the Contractor shall generate a software failure report. The report shall clearly show:

(a) The observed symptoms

(b) The likely cause

(c) The fault category


The report shall also clearly show the following information, which shall be entered when the failure has been investigated:

(a) The actual cause of the failure

(b) The corrective action taken

(c) All software modules affected.

All such reports will be retained as part of the permanent QA record for the SCS.

Table -1 Fault Categories

Category Definition

0 An item recorded as a fault during testing, and subsequently considered to be a normal acceptable occurrence. Testing may continue.

1 Minor fault. An event not affecting the functionality being tested in that session. Testing may continue.

2 Repeatable fault not affecting the functionality being tested in the session. Testing may continue at the discretion of the Engineer.

3 Repeatable fault affecting the functionality being tested in the session. The fault must be rectified before re-test of the affected test session. Testing may proceed on other sessions if permitted by the Engineer.

4 Major fault affecting the functionality being tested in the session. The fault must be rectified before recommencing testing.

5 Non-repeatable fault affecting functionality being tested in the session. The action taken will depend on the severity of the fault. Discussion is needed to establish the most appropriate course of action.

6 Documentation error or deficiency. The error will usually be amended during the test and the test will continue. The documentation shall be corrected before the tests are considered complete.

7 Deficiency in the ability of the test or test equipment to demonstrate the function being tested in the session. Discussion is needed to establish the most appropriate action, which will usually result in a more appropriate test being devised, by the Contractor and the function re-tested using that new test. The test documentation shall be updated to include the new test procedure.

8 Other fault not covered above, but requiring explanation and, in some cases, correction.


15.8 Site Testing and Commissioning

15.8.1 Extent of Supply The scope of the commissioning programme will include the testing of:

(a) All 132 kV and allied 33/11kV primary plant, such as switchgear, buswork, instrument transformers and the necessary interface with the existing system or equipment supplied by others:

(b) Indicating meters, relays control and communications equipment and similar functions associated with the primary plant, including the necessary interface with existing installations or equipment supplied by others:

(c) Station auxiliaries associated with (a) and (b) preceding, and including such items as fans, compressors, lights, batteries and allied chargers and air conditioners:

(d) All energy meters will be tested and certified by MOE.

15.8.1.1 General The Contractor shall be responsible for the commissioning of all equipment covered under the Contract and also be responsible for the successful interface of the equipment with existing facilities and/or equipment supplied by others.

The Engineer shall have the right to witness all tests, and the results must be available to him as the tests proceed. He may recommend waiving of some tests, or may add further tests if considered necessary to prove compliance with the Specification.

The Contractor shall prepare and submit three months prior to the start of commissioning detailed commissioning and testing procedures for approval by the Engineer.

Some equipment specific site test requirements are stated in the “Specific Equipment Tests” clause, above.

15.8.1.2 Objectives (a) The objectives of commissioning work prior to energisation of plant at full voltage or connection

to system include:

(i) integrity (correctness) of installation and confirmation that equipment has not deteriorated since the completion of the Factory Acceptance Tests;.

(ii) integrity of insulation, connections and phasing;

(iii) proof of equipment characteristics;

(iv) review of workmanship;

(v) review of applications engineering and equipment ratings (final field check on design).


(b) The objectives during and following equipment energisation or connection to system include:

(i) performance checks on the various manual and automatic control features;

(ii) ability of the system to accommodate scheduled or unscheduled connection and disconnection of plant without undue disturbance;

(iii) loading and performance tests on primary components (and possibly including verification of losses in some cases);

(iv) integrated system performance tests;

(v) corona and RI tests.

15.8.1.3 Responsibilities The Contractor shall be responsible for all testing in preparation for first energisation or connection to system, with possible constraints imposed by MOE operating staff because of safety or other considerations.

MOE shall retain responsibility for the connection and disconnection of primary equipment to and from system, including first energisation of new equipment, but with the advice and technical assistance of the Contractor.

The Contractor shall be responsible for all testing with the equipment connected to the system, but within the constraints which may be imposed by MOE as a result of the then existing operating configuration. Equipment being so tested will not be classed as being in commercial service and the Contractor shall not be responsible for consequences to equipment on the system as a result of unscheduled operation, or tripping, or error in testing. The Contractor shall remain responsible for the performance of his equipment during the live tests.

15.8.1.4 Owner Participation The Contractor shall plan for MOE staff participation either continuously or on a regularly recurring basis in the commissioning work with the primary intent of:

(a) becoming familiar with the operating and maintenance aspects of the new equipment.

(b) maintaining a continuing assessment of the precautions required in, or possible consequences of, initial energisation of equipment.

These two necessary objectives must be allowed for in the preparation of schedules.

15.8.1.5 Commissioning Staff The Contractor shall be responsible for supplying commissioning personnel, including skilled and unskilled labour, as required, and will be requested to submit a list giving names, experience, and proposed duration on site. Consistent with the construction schedule, staff assigned to commissioning will fulfil that duty only, to the exclusion of others, for the duration of the assignment.

15.8.1.6 Test Equipment and Power Supplies The Contractor shall be responsible for supplying all instruments, tools and other equipment required for testing, commissioning, and transport, and ensure that any calibration etc is maintained and


documented. All such equipment shall be listed in the procedures and offered for sale in the tender document. Prices shall be listed separate to the tender price.

The Contractor shall submit a list of the type, range, and number of test instruments required.

The Contractor shall also be responsible for making available power supplies for testing in the necessary vector configuration and voltage, and current rating at the various stations.

15.8.1.7 Test Jurisdiction and Safety Notwithstanding any other statements in this outline, testing and commissioning work on any equipment which is energised, or which has been transferred to MOE operating jurisdiction can only be carried out under the "hold-off" and "permit-to-work" system of MOE

The Contractor shall be responsible for safety of personnel involved in commissioning and shall take all possible precautions and be fully aware of the dangers involved in testing EHV primary equipment. It is essential that any tests involving high voltage work shall be conducted by personnel specifically authorised by the Engineer for this purpose and that such persons shall be made fully aware by the Contractor of the dangers involved in the tests.

In addition to the scheduling of commissioning tests, the Contractor shall be responsible for preparing procedures for testing high voltage related equipment. After approval by the Engineer these procedures shall be adhered to for the commissioning tests and at the end of the project shall be handed over to the client along with drawings mentioned elsewhere in this specification.

15.8.1.8 Equipment Repair and Replacement Major failure or damage to equipment will require either its return to the factory or assignment of a special crew to carry out repairs. It is expected, however, that for failures in metering, relaying, control, and communications equipment the commissioning staff shall be competent and willing to undertake minor repairs or even temporary redesign and reconnection to preclude delay in energisation and commercial service.

15.8.1.9 Test Methods The Contractor shall, through his supervisor conduct all necessary tests to commission the sub-stations. The following site tests shall be considered to represent the minimum required in addition to those specified under the appropriate IEC, B.S. or ANSI standards or the standard specification of the country of origin and the manufacturer's instructions.

(a) System Phasing

The Engineer will provide the details of electrical phasing and phase notation during the approval of the drawings.

Potential phasing sticks or potential transformers shall be used to establish correct phasing across any open switch or breaker and testing shall always be carried out with reference to a “known system voltage source” where relevant. Control room meters and interconnecting wiring shall not be used for this purpose.


(b) DC Station Services

The Contractor shall test the dc batteries and battery charger, in accordance with the manufacturer's manuals, and perform the necessary adjustments. A discharge test of the battery shall be carried out in accordance with the relevant standards..

Before dc wiring or dc equipment is energised, a 500 volt "megger" test shall be applied to wiring and cabling only.

(c) AC Station Services

The Contractor shall inspect and test all ac wiring and ac equipment to IEC standards or other approved standards and codes. When wiring and equipment standards are questionable, the Engineer's ruling shall prevail without additional charges.

Before ac wiring or ac equipment is energised, a 500 volt "megger" test shall be applied.

(d) Oil filtering Equipment (if applicable)

The Contractor shall conduct the necessary tests on oil-filtering equipment to ensure the system is free from dirt, moisture and other detrimental foreign matter, and free from all oil leaks.

The initial circulating oil tests shall be made without the power transformers until the system is operating to the satisfaction of the Engineer. A final circulation test shall be made with the transformer included in the system but before the transformers are placed "on-load".

(e) Control Cables

The Contractor shall conduct the necessary checks and inspections to ensure all control wiring has been installed in accordance with the cable schedules and drawings. Where changes are necessary, the Contractor shall make the required changes to the appropriate drawings and advise the Engineer, and carry out re-testing of the modified facilities if applicable.

(f) Station Earthing

The Contractor shall test the station earth before final grading of the station. Test values shall be submitted to the Engineer for approval. Where suitable earthing is found to be difficult, the Contractor shall prepare a contour plan of earth resistance together with a proposal for satisfactory additions.

(g) Insulators and Bushings

The Contractor shall inspect all insulators and bushings, in position, for chips and cracks and immediately replace any which may be damaged. All insulators shall be thoroughly cleaned before field tests.

(h) Manual Operation

The Contractor shall install, align, and test all isolating switches, disconnects, earthing blades, circuit breakers and other associated equipment in accordance with the manufacturer's instructions. The torque for manual operation shall not exceed 35 kg-m (3,000 lb-in); a preferred


operational torque shall be 30 kg-m (2,580 lb-in) to allow for increased resistance to movement between periods of switch maintenance.

(j) Power Operation

The Contractor shall conduct the tests and inspections in accordance with the manufacturers instructions for the satisfactory power operation of equipment from the local control kiosks. These tests shall include operations at the minimum air system pressure and/or the reduced dc battery voltage and/or the reduced ac station service voltage, as permitted by the standards of the equipment supplier.

(k) Remote Operation

The Contractor shall conduct the necessary tests to operate all remotely-controlled equipment from both the remote and local locations. These tests shall be undertaken after the control and power cabling have been checked and tested and the SCS commissioned.

(m) Interlocks

The Contractor shall check correct operation of all interlocks, and record the findings accordingly. Any malfunction of the interlocking scheme shall be brought to the attention of the Engineer.

(n) Relay Tests

The Contractor shall undertake all necessary tests to establish the correct functioning of all protective, ancillary and auxiliary relays to the design data of each relay.

The tests shall include, but not be limited to, the following:

(i) Insulation resistance of all secondary circuits (current and voltage transformers, control, indication and alarm circuits).

(ii) Tests to check the magnetisation curve, polarity and resistance of current transformers.

(iii) Secondary injection of voltage transformer circuits.

(iv) Secondary injection of ac and dc relays to check their operating characteristics.

(v) Primary injection of current transformer circuits including overall injection of differential protection circuits to check all connections, fault settings and stability.

(vi) Sequence tests

(vii) Characteristic and accuracy tests

(viii) Calibration and settings tests

(ix) Phasing tests prior to making alive.

(x) On-load checks of protection, indicating and metering circuits.


The Contractor shall make all final relay settings to the approval of the Engineer. Final acceptance tests will be performed by the Contractor, witnessed by MOE. On completion of all tests, all relays will be sealed by MOE

(p) Transmission Line Data Measurement

To get a proper base for relay setting calculation in the substation, the Contractor shall measure line data of all the transmission lines, which are connected to the substation.

(i) Accuracy of the measurement shall be not less than ± 3%.

(ii) Positive and zero sequence resistance, reactance, and parallel susceptance shall be measured, without and with line reactors and neutral reactors if supplied.

(iii) Direct measuring shall be applied (without P.T. and CT)

(q) Testing Under Other Contracts

The Contractor shall co-ordinate the testing under this Contract with the testing by suppliers of other equipment.

15.8.1.10 Particular Constraints & Special Tests Possible low short circuit levels on the 132 kV system may impose constraints on switching. and restrict the response of protection or interfere with the co-ordination of 132 kV relays.

In a similar context, the following list of special tests, which may be required, is intended as representative only, and not necessarily complete:

(a) Interference tests between the earth grid and control circuits:

(b) Single-pole switching tests - with or without initiation by actual fault;

(c) Carrier transmission attenuation or interference tests during fault and live disconnect operation;

(d) Switching surge measurements.

15.8.1.11 Commissioning The Contractor shall place "on line" all work covered by this Contract after all tests have been satisfactorily carried out, together with work by other contractors or with existing installations. The actual scheduling of the commissioning shall be as agreed with the Engineer.

15.8.1.12 Test Schedule The Contractor shall prepare, for approval by the Engineer, a schedule of field testing and commissioning. The schedule shall provide sufficient time for MOE to be present to witness them. Changes and modifications to the schedule shall also be approved by the Engineer.


15.8.1.13 Records (a) Test Results

These shall be witnessed by the Engineer, and documented on forms to be agreed upon by the Contractor. The record shall include other pertinent data such as omissions or unsatisfactory test results. Where disagreement exists, the ruling of the Engineer shall be binding.

The Contractor shall maintain an up to date record of all inspections and tests, which shall be handed over to the Engineer at the completion of the site testing and commissioning.

(b) "As Built" Drawings

The Contractor will be responsible for making available to MOE a minimum of two complete sets of marked up "as built" drawings before leaving the site. Contractor shall correct and reissue the original drawings as soon as possible after this.

MINISTRY OF ELECTRICITY IRAQ SUPERGRID PROJECTS 400/132 kV SUBSTATIONS CONTRACT NO VOLUME 2 CIVIL AND BUILDING WORKS, AND BUILDING SERVICES AUGUST 2005

r List of Revisions

Volume 2 - Technical Specification Civil Works Issue 3 August 05

LIST OF REVISIONS

Current Rev.

Date Page affected

Prepared by


Checked by (quality

assurance)

Approved by

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19.11.04 15.03.05 Aug 05

ALL ALL ALL

JKR JKR PM

PM PM JKR

JW JW JW

JW JW JW

REVISION HISTORY

3 Aug 05 ALL Updated with MOE comments and general alignment across volumes.

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CONTENT SHEET


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CONTENTS

Page No.

1. CIVIL ................................................................................................................1-1 1.1 General.............................................................................................................1-1 1.1.1 Scope ...............................................................................................................1-1 1.1.2 Clearing and Site Preparation ..........................................................................1-5 1.1.3 Excavation........................................................................................................1-5 1.1.4 Fill and Back Fill ...............................................................................................1-7 1.1.5 Asphalt and Concrete Paving, Finish Grading and Reinstatement ................1-11 1.1.6 Oil Containment for Transformer and Reactor Bunds, and Firewalls .............1-18 1.1.7 Concrete.........................................................................................................1-19 1.1.8 Outdoor Steel Structures................................................................................1-42 1.1.9 Water Supply, Drainage and Disposal............................................................1-47 1.1.10 Gates and Fencing .........................................................................................1-49 1.2 Architectural ...................................................................................................1-50 1.2.1 General...........................................................................................................1-50 1.2.2 Scope of Work................................................................................................1-51 1.2.3 Materials.........................................................................................................1-51 1.2.4 Signage ..........................................................................................................1-51 1.2.5 Masonry..........................................................................................................1-51 1.2.6 Cement Rendering .........................................................................................1-52 1.2.7 Roofing ...........................................................................................................1-53 1.2.8 Precast Concrete............................................................................................1-53 1.2.9 Aluminium Windows .......................................................................................1-54 1.2.10 Vehicle Access Doors ....................................................................................1-55 1.2.11 Metal Doors and Frames................................................................................1-55 1.2.12 Wood Doors and Frames ...............................................................................1-55 1.2.13 Door Hardware ...............................................................................................1-55 1.2.14 Gypsum Plaster ..............................................................................................1-56 1.2.15 Tile Work ........................................................................................................1-57 1.2.16 Vinyl Asbestos Floor Tiles ..............................................................................1-58 1.2.17 Acoustic Ceilings ............................................................................................1-58 1.2.18 Carpentry........................................................................................................1-59 1.2.19 Miscellaneous Metal .......................................................................................1-59 1.2.20 Bronze Plaque................................................................................................1-60 1.2.21 Painting ..........................................................................................................1-60 1.2.22 Furnishings.....................................................................................................1-63 2. BUILDING SERVICES .....................................................................................2-1 2.1 General.............................................................................................................2-1 2.2 Scope of Works ................................................................................................2-1 2.3 Design Standards for Building Services ...........................................................2-1

of iii Pages

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2.4 Electrical Power Supplies.................................................................................2-2 2.5 Lighting and Small Power.................................................................................2-2 2.5.1 General.............................................................................................................2-2 2.5.2 Main Technical Data.........................................................................................2-5 2.5.3 Scope of Supply and Services .........................................................................2-6 2.5.4 Equipment Requirements.................................................................................2-7 2.5.5 Earthing and Bonding.....................................................................................2-16 2.5.6 Lightning protection ........................................................................................2-16 2.5.7 Fire Detection and Alarm System...................................................................2-16 2.5.8 Fire Fighting System ......................................................................................2-21 2.5.9 Building Arrangements ...................................................................................2-23 2.5.10 Plumbing Services..........................................................................................2-23 2.5.11 Telephone Installation ....................................................................................2-25 2.5.12 Inspection and Tests ......................................................................................2-25 2.5.13 Special Equipment and Tools.........................................................................2-26 2.5.14 Spare Parts ....................................................................................................2-26 2.5.15 Packaging, Shipping and Transport ...............................................................2-26 2.5.16 Training ..........................................................................................................2-26 2.5.17 Documentation ...............................................................................................2-26 2.6 Heating, Ventilation & Air Conditioning...........................................................2-28 2.6.1 Technical Requirements and Design of Air Conditioning and Ventilation ......2-28 2.6.2 Design Standards for Air Conditioning and Ventilation...................................2-28 2.6.3 General...........................................................................................................2-30 2.6.4 Scope of Works ..............................................................................................2-30 2.6.5 Electrical Supplies ..........................................................................................2-30 2.6.6 HVAC Design Conditions ...............................................................................2-32 2.6.7 Functional Scheme Requirements .................................................................2-34 2.6.8 Air Conditioning Units .....................................................................................2-35 2.6.9 Mechanical Ventilation Units ..........................................................................2-43 2.6.10 Extract Fans ...................................................................................................2-44 2.6.11 Control Systems .............................................................................................2-45 2.6.12 Ductwork ........................................................................................................2-48 2.6.13 Ductwork Accessories ....................................................................................2-50 2.6.14 Grilles And Diffusers (Supply And Extract).....................................................2-53 2.6.15 Air Filters ........................................................................................................2-54 2.6.16 External Louvres ............................................................................................2-55 2.6.17 Instruments & Detectors .................................................................................2-55 2.6.18 Insulation Work...............................................................................................2-56 2.6.19 Civil & Builders Work ......................................................................................2-57 2.6.20 Construction Standards..................................................................................2-57 2.6.21 Equipment Approvals .....................................................................................2-58 2.6.22 Product Selection ...........................................................................................2-58 2.6.23 Product Handling & Storage...........................................................................2-59 2.6.24 Noise Levels...................................................................................................2-59

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2.6.25 Positioning Of Plant ........................................................................................2-59 2.6.26 Foundation Bolts & Alignment ........................................................................2-59 2.6.27 Plant Bases & Anti-Vibration Mountings.........................................................2-59 2.6.28 Connection of Equipment ...............................................................................2-60 2.6.29 Cutting and Drilling of Structural Frames, etc.................................................2-60 2.6.30 Machine Guards .............................................................................................2-60 2.6.31 Painting & Identification..................................................................................2-61 2.6.32 Handover........................................................................................................2-61 2.6.33 Testing & Commissioning...............................................................................2-62 2.6.34 Special Equipment and Tools.........................................................................2-63 2.6.35 Spare Parts ....................................................................................................2-63 2.6.36 Packaging, Shipping and Transport ...............................................................2-63 2.6.37 Training ..........................................................................................................2-63 2.6.38 Documentation ...............................................................................................2-63 2.6.39 Documentation With Tender...........................................................................2-63

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1-1 Volume 2 - Technical Specification Civil Works Issue 3 August 05

1. CIVIL

1.1 General

1.1.1 Scope The civil engineering work to be undertaken for this contract shall consist of the design, construction, testing, supply, delivery, supervision, installation, commissioning and guaranteeing of all works shown on the drawings and specified or implied herein.

The material and workmanship shall be the best of their respective kinds and to a standard not less than specified herein.

1.1.1.1 Extent of Work Reference should be made to the layouts and other tender drawings in Schedule E of Volume 3.

The details shown on the drawings shall be used for the purpose of tendering. The Contractor shall note that he is responsible for submitting all designs and drawings for all elements of the works as required and specified, in accordance with the actual soil conditions and design data that prevail at each Substation site and as instructed by the Engineer.

The Contractor is bound to provide complete works, even if the constructions, equipment or services to be provided are not specifically mentioned in the specification.

The Contractor shall be responsible for, but not be limited by, the following for all substation civil works:

- Site surveys and soil investigations - Testing of soils, water and materials used - Earthworks, grading and landscaping - Temporary and permanent access roads to the substation and any Housing area from public

roads, and service roads inside the Substation - 400 kV Substation building to accommodate the 400 kV GIS switchgear, where GIS switchgear is

specified in the Scope of Works - 132 kV Substation building to accommodate the 132 GIS, where GIS switchgear is specified in the

Scope of Works - Control, Relay and Communication building with offices - 11 kV Switchgear buildings, together with all works for their associated Reactors and Capacitor

Banks - 400/132 kV Transformer foundations, oil containment bunds and fire walls; includings those

facilities for a spare transformer. - 400 kV Reactor foundations and oil containment bunds where specified in the Scope of Works - Auxiliary Transformer foundations and bunds - Earthing Transformer foundations and bunds - Guard House building - Stores building, incorporating Workshops and Carport - A Staff Housing Area where specified in the Scope of Works


- Diesel Generator building - Plant and equipment support structure foundations - Cable trenches, ducts and drawpits - Perimeter fencing and matching main and personnel gates - Plant foundations - Plant and equipment structures - Roads, footpaths and surface chippings - Foul and surface water drainage systems, and septic tank - Communications tower and foundations where specified in the Scope of Works - Heating, Ventilation and Air Conditioning - Building Services - plumbing, water, small power and lighting, telephones, fire detection, etc - Water tanks - Temporary works - Design, preparation of detailed construction drawings, bar bending schedules and all drawings and

documents necessary for completion and maintenance of the works, - Preparation of As-built documentation - Any other works required to complete the substation and put it into operation.

1.1.1.2 Standards and Design Criteria Except where otherwise specified, implied or otherwise agreed in the Contract, the design, and the specification of materials and workmanship shall comply in all respects with the requirements of the latest applicable British Standards (hereafter referred to as B.S.). Other international Standards which meet or exceed the requirements of the appropriate British Standard may be used subject to the prior agreement of the Engineer.

The Contractor shall submit all design calculations to the Engineer for his approval prior to the commencement of preparation of working and shop drawings. After the Engineer has approved the calculations, the Contractor shall prepare all necessary working and shop drawings and submit same for approval by the Engineer, as specified under the “Submittal” Section of the Specifications.

1.1.1.3 Design Loading (a) Dead and live loading

BS 6399 – Loadings for Buildings, shall be used to determine all dead and imposed loads amended only as follows. Snow loading shall be considered if appropriate. Roofs without access should be designed for a sand loading of 1 kN/m2, and where access is provided it should be designed for a loading of 1.50 kN/m2

(b) Wind loading

Wind loadings as determined in CP3 Chapter V plus all amendments, shall be applied to all buildings and structures. Although CP3 is a superseded document it may be used for reference in this case. In determining Vs in the code for wind loading, basic wind speed of 40 m/s equivalent to V of 34.2 m/s 12 m above GL, at 15 degrees C, should be used and factors S1 and S3 should be taken as unity. Factor S2 should be determined from Table 3 in Part 2 of the Code surface category 1 - “Open country with no obstruction”.


(c) Seismic loading

All structures including buildings and their foundations shall designed for seismic events as defined in the “Uniform Building Code” Zone 3.

(d) Short circuit forces

Short circuit forces shall be determined in accordance with IEC 60865-1, or other appropriate IEC or other standards.

(e) Operational loads

The supplier shall define the operational loadings due to the mechanical operation of equipment where appropriate.

1.1.1.4 Load Combinations for Ultimate Limit State Design The combinations set out in the following table shall be used as the minimum basis for the structural design of plant support structures.

Load Factor

Dead

Load Combin-

ation

Loading Condition

Adverse Beneficial

Conductor Tension (if applicable)

Imposed Wind/Earthquake

1 Dead + Short Circuit + Wind

1.2 1.0 1.2 1.2 1.2

2 Dead + Short Circuit +Earthquake

1.2 1.0 1.2 1.2 1.2

3 Dead + Mechanical Operation + Wind

1.2 1.0 N/A 1.2 1.2

Note: The above table does not include for Ice loading. However, this must be included if it likely to be a load in particular areas.

1.1.1.5 Submittals The Contractor shall comply fully with the requirements specified under the Submittal section of this Contract.

The following requirements are specific to the civil engineering and building works specified in this section of the specification. The Contractor shall not commence manufacturing or fabricating any structure, building or other civil works until his working and shop drawings have been approved by the Engineer. The Contractor shall submit the following preliminary drawings for approval, together with such details of his calculations and methods adopted as the Engineer may require, all in accordance with these Specifications and the Contract Schedule.


(a) The General Arrangement of each Substation showing the principal dimensions and positions of buildings, roads, services, switchgear buildings, transformers, etc.

(b) Drawings showing the dimensions of the principal members of all structures.

The final working and shop drawings, which shall be submitted to the Engineer, after the approval of the preliminary drawings and details of calculations specified above, shall be in sufficient detail to show:

(i) The general arrangement, details and dimensions of all parts of buildings, steel structures and of all other civil works to be supplied under the Contract.

(ii) The nature of the materials from which the various parts are to be made together with their surface finish.

(iii) Weld details, machining and assembly tolerances for all assemblies.

(iv) The manner in which such parts are designed to function.

(v) Schedules of materials and details in full for all structural steel members and reinforcing bars.

(vi) Detailed arrangement of various equipments in the switchgear buildings

In addition to the above, the Contractor shall submit to the Engineer any further information that the Engineer may require to enable him to approve the final working and shop drawings. After the drawings have been approved, no changes shall be made to the drawings without the written permission of the Engineer. Changes to facilitate fabrication, to speed up delivery or to permit substitutions of material which is in short supply, may be made if approved in writing by the Engineer.

The Contractor shall furnish the Engineer with duplicate copies of certified mill test reports before fabrication is commenced on any materials covered by such reports.

Approval by the Engineer of the Contractor’s drawings shall not relieve the Contractor of responsibility for the correctness thereof, nor for the results arising from errors or omissions, nor for any faults or defects, nor for failure in the matter of guarantee, which may become evident during erection or subsequent operation.

1.1.1.6 Soil Investigations The Tenderer shall carry out whatever Soil investigations and testing deemed necessary for the proper foundation design and construction to suit the Site conditions.

No claim from the Contractor for price adjustment on account of any changes in the foundation works will be accepted under any circumstances.

The results and interpretation of all soil investigations, testing and calculations in respect of the soil bearing capacity values for the Site shall be submitted in Report format for approval by the Engineer before preparation of the foundation working drawings.


No working drawing will be approved by M.O.E./the Engineer until such test values have been submitted and approved.

Where necessary the Contractor shall adopt pile foundations for heavy equipments and buildings.

1.1.1.7 Topography and Finished Grade Elevation The topographical survey for the Site of the Substation is the responsibility of the Tenderer.

No extra cost shall be paid to the Contractor on account of any increase in quantity of the work to fulfil the requirement given in the tender documentation and drawings.

The site of the Substation shall be raised a minimum of +500 mm above the highest point of the existing ground level around the outside the perimeter fence, to a maximum of +1000 mm centrally between the 400 and 132 kV buildings, as indicated on the tender drawings. For a flooded area the site shall be raised to a level not less than the level of the nearest paved road.

1.1.2 Clearing and Site Preparation 1.1.2.1 General The work in this Section shall consist of all clearing, grubbing and stripping of the topsoil from the Site as directed by the Engineer and specified herein. The Work shall also include the transportation and disposal of all waste materials off the site to the areas arranged for by the Contractor, and to the approval of the Engineer.

1.1.2.2 Clearing and Grubbing Clearing shall include cutting and removing trees, bushes and other vegetation and removing fallen timber and other surface litter. Grubbing shall consist of digging out and removing stumps and roots remaining after the clearing operation.

1.1.2.3 Stripping of Topsoil The Contractor shall, after clearing and grubbing, strip to a minimum depth of 200 mm all topsoil or other surface deposits. If, in the opinion of the Engineer, topsoil extends to a greater depth than 200 mm, the Contractor shall remove all such soil as directed by the Engineer. The Contractor may stockpile approved topsoil for reuse as specified herein subject to the Engineer’s approval. The stripped surface should be compacted to 95% proctor dry density before the starting of the filling operations.

1.1.3 Excavation 1.1.3.1 General Excavation shall include the removal of all material of any nature including rock which interferes with the construction work.

The Contractor must clear all excavations of mud, loose material, dirt and debris, and if required by the Engineer, the bottom 150 mm of excavation shall not be removed until just before the commencement of construction.


All necessary safety precautions shall be taken to avoid injuries. The surfaces of excavation shall be protected at all times from erosion or collapse due to weather or other conditions. Sides of excavations shall be shored up where necessary to the satisfaction of the Engineer.

The Contractor shall at all times keep all excavations and trenches free from water. He shall use pumps, well points or any other method necessary to remove water in a manner that will prevent loss of soil and maintain stability of the sides and bottom of the excavation, all to the approval of the Engineer.

If excavations are carried beyond the lines or elevations shown on the drawings or specified herein, the Contractor shall be required to backfill such excavation with C20 concrete or crushed stone as directed by the Engineer at the Contractor’s own expenses.

The Tenderer shall investigate the water table level at the proposed Substation Site, and no extra cost on account of any difficulty arising out of a high water table will be entertained.

1.1.3.2 Excavation for Foundations The underside of all foundations shall be at a minimum depth of 200 mm below the stripped surface.

Immediately after excavation for foundations is completed and approved by the Engineer, C20 concrete 100mm, thick is to be laid as blinding for the structural concrete foundations.

1.1.3.3 Excavation for Underground Services The minimum area of excavation shall be the project plan area of the various items being installed. However, the Contractor shall make due allowance for working space that he considers necessary and also for placing the specified concrete or other bedding material as shown on the drawings. Variances in unit cost shall be based on the above.

Trenches shall be excavated to the general lines and depths specified and as shown on the drawings.

If the bottom of any trench or excavation is found to be unstable or unsatisfactory, the Contractor shall excavate such unsuitable material to the width and depth ordered by the Engineer. The sub-grade shall then be restored by back-filling with approved materials so as to provide a uniform and continuous bearing and support for the service pipe or duct.

1.1.3.4 Excavation for Roads and Parking Areas Any soft areas which develop during rolling, as specified herein, shall be excavated as directed by the Engineer. All loose rock or boulders and all ridge rock encountered in the excavation shall be removed.

The excavated surface shall be compacted to 95% modified proctor dry density.

1.1.3.5 Disposal of Excavated Materials All materials obtained from the excavations, and approved by the Engineer, for use as general backfilling materials shall be laid aside and afterwards deposited as and where directed by the Engineer.


Any materials not so approved shall be removed by the Contractor and disposed of in areas off the site arranged for by the Contractor at his own cost, and approved by the Engineer. The deposited material shall be spread and trimmed to a uniform surface.

1.1.4 Fill and Back Fill 1.1.4.1 Materials (a) General filling material

The general filling material shall consist of approved natural material obtained directly from the excavation or from borrow areas approved by the Engineer. Only material approved by the Engineer shall be used for general fill, and such material shall be free of vegetation, topsoil, roots, logs, stumps or any other organic, perishable or unsuitable material. All necessary precautions, to the approval of the Engineer, shall be taken to exclude termites from the filling material.

(b) Borrow area operations

Detailed planning of the excavation shall be the responsibility of the Contractor and shall be subject to approval by the Engineer. The Contractor shall pay particular attention to the natural water content of the material.

Prior to the commencement of the work, the Contractor shall submit for approval by the Engineer, a plan showing details of the Contractor’s proposed methods, and the sequence, and the schedule of operations in the borrow area. During construction, the plan shall be reviewed and modified as required. A copy of the modified plan and schedule shall be provided for the Engineer’s approval prior to implementation of any changes.

A system of surface drainage in the borrow area consisting of ditches and other means shall be installed to ensure that precipitation drains away from the borrow area; and that ponding and infiltration is prevented. After completion of excavations, the drainage system shall be left in such a condition that drainage of the borrow area shall continue to be effective.

All final slopes shall be trimmed to stable slopes and shall not be steeper that three horizontal to one vertical.

(c) Granular class A and class B materials

All granular materials intended for use on the work shall first be approved by the Engineer. The Contractor shall submit an analysis from an approved testing laboratory, to show that the materials conform to the specifications. If, in the opinion of the Engineer, further tests are required, then these tests shall be carried out as directed by the Engineer at the expense of the Contractor.

Granular class A

Fill material shall consist of crushed rock or gravel obtained from quarries, deposits of pitrun gravel, Talus rock, disintegrated granite, mine waste and slag, clinkers, cinders and other


material which has a physical structure not affected by water or the elements. Materials such as shale, limestone or stratified limestone are not acceptable. The material shall contain a minimum of 30 per cent of crushed particles. Crushed particle shall have at least one surface or face formed by its fracture from a larger particle. The percentage of crushed material shall be determined by examining the fraction retained on a 5 mm mesh sieve and dividing the weight of the crushed particles by the total weight of the sample. The sizing and grading of granular Class materials shall conform to the requirements specified herein.

Granular class B

Fill material shall consist of either:

(i) gravel from bankrun material; where no crushing is required, but oversize particles shall have been removed and the physical characteristics and sizing and grading shall be according to the specification,

or

(ii) crushed rock screening; having physical characteristics in sizing and grading according to the specification.

Materials shall have a physical structure not affected by water or the elements; and materials such as shale, shaley limestone and clay will not be acceptable in any quantity whatsoever.

(d) Grading of granular fill materials

The grading of the granular Class A and Class B fill materials shall be within the following limits:

Percentage by Weight Passing

Granular Type A Granular Type B

Crushed stone Gravel or Crushed Rock Screenings

B.S. Sieve Nos or equivalent metric sizes Aperture Sizes (mm)

100 52 25 14 7 5 10 20 25 100

0-15 5-20 10-30 15-35 25-45 35-60 50-80

90-100 - -

0-25 5-40 5-60 10-85 15-95

25-100 40-100 55-100 60-100

00

Where rock is deficient in the grading in Granular A, the Contractor may add an approved filler to meet the grading specifications. The Granular B material shall contain no particle over the


maximum of 100 mm. The oversize material may be used if crushed to the required size or it may be removed by screening at the Contractor’s expense. All material passing 5 mm sieve shall be recently well graded. Filler may be used to add to the Granular B material to bring the final product to the required grading. The filler shall be acceptable to the Engineer and shall not contain any organic matter or hard cohesive lumps.

1.1.4.2 Workmanship (a) General

The work in this Section shall include handling, transporting, depositing, compacting, grading of surfaces and trimming of side slopes and verges.

The Contractor will be required, as the Engineer may direct, to adjust the moisture content of the materials used for filling, either by spraying with water or allowing it to dry before placing.

No fill of backfill material shall be placed until the formation level has been inspected and approved by the Engineer.

(b) General filling

The general filling, approved by the Engineer, shall be deposited in regular successive layers, not exceeding 250 mm in depth and shall be thoroughly compacted by rollers or by transport units passing at least twice over all parts of each layer, or by any other approved means to the required grades and levels.

The dry density of the soil after compaction shall be at least 95% of the maximum obtainable Standard Proctor dry density measured in accordance with the requirements of B.S. 1377 or other approved standards.

The general fill shall be laid and compacted in layers as specified, until the elevation at the top of the compacted fill is 50 mm below finished grade level. The Site shall be drained properly to the satisfaction of the Engineer.

(c) Chemical treatment of soil

The prevent the ingress of termites into the works at the new Substations, soil treatment shall be carried out by the Contractors as specified below and to the entire satisfaction of the Engineer. The chemical used to treat the soil shall be of chloridine or equivalent approved by the M.O.E. Engineer.

The rate of application to the soil of the ready for use solution shall be as follows:

(i) Before casting walkways surrounding buildings, excavate perimeter trench 1.0 m deep by 500 mm wide adjacent to the external walls. Apply 6 litres/sq. metre to the excavated bottom of the trench and to each of the 250 mm compacted layers of backfill.

(ii) 6 litres/sq. metre over all building areas and associated paved walkway areas, including the outer faces of all trenches . Applications to be on top of fill below concrete slabs.


(iii) The entire Substation Site including the bermed areas outside the perimeter or boundary fence/wall shall be treated with an approved vegetation/weed killer to the complete satisfaction of the Engineer. This treatment shall be chemically compatible with the soil treatment for termites outlined above.

Once the soil has been treated, it is important that it should not subsequently be disturbed. Any areas of soil which are subsequently disturbed shall be retreated at the expense of the Contractors to the satisfaction of the Engineer.

(d) Backfilling of trenches and foundations

Class “B” material shall be used for backfilling trenches and foundations. Backfill for trenches shall be considered as starting at the top of the bedding over the pipe or conduit. Any materials below this point shall be considered as bedding. Backfill shall be placed in layers not exceeding 250 mm in thickness.

Backfill for manholes shall start at the subgrade and shall be brought up simultaneously to the same elevation on all sides of the manhole in layers not exceeding 250 mm. Except where the pipe must remain exposed for leakage tests and subject to the provisions herein, the Contractor shall proceed as soon as possible with the backfilling operations. Care shall be exercised so that the pipe will not be damaged or displaced.

The material shall be compacted to 95% of maximum density as determined by the modified Proctor density test. The backfill material shall not be dropped from the side of the trench so that there is a clear fall onto the partially covered pipe. Backfill material may be pushed from the filled and of the trench into the partially filled section so that it will roll down onto the covered pipe.

(b) Road foundations

Following the site strip to a minimum depth of 200 mm, described previously, the area of the Site covered by a road or parking area and for a distance of 1 m outside these areas, shall be compacted to a dry density in the upper 500 mm of at least 95% of the maximum density as determined by the modified Proctor test. Soft areas which develop during compaction shall be removed and replaced at the Contractor’s expense with approved fill material. When completed the formation shall be smooth and free from ridges, cracks or loose material.

The base and sub-base courses shall be approved granular materials B and A, respectively to thicknesses shown on the drawings. They shall be placed inlayers, such that, after compaction, the thickness of each layer does not exceed 100 mm.

Each layer shall be compacted to obtain 95% modified Proctor density before proceeding to apply a subsequent layer. Compaction shall be performed with a wobbly wheel roller or an equivalent vibratory roller, as approved by the Engineer. The rolling shall be done longitudinally, commencing at the edge and overlapping each run until the centre line is reached. The rolling shall continue until satisfactory compaction is obtained. On sections inaccessible for the larger equipment, the compaction shall be obtained using approved


mechanical vibratory equipment. The compaction requirements shall be the same as for the rest of the base.

Any irregularities or depressions which develop from the rolling shall be corrected by loosening, adding or removal of material and re-rolling until the surface is smooth and uniform.

The layer of material shall be bladed to the shape of the required crown and the material shall be sprinkled with water to aid compaction and/or reduce dust nuisance. When used to aid compaction, water shall be applied immediately ahead of the compaction equipment. The amount of water added shall be controlled so that the optimum moisture content of the material is not exceeded.

After the final course is laid, giving the required overall thickness, the surface shall be shaped by grading and rolling to produce a surface of required crown and contour. The tolerance permitted in the surface shall be determined by placing a 3 m straight edge, transversely or longitudinally, on any section. The final surface of the base material shall be irregularities no more than 6 mm in the 3 m length.

The final surface of the sub-base material shall have irregularities of no more than 15 mm.

1.1.5 Asphalt and Concrete Paving, Finish Grading and Reinstatement 1.1.5.1 General The work of this Section consists of paving roads and parking areas, general surfacing and surface grading, kerbs and paving slabs. The work shall include supply of all materials placed and compacted as specified herein, all to the satisfaction of the Engineer.

Roads shall be finished with hot rolled asphalt bituminous base and wearing courses, except where fuel spillage may occur where suitable concrete block paving shall be provided.

1.1.5.2 Paving to Roads and Parking Areas (a) General

Major access roads shall be a minimum of 8m wide and 6m wide elsewhere where not required for transformer access unless otherwise indicated on the tender drawings and shall include the necessary kerbs, drainage, road markings and signs. Road widths specified are measured between inside faces of road kerbs. Radii shall be provided on turning areas and corners that are suitable for transporting plant during the construction period and for maintenance purposes. The roads shall be transversely sloped about the centre line of the road. The transverse slope shall be 2 percent. The maximum longitudinal gradient of roads shall be 5 percent and the minimum camber of crossfal shall be 2 percent.

Foundations and base courses for roads may be laid early in the contract and used for construction purposes. Roads shall be designed on the basis of a 25-year life assuming 325 commercial vehicles/day, including construction and plant delivery traffic. After the construction wear is over, and as near to the end of the contract as possible, the surface shall be cleaned of


any debris and foreign matter, and any damage to the foundations and base courses of the new roads shall be repaired to the satisfaction of the Engineer before the wearing course is laid.

Traffic shall not be allowed on any road until the Engineer’s permission for it has been obtained. Notwithstanding the following requirements, the Contractor shall be responsible for ensuring that the loads he proposes to transport do not overstress the final road designs shown on the drawings.

(b) Materials The Contractor shall be entirely responsible for the design mixes for the asphalt which shall be designed in accordance with BS 594 and BS 598, or equal standard approved by the Engineer. Aggregates for the base and wearing courses shall be approved by the Engineer. Coarse aggregate shall consist of clean river gravel, screened and if necessary re-graded. Fine aggregate shall consist of clean natural sand, free from organic or other injurious material. These aggregates shall be thoroughly combined in such proportions as will give an analysis conforming to the grading specified below for base and wearing courses.

Percentage by Weight Passing

Base Course Aggregate

Wearing Course Aggregate

Aperture sizes (mm) B.S. Sieve Nos. or equivalent metric sizes

40 25 12 6 3 14 52

100

60-80 30-40

- 20-30

- -

- -

100 45-60

- 25-55 10-25

(c) Workmanship

Before laying the base course, a tack coat of approximately 0.4 kg per sq m, bitumen shall be sprayed on the road formation. The base course shall consist of between 4% and 5.2% by weight of bitumen mixed with the base course aggregate and shall have a consolidated thickness as shown on the drawings.

Mixing is to be carried out in mechanical mixers of a type approved by the Engineer and suitable for giving accurate control in batching. Immediately before mixing, the bitumen shall be heated to 120° - 150°C and the aggregate to 90° - 120°C. The hot bitumen shall be added to the aggregate and mixed for three minutes.

The mixture shall be laid hot by means of an approved mechanical spreader. Rolling shall be carried out by means of a roller weighing at least 10 tons (or metric equivalent) and passing at least twice over each part.


Before laying a wearing course, the surface of the base course shall be sprayed with a tack coat of approximately 0.4 kg per sq m of bitumen.

The wearing course shall consist of between 5.5% and 6.5% by weight of bitumen mixed with between 10% and 12% by weight of Portland cement and with the wearing course aggregate.

Mixing and application shall be carried out in a similar manner to that specified above except that the mixing shall be interrupted after one minute for the addition of the cement. All internal roads shall be of reinforced concrete suitable for transporting transformers, heavy machinery and equipment. Necessary drains slopes, camber etc. shall be provided.

1.1.5.3 Reinforced Concrete Transformer Access Roads The concrete slab shall be designed to resist stresses and deflections produced by maximum applied axle loads from the transformers to be transported on the trackwork. The function of the longitudinal steel shall be to keep cracks in the concrete slab tightly closed so that there is effective load transfer across the cracks.

The minimum longitudinal steel area shall be 0.4% of the gross cross-sectional area. Transformer-roads shall also be designed for an additional permanent loading of not less than 50 kN per sq m.

Keyed contraction joints shall be provided at intervals not exceeding 12 mm and the longitudinal reinforcement shall be continuous across these joints. No panel section shall be poured adjacent to a panel which is less than 7 days old.

Generally, expansion joints are not required throughout the length of the reinforced concrete slab. If expansion joints are provided they shall be adequately dowelled and totally effective in providing load transfer across the joints.

1.1.5.4 General Site Grading The whole area of the Substation site, except for areas surfaced with other material as specified herein, is to be surfaced with an approved gravel or crushed stone of particle size between 20 mm and 40 mm. The thickness of the surfacing layer shall be 50 mm minimum.

1.1.5.5 Kerbs and Paving Slabs Kerbs shall be provided to roads as shown on the drawings. The kerbs shall be constructed of minimum C30 concrete to the sizes and forms as shown on the drawings. Expansion joints shall be formed with bitumen impregnated fibreboard approved by the Engineer and as shown on the drawings.

Paving slabs shall be cast in site from minimum C30 concrete. The slabs shall be 1000 mm by 1000 mm and to the thickness and details shown on the drawings.

Where fuel spillage may occur the Contractor shall design and install suitable concrete block paving.

Joints between adjacent slabs and blocks shall be filled with cement/sand mortar to the approval of the Engineer. The paving slabs shall be laid on a bed of Grade M grit sand to BS 882 l, as specified herein to a compacted depth of 35 to 50 mm.


1.1.5.6 Reinstatement The work shall include the reinstatement of all excavated and filled areas and areas damaged by the Contractor during the execution of this Contract. Each area shall be reinstated to match in line, grade, type, texture and appearance the material removed by the excavation work and the surfaces adjacent to the reinstated work.

1.1.5.7 Building and Associated Work 400 kV and 132 kV Substation buildings; Single Control, Relay and Communication building; 11 kV Switchgear buildings; Stores, Workshop and Carport building; Diesel Generator buildings; and all other buildings for the Substation shall be designed as reinforced concrete framed structures with reinforced concrete foundations, floors and roofs, and blockwork or brickwork walls unless otherwise noted.

The Guard House shall be designed as a reinforced concrete roof slab, supported on load bearing brickwork and reinforced concrete foundations shall be provided.

The structural framing for all buildings, suspended floors and roof slabs shall be designed in accordance with BS 8110 for reinforced concrete design. Where traffic loads are anticipated indoors, for example in the GIS Switchgear and Maintenance rooms, the floor shall be designed to accommodate the required loadings.

The general arrangement and desired criteria for all buildings is as shown on the drawings. The overall dimensions shown are minimum dimensions to be adhered to and it will be the Contractor’s responsibility to ensure that all actual room sizes and arrangements are adequate for the satisfactory operation and maintenance of the type of equipment that he proposed to provide. Adequate space shall be provided above, behind and in front of all switchgear and control panels and other equipment as shown on the enclosed tender drawings.

The Tenderer shall allow in his tender for any increase in size of the buildings over and above the minimum shown on the drawings required by the equipment provided.

Perimeter infill and load bearing brick walls shall be carried down to reinforced concrete spread footings, to the same depth as the main building foundations and as the Engineer may direct. Details of these foundations shall be as indicated on the drawings and as specified herein.

400 kV and 132 kV Switchgear rooms shall be provided with suitable and approved over head travelling cranes. The Contractor shall be responsible for the design, manufacture, testing, delivery and installation, of the cranes. This shall includes all spare parts, tools and all auxiliary equipment necessary for complete installations. The working capacity of cranes shall be 140% of the max load to be handled.

In the GIS Switchgear Rooms, there should be adequate clearance between the crane rails and lifting hook height to permit the removal of any item of equipment for replacement, repair or maintenance. Sufficient clearance shall be allowed between the top of switchgear and the highest position of the crane hook to permit transfer of equipment over the top of the switchgear if this becomes necessary.


Workshops, maintenance stores and the like shall be provided with suitable and approved over head travelling cranes or suitable fixed crane rails and lifting gear.

Each building of more than one storey shall be provided with a normal working stair case, as well as emergency escape stair case system.

All buildings shall be provided with suitable ladders to roof for inspection and maintenance.

Infill panels between the structural frame shall be constructed using insulated blockwork to achieve the required ‘U’ value. External walls shall be insulated to achieve a thermal transmittance value of 0.57 W/m2K or better. This ‘U’ value must also achieve the requirements of the Local Authority if greater.

All structural roofs shall be double pitched, or flat and be overlaid with a screed, to create falls towards the drainage outlet points as shown on the drawings. The buildings shall incorporate a parapet for architectural effect, and have direct rainwater run-off from the roof gutters at predetermined locations by downpipes discharging into the surface water system. A protected bituminous membrane inverted roof waterproofing system shall be provided in accordance with BS 8217: 2005, and shop drawings showing the build up of the complete waterproofing system and the detailing at all junctions, abutments and penetrations shall be submitted for approval prior to the commencement of the installation. The protective slabs over the roof insulation shall be of a weight to prevent them being dislodged by suction forces in high winds.

Live load deflections of beams shall be limited to 1/500 of the span.

Fire exit signage shall be provided on all escape routes and at all fire exit doors. The main construction and finishes required for the Substation buildings are set out below, these are not exhaustive and the Contractor shall provided suitable good quality finishes for areas not included • Building frame: Cast in-situ reinforced concrete columns, and beams

integrated with concrete roof and floor slabs. • Roof and floor slabs: Cast in situ reinforced concrete slabs integral with the

beams, with roof slabs overlaid with a screed laid to 1 to 80 minimum fall with minimum thickness of 50mm, and insulated to give the specified “U” values.

• Reinforcement: Deformed high yield bar to be used.

• Walls (external): Blockwork incorporating insulation to give the specified “U” values.

• Walls (internal): Non-load bearing blockwork with soft joint between the top of blockwork and the underside of the concrete slabs and beams. Where the internal walls have a fire rating, the soft head joint should incorporate a fire seal of the same fire rating as the rest of the wall.


• Wall finishes (external): Blockwork to be rendered with a painted finish above DPC level, and bituminous paint to all areas below DPC level. The finished face of the render should be in the same plane as the surface of surrounding exposed fair faced concrete, and should have render stops at all edges. Exposed fair-faced concrete in beams, columns, parapets etc. – painted finish to match the rendered areas.

The external wall finishes should be suitable to withstand any heavy pollution that may exist in some areas.

• Wall finishes (internal): Generally painted plaster to all internal wall surfaces unless noted under. Workshop, Stores, Diesel Generator building, and carports shall be painted fairface blockwork internally. In the Battery Room, alkaline resistant ceramic wall tiles with a low surface permeability shall be used to resist the alkaline electrolyte in the nickel cadmium batteries. The tiles shall be bedded on alkaline resistant adhesive and be finished with an alkaline resistant grout up to a height of at least 600mm above the top of batteries, or to the top of the door frame.

In Toilets, glazed ceramic tiles up to top of door frame, and plaster with paint finish above, up to soffit level.

• Ceilings: Fair-faced concrete with a paint finish throughout except where noted below. Exposed building services fixed to the underside of the slabs should be painted the same colour as the concrete. Suspended acoustic ceilings shall be provided in Offices, Meeting rooms, Corridors, Control, Relay and Telecommunications rooms.

• Floor finishes: 400 & 132 kV GIS rooms - 5mm thick epoxy screed. Control, Relay and telecommunication rooms - 700 mm high heavy duty raised modular floors (at upper floor level), to sustain an imposed UDL of 10 kN/sq.m with carpet or vinyl tiles as appropriate, and 100 mm wooden skirtings. The design of the system should be such that full stability is maintained when any number and configuration of the floor panels are removed. 11kV switchgear room – Terrazzo floor tiles and skirting.


Stores, Workshops, and maintenance rooms - 75 mm sand/cement screed with wire mesh finish with proprietary floor paint and 150 mm high varnished hardwood skirting. Toilet - non slip ceramic floor tiles and matching ceramic coved skirtings. In the Battery Room the floor finish shall be 6mm min. thick non-slip alkali resistant ceramic floor tiles with a low surface permeability. The tiles shall be bedded on alkaline resistant adhesive and be finished with an alkaline resistant grout. Movement joints at the perimeter of the tiling, and any intermediate movement joints shall have an alkaline resistant filler, and be finished with an alkaline resistant sealant. Cableways and basements – non slip epoxy paint.

• Windows: Aluminium thermal break frames with Syntha Pulvin powder coated coloured finish to Client’s approval, complete with security grills. All windows double glazed with solar reflecting glazing with low heat transfer value.

• Doors (external): Aluminium framed doors with dividing strip (double doors where shown on the drawings) and tempered bar provided with sun shades/canopies. Aluminium doors should meet thermal transmission requirements and have thermally broken frames. All doors to be fitted with closers. (Aluminium doors shall be finished to match the windows). Painted galvanised steel roller shutter door and personnel doors for GIS switchrooms. Battery room doors should have seals to prevent air movement from the battery room and have door signs “keep this door closed”.

• Doors (internal) Flush ply, solid core construction, stained and clear finished or painted. Doors shall incorporate vision panels where appropriate. Fire proof doors shall be provided between switchgear rooms and other rooms, and in other locations to satisfy the requirements of the fire strategy assessment. Doors to all rooms shall be provided with door closers. Fire rated doors built into fire rated walls should have fire sealant incorporated into the joint between the frame and the wall.


The provision of locking for internal doors shall be agreed with the Engineer/M.O.E. Electrolyte resistant paint to be provided on internal surface of Battery Room door.

• Roof waterproofing: Shall consist of bitumen impregnated polyester waterproof membrane laid on screed to fall, geotextile filter membrane, insulation and protective precast concrete tiles. The insulation shall achieve the specified ‘U’ value.

• Stairs: Stairs and landings shall be constructed in concrete, with stair flights a minimum of 1000mm wide. See further details in section 4.7.19 Miscellaneous Metal of this specification .

1.1.5.8 Staff Housing The Staff Housing shall be designed, constructed and furnished complete consistent with the indications shown on the drawing for typical Staff Housing included in this specification.

The Houses be designed with reinforced concrete roof slabs, supported on load bearing brickwork and reinforced concrete foundations shall be provided. The ceiling, wall and floor finishes shall be complete and as indicated on the typical drawing. All necessary fixtures and fittings are to be provided including all building services and HVAC.

A Carport is to be provided to each House, together with a main and personnel gate, and the Houses are to have individual boundary walls.

All necessary access for vehicular and pedestrian traffic, and a complete drainage system, shall be provided to the Housing areas as required.

Typical drawings and details are to be provided by the Tenderer.

1.1.6 Oil Containment for Transformer and Reactor Bunds, and Firewalls (a) Oil Containment

Power transformers and reactors shall be sited in oil containment areas and drain via a flame trap to an under ground facility to remove oil away from a fire in the event of an incident. The capacity of the underground containment shall be equal to the volume of oil contained within the transformer plus 50% to allow for fire fighting materials externally applied by the fire fighting service. Where there is more than one power transformer on a site, it may be economic to link the oil containment drainage areas of these to a single underground tank with capacity for the largest transformer alone, thus reducing the excavation required. Connecting pipe work shall be designed to ensure rapid discharge of oil to the underground facility that, together with the pipe work, shall be resistant to transformer oil at a temperature of up to 80oC. Underground oil


containment facilities shall be provided with a means of inspection and allow for pumping out of accumulated rain water or oil. The area within the transformer enclosure shall be designed as a water retaining structure to BS 8007 and coated with 2 coats of bituminous paint and be surfaced with a 100 mm thick layer of gravel on steel grating.

The road immediately adjacent to transformers used by oil handling equipment for maintenance shall be bunded/kerbed to contain any oil, and shall also drain to the containment facility to prevent ground pollution in the event of accidental spillage.

(b) Firewalls

Plant within close proximity of power transformers, and adjacent transformers, shall be protected by fire barrier walls or housed within building with a fire resistant face towards the transformers. Protection should be provided for other circuits and transformers, control equipment, and external property. Fire barrier walls and building fire resistant walls will be designed for 4 hour fire resistance and a blast pressure of 0.5 kN/ m2. The fire barrier wall height shall be a minimum of 500mm above the highest part of the transformers.

1.1.7 Concrete 1.1.7.1 Design, Materials and Workmanship Standards of design, materials and workmanship are to be equal to or better than those laid down in the latest amended editions of British Standard BS 8110. Alternative standards to BS 8110 should be international standards and require prior approval by the Engineer before application to the works.

1.1.7.2 Testing General Testing methods are to be in accordance with the relevant BS standard except as approved or requested by the Engineer.

Tests required by the Engineer will normally be carried out at an independent testing station. The cost preparing, storing and transporting test specimens to the place of testing is to be borne by the Contractor. Where there is no independent testing station within a reasonable distance of the Site the Engineer may allow the Contractor to set up his own full laboratories.

The Engineer shall have the right to order that any materials which do not meet with his approval shall not be used in the Works. The Contractor shall have the right to sample, test and give an opinion on such materials. If after this, the materials are rejected by the Engineer they shall be immediately removed from the Site by the Contractor.

The Contractor shall provide the Engineer with facilities for materials testing on Site. The facilities may be those normally used by the Contractor.


All testing facilities on site shall be calibrated at regular intervals in the presence of the Engineer’s representative and whenever deemed necessary by the Engineer.

1.1.7.3 Ready Mixed Concrete Ready mixed concrete as defined in BS 5328, batched off the Site, may be used only with the agreement of the Engineer and comply with all requirements of the Contract.

The concrete shall be carried by truck mixers. The concrete shall be compacted and in its final position within two hours of the introduction of cement to the aggregates, unless a longer time is agreed by the Engineer. The time of such introduction shall be recorded on the delivery note, together with the weight of the constituents of each mix.

When truck-mixed concrete is used, water shall be added under supervision, either at the Site or at the central batching plant, as agreed by the Engineer but in no circumstances shall water be added in transit.

Unless otherwise agreed by the Engineer, truck mixer units and their mixing and discharge performance shall comply with the manufacturers requirement. Mixing shall continue for the number and rate of revolutions recommended in manufacturer’s instructions. In the absence of instructions, mixing shall continue for not less than 100 revolutions at the rate of not less than seven revolutions per minute.

1.1.7.4 Cements - General The cements shall comply with all the requirements of British Standards latest edition.

Sulphate resisting cement shall be used for concrete below ground level.

All cement shall be obtained only from a source approved by the Engineer.

The Contractor shall not use cement varying from that used in the preparation of trial mixes until the permission of the Engineer has been obtained and until any further trial mixes required by the Engineer have been made and tested.

Additional protective measures such as bituminous painting should be applied on below grade concrete surfaces.

1.1.7.5 Cement Total Alkali Content The cement shall be tested to determine the total alkali content in accordance with BS 4550 Part 2:1970. Total alkali should not exceed 0.60%.

The equivalent weight of sodium oxide shall be calculated from the following formula: -

Equivalent weight of Na20=Wt. of Na20+0.658xWt. of K20. The equivalent weight of sodium oxide shall not exceed 0.6% of the weight of cement.

The above restriction shall be waived if the proposed aggregate is proved without doubt to be non-reactive.


1.1.7.6 Cement Delivery and Storage The cement shall be delivered to site packed in sealed bags or proper containers, of which there shall be 20 to the tonne, bearing the name of the brand and manufacturer and the number of the consignment. The approximate weight of the cement shall be legibly marked on each bag. The Contractor shall make the necessary arrangements for deliveries to be made sufficiently frequently to ensure freshness and in sufficient quantities to ensure that there is no suspension or interruption of the concreting work at any time.

The Contractor may use cement delivered in bulk; delivery arrangements shall be to the Engineer’s approval and each delivery must be accompanied by a manufacturer’s test certificate.

Each consignment of cement shall be brought to the site in sufficient time to allow any tests to be carried out before the cement is required to be used.

Cement in bags shall be unloaded under cover and stored in a well ventilated and weatherproof building used exclusively for this purpose. The floor of the building shall be at least 150 mm off the ground and an air space shall be left between the floor and bottom layer of bags.

If delivered in bulk an approved type of cement silo shall be used.

Each consignment shall be stored separately so as to permit easy access for inspection and a record shall be kept so that each consignment may be identified. Storage shall be arranged so that the cement is used in order of delivery.

Cement which is more than 12 weeks old from the date of delivery shall be retested on site for fineness, setting time strength and soundness in the presence of the Engineer’s representative and full test reports shall be submitted within 24 hours.

1.1.7.7 Cement Test Certificates and Samples All cement shall be certified by the manufacturer as complying with the requirements of the appropriate specification. The Contractor shall, when required by the Engineer, obtain for him the manufacturer’s test certificate for any consignment as soon as possible after delivery.

For every 50 tonnes of cement delivered to site and whenever required by the Engineer the Contractor shall take samples, under supervision, of the cement stored on, or delivered to the site. The Contractor shall test such samples as laid down in clause 9.6 above.

1.1.7.8 Aggregates General Before the Engineer can approve any aggregate source the Contractor shall furnish the following data: -

(i) Petrological group of rock (ii) Rock type within the group (iii) Shape (iv) Surface texture (v) Site content (vi) Grading curves


(vii) Specific gravity (viii) Impact value (ix) Water absorption (x) Soundness (xii) Salt content (xiii) Alkali reactivity

The fine and coarse aggregates shall comply with BS 882 and Clauses 9.9 and 9.10 unless exceptions listed by Tenderer in the attached schedule are approved by the Engineer.

The sources of all aggregates shall be approved by the Engineer.

1.1.7.9 Aggregate Physical Requirements (i) The weight of voided shells in fine aggregate shall not exceed 5%.

(ii) The weight of the clay and fine silt fraction (smaller than ASTM sieve no. 200) shall not exceed 5% by weight for coarse aggregates or 10% by weight for fine aggregates.

(iii) Absorption of fine and coarse aggregate shall not exceed 5% as measured in accordance with BS 812 or similar standard.

(iv) The soundness of all aggregates shall be proved by a sodium sulphate test in accordance with ASTM C88-73, from which the loss over five cycles shall not exceed 10% for fine aggregates or 12% for coarse aggregates.

(v) The apparent specific gravity of aggregates as determined by an approved test, such as BS 812, shall not be less than 2.5.

(vi) Loss angles abrasion shall not exceed 37%.

(vii) Alkali reactivity of aggregates should be in accordance with ASTM/C-227 and C-289. Only those aggregates considered to be innocuous should be permitted.

Where quarries win aggregate from bedrock, especially limestone of the dolomitic type, the rock shall be checked for surface alternation to hardpan. This may affect the surface for well over a meter depth and result in salt concentrations near the surface. Such rocks are also prone to other undesirable characteristics, including pockets of clay, salt, chalk or other friable material. Rigorous initial physical inspection is essential.

1.1.7.10 Aggregate Chemical Requirements (i) Fine and coarse aggregates shall not be potentially reactive with alkalis and shall be regularly

tested in accordance with ASTM standard tests C228, C289, C342 and C586.

(ii) Fine and coarse aggregate shall not contain more than 0.5% by weight of acid soluble sulphates (as S03).

(iii) Fine aggregate shall contain no more than 0.1% by weight of chlorides (as NaC1) and coarse aggregate not more than 0.03% should these figures be exceeded the aggregate may still be


considered acceptable in this respect provided the total sodium chloride concentration is not greater than 0.32% by weight of cement in the mix, irrespective of the origin of the chloride.

(iv) Marine aggregates may be used provided that the content of chloride salt in the aggregate, expressed as the equivalent anhydrous calcium chloride percentage by weight of the cement to be used in the concrete, does not exceed 0.3% but where the proportion exceeds 0.1% by weight of cement, marine aggregates must not be used with high alumina cement or for pre-stressed concrete in circumstances where calcium chloride admixtures are not permitted. In addition, in concrete containing embedded metal, calcium chloride shall not be added.

1.1.7.11 Aggregate Storage The aggregates shall be stored at mixer positions in such a manner that intermingling of different sizes and types of aggregates is prevented. The stock-piles are to be protected from rubbish or windblown dust.

Heaps of fine aggregate shall be capable of draining freely. Wet fine aggregate shall not be used until, in the opinion of the Engineer, it has drained sufficiently to ensure proper control of the water/cement ratio.

1.1.7.12 Aggregate Sampling and Testing The Engineer shall have the right to require the Contractor at any time, to draw samples of aggregate from stockpiles on the Site or any other location to be indicated by the Engineer. All sampling and testing shall be in accordance with BS 812, BS EN 1097, or to American standards when no appropriate BS exists.

For each new source of aggregate and for each class of aggregate to be used sampling and testing shall be done at the rate of six samples and set of tests for each new source and each new class.

The Contractor shall allow for the whole range of tests to be carried out. For routine sampling and testing from an approved source the rate shall be one sample per 50 m of aggregate to be used or one sample per month whichever is greater. Such testing shall include those tests from BS 812 as are considered useful by the Engineer for comparison with the results of the initial set of tests but the Contractor shall allow for the full range to be carried out.

Testing is to be carried out at an independent laboratory approved by the Engineer or else on the site in the presence of the Engineer’s representative, where approved by the Engineer.

1.1.7.13 Water for Concrete The water used for making concrete, mortar and grout shall be clean, fresh and free from injurious amounts of oil, vegetable or organic matter or any other deleterious substance in suspension or solution. The mix water shall be continually monitored for salt content and the concrete mix designed accordingly to limit total salt content.

The water should comply with the requirements of BS 3148.


1.1.7.14 Admixtures Admixtures shall not be used without the approval of the Engineer.

Before the use of any admixture can be approved the Contractor must prove by trial mix procedures that the concrete will in no way be adversely affected even when twice the recommended dose is batched.

1.1.7.15 Plant The concreting plant shall be suitable in type, capacity and design for its purpose. The performance of the plant and its disposition shall be to the satisfaction of the Engineer. The plant shall be maintained regularly and standby plant shall be available to avoid any delay in the progress of the works.

1.1.7.16 Concrete Strength Requirements All concrete mixes shall be in accordance with the requirements of BS 5328 or similar approved and as designated on drawings approved by the Engineer.

(a) Reinforced compressive cube strength shall not be less than 30 N/mm² after 28 days, designated C30.

(b) Compressive cube strength of the plain concrete shall not be less than 15 N/mm² after 28 days. Plain concrete shall be laid under reinforced concrete foundations, ground beams, trenches etc., with thickness not less than 100 mm, designated C15.

(c) Compressive strength of the plain concrete which is used for unreinforced parts of the structures shall not be less than 20 N/mm² after 28 days, designated C20.

At least seven weeks before concrete construction is programmed to start the Contractor shall submit for approval all the details listed in the table in this section, below, for each proposed grade of concrete. No concrete drawings will be approved until this data is received.

S ampling rates shall comply generally with the table the Works Test Cubes section, below.

The strength requirements for each grade of concrete proposed in the design shall be proven by means of preliminary trial tests as specified later. The minimum cement content shall be 240 kg/cu.m for 40 mm nominal size aggregate and 280 k/cu.m for 20 mm aggregate. The maximum free water-cement ratio shall be 0.55. These figures shall be revised if the sulphate content of the soil is greater than 0.5% (total S03).

The Contractor’s designs and drawings shall show clearly the characteristic strengths, mix proportion and permissible deviation proposed for each grade of concrete to be used.

The Contractor shall carry out frequent tests to the satisfaction of the Engineer to check the relationship of the strength of concrete cured under site conditions to that cured under laboratory conditions.


Specified requirements of several different mixes to be used on one Contract (Refer to BS 5328).

CONTRACT Mix description used on Drawings

Type of mix

Type of cement BS No.

Type of aggregate Coarse: BS No

Fine: BS No.

Nominal size Aggregate Maximum (mm)

Grade

Minimum Cement Content (kg/m3)

Sampling Rate (mm3)

Workability Slump (mm)

VB(s)

Compacting Factor

Maximum free water/cement ratio

Maximum Cement Content (kg/m3)

Special Cement

Special Aggregate Coarse:

Fine:

Fine Aggregate(%)

Admixture Specified

Prohibited

Amount

Air Content

Temperature of fresh concrete (ºC)

Maximum


CONTRACT Mix description used on Drawings

Minimum

Density of Concrete (kg/m3)

Maximum

Minimum

Additional requirements on attached schedule

1.1.7.17 Concrete Mixing All concrete except where specially permitted by the Engineer in writing shall be mixed in weight batch mixing machines. The machine shall have a large water storage tank with a gauge so that a predetermined quantity of water can be injected direct into the mixer drum.

The dry concrete ingredients shall be mixed until a uniform colour is obtained. After the addition of the water the concrete shall be mixed for a further two minutes or until a uniform colour is achieved. The total water in the mix shall not exceed the amount used in the trial mix.

In computing the quantity of water to be added, due account must be taken of the water contained in the aggregates. The amount of water shall be sufficient to ensure through hydration, good workability and high strength.

The Contractor shall take all precautions to the satisfaction of the Engineer to protect the concrete from the injurious effects of the elements.

1.1.7.18 Workability The concrete shall be of such consistency that it can be readily worked into the corners and angles of the formwork and around reinforcement without segregation of the materials or bleeding of free water at the surface. On striking the formwork it shall present a face which is uniform, free from honey combing, surface crazing or excessive dusting and which shall not, in the opinion of the Engineer, be inferior to the standards laid down in later clauses in this section.

In order to satisfy the Engineer that the workability of the proposed mix in the various grades is adequate for the requirements of the Specification, the Contractor shall carry out a series of workability tests on the preliminary trial mixes required elsewhere in this section. These tests shall be carried out in accordance with BS 1881, or such other procedure as may be approved by the Engineer.

When a specific workability is called for a check shall be maintained by measuring slump at the rate of one test for each ten cubic metres of concrete or three tests for each day of concreting.

1.1.7.19 Transportation The concrete shall be discharged from the mixed and transported to the Works by means that shall be approved by the Engineer and which shall prevent adulteration, segregation or loss of ingredients and ensure that the concrete is of the required workability at the point and time of placing.


1.1.7.20 Placing The concrete shall be placed in the positions and sequences indicated on approved drawings, in the specification or as directed by the Engineer, within one hour of mixing.

All formwork and reinforcement contained in it shall be clean and free from standing water, snow or ice immediately before the placing of the concrete.

The Engineer shall be given 24 hours notice of concrete placement in order that he may check the work.

Except where otherwise directed, concrete shall not be placed unless the Engineer or his representative is present and has previously examined and approved the positioning, fixing and condition of the reinforcement and of any other items to be embedded, the cleanliness, alignment and suitability of the containing surfaces and the adequacy and position of the plant.

The concrete shall be deposited as nearly as possible in its final position and in such a manner as to avoid segregation, displacement of the reinforcement, formwork or other embedded items. Placing shall be continuous between specified or approved construction joints. Works shall be brought up to full thickness in 500 mm maximum compacted layers as the work proceeds.

Where chutes are used to convey the concrete, their slopes shall not be such as to cause segregation and suitable spouts or baffles shall be provided to obviate segregation during discharge. Concretes shall not be allowed to fall freely more than 1.5 metres except with the approval of the Engineer. Where pneumatic placers are used the velocity of discharge shall be regulated by suitable baffles or hoppers where necessary to prevent segregation or damage and distortion of the reinforcement, other embedded items and formwork, caused by impact.

Upon arrival at the places of deposition the concrete truck driver must present to the Engineer’s representative a chit from the concrete batcher stating (a) the grade of concrete (b) the workability (c) the aggregate size (d) type of cement and (e) time of batching of the concrete. Records shall be maintained detailing the placement location of each batch within the works.

If concreting is not started within 24 hours of approval being given, approval shall again be obtained from the Engineer. Concreting shall then proceed continuously over the area between construction joints. Fresh concrete shall not be placed against in situ concrete which has been in position for more than 30 minutes unless a construction joint is formed in accordance with this specification. When in situ concrete has been in place for four hours, or less as directed by the Engineer depending upon the mix, type of cement and weather conditions, no further concrete shall be placed against it for a further 20 hours.

Concrete, when deposited, shall have a temperature of not less than 5ºC and not more than 32ºC. It shall be compacted in its final position within 30 minutes of discharge from the mixer unless carried in purpose made agitators, operating continuously, when the time shall be within two hours of the introduction of cement to the mix and within 30 minutes of discharge from the agitator.


Except where otherwise agreed by the Engineer, concrete shall be deposited in horizontal layers to a compacted depth note exceeding 500 mm where internal vibrators are used or 300 mm in all other cases.

Unless otherwise agreed by the Engineer, concrete shall not be dropped into place from a height exceeding 1.50 metres. When trunking or chutes are used they shall be kept clean and used in such a way as to avoid segregation.

No concrete shall be placed in flowing water. Underwater concrete shall be placed in position by tremie tube, or by pipeline from the mixer. Full details of the method proposed shall be submitted in advance to the Engineer and his approval obtained before placing begins. Where the concrete is placed by a tremie tube, its size and method of operation shall be in accordance with BS 8004. During and after concreting under water, pumping or de-watering operations in the immediate vicinity shall be suspended until the Engineer permits them to be continued.

1.1.7.21 Compaction of Concrete The concrete shall be fully compacted throughout the full extent of the layer. It shall be thoroughly worked against the formwork and around reinforcement and other embedded items, without displacing them. Successive layers of the same lift shall be thoroughly worked together.

All concrete shall be compacted to produce a dense homogenous mass. Unless otherwise agreed by the Engineer, it shall be compacted with the assistance of vibrators. Sufficient vibrators in serviceable condition shall be on site so that spare equipment is always available in the event of breakdowns.

Vibration shall not be applied by way of the reinforcement. Where vibrators of the immersion type are used, contact with reinforcement and all inserts shall be avoided, so far as is practicable.

Concrete shall not be subjected to vibration between 2 and 24 hours after compaction.

1.1.7.22 Vibrators Unless otherwise directed by the Engineer, approved power driven vibrators of the immersion type shall be used.

They shall be inserted at such distances apart or applied in such a manner as will ensure that the concrete is satisfactorily and uniformly compacted.

The Contractor shall ensure that a sufficient number of vibrators are on hand at all times including allowance for breakdown of vibrators.

As a general rule, one working vibrator shall be available for each 6m3/hr of concrete being placed.

Vibrators shall penetrate the full depth of the layer and where concrete is placed over previously placed concrete not more than four hours old the vibrators shall enter and re-vibrate that layer to ensure that successive layers are well knitted together.

Over-vibration, causing segregation, surface laitance or leakage through formwork, shall be avoided. Immersion vibrators shall be withdrawn slowly to prevent the formation of voids. Vibrators shall not be


used to work the concrete along the forms, or in such a way as to damage formwork or other parts of the structure, or displace the reinforcement of other embedded items.

Internal vibrators shall be capable of producing not less than 10,000 cycles per minute and external vibrators not less than 3,000 cycles per minute.

1.1.7.23 Construction Joints Concreting shall be carried out continuously up to construction joints, the position and arrangement of which shall be indicated on the drawings and approved by the Engineer.

When not indicated on the drawings the following general rule shall apply: -

Columns Joints in columns are to be made at the underside of floor members and at floor levels. Haunches and column capitals are to be considers as part of and continues with the floor or roof.

Floors Joints in the floor system are to be located at or near the quarter points of the span in slabs and beams, except where otherwise instructed.

Walls Vertical joints away from corners. Horizontal joints above splays or openings.

Whenever the placing of the concrete is discontinued other than at the exposed faces, this dis-continuity shall form a construction joint. Construction joints are to be made only along a horizontal or vertical plan except that in the case of inclined or curved members they shall be at right angles to the principal axis. Care shall be taken to prevent off setting of the joint and to ensure water tightness. The joints shall in every way satisfy the requirement of the Engineer, and be fully detailed on drawings prior to submission for approval.

When work is resumed adjacent to a surface which has set, the whole surface shall be thoroughly roughened. It shall be cleaned of all loose and foreign matter and laitance and washed with water immediately before placing the fresh concrete which shall be well compacted against the joint.

1.1.7.24 Construction Bays The Contractor shall agree with the Engineer, prior to the commencement of concreting, upon the sequence of placing concrete and positions of vertical and horizontal joints, whether shown or not on the drawings.

In general, slabs in excess of 6 metres in length and/or width and walls exceeding 6 metres in length shall not be poured in one operation and subsequent adjacent bays shall not be concreted within seven days. The maximum area of any pour shall be 100 sq.m.

In the light of experience the Engineer may consider the above pour size limits to be excessive and will have the authority to reduce them.


As an alternative to alternate bay construction, shrinkage gaps of up to 1 metre in the width may be left a 6 metre intervals; the shrinkage gaps shall not be concreted until concrete on all sides is at least seven days old.

Expansion joints shall be fully detailed on construction drawings before submission for approval. Minimum width of expansion joints to be 25 mm except for shaded areas 12 mm.

Expansion joints shall be filled with bitumen impregnated fibreboard to full depth and width. The infilling will be permitted to be used as permanent formwork only for the second casting. where the fibreboard is exposed it shall be cut back for a depth of at least 2 cm from the chamfered edge, filled and pointed with a resilient liquid polysulphide polymer sealant to the manufacturer’s instructions.

Where dowel bars are indicated on the drawings forming part of a joint they shall be held securely horizontal and perpendicular to the joint during concreting.

Dowel bars shall be plain mild steel bars conforming with BS 4449; they shall be straight and coated at one end with approved bond breaking compound, which shall consist essentially of 66% of 200 pen bitumen blended not with 14% light creosote oil and, when cold, brought to the consistence of paint by the addition of 20% solvent naptha, or other approved compound.

Plastic caps used in expansion joints shall be rigid and securely fixed to the dowel to prevent the ingress of concrete during casting of the slab. The packing used within the cap shall be an insert compressible material. All dimensions must be shown on drawings prior to submission for approval.

1.1.7.25 Joining New Concrete Work to Existing Existing concrete shall be broken out as described or directed and scabbled to form a suitable key for the concrete.

Where necessary the reinforcement in existing concrete shall be exposed, cleaned and bent to its correct shape.

New reinforcement shall be securely wired to the existing.

1.1.7.26 Curing Concrete shall be protected during the first stage of hardening from the harmful effects of sunshine, drying winds, cold, rain or running water. The protection shall be applied as soon as practicable after completion of placing by a method to be approved by the Engineer.

The Contractor shall put forward his proposals for curing concrete to the Engineer for approval, before any concreting work commences.

On vertical surfaces, the curing membrane shall be applied immediately after removing the formwork.

No concrete shall be allowed to become alternately wet and dry.

The temperature of curing water shall be the same as the concrete +10ºC. General concrete shall be wet cured for at least seven days with further four days of dry protection.


1.1.7.27 Trial Mixes The Contractor shall submit not less than three weeks before the commencement of manufacture of preliminary trial design mixes the following information to the Engineer in respect of each grade of concrete.

(a) Grade of concrete.

(b) Title of particular trial mix.

(c) The grading of the aggregates.

(d) The ratio by weight of all the constituents of the concrete.

(e) The expected compacting factor and slump.

(f) Full details of the proposed site quality control.

(g) Full details of the proposed laboratory for testing.

The Contractor shall also confirm his proposed testing regime and acceptance criteria for the Preliminary Trial Mixes which should be based on BS 5328. Should the proposal not be approved by the Engineer, then the Contractor shall comply with the paragraph on preliminary test cubes and the two following paragraphs below.

At least four weeks before commencing any concreting in the Works, the Contractor shall make trial mixes using samples of aggregates and cements typical of those to be used. If possible, the concreting plant and the means of transport to be employed in the Works shall be used to make the trial mixes and to transport them a representative distance. A clean dry mixer shall be used to make the trial mixes and the first batch shall be discarded.

Before commencing the Works the Contractor shall submit to the Engineers for his approval, full details of the mixes he proposes to use, with their anticipated strength, which must be based on the satisfactory results of these preliminary tests.

The Engineer shall if he so desires be present at all preliminary tests. The Contractor shall inform the Engineer of his intention to carry out such tests and the time and place of the tests a least 24 hours before they take place.

Neither the mix proportions nor the source of supply of materials shall be altered without the prior approval of the Engineer except that the Contractor shall adjust the proportions of the mix as required, to take account of permitted variations in the materials. Such approval shall be subject to the execution, to the Engineer’s satisfaction, of trial mix procedures set out herein.

1.1.7.28 Works Test Cubes Before commencing any concreting in the Works the Contractor shall submit for approval his proposed testing regime for the Works’ concrete. Should the proposals not be approved by the Engineer, the Contractor shall comply with the next two paragraphs below.


For the first ten days that a particular grade of concrete is produced, or where there is a lapse of two weeks or more between successive pours of the same grade of concrete, three samples shall be taken on each day and three cubes shall be made from each sample. Two shall be tested at seven days and the other at 28 days.

After the initial ten days, samples of designed mixes shall be taken at the reduced rate given in the table below with the provision that at least one sample shall be taken on each day that concrete of that grade is used. Three cubes shall be made from each sample, one being tested at seven days and the remaining two at 28 days.

Sampling rates for design mixes after ten day run-in of concrete grade (3 cubes shall be made from each sample).

Rate One Sample to be taken every day or every:-

A Critical Structures e.g. cantilevers, columns

10 m3

B Intermediate Structures e.g. beams, slabs, bridge decks

40 m3

The cubes shall be made, cured, stored and tested in compression in accordance with BS 1881. The tests shall be carried out in a testing laboratory approved by the Engineer. The laboratory must provide evidence that its equipment and procedures comply with BS 1610 and BS 1881 and that its testing machines are regularly checked and adjusted for accuracy. Full details of the qualifications of all laboratory staff will be required by the Engineer.

Reports of all tests made shall be supplied direct from the laboratory to the Engineer within 24 hours of the cubes being tested. The Engineer’s representative one site shall have the authority to stop all further concrete work until acceptable tests results are forthcoming.

Up-to-date records shall be kept by the Contractor at the Works of positions in the Work of all batches of concrete, of their grade and of all test cubes, cores and other specimens taken from them. Copies of these records shall be supplied to the Engineer at weekly intervals or upon request by the Engineer.

1.1.7.29 Compliance of Works Test Cubes with Specification When submitted proposed testing regimes the Contractor shall also detail his proposed acceptance criteria for the Engineer’s approval. When this is not forthcoming the Contractor shall comply with the next two paragraphs below.

The rules of compliance for works cubes are different to those in Clause 9.27 for Trial Mixes. Compliance with the characteristic strength shall be assumed if the conditions given in both (a) and (b) are met: -

(a) The average strength from any group of four consecutive test results exceeds the specified characteristic strength by


3 N/mm2 for concrete of grade C-25 and above (i.e. characteristic strength = 25 N/mm²).

2 N/mm² for concrete of grade C-15 and below (i.e. characteristic strength = 15 N/mm²).

(b) The strength determined from any test result is not less than the specified characteristic strength minus.

3 N/mm² for concrete of grade C-25 and above

2 N/mm² for concrete of grade C-15 and below

The quantity of concrete represented by any group of four consecutive test results shall include the batches from which the first and last samples were taken, together with all intervening batches. When a test result fails to comply with (b), only the particular batch from which the sample was taken shall be at risk.

Compliance criteria remain the same irrespective of every rate of sampling or the same grade concrete in different structures.

Where a minimum or maximum cement content of a designed mix is specified and compliance is assessed by observation of the batching or from autographic records, the cement content shall not be less than 95% of the specified minimum or more than 105% of the specified maximum.

Where compliance of cement content is assessed from the results of analysis tests on fresh concrete, the cement content shall not be less than 90% of the specified minimum or more than 110% of the specified maximum.

1.1.7.30 Failure of Concrete to Meet Test Requirements If the strength of the specimen is less than the appropriate specified minimum crushing strength or if, in the opinion of the Engineer, the concrete fails to meet the specified requirements in other respects, the concrete in that part of the Works of which it is a sample will be considered not to comply with the specified requirements.

As and where directed by the Engineer, cylindrical core specimens shall be cut from the hardened concrete in the Works for the purposes of examination and testing. The cutting equipment and the method of doing the work shall be approved by the Engineer. Prior to the preparation for testing, the specimens shall be made available for examination by the Engineer. Testing of the core shall be in accordance with approved standards.

Recourse may also be made by the Engineer to such non-destructive means of testing as ultrasonic pulsing and Schmidt rebound hammers.

If the specified requirements have not been met, the Contractor shall propose such remedial action as may be required. Such action is subject to the Engineer’s satisfaction and approval. If no satisfactory remedial measures are proposed by the Contractor and approved by the Engineer then the Engineer shall order the removal of all work not complying with the Specification at the Contractor’s expense. Before proceeding with similar work the Contractor shall submit to the Engineer, for his approval,


details of action proposed to ensure future concrete to be placed in the Works will comply with the Specification.

1.1.7.31 Formwork Forms shall be so designed and constructed that the concrete can be properly placed and thoroughly compacted and that the hardened concrete while still supported by the forms shall conform accurately to the required shape, position and level, subject to the tolerances specified and to the standards of finish specified later in this Section.

The Engineer may request the Contractor to provide sample panels of formwork for approval, at the Contractor's expense.

When concrete is to be vibrated, special care shall be taken to maintain the stability of the formwork and the tightness of the joints during vibrating operations.

The material and position of any ties passing through the concrete shall be approved by the Engineer. The whole or part of the tie shall be capable of being removed so that no part remaining embedded in the concrete shall be nearer the surface of the concrete than the specified thickness of cover to the reinforcement. Any holes left after the removal of ties shall be filled, unless otherwise directed by the Engineer, with concrete or mortar of approved composition.

1.1.7.32 Removal of Formwork All forms shall be removed without damage to the concrete. The use of mould oil or other material to facilitate this shall be subject to the approval of the Engineer.

All formwork for pits, ducts and holding down boltholes must be so constructed that it can be easily collapsed to facilitate withdrawal after the initial set of the concrete.

The Contractor's proposed method for the construction and fixing of the formwork for boltholes pockets shall be submitted to the Engineer for approval before construction. The top of the shuttering shall be suitably covered to prevent entry of excess grout, materials used for curing, etc.

Solid timber must not be used for forming holding down boltholes. Boltholes formers may be made of plywood, expanded metal, polystyrene or other method approved by the Engineer, who may require the Contractor to carry out a test pour, using the proposed bolthole former.

The Engineer shall be informed in advance when the Contractor intends to strike any formwork.

The time at which the formwork is struck shall be the Contractor's responsibility. The formwork may be struck when the concrete has, in the opinion of the Engineer, attained a compressive strength of not less than 10N/mm2 or twice the stress to which it will then be subjected, whichever is the greater.


In the absence of cube test results the periods before striking given in the table below may be used for ordinary Portland cement: -

Location Surface temperature of concrete Not less than

>16 C Not less than 7 C

Beam side, walls and columns Slab soffits (formwork)

12 hrs 4 days

18 hrs 6 days

Formwork props to slabs 10 days 15 days Beam soffits (formwork props undisturbed) 10 days 15 days Formwork props to beams 15 days 21 days

Formwork shall be constructed so that the side forms of members can be removed without disturbing the soffit forms and its props are to be left in place, when the soffit forms are removed these props shall not be disturbed during the striking.

1.1.7.33 Finishes of Concrete The Contractor shall state precisely on his plans which of the types of finishes d described hereunder he intends to use in the various locations. Any defective concrete finish will be rejected. The Engineer may at his discretion order the defects to be cut out and made good.

Plastering of defective concrete as a means of making good will not be permitted, except that in case of minor porosity on the surface the Engineer may approve a surface treatment by rubbing down with cement and sand mortar of the same richness as in the concrete. This treatment shall be made immediately after removing the formwork.

1.1.7.34 Formed Finishes for Concrete (a) Type F.1

This finish is for surfaces against which backfill or further concrete will be placed. Formwork shall consist of sawn boards, sheet metal or any other suitable material, which will prevent the loss of grout when the concrete is vibrated.

(b) Type F.2

This finish is for surfaces, which are permanently exposed to view but where the highest standard of finish is not required. Forms to provide a Type F.2 finish shall be smooth and boards shall be not less than 18mm thick with edges, arranged in a uniform pattern. Alternatively, metal panels may be used if they are free from defects likely to detract from the general appearance of the finished surface. Joints between the boards and panels shall be horizontal and vertical unless otherwise directed. This finish shall be such as to require no general filling of surface pitting, but fines, surface discoloration and other minor defects shall be remedied by methods approved by the Engineer.


(c) Type F.3

This finish is for surfaces prominently exposed to view where good appearance and alignment are of special importance. To achieve this finish, which shall be free of board marks, the formwork shall be faced with plywood or equivalent material in large sheets. The sheets shall be arranged in an approved uniform pattern whenever possible.

Joints between sheets shall be arranged with architectural feature, sills, window heads or drainages in direction of the surface. All joints between panels shall be vertical and horizontal unless otherwise directed. Suitable joints shall be provided between sheets to maintain accurate alignment in the place of the sheets. The joints shall be arranged and fitted so that no blemish or mark is imported to the finished surface. Unfaced wrought boarding or standard steel panels will not be permitted for Type F.3 finish. Permanent forms shall be constructed of slabs or blocks of precast concrete, natural stone, brickwork of other approved material as directed. Such slabs or blocks shall have an exposed surface of the quality shown on the drawings and as specified. They shall be fixed to the structure by approved means and the joints between them shall be made tight with mortar or other means of preventing leakage. The use of internal metal ties shall not be allowed.

(d) Type F.4

This finish is identical to type F.3 except that internal metal ties are permitted.

1.1.7.35 Unformed Finishes to Concrete (a) Type U.1

This is a screeded finish for surfaces of roads or of foundations, beds, slabs and structured members to be covered by backfills, subsequent stages of construction, bonded concrete, topping or cement mortar beds to receive pavings and on exposed surfaces or paving where superior finish is not required. It is also the first stage for finishes Type U.2 and U.3. The finishing operations shall consist of levelling and screeding the concrete to produce a uniform plane or ridged surface, surplus concrete being struck off by straight edge immediately after compaction.

(b) Type U.2

This is a floated finish for surfaces of beds and slabs to receive mastic pavings or block or tile pavings where a hard smooth steel trowelled surface is not required. Floating shall be done only after the concrete hardens sufficiently and may be done by hand or machine. Care shall be taken that the concrete is worked no more than is necessary to produce a uniform surface free from screed marks.

(c) Type U.3

This is a hard smooth steel-trowelled finish for surfaces of concrete pavings, tops of walls, exposed surfaces of engine and plant foundations and in the vicinity of holding down bolt chases, copings and other members exposed to weathering, surface beds and slabs to receive


thin flexible sheet and tile pavings bedded in adhesive and seatings for bearing plates and the like, where the metal is in direct contact with the concrete.

Trowelling shall not commence until the moisture film has disappeared and the concrete has hardened sufficiently to prevent excess laitance from being worked to the surface. The surface shall be trowelled under firm pressure and left free from trowel marks.

1.1.7.36 Surface Treatments Where concrete is to be treated with sodium silicate or a similar dust preventive coating, this must be carried out within 14 days of the concreting of the foundation and be applied in accordance with the manufacturer's instructions.

1.1.7.37 Reinforcement Steel reinforcement shall be one of the following: -

(a) Hot rolled mild steel round bars complying with BS 4449 or equivalent standards, as approved by the Engineer.

(b) High tensile steel either (i) cold worked deformed bars or (ii) hot rolled bars complying with BS 4449 or as approved by the Engineer.

(c) Welded steel mesh reinforcement complying with BS 4483 or similar approved.

Bars greater than 40 mm diameter will not generally be used.

Reinforcement shall be stored clear of the ground on sufficient supports to prevent distortion of the bars. Mild steel and high tensile steel are to be stored separately.

The Contractor shall supply the Engineer with a certificate for each consignment from the steel manufacturers showing that the steel meets the requirements of the Specification. One tension test and one bond test shall be made for each lot of 50 tonnes or less supplied for the permanent works.

Steel reinforcing bars shall be kept clean and shall be free from pitting, loose rust, mill scale, oil, grease mortar, earth paint or any material which may impair the bond between the concrete and reinforcement or disintegration of the concrete.

Reinforcement may be bent on site, or alternatively off the site, by an approved method. The Contractor shall arrange for bending equipment suitable for bending both mild steel and intermediate grade bars. Mild steel shall be bent at temperatures in the range 5oC to 100oC. The shapes of the bends and lengths must comply with the applicable recommendations of BS 8666 AND BS EN ISO 4066 or otherwise specified on the Drawings and Bending Schedules as approved by the Engineer.

The Contractor shall provide any chairs or other subsidiary reinforcement necessary to keep the reinforcement in its correct position. The concrete cover over such subsidiary reinforcement shall not be less than that over the reinforcement generally.

The Contractor shall provide adequate scaffold boards to ensure that the reinforcement is not displaced by being walked upon during the placing of the concrete or other operations.


Mesh reinforcement shall be fixed flat in the works over the whole of the areas indicated on the approved drawings. Adjoining sheets of mesh shall overlap by at least 300mm.

Loose small pieces of fabric shall only be used where they are essential for fitting into small confined parts of the works. Areas of fabric reinforcement shall be nett with no allowance included for laps or waste. Fabric reinforcement shall be delivered to site only in flat sheets.

Bends, cranks and other shapes of reinforcement shall be to the dimensions specified, otherwise all bars shall be truly straight. Bending of reinforcement shall be carried out round a former having a diameter of at least four times the diameter of the bar. The bending dimensions shall comply with BS 8666 AND BS EN ISO 4066 unless otherwise specified on the bending schedules.

Cover blocks used for the correct positioning of reinforcement shall be of a type approved by the Engineer. They shall be rigid, inert and capable of supporting the reinforcement in its correct position with the required cover without deforming. They shall not impair the finish on the concrete nor cause the formwork to deform locally.

Reinforcing bars shall be tied together at every intersection using 16 swg soft pliable annealed steel wire. When an F3 finish soffit is specified, stainless steel tying wire shall be used to prevent rust staining.

Immediately prior to concreting, all reinforcement shall be cleaned as required or directed by the Engineer by suitable approved methods to ensure the absence of any contaminates such as wind blown salt.

Concrete Cover to Reinforcement

(a) The minimum concrete cover for durability to any reinforcing bar shall be as follows:

Concrete Above Ground

Internal faces of suspended slabs 30 mm

Exposed faces of slabs, beams, walls and columns 50 mm

Internal faces of columns and walls 50 mm

Concrete Below Ground

Faces in contact with soil including blinding concrete 75 mm

All other faces (e.g. internal faces of basement wall) 50 mm

For other locations the exposure condition and cover shall be approved by the Engineer.


1.1.7.38 Testing of Reinforcement The Engineer shall have the right to select at any time samples of steel reinforcement for testing in accordance with the relevant approved standard.

1.1.7.39 Bar Bending Schedules The Contractor shall provide fully dimensioned Bending Schedules giving the location and bending of every bar shown on the drawings. Unless otherwise stated on the Bending Schedules all bars shown will be dimensioned in accordance with a national or international standard to be approved by the Engineer, e.g. British Standard 8666 and BS EN ISO 4066.

1.1.7.40 Bituminous Protection of Concrete The Contractor shall provide additional protection for concrete foundations from the action of sulphates in the soil by the application, to the satisfaction of the Engineer, of a protective coating of bitumen not less than two millimetres thick to contact surfaces.

The bitumen coating on the underside of the foundations shall be applied to the surface of the blinding concrete before the deposition thereon of the structural concrete.

The bitumen coating on vertical faces shall be applied in more than one layer to ensure the complete absence of pinholes and bare patches.

Alternatively protection may be achieved by a self adhesive waterproofing membrane approved by the Engineer.

1.1.7.41 Additional Requirements in Hot Weather General

In hot weather the Contractor shall present for the Engineers approval his proposals for dealing with the following problems: -

(i) Reduced workability

(ii) Excessive plastic shrinkage

(iii) Rapid strength gain but possible low final strength

(iv) Rapid drying out of concrete

Concrete Mixing

Aggregate stock piles shall be shielded from the directed pays of the sun or cooled by spraying with water; and water tanks and pipes shall be insulated to ensure that the temperature of concrete when deposited shall not exceed 320C.

With the approval of the Engineer admixtures may be employed to related setting time or enhance workability, or induce early bleeding etc.


Concrete batched off-site shall be transported by truck mixer with the mixer rotating only after it arrives on site. Alternatively, the aggregates and 80% of the required water may be batched off-site with the cement and remaining water being added on site not more than 15 minutes before the pour commences. Concrete transporters shall be kept as cool as practicable.

Concrete placing

Placing shall not commence until sufficient standby pumps and vibrators are on site to cope with breakdowns.

No concrete shall be batched until formwork is ready and all reinforcement fixed in place.

The area of each concrete pour frontage shall be kept to a minimum and suitable means shall be provided to avoid premature stiffening of concrete placed in contact with hot dry surfaces. Where necessary the surface, including reinforcement, against which the concrete is to be placed shall be shielded from the rays of the sun and shall be sprayed with water to prevent excessive absorption by the surfaces of water from the fresh concrete.

In hot weather concrete shall be deposited in horizontal layers to a compacted depth not exceeding 300mm and internal mechanical vibrators shall be used.

Due to rapid stiffening in hot weather all clean-up operations such as application to resin cure membranes and dust reducers and surface finishing, etc. shall follow closely behind final tamping.

Curing

All concrete shall be covered for at least 14 days after placing and kept continuously wet for the initial 7 days. The temperature of curing water shall be within 10oC of that of the concrete. Air shall not be permitted to circulate between concrete and curing materials.

Testing

Initially the Contractor shall double the number of test cubes made. A limited number shall be cured under site conditions in order to ascertain the relationship between site-cured samples and lab-cured samples.

The number of slump tests shall initially be twice that normally required.

Air temperature shall be measured every two hours, and the temperature of every batch of concrete shall be recorded as it is deposited at the work place

1.1.7.42 Additional Requirements in Cold Weather During cold weather daily temperature forecasts shall be obtained from a source approved by the Engineer, and concreting programmed accordingly.

The precautions detailed below shall be taken when either the ambient temperature is 2oC and falling or the temperature of the freshly placed concrete is 9oC and falling, to ensure that the temperature of the concrete when placed does not fall below 5oC until it has thoroughly hardened.


Calcium chloride may be used as an accelerator only with mass concrete. No concrete containing embedded metal may have calcium chloride added.

Adequate measures to the Engineer's approval shall be taken to ensure that the aggregates are free from frost, ice and snow and that the mixing water which shall not exceed 60oC, is of sufficient warmth to ensure that the temperature of the freshly placed concrete shall be not less than 5oC. No aggregate shall be drawn from a storage bin or stockpile covered with ice, frost or snow unless the top layer is removed in such a manner as to ensure that any aggregate used is not contaminated by ice, frost or snow.

If the ambient temperature is likely to fall below 0oC all freshly placed concrete shall be protected by means of braziers, lagging or steam heat under covers, the method to be used being left to the discretion of the Contractor provided it prevents the water in or on the surface of the concrete from freezing. The method to be used shall be agreed by the Engineer before the cast has commenced and the necessary steps taken to ensure that the protective measures are ready to be carried out as soon as required.

All concreting shall cease, as soon as it is practicable to stop placing, immediately the air temperature falls below 5oC. In the case of large masses of concrete this may be waived at the Engineer's discretion.

1.1.7.43 Foundations for all Buildings and Structures Foundations to all buildings, concrete and steel structures shall be of reinforced concrete minimum grade C30. The foundations shall be designed in accordance with BS 8004 and BS EN 1998-5, using the most critical combination of vertical and horizontal loading. The type of footing/foundation selected for each Substation shall be suitable for the soil conditions and subject to approval of the Engineer. All foundations for plant support structures shall be finished 150 mm minimum above finished substation level (150 mm above ground level).

A protective coat of bitumen, as specified elsewhere in these specifications, shall be applied to surfaces of formed footings in contact with the soil. All reinforcing steel augured footings shall be galvanized.

1.1.7.44 Cable Trenches, Drawpits and Duct Banks Reinforced concrete cable trenches, drawpits and duct banks shall be cast in C30 concrete and to suit the requirements of the cable arrangements, all to the approval of the Engineer. Reinforced concrete duct banks shall be provided at all road crossings with transition chambers at each end. The ducts shall be sloped to a low point and drained. The duct banks shall consist of Transite or equivalent approved pipes with sufficient concrete cover to pipes and shall be designed safely to carry all loads to be transported over the roads. All necessary fittings and inserts shall be cast in place and slots shall be provided in the centre walls of cable trenches to suit the cable arrangement requirements. Reinforced concrete drawpits shall be constructed where required to facilitate pulling cables. They shall be covered with suitable covers, designed to accommodate their likely loading, and be suitable for ease and safe removal.

Reinforced pre-cast concrete shall be cast in C30 concrete. The maximum weight of each unit shall be 80 kg and every fourth unit shall be provided with lifting loops. The pre-cast concrete covers shall


be designed to support a concentrated live load of 10 kN placed anywhere on the span. Maximum deflection shall be 1/500 of span. The cable trench arrangement in all buildings shall be designed by the Contractor to suit the requirements of the panels to be installed. The cable trenches in all buildings shall be provided with aluminium chequer plate covers as required, and approved by the Engineer.

Each plate shall have a maximum weight of 20 kg and shall be designed to carry a concentrated live load of 10 kN placed anywhere on the span. Each chequer plate shall be securely fixed, with a minimum of 4 countersunk screws, to steel angles and channels cast into the trench walls. Nuts shall be welded to the angles and channels to receive the screws.

1.1.8 Outdoor Steel Structures 1.1.8.1 General The work of this section shall include the design, and the provision of all labour, equipment and material for the fabrication and erection of all steel structures necessary to carry all mechanical and electrical equipment required at each Substation. Design of steel structures shall be to BS 449 Part 2 or BS 5950. Alternative international design Standards may be used only after the prior approval of the Engineer.

1.1.8.2 Materials All structural steel shall comply with the requirements of BSEN 50341 or BS 5950 as appropriate or to any other approved design Standard. Preferably, only freshly rolled materials shall be used and any materials showing rust, scale or appreciable weathering will be rejected by the Engineer.

All welding electrodes shall comply with requirements of BSEN 499:1995.

1.1.8.3 Workmanship (a) General

All work shall be carefully and accurately performed. All members shall be in accordance with the drawings and shall be supplied straight and true so that the structure can be erected with all parts in true alignment without straining and distorting of the parts.

Ease of assembling in the field is of the utmost importance and all similar parts shall be interchangeable. All holes should be accurately punched so that the structures can be erected without “drifting” the holes.

Each separate part shall be plainly stamped before galvanizing with a mark which is clearly visible after galvanizing. All like parts shall have the same mark placed in the same relative position on each piece, and all unlike parts shall have different marks to distinguish them.

(b) Welding

All welding shall be carried out by welders who have satisfactorily completed the relevant tests described in BS 449 or BS 5950, or in other recognised standards, subject to the approval of the Engineer.


(c) Gas Cutting

The use of a torch is permissible for cutting members provided all irregular edges are trimmed smooth before galvanising. Stresses shall not be transmitted into the metal through a burned surface.

The use of a torch for cutting bolt holes will not be permitted.

(d) Splices

Members that are too long for galvanizing in one piece may be spliced. A sufficient number of bolts shall be provided at all splices to develop the full strength of the member.

Chord angles of latticed girders shall be butt-spliced with butting ends faced to bear. A splice angle shall be placed inside the chord angle with the heel of the splice angle ground off to fit the fillet of the chord angle. Splices in chord angles of lattice girders shall be staggered.

Structure legs may be butt-spliced as above, or lap-spliced. For lap splices the heel of the inside angle shall be grounded off to clear the fillet of the outside angle.

Splices shall be made at or above, and as close as possible to the main panel points.

(e) Connections

All connections, unless specified otherwise, shall be bolted. In general, the diagonals and struts shall be bolted directly to the structure legs, chord angles and to each other and the use of gusset plates kept to a minimum. Eccentricity of members and connections shall be reduced to the least practicable value. Single bolt connections shall be used where design stresses permit except where one bolt does not provide the adequate rigidity.

Where a member consists of two angles placed back to back, the angles shall be fastened together at intervals not exceeding 600 mm for compression members, or 1 m for tension members.

(f) Holes

All punched or drilled holes shall be round, true to size, free of ragged edges and burrs and shall be at right angles to the place of the material. All holes shall be accurately spaced, well-matched and centred exactly on the gauge lines as called for on the drawings.

Holes in material 20 mm thick or over shall be sub-punched and reamed or drilled from the solid. The bolt holes shall not exceed the diameter of the bolt by more than 2 mm except where otherwise noted on the drawings.

The minimum distance from the centre of any hole to the edge of a plate and the minimum and maximum pitch of the holes shall be in accordance with the requirements of BS 449 or BS 5950.


(g) Bolts, nuts and washers

All bolts, nuts and washers shall meet the requirements of the British Standard Specifications. The minimum size of bolts shall be 10 mm diameter. The shank shall extend full size completely through the members connected and the members shall not bear on the thread. Tight nuts shall be ensured by the provision of washers. Bolts shall be of as few different lengths as practicable.

All bolts shall be galvanised including the threaded portions. The threads of all bolts shall be cleared of spelter by spinning and bushing. A die shall not be used for cleaning the threads. All nuts shall be galvanised with the exception of the threads, which shall be oiled. Galvanising shall be carried out as specified below.

(h) Galvanising

Galvanising shall be applied by the hot process and for all parts other than steel wires shall consist of the thickness of zinc coating equivalent to not less than that prescribed in BS EN 1S0 1461. The zinc coating shall be smooth, clean and of uniform thickness and free from defects. The preparation for galvanising, and the galvanising itself, shall not adversely affect the mechanical properties of the coated material.

All drilling, punching, cutting and bending of parts shall be completed and all burrs shall be removed before the galvanising process is applied.

Galvanising of plates and shapes shall be tested in accordance with the applicable BS specifications. In addition, the uniformity and coating shall be tested by the Preece test, the minimum number of one-minute dips being six.

Galvanisation of bolts, nuts, washers and similar hardware shall be tested in accordance with the applicable BS specifications. The above tests and galvanisation shall be witnessed by the MOE Engineer.

(j) Bonding

Means shall be provided for fixing and bonding copper conductors to the steel work at sufficient points to secure efficient grounding as specified in the Electrical Section of these Specifications. Ground connections shall be made to a vertical face clear of the ground; and foundation bolts shall not be used for their attachment.

(k) Climbing devices

To facilitate inspection and maintenance, the structures shall be provided with stepladders, handrails, screens, guard and other facilities in approved positions. Step bolts are not acceptable for Substation Structures.


1.1.8.4 Design Requirements (a) General

Structures to be provided shall conform to these specifications and the accompanying drawings. The structures shall be designed to carry all plant, equipment, conductors, insulators, sealing ends or cable boxes and cables where necessary, instrument transformers and other fittings including lightning spikes, sky (shield) wires and the line and ground conductors of the incoming overhead transmission lines under the specified conditions of loadings and factors of safety as required.

The structures shall be designed to suit the clearance conditions specified in the Electrical Section of these Specification.

Where typical layouts of switchgear are shown on drawings attached to this specification the structure shall be of the approximate general proportions given on these drawings. The structures shall be so designed that if at a later date the Engineer decides to modify the original installations, within the limits specified below, the structures will still meet all the requirements of these Specifications including those for clearances. Such modification shall be assumed not to involve:

(i) A greater final length of conductor insulator string than that specified plus one additional unit.

(ii) The addition of more than 25 per cent to the overall length of the post-type insulators.

The rigidity of the structures shall be such that the alignment of the apparatus which they carry shall not be disturbed by the loads to which the structures are subjected. In general, the width and depth of latticed girders shall be not less than 1/16 of the span taken as centre to centre of the supporting columns/legs. Lattice girders shall be fabricated with a camber. The minimum width for battered columns/legs shall preferably be not less than 1/6 of the total height. A cross-frame shall be provided in columns/legs and girders at points where required to distribute loadings and to provide adequate stiffness.

Care shall be taken in the design to allow for any additional vertical loads to which the structure may be subjected during the erection process and plant and equipment installations.

The minimum permissible thickness for steel sections and gussets shall be 4 mm, and the smallest angle size shall be 35 mm x 35 mm x 4 mm.


(b) Assumed working loads

The assumed maximum simultaneous working loadings on the structures shall be as follows:

(i) Wind loadings

Wind loadings, as specified previously shall be applied to the whole projected area of all conductors, insulators and apparatus carried on the structures. For lattice steel structures, the wind loadings shall be applied to the projected areas of the members on both faces, recognising the Shielding Factor and the Solidity Ratio as described in CP3, Chapter V.

(ii) Vertical loadings

The dead weight of all conductors, insulators and apparatus carried by the structures, and of the structures themselves.

(iii) Tension loadings

Tensions in the station conductors and in conductors of incoming lines shall be as specified in the system performance section of these Specifications. The directions of the incoming line conductors may vary from those shown in the typical layouts within the ranges of +/- 30 degrees laterally and +/- 20 degrees vertically. Due allowance shall be made for broken conductors leading to unbalanced load conditions.

(iv) Temporary loadings

Temporary loadings caused during erection and maintenance with a minimum vertical concentrated loading at the centre of the member as follows:

All main horizontal members 1.5 kN

All secondary horizontal members 0.75 kN

Proper precautions shall be taken to ensure that structures are not strained or damaged in any way during erection of the structures themselves, or of the conductors and other apparatus. Care shall be taken in the design to allow for any additional vertical loads to which the structure may be subjected during the erection of line and earth conductors and cables.

(v) Substruts

Substruts shall be capable of carrying 2.5% of the actual load of the members which they stay in addition to their calculated load, if any.

(vi) Secondary stresses

Wherever the neutral axes of intersecting members do not meet a common point, the resulting secondary stresses shall be provided for.


(vii) Combined stresses

Members subject to both direct axial and bending stresses shall be designed taking into consideration the effects of these combined stresses.

(c) Factors of safety and calculations

All working loads shall be multiplied by the appropriate load factor according to the load combination being considered in accordance with the design code being used.

(d) Slenderness ratios

Slenderness ratios shall be determined as dictated by the design Standard being used.

(i) Limits of slenderness ratios

The slenderness ratio KL/r for outdoor lattice-type supporting structures shall not exceed the following:

(1) For main compression members (main columns and chord angles of lattice girders) – 120.

(2) For secondary compression members (all compression members carrying calculated loads except those specified above) – 180.

(3) For secondary compression members not carrying calculated loads but providing support for other members and redundant members – 220.

(4) For tension members – 300.

For members in buildings:

(5) For compression members it shall not exceed 180

(6) For tension members it shall not exceed 300.

1.1.9 Water Supply, Drainage and Disposal 1.1.9.1 Water Storage Tank (a) General

Water storage incorporating high level and low level storage tanks shall be sized to meet the requirements of the substation water consumption calculated on the basis of the projected occupation specified by ME and using the USA Standard Plumbing Code.

The position, type and method of construction of the tank shall be to the approval of the Engineer. The requirements for inlet, outlet, gauging, venting etc shall be in accordance with the requirements of British Standards.


The routing, excavation, bedding, backfilling etc for the water distribution system from the storage tank shall be in accordance with the requirements shown on the drawings and specified herein.

(b) Protective coatings

The interior tank surface shall be commercially blast cleaned and an approved tar epoxy shall be applied in two coats of different colour and to a minimum dry film thickness of 38 µm each. The type of tar epoxy shall be suitable for drinking water containers and shall be applied strictly in accordance with the manufacturer’s specifications, and to the approval of the Engineer.

The exterior tank surface shall be free from rust, grease, oil etc and an approved epoxy red-lead primer shall be applied to obtain a minimum dry film thickness of 38 µm. Additionally coats of an approved epoxy enamel, blue in colour, shall be applied to a minimum dry film thickness of 51 µm each. Application of the primer and the epoxy enamel shall be ins strict accordance with the manufacturer’s specifications.

All mechanical piping, fittings, equipment etc shall be galvanised as specified elsewhere in these Specifications.

1.1.9.2 Drainage and Sewage Disposal (a) General

The design, laying, bedding, jointing and testing of all drainage pipes and structures shall be in accordance with BS 8301, or other approved Standard agreed to by the Engineer prior to its use. Rocker pipes are to be provided at the edges of road crossings and manholes when there is likely to be differential settlement.

(b) Kerb drainage

All road surface runoff shall be directed into soakaway pits through slots in the kerbs and as detailed on the drawings.

The sides and bottoms of these pits shall be lined with celanese “Mirafi 140 Fabric” or approved equivalent, to prevent the migration of fine material from the pits. After the placing of the filter fabric the pits shall be backfilled with 20 mm crushed stone or gravel to the level of finish grade.

(c) Building drainage

Roof drainage for all Substations shall be disposed of by means of soakaway pits. The locations and sizes of these pits shall be as shown on the drawings or suitably fixed. These pits shall not be located closer than 5 m from the building face.

The sides of these pits shall be lined with celanese “Mirafi 140 Fabric” or approved equivalent and the pits shall be backfilled with 20 mm crushed stone or gravel to the level of finished grade.


The roof drainage shall be collected in a manhole from which a a pipe of suitable diameter shall be laid with a slope in accordance with the design to the soakaway pits. Roof drainage from all other buildings shall be disposed of by means of rainwater down spouts and discharged at grade in a direction away from the buildings.

(d) Sewage disposal

Effluent from the buildings is to be drained into septic tank and disposed of through filter beds or seepage pits all as shown on the drawings.

At all road crossings the pipes shall be bedded on and surrounded with C20 concrete to a minimum thickness of 150 mm, and the concrete surround shall extend for a minimum distance of 1 m beyond the road edges. The class and type of pipe shall be capable of sustaining the maximum design wheel loads that the Contractor proposes to use.

(e) Manholes

Manholes shall be constructed with brick walls 230 mm thick on a C20 concrete base 150 mm thick.

The bottoms of the manholes shall be benched up to fall with C20 concrete and the remaining internal brick surfaces and the tops of the brick walls rendered with cement mortar to a minimum thickness of 10 mm,then trowelled smooth.

The internal dimensions of each manhole shall be 1 m square where more than two pipes enter and leave the manhole. All other manholes shall be 600 mm square, with depth to suit and to the approval of the Engineer. In addition they shall be equipped with 75 mm thick reinforced concrete covers with lifting holes.

(f) Concrete culvert

If necessary a reinforced concrete pipe culvert or box-culvert of suitable size shall be provided under the new access roads and adjacent to the existing main road, to provide continuity of drainage. The invert and slope of the culvert shall suit the existing grade and slope of the drainage ditch or stream. The reinforced concrete pipe shall be of sulphate resisting Portland Cement and shall comply with the requirements of BS 4027. The class of pipe and bedding shall be in accordance with the maximum loads the Contractor proposes to transport. If more culverts are needed these shall also be provided.

1.1.10 Gates and Fencing 1.1.10.1 General Each of the new Substations and the transmission yard storage areas within the Substations shall be surrounded with a galvanised chain link boundary fence fixed to concrete posts and with gates providing access.

The complete construction shall meet the requirements of BS 1722, Part 10 and shall be in accordance with the drawings.


1.1.10.2 Chain Link Fencing The chain link fencing shall be 1.8 m high woven from 9-1/2 SWG wire, 50 mm nominal mesh and galvanised, all in accordance with the requirements of BS 1722, Part 10. Three rows of 9-1/2 SWG galvanised tension wire and three tows of 2 ply, 12-1/2 SWG, galvanised barded wire with four-point barbs spaced at 75 mm centres shall be provided.

The tensions wires and the barbed wires shall be strained between straining posts and shall be secured to intermediate posts with 12-1/2 SWG galvanised wire stirrups. The galvanised chain link fencing shall be secured to the tension wires with galvanised 14-1/2 SWG tying wire at 300 mm centres.

Fittings for fences shall be galvanised and meet the requirements of BS 1722, Part 10.

Additional security barbed wire in lose rolls 1.8 m high x 2 m wide shall be provided around the Substation perimeter along theoutside face of the fence. Those wires shall be fixed properly to the fence as well as to the ground, or any other method noted in the drawings.

1.1.10.3 Concrete Posts and Struts Intermediate and straining posts and struts shall be manufactured from reinforced concrete C30 and shall comply to BS 1722, Part 10. Gate posts shall be of similar reinforced concrete construction. Bolting of all posts and struts shall be set in C20 concrete as shown on the drawings.

1.1.10.4 Concrete Sill for Chain Link Fence As indicated on the drawings a continuous plain C20 concrete, cill 150mm wide by 400 mm high shall be cast between the posts with the top of the cill 100 mm above finished grade level, and into which hairpin staples securing the fence shall be set.

1.1.10.5 Gates Each Substation shall be provided with two double gates 5 m wide and two single personnel gates 1 m wide as indicated on the drawings.

The gates shall be constructed with mild steel tubes complying with the requirements of BS 1387 and shall be welded.

Hinges, lock plates, padlocks and mild steel cane bolts and infilling shall be provided as indicated on the drawings and shall comply with BS 1722, Part 10.

The gate frames and appurtenances shall be galvanised after manufacture in accordance with the requirements of BS EN 12502-3.

1.2 Architectural

1.2.1 General The work described herein shall form a basis for the preparation of detailed drawings and specification to be prepared by the Contractor and submitted to the Engineer in accordance with the specifications.


1.2.2 Scope of Work (a) The work to be performed by the Contractor shall include the design, supply and installation of

the various building trades applicable to the Substation building structures as specified herein and as indicated on the drawings.

(b) General details are indicated in the drawings for specific parts of the structures. These details shall also typify the requirements for all other similar conditions.

1.2.3 Materials (a) Materials shall be obtained from manufacturers approved by the Engineer, and shall be new,

free from defects impairing strength durability or appearance, and shall be of the best quality available for the purposes specified.

(b) The Contractor shall submit samples of all materials to the Engineer for approval. Any material rejected by the Engineer shall not be delivered to the site. Any material rejected at site by the Engineer shall immediately be removed from the site.

(c) All materials shall be delivered to the Site undamaged, and stored at the site in such a manner that damage from construction plant or weather will not occur. Materials subject to damage by weather shall be stored in sheds or provided with other suitable protective covering to prevent damage or deterioration to the materials.

1.2.4 Signage All necessary signs are to be provided at all Substations, including but not limited to the following:-

Substation name, traffic, road, room titles, emergency exits, building services and HVAC equipment, safety signs, etc all in accordance with British Standards.

1.2.5 Masonry (a) Bricks shall be the best quality available from local manufacturers. Over-burnt bricks may be

used in masonry work below grade or in partition walls which are to receive a plastered finish. The size of brick units shall be 240 mm by 120 mm by 80 mm, or near sizes.

(b) Masonry mortar shall consist of one part Portland cement to three parts of sand by volume. Mortar shall be mixed in batches.

Any mortar not used within one hour of the addition of cement shall be discarded.

(c) Brick units shall be wetted before building into the work to prevent absorption of moisture from the mortar. Adequate measures shall be take to prevent efflorescence occurring in the finished work.

(d) Masonry shall be carried up in a uniform manner, no one portion of the work being carried up more than 750 mm above another at one time. Completed bed joints shall be maintained in a


wet condition during construction before mortar is placed for succeeding courses. The tops of walls on which work has been interrupted shall be moistened before work is resumed.

(e) All masonry corners and intersections shall be properly bonded together using the best trade practice. Masonry walls shall be securely anchored to the building structure using galvanised steel ties or equivalent at approximately every four courses in height. Ample provision shall be made for expansion and contraction at junctions of masonry with the structural frame and in long lengths of masonry walls. Details of expansion joints shall be subject to approval by the Engineer.

(h) Mortar joints in masonry which is to be left exposed shall be made concave at the exposed face using a non-staining pointing tool. Mortar joints in masonry which is to receive plaster or cement rendering shall be raked, after curing, to a depth of 6 mm to provide a key.

(j) A bituminous felt or equivalent approved damp proof course shall be installed in masonry walls for their full thickness at grade floor levels, copings, window and door heads as indicated on the drawings. A further damp proof course consisting of a 100 mmthick continuous concrete course, with Sika densifying additive as specified elsewhere, shall be placed at grade floor levels as indicated on the drawings.

1.2.6 Cement Rendering (a) Cement rendering shall be applied to exterior masonry, exterior concrete surfaces, eaves and

balcony soffits, wall bases above concrete floors and over tiled areas of Sanitary Rooms as indicated on the drawings.

(b) Cement rendering shall be applied in three coats producing a minimum total thickness of 20 mm having a course, granular finish texture except where required on interior work which shall be trowelled to a smooth, dense finish. Cementitious materials shall comply with current British Standards and shall consist of:

Normal Portland Cement

White Portland Cement (finishing coat)

Hydrated lime

Aggregates shall consist of clean, fine granular material composed of natural sand free from any impurities, and shall be well graded from course to fine consistent with good workability. Water shall be drinkable.

(c) Suspended soffits shall be securely attached to the building structure using corrosion resistant metal components. Metal lath shall be expanded sheet steel as locally supplied. The metal lath shall be supported from the suspension system at 600 mm maximum spacing between supports.

(d) All rendering coats shall consist of one part Portland cement to three parts damp, loose aggregate and ¼ part (maximum) hydrated lime. All ingredients shall be thoroughly dry-mixed.


Water shall be added until mix is in a uniformly plastic condition for good plastering consistency. When necessary, plasticity shall be restored by reworking mix without further addition of water.

(e) Before each application, the base material shall be evenly dampened to control suction. The “first” coat shall be applied with sufficient pressure to form a good bond and shall be uniformly scratched. The “second” coast shall be applied a minimum of 24 hours after the “first” coast and shall be floated to a true surface and left rough. The finish coat shall be applied a minimum of 24 hours after the “second” coat. The Contractor shall submit samples of the finish coat texture and colour for approval by the Engineer. Each intermediate coat shall be kept moist for a 48-hour period following application. The final coat shall be moisture cured for a 7-day period.

(f) The Contractor shall make all necessary provision for expansion joints in the cement rendering. Cracked or crazed areas shall be removed and replaced at no additional cost to the Owner. Decorative sinkage joints shall be formed in the finish coat where indicated on the drawings.

1.2.7 Roofing (a) Bituminous roofing materials shall be of the best quality obtainable from local suppliers.

(b) Concrete structural roof decks shall be cleaned of all loose and deleterious materials before application of roofing is commenced.

(c) The roof waterproofing and insulation shall incorporate an inverted roof system complying with the recommendations of BS 8217:2005.

(d) Insulating material having a water absorption in excess of 1.5% by volume in seven (7) days at 20 ºC shall not to be used.

(e) The insulation is to be covered by a layer of permeable filter membrane, laid loose and lapped 200 mm at all intersections before the paving slabs or solar reflective chipping is laid.

(f) Paving slab protection is to be loose laid with 6 mm open joints on 100 x 100 x 6 mm inorganic spacers positioned at the corner junctions of the slabs. The paving slabs will have a minimum thickness of 40 mm on insulation boards of up to 50 mm and for every 10 mm increase in the insulation thickness the slab thickness should be increased by 5 mm.

(g) The Contractor shall submit full details of the roofing system to the Engineer for approval. Details shall include all methods of drainage outlets, projections through the roofs for mechanical services, metal flashings at expansion joints, etc.

(h) For the Control, Switchgear and Relay buildings, the completed roofing system including the structural concrete deck shall have a coefficient of thermal transmission (“U) value) of not greater than 0.57 watts per sq m per degree k, (0.57 W/m2K).


1.2.8 Precast Concrete (a) The contractor shall perform all work necessary for the design, manufacture and installation of

precast concrete units which shall include roof paving slabs, parapet coping, window and door sills and window canopies. Special mitred sections shall be provided where required. The design and manufacture of precast concrete units shall conform to BS 8110.

(b) Precast concrete units shall be cast in precision-made forms the profiles of which shall be in accordance with details approved by the Engineer. The door and window cills and canopy units shall be reinforced with steel mesh or bar type reinforcing to safely withstand all stresses due to dead loads, live loads, temperature changes, lifting, handling and wind. All inserts and anchors, including those required for lifting, shall be attached to the reinforcing wherever possible.

(c) Prior to manufacture, the Contractor shall submit samples of aggregates to the Engineer for approval. All concrete used in the manufacture of precast concrete units shall have a mix of C30 concrete. Concrete shall be machine mixed using a minimum of water. Measuring of ingredients and mixing shall be carried out with precision to ascertain the correct proportion of water necessary to obtain a fine, dense surface free from crazing. Trial mixes shall be made to ensure concrete quality and finish.

(d) Precast concrete roof paving slabs 800 mm by 800 mm by 50 mm thick shall be machine pressed by an approved local manufacturer. The slabs shall have smooth, flat surfaces free from projections and depressions. All rises shall be sharp and true. Special precast skirting sections shall be manufactured for installation at the base of parapet walls. The skirtings shall have rounded top edges and shall be coved at the junction with horizontal slabs.

(e) All precast concrete components shall be moisture-cured under cover for a period not less than 7 days.

1.2.9 Aluminium Windows (a) All windows shall be of anodised aluminium in accordance, with the relevant B.S. They shall be

provided with all necessary anchors at the perimeter of the frames for building-in. Jamb anchors shall be adjustable for locating in masonry coursing.

(b) Opening lights for windows shall be either side hung or bottom projected as indicated on the drawings. All opening lights shall be inward opening and shall be completely dust-proofed by neoprene, vinyl or other approved gaskets fitted to the contact surfaces. The method of dust-proofing shall be subject to approval and inspection by the Engineer. Opening sashes which are deemed not to be dust-proof by the Engineer will be rejected.

(c) Fasteners, stays and hinges shall be of a non-ferrous, heavy-duty design as approved by the Engineer. High-level windows shall be remotely controlled from 1m above floor level by a hand-operated, mechanical system approved by the Engineer.

(d) Active leafs shall be fitted to the out side with mosquito-proof bronze in removable metal frames.


(e) Windows shall be fabricated with aluminium frames and glazing bars and have fixed lights. The size and gauge of the sections shall be suitable for the design, loading, sizes and arrangements used. All windows shall be constructed with thermal break frames. All windows shall be fitted with double glazing with solar reflecting glass, 6 mm thick minimum with low heat transfer values.. All windows shall be fitted with security grills with fixing points located in precast concrete surrounds. Windows which can be subject to direct sunlight at any time of the day throughout the year should be provided with external shading. Glazing in Sanitary room windows shall be obscured type.

(f) All windows shall be securely mounted in their openings and shall be plumb and in a flat pane. Each window shall be properly sealed and made perfectly weathertight at the head jamb and cill in a manner approved by the Engineer.

1.2.10 Vehicle Access Doors (a) Roller shutter vehicle access doors shall be provided as indicated on the drawings, and where

considered necessary for the operation of the Substation. The core of each door leaf shall be insulated with a minimum of 50 mm thick rigid insulation of an approved type.

(b) Vehicle door frames shall be fabricated from welded structural steel sections with welded on strap anchors for embedment into concrete or masonry.

(c) The roller shutter doors shall be provided and installed complete with all necessary door furniture, fittings including lockable latches mounted on the interior.

(d) All vehicle doors shall be provided with dust seals on all edges to the approval of the Engineer.

1.2.11 Metal Doors and Frames (a) All exterior doors shall be anodised aluminium, with aluminium frames. The sections thickness

of sheets frames shall be as per relevant B.S. and approved by the Engineer.

All external doors shall be provided with dust seals on all edges to the approval of the Engineer.

1.2.12 Wood Doors and Frames (a) All interior doors shall be teak wood faced with a finished thickness of 40 mm, except doors in

toilet rooms which shall be of aluminium.

(b) Wood doors shall be glazed where indicated on the drawings using 6mm thick welded wire reinforcing having a mesh size of 13mm square.

(c) Wood door frames shall be teak 120 mm wide and shall have planted stops. Architraves shall be bevelled and neatly mitred, and arises shall be slightly rounded.

1.2.13 Door Hardware (a) Door furniture, fixtures and fittings shall be the best commercial quality available and of a

manufacture and type approved by the Engineer. Locksets, latchsets, push and pull plates,


shall be manufactured from wrought brass of bronze having a sation-chrome finish. All lock mechanisms shall be corrosion-resistant.

(b) Hinges shall be non-ferrous, ball-bearing type. Three hinges per door shall be provided in all buildings.

(c) All exterior doors, interior storage room, offices, mechanical room and communications room doors etc. shall be fitted with mortice type cylinder locksets with integral dead bolts and latch bolts. Latch shall be operable by knob on each side of door. Double doors shall be fitted with top and bottom bolts on the inactive leaves. All other interior doors shall be provided with latchsets.

(d) Automatic, hydraulic piston type closers having machined cast-iron casings and malleable iron control arms shall be fitted to the following doors, and doors to similar type areas:

• all exterior doors except Operators Housing

• Control Building interior vestibule doors (both leaves)

• interior doors to Control Rooms (both leaves)

• interior doors to Communications Rooms (active leaf only)

• interior doors to battery, switchgear and relay rooms (active leaves only)

• doors to Sanitary Rooms

(e) Control Room interior and exterior entrance doors and vestibule doors shall be fitted with ornamental push-pull hardware as approved by the Engineer. Doors to Sanitary Rooms shall be provided with push plates and pull handles. Doors to water closets shall have slide bolts, self-closing hinges and coat hooks.

(f) All wooden doors having automatic closers shall be fitted with kickplates 250 mm high and 50 mm less than width of door leaf.

(g) The Contractor shall submit to the Engineer for approval full specifications, manufacturer’s data and an itemized list indicating details of all hardware to be installed on each door.

(h) All emergency exitssuch as exterior doors to the relay rooms, shall be fitted with approved “panic” locks and push-bars.

1.2.14 Gypsum Plaster (a) Masonry and concrete surfaces to receive a plaster finish shall be thoroughly brushed to

remove all dust and loose matter and shall be rough-textured to form a key. The surfaces thus prepared shall receive a spattering coat of 1:1 cement/sand applied before plastering commences. All surfaces shall be dampened with clean water immediately before each coat is applied. Each base coat shall be moisture-cured to ensure proper setting and shall be allowed to dry thoroughly before the finish coat is applied. Plaster work shall include all small and


narrow areas, internal angles, square or pencil rounded external arises, joints at flush or projecting corners rounded to openings, making good around pipes and other projections through walls, roof slabs, etc.

(b) Gypsum plaster shall be best quality local just conforming to B.S.1191 for Class B and C finishing plaster. Gypsum shall be stored in weathertight enclosures until ready for use.

(c) Plaster work shall be 16 mm thick applied in two layers. The first layer shall consist of one part gypsum bond plaster to three parts sand (by volume) applied with sufficient material and pressure to cover well and provide good bond. Before setting, double back with additional material to bring plaster out to grounds, straighten to a true surface and leave rough for finish coat. Gypsum bond plaster shall consist of calcined gypsum with 2% to 5% lime by weight. The second or finish coat shall consist of one part gypsum to three parts lime putty, applied as thinly as possible and finished to a smooth, even, steel-trowelled finish. Under no circumstances shall gypsum plaster be wetted after it has fully set.

1.2.15 Tile Work (a) Mosaic floor tiles shall be a minimum 300 m x 300 m by 9.5 mm as a thickness of mosaic layer,

glazed, with smooth, even surface, uniform in texture and free from blemishes, chips or other imperfections. Skirting sections shall be 250 mm by 125 mm coved at the base and rounded at their top edges. The floor tiles shall have a water absorption rating between 0.5% and 3.0% by weight after oven drying, boiling in distilled water for 2 hours and cooling in water up to 24 hours. The floor tiles shall be of a colour approved by the Engineer.

(b) Glazed wall tiles shall be 150 mm by 150 mm by 6 mm thick, flat and free from flaws. The wall tiles shall be white in colour and shall be complete with all special edge, trim and corner sections. Glazed tiles shall be to the full height of the wall.

(c) Surfaces to receive tile works shall cleaned of all dust and loose matter. Floor surfaces shall be free from oil and other impurities which may prevent the proper bonding of the tile mortar bed.

(d) Floors to receive tiles shall be wetted down. A slurry bonding coat consisting of Portland cement and water mixed to a creamy consistency shall be brushed onto the floor surface. The mortar setting bed consisting of one part Portland cement, one-half part hydrated lime, four parts sand, and one part water (by volume) shall be placed to a thickness of 30 mm, uniformly trowelled and slightly sloped towards floor drains. The floor tiles shall receive a 3 mm setting coat of one part Portland cement to one part water (by volume) and shall be firmly and accurately set into place. Tile joints shall be straight, uniform and true in both directions. Twenty-four hours later, the tile shall be wetted, and the joints grouted, using a mixture of one part white “Medusa” grouting cement or approved equivalent to two parts sand mixed with clean water. Foot traffic shall not be permitted for minimum of 48 hours.

(e) Walls to receive tiles shall be dampened and shall receive a 6 mm scratch coat consisting of one part Portland cement, half part hydrated lime, four parts sand and one part water (by volume), trowelled rough and scored. The scratch coat shall be allowed to cure at least 24 hours, before applying a 9 mm thick mortar bed using same mix as scratch coat. Soak tiles in water for at least 30 minutes, and drain off excess water prior to installation. Apply a 3 mm


setting coat of one part Portland cement to one part water (by volume) and tap firmly into position. Tile joints shall be straight uniform and true in both directions, accurately cut and fitted at all intersections and projections. Twenty-four hours later, the tile shall be wetted and the joints grouted using a mixture of one part white “Medusa” grouting cement or approved equivalent to two parts sand mixed with clean water.

(f) All floor and wall tile shall be thoroughly cleaned following installation. Protective coverings shall be used as directed by the Engineer.

1.2.16 Vinyl Asbestos Floor Tiles (a) Vinyl asbestos floor tile shall be nominally 30 mm by 30 mm by 3 mm thick supplied and

installed complete with 100 mm high coved vinyl base. Tile pattern and colour shall be as selected by the Engineer.

(b) Concrete floors to receive vinyl asbestos tile shall be thoroughly cleaned and all cracks and depressions filled with grouting mortar. Floors shall be primed and coated with adhesive compound of a type recommended by the tile manufacturer and approved by the Engineer.

(c) Vinyl asbestos tile shall be laid with joints in moderate contact. Tiles shall be laid symmetrically with and parallel to the axis of the room. Perimeter tiles shall be one-half tile minimum width.

(d) The tiles shall be accurately scribed against walls, columns, corners and any projections through the floor. Tiles shall fit tightly against breaks, fixtures, door jambs and all other vertical surfaces.

(e) The base shall be firmly cemented to the walls with tight, vertical joint. Corners shall be neatly mitred.

(f) Following installation, vinyl asbestos tile shall be thoroughly cleaned and three coats of an approved type floor polish shall be applied, buffed to a glossy finish. Complete floors shall be protected as directed by the Engineer.

1.2.17 Acoustic Ceilings (a) Acoustic ceilings shall consist of a suspended metal grid system and mineral fibre tiles. The

metal grid shall be complete with all wall angles, galvanized suspension rod and wire, and cold-rolled carrying channels. Ceiling tiles shall have a fissured surface pattern and shall be white in colour. Tile thickness shall be 16 mm. The Contractor shall submit all pertinent manufacturers data including the method of connection to structural slabs, to the Engineer for approval.

(b) The design and installation of the suspended ceiling shall be closely co-ordinated with mechanical and electrical requirements. Lighting fixtures ducts, diffusers and grilles shall all be installed as the work on the suspension system proceeds. The installation shall adequately support all lighting fixtures and mechanical air distribution.

(c) Suspended ceilings shall be installed square and level in strict accordance with the manufacturer’s printed instructions.


1.2.18 Carpentry (a) Carpentry work shall include all necessary wood grounds and blocking, counters, plastic

laminate counter tops, cupboards, benches, partition framing and shelving.

(b) All materials shall be of the best merchantable species suitable for the intended use. Moisture content shall not exceed 12% for softwood and 8% for hardwood. Plywood shall be best quality hardwood-faced veneer, paint grade, sanded. Hardboard shall have a minimum density of 800 kg per cu m. and shall have one face suitable for sanding and painting.

(c) Kitchen counters in Control Buildings, Maintenance Buildings and staff houses Shall be constructed of plywood with divisions of approximately 400 mm wide. Each division shall contain a cupboard with recessed shelf and drawer beneath counter level. All exposed plywood edges shall be provided with a 100 mm high recessed base. Counter tops shall be covered with laminated plastic secured to plywood with contact cement. Colour of laminated plastic shall be as selected by the Engineer. Cabinet hardware shall be of the best quality to the approval of the Engineer.

(d) Work benches shall be strongly constructed from wood members of 40 mm minimum thickness with open shelving and tool drawers 400 mm wide fitted below bench tops. Bench tops shall be constructed of heavy tongued and grooved boards. Bench tops in Battery Rooms shall be covered in sheet lead.

(e) Guardhouse benches shall be constructed of hardwood planks with chamfered edges fixed to metal brackets attached to adjacent walls.

(f) Shelving where indicated, shall be plywood with hard-wood edging.

1.2.19 Miscellaneous Metal (a) Ornamental handrailing for G.I.S. Building entrance Control Building or maintenance building

stairs or elsewhere shall be fabricated from plain anodised aluminium bar sections, arranged suitably. The handrailing shall be securely fastened to the concrete steps and shall be provided with escutcheon plates. The handrail cap shall be of solid vinyl. A removable section of handrailing shall be provided at loading plate form. Aluminium in contact with concrete shall be insulated by approved means.

(b) Tubular handrailing for G.I.S. Building stairs and control building from rear side or elsewhere shall be fabricated from 40 mm nominal diameter steel pipe securely anchored to concrete steps. The associated steel ladder at the upper landing of staircase, shall consist of flat bar stringers with 20 mm diameter rungs spaced at 300 mm centres. Ladder rungs shall be tennoned to stringers and plug-welded. The floor hatch above the ladder shall have a steel angle frame embedded in the concrete floor with a 33 mm nominal thickness chequer plate cover provided with securing handle, heavy-duty hinges and spring-loaded opening device of a type approved by the Engineer.

(c) Metal framing above Control Room windows shall be fabricated from aluminium angle and channel sections, rigidly constructed and securely braced, and suspended from the concrete


roof deck. Exposed joints in the channel head sections shall be seal-welded and ground smooth. Corner joints in the Channel head shall be mitred.

(d) The Contractor shall provided and install all miscellaneous steel lintels, frames, embedded steel parts, anchors and bolts, not specifically described herein, but which are essential to the proper completion of the work.

(e) Actual member sizes shall be suited to their intended functions and shall be subject to the approval of the Engineer. All steel components if any shall be thoroughly cleaned of all rust, oil and other deleterious matter before fabrication, and shall receive one coat of rust inhibiting primer before shipment to site.

1.2.20 Bronze Plaque (a) The Contractor shall provide and install a cast bronze plaque, wall-mounted adjacent to the

main entrance of each Substation main building. The plaque shall consist of the Owner’s graphic symbol and lettering all in accordance with design to be provided by the Engineer. All fastenings shall be concealed and tamper proof. Size of plaque shall be approximately 500 mm by 700 mm.

(b) Eight cornered star emblems shall be suitably and conspicuously displayed at the entrances of all buildings except staff houses.

1.2.21 Painting (a) Paint materials shall be of the best quality available and shall be obtained from a single

manufacturer approved by the Engineer. All materials shall be delivered to the site in unbroken, sealed and labelled containers of the paint manufacturer. They shall be stored in a separate buildings or rooms well ventilated and free from excessive heat, sparks, flame or direct sunlight.

(b) All containers of paints shall remain unopened until required for use; containers which have been opened shall be used first. Paint which has deteriorated during storage shall not be used.

(c) Paints shall be thoroughly stirred, strained and kept to a uniform consistency during the application. Mixing of pigments to be added shall be done strictly as recommended by the manufacturer. Where thinning is required, only the products of the manufacturer furnishing the paint and recommended for the particular purpose shall be allowed, according to the manufacturer’s instructions.

(d) All surfaces to be painted shall be thoroughly cleaned, by effective means, of all foreign substances. Cleaning shall be done with approved solvents, or wire brushing. Hardware, electrical fixtures and similar accessories shall be removed or suitably masked during preparation and painting operations.

(e) Metal surfaces shall be cleaned and free from flaking, bubbling, rust, loose scale and welding splatter. Sharp edges shall be dulled by grinding. Oil and grease shall be thoroughly removed by Varsol or similar approved. Priming shall be done immediately after cleaning to prevent new


rusting. Damaged prime coats of items delivered to site shop primed shall be repaired using same type primers. Edges shall be “feathered” to make patching inconspicuous. The Contractor shall apply one full coat of primer to all items to be finish painted which have not been previously shop primed.

(f) Wood surfaces shall be sanded to a smooth surface. No wood shall be painted unless it is sufficiently dry. All sapwood, streaks and knots shall be sealed with knotting to B.S. 1336.

Excess resin shall be removed with a blowtorch, scraper or solvent. The prime coat shall then be applied and, when dry, nail and knot holes shall be filled with putty, allowed to dry and sandpapered.

(g) Plaster surfaces shall be brushed to remove dust and efflorescence. Any holes or cracks shall be cut with edges undercut, made good and rubbed down.

(h) Concrete and masonry surfaces shall be left at least one month before painting. They shall be etched using a 15% to 20% muriatic acid solution completely removing all foreign matter and efflorescence, then thoroughly rinsed with water and allowed to dry. Concrete and masonry surfaces to be painted shall include precast concrete window canopies, parapet coping, window cills and decorative grillage blocks.

(j) Paint shall not be applied in rain, or when the relative humidity exceeds 85%. Paint shall not be applied to wet or damp surfaces. When paint must be applied during inclement weather, the surfaces shall be protected under cover. Such surfaces shall remain under cover until weather conditions permit exposure.

(k) The work shall be done strictly in accordance with the paint manufacturer’s printed instructions and recommendations. The Contractor shall apply paint coatings producing an even film of uniform thickness using brush, roller or spray gun. If paint has thickened, or must be diluted for application by spray gun, the coating shall be built up to the same film thickness achieved with undiluted material. The coverage of paint shall remain the same whatever method of application is used. Each coat of paint shall be in a different tint to the succeeding one. All surfaces shall be sanded lightly between coats and be dusted before the succeeding coat is applied.

(m) Each coat of paint shall be in a proper state of cure before the application of the succeeding coat. Paint will be considered dry when an addition coat can be applied without the development of any detrimental film irregularities such as lifting or loss of adhesion of the undercoat. The manufacturer’s recommended drying time shall be regarded as the minimum permissible time and shall in no way relieve the Contractor of his obligation to produce a satisfactory succeeding coat.


(n) Paint shall be applied either with brushed, or by means of rollers or spraying machines to obtain a uniform even coating.

(i) By Brush

The primary movement of the brush shall describe a series of small circles to thoroughly fill all irregularities in the surface, after which the coating shall be smoother and thinned by a series of parallel stroke.

(ii) By Roller

This application shall be done by rolling the second coat at right angles to the first coat.

(iii) By Sprayer

Spray equipment shall be of ample capacity for the work and shall at all times be kept clean and in good working order. Spray guns shall be suited to the type of paint specified and shall be operated with orifices, nozzles and air pressure adjusted to consistency.

Paint pots shall be of ample capacity and shall be equipped with means of controlling air pressure on the pot independently of the pressure of the gun.

Air lines shall be equipped with water traps to positively remove condensed moisture.

(p) If satisfactory work with one of the application methods is not expected or not obtained, the Engineer will decide which method shall be used. Where surfaces are inaccessible for brushes, and where spraying is not being employed, the paint shall be applied with sheepskin daubers specially constructed for the purpose. To the maximum extent practicable, each coat of paint shall be applied as a continuous film of uniform thickness, free of pores. Any thin spots or areas missed in the application shall be repainted and permitted to dry before the next coat of paint is applied. Doors to be weatherstripped shall be fully painted before weatherstripping is installed.

(q) Shop painting shall be carried out to the extent and as required elsewhere in these specifications. The Contractor shall be responsible for checking the compatibility of the previous coating with the finish coats specified herein.

(r) The finished surfaces shall be free from runs, drops, sags and brush marks, exhibiting good coverage, spreading and levelling.

(s) Colours shall be as shown in a painting colour schedule to be approved by the Engineer. The Contractor shall submit before start of work, actual paint colour samples to the Engineer for approval.

(t) The Contractor shall conduct a thorough inspection of all surfaces finished by himself before work is considered complete. This is to be done to ensure that all surfaces are properly and


satisfactorily retouched wherever damaged by his tradesmen, prior to the removal of his equipment and materials.

Surfaces to be painted shall received the following coating systems:

(i) For interior exposed galvanised steel ductwork and piping:

1 coat vinyl pre-treatment

2 coats alkyd interior enamel, semi-gloss finish

(ii) For interior primed structural steel framing, metal doors and frames:

2 coats alkyd interior enamel, semi-gloss finish

(iii) For exterior primed steel windows, doors and interior and exterior primed miscellaneous steel stairs, ladders and railings:

2 coats alkyd equipment enamel , gloss finish

(iv) For interior wood surfaces

2 coats latex, flat finish

(v) For interior wood surfaces

1 coat interior primer

2 coats alkyd enamel, semi-gloss finish

(vi) For interior and exterior wood doors:

2 coats penetrating oil and resin finish

(vii) For unprimed steel piping:

1 coat iron oxide zinc chromate

2 coats alkyd equipment enamel, gloss finish

(viii) For concrete and masonry surfaces:

2 coats polyvinyl acetate latex, flat finish

1.2.22 Furnishings (a) The Contractor shall supply and install interior furnishing items as specified herein. Furnishings

shall be of good commercial quality, suited to their intended purposes and as approved by the Engineer. Colours of plastic laminate, baked enamel and woven fabric finished shall be as selected by the Engineer.


(b) All furnishing items shall be supplied adequately crated to prevent damage during shipment and storage. Furnishings shall be stored in a dry weatherproof area and shall remain crated until time of installation as required by the Engineer.

(c) Steel lockers shall be nominally 300 mm by 400 mm by 1800 mm high in size, fabricated from rigidized sheet steel having two coats of baked enamel finish. Lockers shall have recessed bases. Doors shall be flush-panelled, each side fitted with rubber bumpers for silent operation and equipped with padlock latch. Locker interiors shall have one high shelf and three clothes hooks. Number required – six per Control Building Locker Room.

(d) Swivel chairs shall have chromium-plated square-tube framing and a five spoke stable base. The base shall be complete with hooded, rubber casters. Torsion bar mechanism shall provide quiet tilting action and the bar spindle shall be capable of height adjustment. The chair seat and arm rests shall be fully upholstered with cushion foam cover with woven fabric. Chair seats shall be 480 mm wide at the front and 460 mm deep. Number required – two per Control Room Operator desk, and two per office in the Control Building and maintenance building.

(e) File cabinets shall be four-drawer type of flush reinforced steel construction with baked enamel finish. Nominal size shall be 380 mm by 660 mm by 1300 mm high. Drawers shall be siding type on telescopic track with ball-bearing rollers. Drawer fronts shall have sidelocking thumb latches and label holders. Number required: one for each office in the Control Building and Maintenance Building..

(f) Lunch room table shall be 1800 mm by 800 mm in size with plastic laminate on ply wood top and tubular stainless steel frame with nylon feet. Table to be provided with chairs. Number required: one table and 6 (six) chairs for both Control Building and Maintenance Building.

(g) Side chairs shall have stainless steel rolled tube legs one per construction each side joined by welded cross members. Chairs shall be without arms and have foam cushion upholstered seat and back covered in woven fabric. Number required: Two per office in Control Building and Maintenance Building..

(h) Office desk shall be nominally 1500 mm by 750 mm in size with sliding drawers neatly finished with stainless steel frame and top laminated with scratch resistant cover. Number required. One for each office in Control Buildings and Maintenance Building.

(j) If any other building is included in the contract, Contractor shall furnish rooms of those buildings suitable to the functions of the rooms as detailed above.


2. BUILDING SERVICES

2.1 General

This section should be read in conjunction with other relevant sections of this Specification.

The following building services are covered by this section:

• Plumbing services,

• Internal lighting,

• External lighting,

• Small power installations,

• Earthing and bonding connections,

• Fire alarm system, and Fire fighting system,

• Telephone installation

Detailed calculations and layouts shall be submitted on time for approval before any order placement or site work is undertaken. For Tender purposes the Contractor must identify the capacity, manufacture/make, model Number, construction standard and type of any equipment or subcomponent being offered together with the selection procedure.

Any exclusions to the complete and satisfactory performance of the design and installation must be clearly indicated in the offer, otherwise it will be assumed that everything necessary has been included at the Contractor’s cost.

2.2 Scope of Works

The supply and services to be performed by the Contractor shall comprise the design, manufacture, shop testing, packing, transport, insurance, unloading, storage on Site, construction works and erection, corrosion protection, site testing, submission of documentation, commissioning, training of M.O.E’s personnel and warranty of the works.

The Contractor is bound to provide complete works, even if the equipment or services to be provided are not specifically mentioned in the specification.

2.3 Design Standards for Building Services

The design of the electrical building services shall be in accordance with BS 7671 Requirements for Electrical Installation (the sixteenth edition) of the Institution of Electrical Engineer’s Wiring Regulations including latest amendments. Individual items of equipment shall be in accordance with the latest issue relevant IEC or British Standard.

The design of fire alarm and detection systems shall comply with the requirements of BS 5839


The design of the mechanical building services elements shall be in accordance with the following:

(a) The Contractor shall include for the Building Services design and calculations, to be carried out by a consultant approved by the Engineer.

(b) Chartered Institution of Building Services Engineers (CIBSE) Guides to Good Practice, Inter-related Documents and TM4.

(c) American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc, Reference Handbooks. (ASHRAE) USA

(d) Latest issue of relevant IEC or British Standards.

(e) Building Services Research and Information Association Technical Notes.

(f) UK Heating and Ventilation Contractors Association (1982) Specifications for sheet metal ductwork DW/143/144 (HVAC) UK

2.4 Electrical Power Supplies

The electrical power supply available will be 220/380 ± 10% V, 3 phase 4 wire with earthed neutral, 50 Hz. All equipment shall be suitable for use with this electric supply system unless otherwise specified.

The main and local distribution boards shall be located in the relay room of the Substation, from which final sub-circuits shall supply the lighting circuits and all other current consuming accessories, socket outlets, etc.

LV combined power/control board for Air Conditioning and Ventilation shall have duplicate supplies to ensure that at least one of the duplicate plants is available on loss of one source of supply.

2.5 Lighting and Small Power

2.5.1 General 2.5.1.1 Description This Specification covers the rating, design, equipment requirements, installation, inspection and testing of complete Lighting and Small Power.

This Specification does not enumerate nor describe all the materials and equipment to be supplied nor all the services to be performed. All materials and equipment shall be provided as are required to make a complete, properly functioning installation and shall conform to the highest standards of engineering design and workmanship.

The design and installation of lighting and small power shall be based on the following Regulations/Standards:

• Requirements for Electrical Installations, IEE wiring regulations BS 7671 as issued by the Institution of Electrical Engineers, London and British Standards, U.K.


• The Code for Lighting, Lighting Guides, as issued by the Chartered Institution of Building Services Engineers (CIBSE) London, U.K.

• BS 5266 – Emergency Lighting code of practice for the emergency lighting of premises.

• IEC Standards as applicable.

• Local laws, rules and regulations including those of Statutory Authorities.

• Other Standards as detailed in the Specification text.

Materials, workmanship and tests shall conform at least to the following Standards and Codes of Practice:

• IEC 60364-5-54 Earthing arrangements and protective conductors for indoor installations up to 1000 V a.c. and 1500 V d.c.

• IEC 60064 Specification for tungsten filament lamps for general service (BS 161) (batch testing).

• BS 546 Two-pole and earthing-pin plugs, socket outlets and socket adapters for circuits up to 250 V.

• BS 1363 13 A plugs, socket outlets, adapters and connection units switched and un-switched 13A socket outlets and boxes

• BS 5649 Steel columns for street lighting

• IEC 60598 Luminaires

• IEC 60081 Tubular fluorescent lamps for general lighting service

• IEC 60921 Specification for ballast for tubular fluorescent lamps

• IEC 60309 Plug and socket outlets

• IEC 60188 High-pressure mercury vapour lamps

• IEC 62035 Discharge lamps (excluding Fluorescent Lamps)

• IEC 60898 Specification for circuit breakers for overcurrent protection for household and similar installations.

• IEC 61024 Protection of structures against lightning.

• IEC 60923 Specification for performance requirements for ballasts for discharge lamps (excluding tubular fluorescent lamps)

• IEC 61347 (Various parts) Lamp Control gear


• IEC 60947 Low-voltage switchgear and control gear

• IEC 60227 PVC - insulated cables of rated Voltage up to and including 450/750

• BS 6004 Electric cables. PVC insulated, non-armoured cables for voltages up to and including 450/750 V, for electric power, lighting and internal wiring

• BS 6500 Electric cables. Flexible cords rated up to 300/500 V, for use with appliances and equipment intended for domestic, office and similar environments.

• BS 6724 Specification for 600/1000 V and 1900/3300 V armoured cables having thermosetting insulation and low emission of smoke and corrosive gases when affected by fire.

• BS 6121 Mechanical cable glands for elastomer and plastics insulated cables

The Contractor is required to make himself aware of all relevant standards and regulations that are applicable to the work under this Contract.

The detailed design shall be approved before proceeding with any purchase of equipment of any installation work. The Contractor shall submit adequate and full supporting documentation (calculations, schematics, schedules, general arrangement drawings, technical and descriptive manufacturer's data, his own text and/or samples, etc.), for the Engineer to ascertain that the requirements of the Specification are being fully complied with. The Calculations shall identify all assumptions made which must be agreed with the Engineer before all the detail design is finalised.

Location of the lighting and small power equipment shall be reviewed at site before installation so that satisfactory co-ordination with pipework, ductwork, power cables and other plant and equipment can be assured.

Each luminaire/socket outlet or any other item of equipment shall have a unique code that shall comprise letters and figures so compiled that the following information can be readily identified:

• The lighting distribution board to which the luminaire or socket outlet is connected.

• Connection to the normal supplies or to the emergency supplies.

• The circuit number and phase of distribution board to which the equipment is connected.

• The sequence of the equipment in a particular circuit.

The lighting and small power system are broadly divided into the following categories:

• Indoor, normal lighting system.

• Outdoor, normal lighting system.

• Indoor, emergency lighting system.


• Small power socket outlet system.

• Access road lighting.

• Guard House supplies including associated lighting and small power installations.

All lighting systems are to be fed by final sub-circuits from distribution boards located in the relay room of the substation.

There shall be separate distribution boards for both the normal lighting and emergency lighting, and also the small power loads to include the socket outlets.

The types of luminaires to be installed in different areas of the substation will vary from normal indoor fluorescent types to external and internal, specially sealed, luminaires selected to suit the specific location and environment.

All lighting circuits shall operate on a 220 V - 50 Hz supply from miniature circuit breakers within their respective distribution boards.

Each outgoing circuit shall supply a varying number of luminaires and the lighting in an individual room shall be controlled by local room light switches within the individual room.

External lighting shall be controlled automatically by photocells that will operate and switch a number of relays or contactors for these final sub-circuits.

All emergency lighting circuits are to be supplied from the designated emergency lighting distribution board.

110 V DC supplies shall be used for emergency lighting.

There are to be no local facilities to control the emergency lighting circuits. If required control can be achieved at the emergency lighting distribution board.

Illuminated exit and escape signs are also to be part of the emergency lighting system, these shall be provided to cover all areas of the substation buildings.

2.5.2 Main Technical Data The lighting and small power distribution boards shall be rated for 220/380 V, 50 Hz. Supplies shall be taken from the LV AC Distribution switchboard to the installation for normal supplies, and from the 110 V DC switchboard for emergency supplies.

Local distribution boards shall be provided for each of the systems as follows:

• One board to feed all normal internal lighting.

• One board to feed small power installations.

• One board to feed external lighting.


Separate boards shall be provided in each Building. Each of the local distribution boards shall be equipped at least with:

• Four-pole incoming differential circuit breaker.

• Four-pole outgoing differential circuit breakers (for socket outlets).

• Two-pole outgoing differential circuit breakers (for socket outlets).

• Three-pole outgoing circuit breakers.

• One-pole outgoing circuit breakers.

• Three-phase Busbar system.

• Neutral Bar.

• Earthing Bar.

• Push button and contactors as necessary.

• Other equipment and material as necessary.

Each board shall be equipped with 20% spare feeders.

The local distribution boards may be proposed as the integral parts of the main distribution board with separate compartments, subject to the Engineer’s approval.

The distribution board for emergency lighting shall be equipped at least with:

• Two-pole incoming circuit breaker.

• Two-pole outgoing circuit breaker.

• Earthing Bar.

• Other equipment and material as necessary.

Each board shall be equipped with 20% spare feeders.

2.5.3 Scope of Supply and Services The lighting and small power system including but not limited to:

• Distribution boards.

• Cables.

• Cable trunking, containment systems

• Socket outlets and plugs.


• Luminaires.

• Lighting switches.

• External lighting control systems

• Earthing and bonding

• Lightning Protection of all buildings.

• Labelling and identification of all the installation.

• Special tools and equipment for maintenance, inspection and repair.

• All standard equipment and accessories which are normally included in the supply schedule but which are not separately listed.

• Spare parts

• Complete documentation as specified, etc.

2.5.4 Equipment Requirements 2.5.4.1 General All fixings shall be of a type approved by the Engineer. All supporting metalwork used in surface installations shall be galvanized. Fixing to structural steelworks shall be with purpose-made brackets or clamps. Drilling of structural steelworks will not be permitted.

Switches and pushbuttons for lighting circuits shall be mounted 1300 mm above finished floor level. Socket outlets shall be mounted 300 mm above finished floor level. Any socket outlets required that are associated with work benches shall be mounted 150 mm clear of the bench working surface. All lighting switches shall have a minimum continuous rating of 13 A and a 50% derating factor shall be applied for fluorescent lighting loads.

Luminaires shall be secured to ceilings, walls, trunking systems, roof steelwork or suspended as required by the approved design.

Final connections to all suspended luminaires shall be by heat resistant flexible cable terminated in heat resisting connectors in the ceiling or junction box which shall also terminate the final sub-circuit cable. The cable length shall be such that the suspension unit supports take the full weight of the luminaires.

Where luminaires are mounted fixed on to walls or ceilings the final sub-circuit cables may be connected into the luminaires own terminal block provided that the cables are routed to avoid any heat generating components inside the luminaire. Where terminal blocks are not provided as part of the luminaire flexible heat-resistant cable shall be used and connected to a separate external junction box.


2.5.4.2 Distribution Boards The distribution boards and all component parts shall be manufactured and tested in accordance with IEC 60947 and be capable of withstanding, without damage, the mechanical and electrical stresses that can exist by any fault current. The withstand shall be for twice the period required to disconnect such fault on any circuit.

Each distribution board shall have a dustproof metal case of sheet steel with an enamelled finish and shall have hinged doors. The doors shall incorporate a gasket and have a push-button handle incorporating a cylinder type lock. Each lock shall be unique and shall be supplied with 3 keys. The colour of the enamel finish shall match the colour of other switchgear installed in this project. The distribution board metal casing shall be provided with a gland plate for cable entry corresponding to the cable size required for the overall design circuit capacity of the distribution board. It shall also incorporate and a suitable screened brass earthing stud.

Each current carrying component shall be designed so that under continuous rated full load conditions in the environmental conditions at site and that the maximum total temperatures permitted under the relevant Standards are not exceeded.

All distribution boards shall incorporate a disconnector which shall be used to isolate the incoming supply to the distribution board this shall be an on-load switch.

Outgoing circuits for socket outlets and air conditioning equipment shall be provided with residual current protection with a tripping sensitivity 30 mA.

Where a distribution board feeds critical equipment individual residual current protection shall be used to avoid loss of all power supplies. The cables feeding the distribution boards shall be connected directly to the incoming isolator or neutral bar as appropriate unless indicated otherwise by the Specification.

Neutral bars shall have an appropriate number of ways relative to the size of the board.

The metal surface adjacent to any live part and all spaces between phases shall be protected by barriers made of fireproof insulation material.

The current rating of the busbars in each distribution board shall not be less than the sum of maximum current rating of all outgoing circuits. The neutral connection for each circuit is to be direct to the neutral busbar.

Approved type labels shall be fitted externally on the front cover of each distribution board giving details of the points controlled by each circuit. The circuit list shall be typed or printed stating the location of the equipment served, rating of the protective unit, circuit loading and the cabling size and type. The lists shall be mounted on the inside of the cover door and shall be protected by an acrylic sheet slid into a frame over the circuit list, the list and cover to be easily removable to permit circuit modifications.


2.5.4.3 Main Switches Air break switches, disconnector and MCCB's shall be used as appropriate. They shall be designed and rated in accordance with IEC 60947-3 and IEC 60898 as appropriate for expected symmetrical fault rating and shall be capable of breaking rated load current.

2.5.4.4 Miniature and Moulded Case Circuit Breakers All Moulded Case Circuit Breakers (MCCB’s) and miniature circuit breakers (MCB’s) shall be constructed to IEC 60947.

Circuit breakers shall be of the high-speed fault limiting, thermal/magnetic type with quick-make and quick-break trip free mechanisms which prevent the breaker being held-in against overloads of fault conditions.

Breakers shall have silver tungsten contacts and be derated to suit the environmental nature of the enclosure and/or load.

Tripping arrangements shall ensure simultaneous opening of all phases.

2.5.4.5 Cables The cables for indoor lighting and socket systems installed between distribution boards and final connections shall be:

The cables for outdoor lighting and socket systems installed between distribution boards and final connections and all cables up to distribution boards shall be XLPE insulated 3 and 5 cores or 4 cores (P+N+E and 3P+N+E or 3P+N with earth conductor separate): Steel wire armoured, Copper conductor, PVC sheathed and 0.6/1 kV.

All cables shall include an adequately sized neutral and earth continuity conductors.

All cables shall be protected from direct sunlight.

The Contractor shall select conductor sizes for the respective final circuits to meet the following conditions:

• The minimum conductor size for lighting and socket outlets circuits is 2.5 mm2.

• The size is adequate for the current to be carried as set out in the cable manufacturers specification taking account of the site ambient temperature.

• The size is sufficient to keep the voltage drop in the phase and neutral conductor to the farthest lighting or power point under normal full load conditions to the final circuit limit specified in the BS 7671 (IEE Wiring Regulations). No diversity is to be applied in any calculations.

Cables shall run at least 150 mm clear of all plumbing and mechanical services. The space factor for cables shall not exceed 40%.


2.5.4.6 Socket Outlets and Plugs 2.5.4.6.1 General The Contractor shall supply and install and test all power outlets, containment systems, trunking and accessories to form a complete power installation.

These outlets shall be

13 A, 220 V a.c. single-phase, 2-gang, neutral and earth BS 1363 socket outlets and shall be provided in each room in all buildings as required.

All socket outlets shall be fed via Residual Current Circuit Devices (RCCD). They shall have a tripping sensitivity of 30 mA and a maximum operating time of 30 ms.

BS 1363 socket outlets shall be of a flush fitting pattern where the wiring installation is concealed.

In general the wiring installation for socket outlets and lighting shall be kept separate except where run in common trunking.

2-gang socket outlets shall be installed in a density of one per 10 sq.m and a minimum of 2 per room, excluding bathrooms and toilets.

Facia plates shall be of an insulated type coloured white.

A plug shall be provided for each socket outlet and in the case of fused plugs a fuse shall be provided.

Installation and/or samples of all socket outlets and plugs that the Contractor proposes to use on the project shall be submitted to the Engineer for approval.

The other sockets required eg mobile oil purification plant for oil-filled transformer and reactor bay areas, portable welding equipment, 110 V a.c will be provided under the lv distribution switchgear section of Volume 1.

2.5.4.7 Lighting 2.5.4.7.1 General Complete lighting installations shall be provided internally and externally in all buildings, and in all areas of the Substation and Housing Area.

Lighting shall be designed to provide visual performance, safety and economical usage of power.

Visual performance shall be free of excessive stroboscopic effects and flicker from discharge type lighting.

Where visual display units are to be installed, the design shall take account of the need to avoid operator fatigue.

Fluorescent luminaires shall be used for general lighting.

High-pressure sodium luminaires shall be used for area floodlighting.


Low-pressure sodium luminaires shall be used for road lighting and security lighting.

The Contractor shall establish the parameters for the lighting design and ensure that the latest definition of maintenance factor is applied in the calculations. This includes for taking into account all losses associated with the luminaires including lamp lumen maintenance, anticipative switching and lighting operation. The Contractor shall assume that the luminaires will be cleaned once a year.

The design adopted shall ensure satisfactory operation over the life of the Substation.

The lighting design shall take full account of the drop-off in performance of lamps and luminaires over their expected working life and shall indicate required maintenance to maintain these minimum lighting levels.

2.5.4.7.2 Luminaires Illustrations and/or samples of all luminaires that the Contractor proposes to purchase shall be submitted to the Engineer for approval before issuing any suborders.

Luminaires for interior and exterior use shall be manufactured and tested in accordance with IEC 60598 or equivalent and together with all components shall be suitable for service and operation in the environmental conditions stated.

Each luminaire shall be complete with lamp holders, control gear, internal wiring, fused terminal block, earth terminal and reflectors or diffusers as specified. The design of each fitting shall be such as to minimise the effect of glare, and such that the ingress of dust, flies and insects is prevented.

Preference shall be given to fittings with low maintenance and high efficiency.

Fluorescent luminaires shall be of the high efficiency electronic start, having hermetically sealed ballasts of the low noise level pattern. The power factor of the luminaires control gear shall not be less than 0.9.

Internal connections shall comprise stranded conductors not less than 0.75 sq mm covered with heat-resistant insulation to IEC 60245-3 or equivalent. All internal wiring shall be adequately secured inside the luminaire casing with an approved form of cleat. The finish of fittings for interior use shall have a vitreous enamel, natural aluminium or galvanised finish according to the manufacturer's standard product.

Lamp holders as applicable shall be suitable for the lamps specified.

Luminaires shall be of the type specified. The type references used shall be repeated in the Technical Schedules.

The lighting installations shall be designed to give the standards service illuminations specified in this specification.

The number of different types of luminaires shall be rationalised by the Contractor to keep the number of types of luminaires on the project to a minimum.


2.5.4.7.3 Lamps The Contract includes the supply and erection of all lamps and tubes necessary to complete the installation, together with one complete spare set for the first change, plus an additional 10% to allow for early failures. This shall include all normal and emergency lamps.

Fluorescent lamps shall be manufactured and tested in accordance with IEC 60081 and shall have natural colour rendering for internal use and daylight colour rendering for external use.

Tungsten lamps shall be manufactured and tested in accordance with IEC 60064 and shall have Edison screw caps.

Discharge lamps shall be manufactured and tested in accordance with IEC 60188 or equivalent.

Mercury vapour lamps shall be fluorescent types having a 10% red ratio correction fluorescent coating.

High Pressure Sodium (HPS) lamps shall have a hot re-strike time not exceeding 1 minute.

All lamps used on the project shall be of types and sizes that can be readily obtained in Iraq. The Contractor shall indicate suppliers in the O&M manuals.

2.5.4.7.4 External Lighting Columns for Roadway, Perimeter Fence and General Floodlighting

Lighting Columns shall be of hot-dip galvanised steel of octagonal shape and shall be approved by the Engineer.

Columns for roadway and perimeter wall/fence lighting shall support the lanterns at a normal 10 m above ground level and columns for floodlighting may exceed 10 m.

Each column shall be equipped with a weatherproof base section of sufficient size to house an inspection trap, lockable door, fused cut-out, cable entry and terminations for both the incoming and secondary cables feeding the light source. Facility shall be included for cable looping.

All luminaires for external lighting shall be suitable for outdoor duty and shall be adequately earthed and all earth terminations and fittings, fixing brackets and supports shall be included.

The Contractor shall ensure that each column is provided with foundations suitable for the ground conditions existing at the site.

The substation site boundary perimeter wall/fence shall be provided with a lighting system that shall be mounted 10m above ground level at the wall/fence line and shall be placed 1 m inside the perimeter wall/fence boundary.

The distance between lights shall provide the illumination levels specified.

Low-pressure sodium discharge lamps shall be used having the following characteristics:

• The lamp shall be tubular horizontal burning, clear quartz.


• Lamps, ballast and control gear shall be suitable for operation with a power supply 220 V, 50 Hz, single-phase.

• The lamps shall have a minimum lighting design output of 20,000 lumens.

All exterior lighting shall be designed so that it shall be automatically switched by photo-sensitive switches (photocells) and the Contractor shall arrange that there is a time delay between the various groups of circuits being energised to even out the switching peaks. Manual override facilities shall also be provided so that each circuit can be controlled individually.

All external doors of building including switchrooms and stores shall have external luminaires installed adjacent to the doors to provide illumination immediately outside entrances. This is in addition to the requirements for any roadway or other external lighting.

2.5.4.7.5 Emergency Lighting An emergency lighting system shall be provided to allow for the safe movement of personnel at all times in the event of a failure of the normal lighting system. Emergency lighting shall also be provided at the entrances of the switchgear rooms and in the transformer areas.

The emergency lighting system shall comply with BS 5266.

The emergency operational lighting shall operate from a separate distribution board supplied from the 110 V DC main switchboard.

A method of testing emergency lighting shall be provided if it is not part of a maintained system which is directly connected to the distribution boards

Escape routes, egress lighting and associated signs shall be clearly marked and lit to facilitate emergency escape in safety. The luminaires shall be self-contained battery pack units. At least one emergency light must be visible from every point in every room. “Fire Exit” signs to be provided throughout the buildings, at appropriate places in the substation and Guard Room. These shall be self-contained battery backed units with a three-hour minimum emergency duration.

The design procedure in BS 5266 shall be followed to provide the escape lighting/signage as detailed in IEC 1838. All self-contained emergency luminaires shall have a minimum guaranteed life of 5 years. The contract shall allow for one complete set of replacement batteries to allow for the first change.

The battery packs may be mounted remote if the temperatures within the luminaires will not allow the Contractor to guarantee the minimum life required.

2.5.4.7.6 Photocells Photocells shall be mounted within a waterproof and dustproof enclosure to IP65 which shall be fully corrosion resistant.

Means shall be provided for on site adjustment of the ambient light threshold levels at which the photocell actuates the lighting systems.


2.5.4.7.7 Lighting Switches Switches for use in a.c. circuits shall be rated for 16 or 20 A and shall be single pole type provided with an earth terminal.

Switches for use in areas designated for surface installation shall be quick-make quick-break fixed grid industrial types mounted in galvanised malleable iron boxes with protected dolly and These shall be arranged where for multi-gang switching in a room if more than one switch is required in a room.

Switches for use in areas designated for flush installation shall be micro-break types fixed to white plastic cover plates and mounted in galvanised steel flush type boxes.

Lighting switches which are used in an external locations shall be of the surface mounting 13 A rotary quick-make quick-break pattern mounted in a cast iron galvanised weatherproof box to IP65.

The terminals for all switches shall be adequate to accommodate 2 conductors, each with a CSA of 2.5 mm2.

Lighting circuits shall be designated such that no individual light switch has to operate with more than 50% of its nominal rating. Toilets and shower rooms shall have light switches located outside of the entrance doors.

Light switches shall be installed such that the operating dolly shall be pushed up for OFF and down for ON. Similarly, rocker-operated switches shall be installed such that the upper portion of the rocker is pushed for OFF and the lower portion for ON.

2.5.4.8 Service Illumination Levels 2.5.4.8.1 Internal Lighting The following levels of minimum illuminance shall be provided;

• Entrance lobbies 200 lux

• Corridors 100 lux

• Toilets 150 lux

• Offices 350 lux

• Switchgear rooms 400 lux

• GIS rooms 400 lux

• Battery room 200 lux

• Telecommunications room 300 lux

• Control room 400 lux

• Relay room 400 lux


• Workshop 400 lux

• Diesel Generator Building 200 lux

• Store 150 lux

• Guard Room 200 lux

• Houses (where applicable) 100 – 300 lux as required

On local measuring, control stands and instrument panels 200lux shall to be provided.

Illumination shall be of uniform intensity free from glare.

Illumination levels generally shall be measured in a horizontal plane 1 m above the floor level.

Illumination levels at control in instrument panel shall be measured in a vertical plane at the panel position.

2.5.4.8.2 Emergency Lighting The emergency lighting system shall be designed as emergency escape route lighting and shall cover all of the defined escape routes, plus, operational areas, defined as follows shall have an average emergency luminance of;

• Switchgear rooms 50 lux

• Control room 50 lux

• Telecommunications room 50 lux

• Relay room 50 lux

• Battery room 50 lux

• Diesel Generator building 50 lux

• Guard room 50 lux

Also at entrances to switchgear rooms and transformer areas.

At least one emergency light must be visible from every point in every room.

2.5.4.8.3 External Lighting The following minimum external horizontal illumination levels are to be provided in external locations in the Substation and Housing Areas;

• Access roads/pedestrian routes 20 lux

• External Lighting 20 lux


• Outdoor equipment locations 20 lux

• Perimeter fence/boundary walls 50 lux

• Transformer areas 50lux

• A/C plant areas 50 lux

• Main entrance 100 lux

2.5.5 Earthing and Bonding The earthing provided for the Building Service and Air Conditioning plant shall be coordinated with the substation equipment earthing requirements.

All equipment being shall be effectively bonded to ensure electrical continuity throughout the system. A separate earth continuity conductor shall be included with all wiring in conduits or trunking. No reliance shall be placed on metal-to-metal joints in conduits, trunking or trays for earth continuity. The earth continuity conductors shall as far as possible be in one continuous length to the conductor connecting all metal cases housing electrical equipment. The branches shall be connected to the main conductor by permanently soldered-on mechanically clamped joints.

2.5.6 Lightning protection The substation buildings shall be protected within the overall substation lightning and earthing system as specified for the substation equipment. All buildings shall be protected in accordance with the requirements of BS 6651 or IEC 60124 generally to comprise a copper tape grid at roof level with copper down conductors at all corners and at 20m spacings for longer walls. The down droppers from the building shall be earthed individually to separate earth rods.

2.5.7 Fire Detection and Alarm System 2.5.7.1 General This clause deals with the technical requirements for Fire Detection and Alarm System to be used in all operational plant rooms, that shall be designed to comply with the requirements of British Standard 5839 Fire detection and alarm systems for buildings.

This Fire Detection and Alarm System shall comprise fire detectors to be installed in the operational plant rooms and control and indicating equipment as well as a linear heat detection systems to be designed and installed in all concrete cable trenches, cable basements and tunnels and below raised floors in the Substation building to provide early detection of any possible fire which might occur to the cabling system.

2.5.7.2 Scope of Supply and Services The substation shall be split into protected areas that shall be divided into zones. The number of zones and number of devices shall be determined by the Contractor in accordance with the applicable standards and regulations, as well as manufacturer’s recommendations.


The works shall include the supply of Spare Parts and the following items:

5%, or a minimum of two, of each type of automatic fire detectors, fire alarm devices, response indicators, heat detection system accessories (including line type cable which shall be the maximum length required for the longest zone) and 10 frangible elements for Manual Pull Stations.

In addition to the above specified spare parts the Contractor shall recommend and include in his offer the spare parts which he considers necessary for the 2-year operation of the Fire Detection and Alarm System Equipment. The Contractor shall recommend and include in his scope of Works special equipment, tools and test and calibration instruments for the line type heat detection cable that he considers necessary for the proper maintenance of the Fire Detection and Alarm System Equipment. To enable satisfactory maintenance of the equipment by M.O.E, the Contractor shall provide complete sets of as-built wiring diagrams showing all interconnections, alarms, contacts for air-conditioning system shutdown, wiring diagram of each device used in the system, plan drawings, etc. together with operational and maintenance instructions.

All catalogues and literature shall be provided in original form of the manuals with the final submission of O & M Manuals, which provide:

• General Description

• Feature of each device

• Principle of operation and design selection criteria

• Fire risk classification and assessment

• Full specification and physical details

• Battery sizing calculations.

2.5.7.3 Equipment Requirements 2.5.7.3.1 System Operation The fire alarm and detection system shall comply with the requirements of British Standard 5839 and European Standard for fire alarm system EN 54 in all respects.

The fire alarm system devices shall be wired to the fire alarm control panel located adjacent to the main entrance to the substation building.

Wiring for the fire alarm system shall be in accordance with British Standards, and wiring shall be surface mounted.

All devices and cables that belong to the Fire Alarm System and Line Type (linear) Heat detection system shall be properly labelled. All cable terminations and cores shall be provided with ferrules as detailed on the Contractors approved wiring diagrams.


System to be zoned, non coded, open circuit, supervised, electronically monitored type, with facilities for selective zone alarm initiation from key positions for evacuation purposes where specifically indicated hereinafter.

The control panel is divided into a number of zones. The number of zones required shall be the responsibility of the Contractor. Connection to the control panel with the fire alarm devices, including cabling, relay, etc. shall be provided by the Contractor.

The actuation of any manual or automatic alarm initiating device is to light its respective zone lamp on the control panel.

The general audible alarm shall be enunciated immediately upon initiation of a fire alarm signal, the system controls shall cause the alarm sounders to pulse 1.0 second 'ON' and 1.0 second 'OFF'.

A 'SILENCE ALARM' blue coloured push button shall be incorporated in the control panel which shall silence the alarm .

A 'RESET' green coloured push button shall be incorporated in the control panel which shall restore the system to normal non-alarm mode.

The fire alarm system devices shall be wired to the fire alarm Control panel located in the control room.

All rooms and areas throughout the substation shall have a system installed which shall contain a sufficient number of detectors and manual alarm call points. In the case of fire, the fire control panel that monitors all automatic fire detectors shall generate commands to:

• Shut-off ventilation and air conditioning systems, and

• Activate alarm bells or siren on the substation site

2.5.7.4 Control Panel Provisions The Control and indicating equipment panel shall be of the flush mounting pattern with the alarm and fault indication by illuminated numbered panels, cross referenced to adjacent mimic diagram in English lettering.

Panel facilities to comprise:

(a) 'Power On' lamp.

(b) 'Battery Fault' lamp.

(c) 'Earth Fault' lamp.

(d) 'System Fault' lamp.

(e) 'Reset Alarm' push button.

(f) 'Silence Alarm' push button.


(g) 'Test' key switch and supervisory lamp. This test shall permit testing of zone detectors and break glass stations without activating plant alarm relays.

(h) 'Lamp Test' bush button.

The required number of zone alarm and fault lamp displays for the panel shall be a minimum number of zones as determined by the Contractor.

Provide facilities for individual simulation of alarm and fault conditions, located inside the control panel enclosures.

Provide output terminals for each ring wired zone sounder circuit and a supervisory trouble sounder within the control, enclosure.

Provide monitored output terminal and the necessary control modules for repeating of all zone alarm and fault conditions to the control engineers at the Substation Control Centre.

Zone legend and schematic diagram/general layout of fire alarm and detection system, as well as the Line Type Heat Detection System should be provided and installed near the respective Control Panel.

All outside cable trenches (troughs) installed with the Line Type Heat Detection System shall be marked in red, zone-wise for proper identification.

A separate control panel, located next to the Main Fire Alarm Control Panel, shall be provided for the Line Type Heat Detection System provided for high voltage and low voltage cables in cable trenches and below raised floors. This shall connect into the main building fire alarm control panel on a zone-by-zone basis. Fault and fire indication signals shall be sent from the line type heat detection panel to the main fire alarm panel.

A “Fire Action” signboard should be provided on the wall in the Switch room.

2.5.7.5 Battery/Charger Units Provide battery/charger units for powering all systems components. Each shall provide a 24 volt d.c. output and each unit shall consist of a 220 V 50 Hz single phase mains operated battery charger unit and a standby battery bank, housed in a metal clad compartment separated from the associated control panel. The compartment shall be a compact enclosure, with battery shelves and be ventilated adequately.

The charger unit shall be automatic constant potential type, suitably rated to float charge the battery bank at an ambient temperature of 35°C.

The battery bank shall be of a suitable (gas tight or similar) type, requiring minimal maintenance attention. The battery banks for each panel system shall be suitably sized to provide a minimum of 72 hours standby for the entire associated system at an ambient temperature of between 10oC and 35°C, with provision to operate all fire alarm devices (Sounders and flashing lights) for one hour thereafter in the alarm condition.

The sizes of battery and charger units to meet the above parameters shall be determined by the equipment supplier and shall allow for adequate de-rating of the batteries as required by BS 5839,


Annex D. This shall allow for the standby load, alarm load, derating for ageing, temperature derating and the non-linear standby and alarm conditions.

All battery charger units shall incorporate the following facilities:

(a) Ammeter marked 'charge' and 'discharge'.

(b) Voltmeter.

(c) Charge/boost control and indicators.

(d) Earth fault alarm relay and indicator.

(e) Charger fail alarm relay and indicator.

(f) Electrolyte level alarm relay and indicator.

(g) Fused outputs.

2.5.7.6 Automatic Detectors Automatic detectors (optical and heat type) shall be suitable for a ceiling mounting box fitted with terminals and contacts. The mounting box shall be fixed in position and fully wired before the detector head is plugged in and locked into position. All detectors shall operate on the open circuit monitored circuit principle. Detectors should not be sited within 2 m of air-conditioning supply or extract grilles and should be located away from the direction of air-flow.

All detectors shall have encapsulated electronic circuitry.

The body of each detector shall have a visible red light emitting diode in the side which shall illuminate when the head is in an alarm state.

The detectors shall require no replacements after initiating an alarm to restore it to its original quiescent condition, when the alarm condition has been reset.

All detectors shall be suitable for reliable operation within the environmental temperature and humidity ranges given in this Specification.

Duct mounted smoke detectors shall be provided as required for the heating ventilation and air conditioning systems and provide alarm/fault indication on the main panel.

Thermal rate of rise type detectors shall meet the following requirements.

These shall be electronic combined rate of rise and fixed temperature type detectors complying with EN 54.

The detectors shall have an electronic temperature responsive element of heat detection and shall be suitable for operating continuously in up to 95% R.H. The rate of rise sensing circuitry shall be calibrated to respond to an increase in ambient temperature of 3°C per minute.


All cables trenches and raised floors within the substation building shall be protected by line type heat sensing cables. These cables require are to be resistant to rodent attack and installed over the cables throughout the areas. If rodent resistant cables are not provided, protection against attack should be provided by mechanical means.

2.5.7.7 Manual Call Points All manual call point units shall be of open circuit monitored type, and shall be generally flush red enamel surface pattern. Breaking the glass shall operate the contacts and raise an alarm.

All call points shall be complete with a glazed, hinged front covering fascia labelled "FIRE BREAK GLASS" in English and Arabic. The glass element shall incorporate a translucent plastic coating to eliminate loose fragments of glass when broken. It shall be possible to break the glass element of station without the use of a hammer. The frangible glass elements shall be easily replaced and spares provided for 10 call points. Call points installed indoors shall incorporate a key test facility and outdoor units shall be weatherproof and come complete a hammer. These shall be protected from exposure to direct sunlight.

2.5.7.8 Alarm Bells and Sounders Notification of a fire shall be by either alarm bells or electronic sounders suitable for 24 Volt d.c. operation, these shall have a minimum sound output of 85 dBA at 3.0 metres from the device. The notification device shall have a unique sound that is different from any other used on the project. If a similar sound is found is used on the site an electronic two tones sounder shall be used.

Bell mechanisms shall be contactless, totally enclosed type, polarized and suppressed, so that operation does not interfere with radio or television. There shall be automatic compensation for plunger wear.

Bell domes shall be finished red stove enamel, and labelled “FIRE ALARM” in English and Arabic.

Bells when located outdoors, shall be weatherproof type suitable for mounting to surface conduit box. Elsewhere bells shall be suitable for internal application and mounting to a flush conduit box.

For the Line Type Heat Detection System, a separate sounder shall be installed just above the Heat detector cable Sensing Control Panel.

2.5.8 Fire Fighting System 2.5.8.1 General Portable and mobile fire-fighting apparatus as specified shall be for the suppression of major and minor fires in all substation buildings and outside in the switchyards, and to meet the requirements of the Local Fire Authority.

The portable apparatus shall be suitable for use by only one person and shall be able to be readily recharged on site. These shall be installed on walls around the project with a maximum spacing of 15 m.


The extinguishers shall be suitable for use on oil or electrical fires and shall not include toxic gases or corrosive fluids. Toxic gases shall not be emitted by the discharge when heated.

Suitable recharges shall be supplied for the foam extinguishers and replacement cylinders for the portable CO2 - extinguishers. For portable and mobile equipment a suitable weighing machine shall be supplied.

The large extinguishers shall be provided with wheeled trolleys.

Sun shade structures shall be provided for outdoor wheel mounted fire extinguishers.

The hand held extinguishers shall be complete with wall brackets and fittings to be positioned to the Engineer’s approval.

Full details of the proposed equipment shall be included in the Tender.

2.5.8.2 Scope of Supply and Services Within the buildings portable fire extinguishers are to be provided and located in an adequate number of locations such that personnel movement is not affected. In addition they shall be installed at easily visible and accessible places.

In addition to the portable extinguishers within all buildings, mobile extinguishers shall be provided and installed for outside the building.

The location, choice and number of fire extinguishing equipment shall be arranged so such that it is possible for operatives to undertake an effective extinguishing attack to any given point in all rooms or areas that contain high technology or otherwise valuable apparatus or equipment.

Basically all areas where cabinets or cubicles for switchgear, measurement and control devices for automatic systems and protective gear are installed, shall be provided with portable gas extinguishers these shall be sized to cover all of the cabinets in that room.

Outbreak of fire will be indicated by means of the fire alarm system specified elsewhere under the contract.

The layout of the switchgear installations, and the cabinets and housings for measurement and control devices for automatic systems and protective gear, for the computer and other control equipment can be seen in the relevant layout and construction drawings.

2.5.8.3 Equipment Requirements The fire - fighting equipment shall consist of portable and mobile fire extinguisher as follows:

• In the technical rooms of the substation buildings, wall - mounted, hand-operated CO2-gas extinguishers shall be permanently installed and spaced adequately all round. These fire extinguishers shall be appropriate to their purpose for the “protection of electrical apparatus”. To suit their purpose these hand-operated gas fire extinguishers shall be graded under fire class E (live electrical apparatus and installations) without restriction, in accordance with DIN 14406 or equivalent.


• The hand operated CO2 fire extinguishers shall be filled with a minimum of 5 kg medium capacity, and shall be equipped with the necessary extension hose and fire - quenching nozzles. They must be fitted with spring-loaded, interchangeable safety valves, in accordance with the acknowledged international standards.

• In other non-technical rooms of the substation buildings as well as in the gate-house portable dry-powder extinguishers with 6 kg content of extinguishing powder shall be installed. Dry-powder extinguishers should be stored pressure type with ABC powder and a gauge fitted.

• In addition to the above mentioned portable equipment the following mobile equipment mounted on handcart with solid rubber tyres shall be installed outside in the switchyards at a shelter specially foreseen for this purpose.

• Portable fire extinguishers shall comply with requirements of IEC 3-1, IEC 3-2 and IEC 3-6 and be sized to match the anticipative fire risk.

• Wall-mounted extinguishers shall be mounted on secure brackets in such a manner that base of the appliance is approximately 760 mm from the floor.

• “Know your fire extinguishers” colour code sign (in English and Arabic) should be provided near the fire extinguishers.

• The Operational instructions of all extinguishers to be both in Arabic and English.

• Technical specifications and features along with a sample of all fire fighting equipment should be submitted to the Engineer for approval. Approval from local Fire Brigade authorities shall be obtained for all fire fighting equipment.

• One mobile foam extinguisher, 100 l capacity, CO2 cartridge type.

2.5.9 Building Arrangements All ductwork and cabling penetrations shall be positively sealed to prevent the ingress of moisture, dust, vermin etc. and to suit local weather conditions. All condensation and weather drainage shall be externally piped to the perimeter of the building and to ground level.

2.5.10 Plumbing Services 2.5.10.1 General The Contractor shall include for the design, supply and installation of the internal plumbing work associated with the substation. The hot and cold installations shall be constructed to ensure that the water delivered is not liable to become contaminated, is not hazardous to health, and is fit for its intended use. The relevant provisions of BS 6700 shall be used for the specification for design, installation, testing and maintenance of services supplying water for domestic use within buildings.

The work comprises the hot and cold water supplies, including hot and cold supplies to the bathroom, battery room, toilet and guard house, and drainage from all sinks, wash hand basins, toilets, eye-wash fountain and air-conditioning plants, and all work associated with the cold water supplies to and from the storage tanks.


The water supplies to the substation shall preferably be by a connection to the Water Authority's mains, or to the substation water tank. An overhead tank shall be provided on top of the substation building.

2.5.10.2 Pipe Materials (a) Copper pipework shall comply with the relevant provisions of BS 1057.

(b) Polyethylene pipework shall comply with the relevant provisions of BS 6572 for below ground, and BS 6730 for above ground, and BS 4991 for pressure pipework,

(c) Unplasticized polyvinyl chloride (PVC-U) pipes shall comply with the relevant provisions of BS 3505.

All piping and fittings shall be cleaned internally and be free from particles of sand, dirt, grease, and metal filings. All jointing shall be in accordance with the requirements of British Standards and the manufacturers instructions.

Pipework above ground shall only be used where strictly necessary, and shall be insulated and protected with galvanised steel or aluminium; and all materials and proposals are to be approved by the Engineer prior to work commencing.

2.5.10.3 Pipe Installations To reduce the risk of air locks forming, pipes within buildings shall be laid to a gentle fall.

The Contractor shall be responsible for measures to control the thermal movement of piping and apparatus. Where possible, the provision for movement shall be obtained by providing changes in direction, special expansion joints or loops in the pipe runs, supplemented by the necessary guides, anchors and limit stops.

Pipes entering buildings shall be installed through sleeves solidly built in, and the annular space between the sleeve and pipe shall be filled with non-cracking, non-hardening, water resistant, and vermin proof material.

2.5.10.4 Plumbing Fixtures Unless otherwise noted, all plumbing fixtures shall be white glazed stone-ware (vitreous china) without cracks or blemished, and be complete installations. They shall be connected to hot and cold water, drain and vent as required. Water closets and urinals shall be flushable.

(a) Iraqi type water closets shall be elongated bowl type, flush mounted with the floor and complete with integral trap.

(b) European type water closets shall be floor-mounted with integral trap, complete with close coupled or elevated flush tank.

(c) Urinals shall be wall hung.

(d) Sinks in battery rooms to be 14-1/2% silicon content acid resistant cast iron.


(e) Workshop sinks to be heavy gauge stainless steel complete with ledge.

(f) Shower fittings shall consist of a combination hot and cold water fitting and an adjustable spray pattern shower head with volume control.

2.5.10.5 Disinfection Before being placed in service, the hot and cold water distribution system shall be thoroughly flushed and chlorinated by the application of an approved chlorinating agent.

The chlorinating solution shall have a chlorine dosage of 50 mg/l and shall be injected into the system at one end through a cock or trapped connection. All valves and accessories on the system shall be operated to ensure treatment of the entire system. The solution shall be retained in the system for a period of at least 24 hours. At the end of this period the water shall be flushed from the line at its extremities, and tested using a Comparator, until the water at these points is of the same quality as the source of supply.

2.5.11 Telephone Installation The Contractor shall design, supply and install the necessary infrastructure (PVC duct, draw pits or manholes) and block wiring for the connection of all necessary operational, internal and external telephone outlets in the substation buildings. Design and works shall be done fully in accordance with Telecommunication system required for the New Buildings.

2.5.12 Inspection and Tests Tests shall be carried out in order to determine whether the material and equipment comply with the specified requirements.

All tests on the materials and equipment shall be made in accordance with IEC standards. If some tests are not covered or a method of testing is not specified in IEC standard, or if there are options in relevant IEC standards, the Contractor shall submit the method by which he proposes to conduct the test to the Engineer for approval.

Test certificates shall be submitted for approval to the Engineer.

The Contractor shall submit a programme of testing to be performed for the Engineer’s approval.

2.5.12.1 Insulation Tests Insulation tests shall be carried out on all cables between cores and to earth after terminations have been made and before the cores are connected to the equipment, and records of these kept.

Tests shall also be made on complete circuits for lighting, socket outlets, etc., between poles and to earth and shall include associated switches, distribution switch and fuse gear.

2.5.12.2 Continuity Tests Earth continuity tests shall be made for each item of electrical equipment, luminaires, switch and socket outlets to the main earthing connections for the installation. This shall be the point where the


main bonding conductor to the earth electrode system is connected to the main earthing terminal on the main switchboard.

2.5.12.3 Earth Loop Impedance Tests Earth loop impedance tests shall be made for all socket outlets in the installation and shall show the complete earth loop impedance from the socket outlet to the sub-distribution board.

2.5.12.4 Earth Electrode Tests The resistance of all earth electrodes including those provided for main earthing anti-static protection and lightning protection shall be measured, recorded and test certificates submitted.

2.5.12.5 Phase Rotation Tests The phase rotation at each three-phase socket outlet shall be checked and verified to be standard anti-clockwise phase rotation and sequence R-Y-B.

2.5.13 Special Equipment and Tools Works to be done under this section include the delivery of special equipment and tools for erection, installation, maintenance, setting to work and other purposes.

2.5.14 Spare Parts Works to be done under this section include the delivery of spare parts.

2.5.15 Packaging, Shipping and Transport Packing, shipping and transport shall be arranged by the Contractor.

2.5.16 Training Works to be done under this section include training of M.O.E’s personnel to operate and maintain equipment efficiently and safely. There shall be no constraints on the number and category of M.O.E’s personnel to be trained.

2.5.17 Documentation The Contractor shall provide all necessary drawings, design specifications, design details, operation and maintenance manuals and other required information.

2.5.17.1 Documentation With Tender The Tender shall contain at least the following information and documents:

(a) General layout drawings of the Building Services equipment;

(b) Single line diagrams for normal lighting, emergency lighting and socket outlet distribution boards;


(c) General arrangement, construction and overall dimension drawings of the Building Services equipment;

(d) Description of equipment and services offered;

(e) Manufacturing specifications of the Building Services equipment;

(f) Catalogues, literature and reference lists of the Building Services equipment;

(g) Quality Management System Manual and ISO Certificate of the equipment manufacturer.

2.5.17.2 Documentation after Award of Contract All documents required for the Engineer’s approval shall be submitted by the Contractor.

In addition, the Operating and Maintenance manuals shall be produced in sufficient details to enable inexperienced operatives to maintain and adjust the plant and systems.

They shall be written in a clear concise technical style.

Operating and maintenance manuals shall contain the following:

(a) A description of the building to which services are applied stating their duty and functions.

(b) A listing and description of the services as installed.

(c) Functional diagrams and wiring diagrams for the main and sub-systems.

(d) Details of the manufacturers installation, operating and maintenance requirements that must be edited or otherwise reproduced to be specific for the installation.

(e) A detailed list of equipment supplied, manufacturer, address, telephone number and official order number/date.

(f) A schedule detailing the regular maintenance requirements with space for remarks and service history.

(g) A fault tree analysis of the system(s).

(h) A copy of the 'As fitted' record drawings.

(j) Copies of all test and commissioning data including pre-commissioning check lists including those required by BS 7671.

(k) A schedule giving the finally adjusted set points for plant, equipment and controls.

(m) A detailed listing of all spare parts giving part number and description, typical cost and availability.

(n) Any item deemed necessary by the Engineer to clearly identify to the use/operator the function and intended performance of the plant and systems.


2.6 Heating, Ventilation & Air Conditioning

2.6.1 Technical Requirements and Design of Air Conditioning and Ventilation

The design parameters and necessary requirements to meet the design intent must be read in conjunction with other appropriate sections.

The services to be allowed for in the design and construction of the substations are:

• Air conditioning and ventilation,

• Associated electrical distribution systems and control systems, including cabling, containment and power/control board.

Air conditioning within the control, relay and communication building, workshop/store building and guard house shall be achieved using wall or floor mounted split package units for cooling. Units should consist of not more than two standard sizes. Heating to be achieved using small separate units.

The Contractor shall develop fully detailed site working drawings to the approval of the Engineer in accordance with the prescribed standards.

Detailed calculations and layouts shall be submitted on time for approval before any order, placement or site work is undertaken. For tender purposes the Contractor must identify the capacity, manufacture/make, model No, construction standard and type of any equipment or subcomponent being offered together with the selection procedure. Capacity and model numbers shall be subject to the approval of design calculations, by the Engineer whose decision will be final in this respect.

Any exclusions to the complete and satisfactory performance of the design and installations must be clearly delineated within the offer, otherwise it will be assumed that everything necessary has been included at the Contractor cost.

2.6.2 Design Standards for Air Conditioning and Ventilation The design of the electrical building services elements shall be in accordance with BS 7671 (the sixteenth edition) of the Institution of Electrical Engineers Wiring Regulations including latest amendments. Individual items of equipment shall be in accordance with the relevant IEC or British Standard.

The design of the mechanical services elements shall be in accordance with the following standards provided that necessary corrections and provisions are made to suit Iraq climate and design conditions, power supply system and other required codes:

(a) ASHRAE: American Society of Heating, Refrigerating and Air Conditioning Engineers (USA),

(b) CIBSE: Chartered Institution of Building Services Engineers (UK)


(c) ASME: American Society of Mechanical Engineers (USA),

(d) ARI: Air Conditioning Refrigeration Institute (USA),

(e) ASTM: American Society for Testing and Materials (USA),

(f) AWS: American Welding Society (USA),

(g) UL: Underwriter Laboratories (USA),

(h) HVCA: Heating and Ventilation Contractor's Association (UK).

Other International Standards may be considered provided they meet with the above standards as a minimum.

The Contractor must clearly state in his proposal which standards or codes shall be applied. Materials or workmanship that is not in accordance with the standards mentioned above may be accepted at the discretion of the Engineer. A copy in the English language of any such alternative standard proposed by the Contractor shall be submitted to the Engineer for approval.

The Contractor shall include for the HVAC design and calculations, including associated electrical design, to be carried out by a consultant approved by the Engineer.

In preparing the design for the purpose of tendering, the Tenderer shall calculate and advise the following for each building in relation to the HVAC systems:

• Cooling loads

• Heating loads

• Air handling plant and equipment capacities

• Duct sizes

These shall be determined from the building layout at the date of Tender, the lighting design, estimated heat from plant and equipment, cable etc, occupants, and room environmental conditions.

The Contractor shall study, verify and satisfy himself the system and equipment designed offered is sound and shall ensure that the system and equipment will function satisfactorily together with its auxiliaries as an integral part of the final installation.

The Contractor shall review the entire HVAC design prior to commencement of construction and provide all calculations to show compliance with the Specification.

During the engineering stage the Contractor shall submit all calculations and working drawings of each system that shall be subject to review and approval by the Engineer.


2.6.3 General The electrical supply available will be 220/380V 3 phase, 50 Hz, 4 wire with earthed neutral. All equipment shall be suitable for use with this electric supply system, unless otherwise specified.

The electrical distribution shall be derived from the LVAC and DC rooms Board and arranged so that on loss of a feeder and/or a section of the main switchboard electrical supplies for building services will be maintained.

Low voltage combined power/control board for air conditioning equipment shall have duplicate supplies from isolators arranged on each side of the bus section switch to ensure that at least one of the duplicate plant is available on loss of a source of supply.

2.6.4 Scope of Works The supply and services to be performed by the Contractor shall comprise the design, manufacture, shop testing, packing, transport, insurance unloading, storage on Site, construction works and erection, corrosion protection, site testing, submission of documentation, commissioning, training of M.O.E’s personnel and warranty of the works.

The Contractor is bound to provide complete works, even if the equipment or services to be provided are not specifically mentioned in the specification.

2.6.5 Electrical Supplies 2.6.5.1 Motors All motors shall be continuously rated and shall conform to BS 4999, IEC 50347 and IEC 60034. All motors shall be designed to suit the maximum temperature of air passing over the motors and the additional temperature rise caused by exposure to the sun. The winding motor insulation shall be not less than class "B". This shall not apply to motors built within sealed or semi-sealed compressors, which shall be insulated to suit the refrigerant and lubricant used in the system. The nominal rating of each motor shall not be less than 20 percent higher than the maximum kW demand of the driven appliance at the specified duty and the maximum motor speed shall be 25 rev/sec unless otherwise specified or approved. The motors shall be suitable for sea level operation and a maximum ambient temperature of 50°C.

Unless otherwise specified, the types of motor enclosure shall be in accordance with BS 4999-105 and as follows:

Fans with driving motors outside the air stream - Drip-proof to IP 54.

Supply air fans with driving motors in the air stream - Totally enclosed with fan cooling to IP 54.

Extract air fans with driving motors in the air stream - Suitable for Group II gases.

Motors fitted externally shall be weatherproofed to IP 65.

Motors operating in moisture-laden air shall be suitably protected to IP 53.


Motors up to 0.75 kW (1 hp) shall be single phase except where the motors are fitted in the plant rooms or otherwise specified. All motors fitted in the plant rooms/areas shall be three-phase machines.

Each motor shall be fitted with a substantial terminal box to match the cable sizes and to receive flexible conduit or cable glands as necessary.

Motors shall have ball or roller bearings unless otherwise specified. The starting torque of each motor shall be suitable for the plant with which it is associated.

Generally all motors shall be suitable for the following methods of starting unless otherwise specified:

• Up to 15 hp - Direct-on-line,

• Over 15 hp and up to 37 kW (50 hp) - Star delta,

• Over 37 kW (50 hp) - Auto transformer or stator rotor.

The maximum starting currents for the motors shall be as follows:

• Up to 15 hp - 7.0 times rated full load current,

• Over 15 hp and 37 kW (50 hp) - 4 times rated full load current,

• Over 37 kW (50 hp) - 2 times rated full load current.

2.6.5.2 Starters Motor starters shall be supplied and installed under this Contract. Starters shall comply with IEC 60470 with switch or push-button control as specified elsewhere and shall be complete with the following:

• Load breaking isolator,

• Adjustable thermal overload device with single phase preventers,

• All necessary auxiliary contacts, switches, relays, etc. to work in conjunction with the pilot lights, automatic controls and control panels specified later,

• Ammeters for motors of size 20 hp and above,

• Contactor coil,

• Provision to receive conduit or cable glands as necessary,

• No-volt release.

Contactor coils, pilot lights and control circuit contacts shall be suitable for 220 V supply.

Starters for motors above 15.0 kW (20 hp) serving interlocked plant shall be suitable for cascade starting at 5 second intervals to reduce the starting current at any one instant.


All starters shall be clearly marked with rear engraved and filled clear Perspex labels. The rear of each label shall be painted after engraving and filling.

Unless otherwise specified the starters shall be panel mounted. Where the Specification calls for starters to be individually mounted they shall be enclosed in dustproof casings with front access doors and where necessary, rigid steel pedestals for mounting the starters at hand level.

The resistors associated with an accelerating contactor shall be enclosed in ventilated sheet steel enclosure mounted integrally with the starter or adjacent thereto.

Where starters with isolators are not mounted sufficiently close to the motor served to comply with regulations, a further on-load isolator shall be provided at the motor. Unless otherwise specified all local isolators adjacent to equipment shall be supplied and fixed by the Contractor. All isolators shall have provision for padlocking in the "OFF" position.

Plant and equipment constructed with open drives even if contained by unitary casing or otherwise guarded shall be completed with emergency safety panic switches so arranged as to isolate the power source. The switches shall be fitted within easy reach and adjacent to personnel maintaining the driven devices.

All starters shall be of the same manufacture unless otherwise approved by the Engineer.

2.6.5.3 Earthing and Bonding Connections All electrically conductive incoming service mains shall be fitted with a 6.5 mm female welded or brazed boss (complete with 6.5 mm steel or brass bolt, two plain washers, one spring washer). The boss shall be fitted within 300 mm of the entry point, but must in all cases be accessible for bonding. Where pipes are to be insulated the boss shall be of sufficient size to clear insulation by not less than 25 mm.

All plant and equipment provided shall be complete with suitable earthing and equipotential bonding studs. This requirement shall also apply to ventilation ductwork which shall be provided with a stud or studs and necessary washers and locknuts for each jointed section.

2.6.6 HVAC Design Conditions 2.6.6.1 External (Outside) Design Conditions: Refer to the General Requirements section of this Specification for details regarding external design conditions.


2.6.6.2 Indoor Design Conditions

Temperature (DB) & % RH Room

Summer Winter

Noise Level (NC)

Relay Room

Control Room

Telecommunications Room

Battery/Charger Rooms

11 kV Switchgear Room

Workshop

Offices and Corridors

30°C d.b. + 2 deg C 50%

R.H. (See Note 1)

Not controlled

(<30oC)

45

Toilets (See Note 2) - 45

Guard House 26oC d.b +2 deg C 50% R.H.

22oC 45

400 kV GIS Room

132 kV GIS Room 50oC max Not controlled 50

Cable Basements Ambient Ambient -

Notes:

1. R.H not controlled. Nominal value only for calculations.

2. Indirect cooling only by spill air.

2.6.6.3 Ventilation and Fresh Air Supply All rooms, other than toilets and battery rooms, shall be kept under positive pressure to reduce dust penetration, by providing 1.0 AC/h fresh air to air conditioned areas and 1.0 AC/h fresh air to ventilated areas.

Toilets shall be kept under negative pressure by extract ventilation (8 AC/h), with spill air from the cooled supply air system to corridors or adjacent areas.

Battery rooms shall be provided with dedicated extract ventilation, and kept under slight negative (20 Pa) pressure. Extract ventilation rate shall be sufficient to maintain hydrogen level at below 1% under maximum charge conditions, but be not less than 6 AC/h. Duplicate (duty/standby) bifurcated extract fans shall be provided. Re-circulation of the air from the Battery Room will not be permitted.

2.6.6.4 Building Construction Reference shall be made to the thermal insulation regulations and requirements in order to achieve economic design.


All necessary precautions shall be taken by the Contractor to ensure that insulation values and other factors used in the HVAC design calculations are reflected in the building design and construction.

2.6.7 Functional Scheme Requirements 2.6.7.1 Air conditioning An air-conditioning system is required to serve all areas cooled to 26/30oC in sum mer, as indicated in the table above. The system shall comprise wall or floor mounted, split package air-conditioning units with ranges of supply and return air ductwork, ductwork accessories, controls and wiring to provide a complete system. Extract ventilation shall be provided from the Battery Room and Toilets.

2.6.7.2 Mechanical Ventilation Supply ventilation shall be provided to the following non-air conditioning areas to provide pressurisation and reduce the ingress of dust.

• 400 kV GIS Switchgear Rooms

• 132 kV GIS Switchgear Rooms

• Cable Basements

The supply ventilation systems for the above shall provide a minimum of 1AC/hr. For the 400 kV and 132 kV GIS Rooms, additional supply and extract ventilation systems shall be provided, to operate during high ambient conditions to limit the room temperature to 50oC maximum. These systems shall run in lieu of the basic pressurising systems, but extract rate shall be less than supply rate to maintain the room pressurisation.

2.6.7.3 HVAC System Diagrammatic The Tender drawings are prepared primarily to describe in a basic manner the design intent of the Contract Works and the working principles of the system. They are to be read in conjunction with the specification:

• For the purpose of enabling the Contractor to submit a Tender,

• To enable the Contractor to prepare, when read in conjunction with the architectural and structural drawings, detail design drawings and construction drawings incorporating manufacturer’s drawings and details of specified or selected plant and equipment.

The Tender drawings are accordingly diagrammatic with runs of piping ducts cable conduit and the like being shown to small scale and not necessarily indicating exact installation positions.

The Contractor shall provide fully developed system diagrammatic showing all requirements, in addition to construction drawings.


2.6.8 Air Conditioning Units 2.6.8.1 Design Parameters • Each packaged air conditioning units of the single zone direct expansion type, to serve all air

conditioned areas in the main buildings.

• An insulated return air ductwork system to equivalent standards shall be provided.

• All supply and return air ductwork shall be insulated and vapour sealed.

• Each air conditioning unit shall be complete with electrically powered isolation dampers on the supply and return air ducts to enable automatic unit selection and maintenance functions to be carried out whilst the alternative unit is running. Visible indication lamps shall be provided for the motorised dampers position on the control panel.

• Time delay should be provided between the opening of motorised dampers and starting of the stand-by packaged A/C units blower so that blower starts only upon full opening of the motorised damper.

• A water connection with hose reel of appropriate length and water pump of suitable capacity shall be provided for condenser and filters cleaning.

• All units shall be suitable for a 380V, 3 phase, 50 Hz, 4 wire electrical supply. Weatherproof local main power isolators lockable and emergency stop locks shall be provided for each unit.

2.6.8.2 System Description The Contractor shall provide and fix packaged air conditioning units of the single zone direct expansion type, to serve all air conditioned areas.

Each unit shall be fully packaged with all components fully assembled, pre-charged with refrigerant and lubricant oil, all pre-wired and works tested ready to receive site connections, and comprise of the following components:

(a) Room Side

• Mixing box for fresh/return air, each with manual dampers. Fresh air inlet to include external louvre, sand louvre, vermin screen and washable metallic filter. The air inlet shall be at least 1.2m above ground level, with gooseneck connection to prevent ingress of rainwater.

• Filter section, with washable metallic pre-filter and high efficiency cleanable secondary filter.

• Cooling coil section with DX split cooling coil, minimum two sections. The coil shall be constructed from copper tubes with aluminium fins. Coil face velocity shall not exceed 2.5m/s and, if required, the coil shall be complete with eliminator plates.

• The evaporator coil and fins shall be protected by a coating of 'Blygold' or equivalent proprietary anti-corrosion protection approved by the Engineer. All such coatings shall be applied at the manufacturers works.


• Fan section, with backward-curved high efficiency centrifugal fan, with flexible connection to the unit casing air discharge. The fan shall be belt driven, and the fan/motor assembly mounted on a steel frame with anti-vibration supports to the main frame of the unit.

• Access/inspection sections to all components.

(b) Air Side

• Compressor section, with a minimum of two refrigerant circuits for capacity control.

• Condenser section, with split condenser coils and a minimum of two condenser fans. 2.6.8.3 Control Requirements • The estimated room cooling loads shall be offset by the volume of air supplied to each space.

• The mean room air temperatures shall be monitored within the common return air duct by flange-mounted detectors.

• The air temperature detector shall interface to the packaged unit controls to give step-cooling adjustment.

• The systems are to be arranged for continuous operation.

• Should a smoke detector detect a fire then the packaged air conditioner evaporator fan(s) shall stop to prevent the spread of smoke and flame.

• The automatic change over should be through the air-flow differential pressure switch installed in the duct and also through the high temperature thermostat installed in the space.

• An "off-cool-Auto" switch shall be provided for each packaged unit together with a unit selector switch on the control panel.

2.6.8.4 Plant and Equipment • Type - Ceiling mounted cassette multi flow. • Application - Air conditioning for relay room, control room, telecommunications room battery room,

11kV switchgear room, workshop, offices, corridors. • Manufacturer and reference - To be confirmed by contractor • Provide room unit as part of split coil air conditioning system.

• Mounting - Ceiling mounted cassette multi flow. • Duty - To be confirmed by contractor • Number off - To be confirmed by contractor • Refrigerant - R407C. • Air volume (l/s) - To be confirmed by contractor • Resistance (Pa) - To be confirmed by contractor • Air on condition - summer

• Dry bulb (oC) AC plant control room: 40 Other areas: 30 with 2 acceptable variation

• RH (%) 50


• Air on condition - winter • Wet bulb (oC) - Not Controlled • Dry bulb (oC) - Not Controlled • RH (%) - Not Controlled

• Air off condition - summer • Wet bulb (oC) To be confirmed by contractor • Dry bulb (oC) To be confirmed by contractor • RH (%) To be confirmed by contractor

• Air off condition - winter • Wet bulb (oC) To be confirmed by contractor • Dry bulb (oC) To be confirmed by contractor • RH (%) To be confirmed by contractor

• Cooling load • Sensible (kW) - To be confirmed by contractor • Latent (kW) - To be confirmed by contractor • Total (kW) - To be confirmed by contractor

• Room noise level NC AC plant control room: 50 Other areas: 45

• Electrical supply to BS 7697 - Three phase. • Standards

• BS EN 255. • BS EN 810. • BS EN 814. • BS EN 60335-2-40. • PAS 57.

• Casing - Unit casing shall be manufactured from zinc coated steel sheet, coated with dry powder epoxy resin paint baked after application, or other suitable protection to provide a 10 year service life

• Finish - Coated with dry powder epoxy resin paint baked after application, or other suitable protection to provide a 10 year service life.

• Access - Provide access to filter, fan and motor. • Roomside fan - Backward-curved high efficiency centrifugal fan. • Filter - Washable metallic pre-filter and high efficiency cleanable secondary filter. • Grille type - To be confirmed by contractor • Insulation - Provide thermal and acoustic insulation. • Controls

• Display • Operating. • Program dry function. • Defrost/hot start. • Filter dirty. • Temperature setting. • Timer. • Air flow. • Fault.

• Auxiliary contacts to wire to external source • Normally open contacts.


• Momentary open contactor. • Alarm/fault. • Temperature setting. • Start/stop. • Temperature monitoring. • Monitor all unit functions.

• Controls type • Fixed surface mounting. • Temperature setting. • Timer settings (units of 1 hr to 72 hr). • Air flow setting. • Send command to external source.

• Condensate drainage - Drain with a trap of sufficient depth to overcome the differential static pressure within the unit.

• Provision for fresh air supply via ducting or otherwise. • Each air conditioning unit shall be connected to a common ducted insulated air supply system.

The ductwork shall be complete with fusible link operated fire dampers (and mounting frames), volume control dampers and air diffusers/grilles all installed to DW/144/143 construction standards with a pressure rating of class "A".

• Cooling coils shall be tubes of copper with aluminium fins.

2.6.8.5 Control and Alarm System • Type - Each unit complete with stand alone controller. • Application - Control of air conditioning units in main building. • Supply a control panel to house all contactors, overloads, relays and circuit breakers or fuses. • Functions

• Automatic compressor sequencing. • Condenser head pressure control. • Electronic controller for cooling • Autochanger of duty and stand-by units • Temperature control • Fan speed adjustment • Interlock with fire alarm system • Interface with site wide control system

• Facilities • Connections for remote checking and adjusting. • Standby control system capacity. • Remote monitoring system. • Battery back-up. • Report printer. • Security access codes.

• Panel lamps • Supply on. • Fan running. • Fan trip. • Cooling on.


• Panel Switches • Unit off/on. • Manual/off/auto. • Lamp test button

• Controls • Thermostat - Cooling. • Compressor control. • Each unit controller is linked to main controller that relays faults to the Substation Control

System and can regulate each area • Common return duct control • Interface with fire alarm system • Step control of cooling • Time clock • Automatic changeover of duty/stand-by units

• Alarms • LED displayed alarm. • Remote alarm.

• Alarm sensors • High temperature • Low temperature • Loss of airflow • Fire/smoke detected • Sandstorm monitor warning

2.6.8.6 Vibration Isolation • Type - Each remote condensing unit to be mounted on a concrete base with a level top or

structural frame work. • Application - For remote condensing unit. • Manufacturer and reference - To be confirmed by contractor • Provide additional vibration isolation to manufacturer's standard vibration isolation. • Flexible material in unit support - Multi layer pads shall be composed of rubber sheets, preferably

with square grid pattern on both sides, and steel sheet inserts of 16 gauge. The composite pad thickness shall be selected to suit the equipment, but shall be not less than 32 mm.

• Include heavy base for unit support. • Incorporate specialist vibration isolation mounts. • Suitable working platforms/ladders shall be provided for future maintenance 2.6.8.7 Refrigerant Pipework • Type - Refrigerant • Application - Connects room units with the condenser unit. • Manufacturer and reference - To be confirmed by contractor • Seamless, round copper tube to BS EN 12449. • Jointing - Manipulative compression (flared). • Support

Support all pipework and controls cabling throughout their length using cable tray, firmly fixed to the building fabric.


• Perforated cable tray • Flanged. • Return.

• Perforations and thickness • Manufacturer's standard.

• Fittings Use factory made fittings throughout of same material type, pattern, finish and thickness as tray.

• Finish Copper pipework with insulation. 2.6.8.8 Drainage Pipework • Type - Copper drain to waste • Application - Removing the condensate to waste. Provide condensate drainage pipework from all units to drain. • Copper tube to BS EN 1057.

• Fittings solder. • Fittings compression. • Install tees rather than bends to allow cleaning.

• Provide trap - depth minimum 1.5 times negative pressure on inlet and 0.5 times negative pressure at discharge.

• The drain shall be complete with a trap of sufficient depth to overcome the differential static pressure within the unit.

2.6.8.9 Pipework Insulation • Type Nitrile rubber insulation • Application Retaining heat of refrigerant in pipework between indoor and outdoor units Insulate entire length of pipework for thermal insulation and to avoid contact between copper and galvanising of support tray. • Closed cell nitrile rubber preformed flexible sections

• CFC free. • Fire rating (class) class 'O' • Install un-split wherever possible. • Use manufacturer's standard glue for jointing. • Ensure vapour barrier is maintained on

• all pipework. • suction pipe only.

Insulation thickness (mm) - To be confirmed by contractor 2.6.8.10 PLANT AND EQUIPMENT INSTALLATION: Install equipment in accordance with manufacturer's recommendations. 2.6.8.11 REFRIGERANT PIPEWORK INSTALLATION: Arrange all pipework to be hidden but where it has to be exposed, pipe runs to present neat appearance, parallel with other pipe or service runs and building structure. Ensure all vertical pipes are plumb or follow building line.


Space pipe runs in relation to one another, other services runs and building structure, allow for specified thickness of thermal insulation and ensure adequate space for access to pipe joints, etc. Take precautions to prevent the discharge of refrigerant gases to atmosphere. 2.6.8.12 COMMISSIONING • Ensure that the control system functions in accordance with the requirements specified in clause

100.030. • Keep a systematic record of commissioning results. • commission units in accordance with manufacturer's recommendations. 2.6.8.13 BS APPENDIX BS 7697:1993 Nominal voltages for low voltage public electricity supply system BS EN 1057:1996 Copper and copper alloys. Seamless, round copper tubes for water and gas

in sanitary and heating applications BS EN 12449:1999 Copper and copper alloys. Seamless, round tubes for general purposes BS EN 12450:1999 Copper and copper alloys. Seamless, round copper capillary tubes BS EN 1452-1:2000 Plastics piping systems for water supply. Unplasticized poly(vinyl chloride)

(PVC-U). Part 1 General BS EN 1452-2:2000 Plastics piping systems for water supply. Unplasticized poly(vinyl chloride)

(PVC-U). Part 2 Pipes BS EN 1452-3:2000 Plastics piping systems for water supply. Unplasticized poly(vinyl chloride)

(PVC-U). Part 3 Fittings BS EN 1452-4:2000 Plastics piping systems for water supply. Unplasticized poly(vinyl chloride)

(PVC-U). Part 4 Valves and ancillary equipment BS EN 1452-5:2000 Plastics piping systems for water supply. Unplasticized poly(vinyl chloride)

(PVC-U). Part 5 Fitness for purpose of the system BS EN 255-1:1997 Air conditioners, liquid chilling packages and heat pumps with electrically

driven compressors. Heating mode. Part 1 Terms, definitions and designations

BS EN 255-2:1997 Air conditioners, liquid chilling packages and heat pumps with electrically

driven compressors. Heating mode. Part 2 Testing and requirements for marking for space heating units

BS EN 255-3:1997 Air conditioners, liquid chilling packages and heat pumps with electrically

driven compressors. Heating mode. Part 3 Testing and requirements for


marking for sanitary hot water units BS EN 255-4:1997 Air conditioners, liquid chilling packages and heat pumps with electrically

driven compressors. Heating mode. Part 4 Requirements for space heating and sanitary hot water units

BS EN 295-1:1991 Vitrified clay pipes and fittings and pipe joints for drains and sewers. Part 1

Requirements BS EN 378-1:2000 Specification for refrigerating systems and heat pumps. Safety and

environmental requirements. Part 1 Basic requirements, definitions, classification and selection criteria

BS EN 378-2:2000 Specification for refrigerating systems and heat pumps. Safety and

environmental requirements. Part 2 Design, construction, testing, marking and documentation

BS EN 378-3:2000 Specification for refrigerating systems and heat pumps. Safety and

environmental requirements. Part 3 Installation site and personal protection BS EN 378-4:2000 Specification for refrigerating systems and heat pumps. Safety and

environmental requirements. Part 4 Operation, maintenance, repair and recovery

BS EN 60335-2-40:2003 Specification for safety of household and similar electrical appliances.

Part 2-40 Particular requirements. Electrical heat pumps, air-conditioners and dehumidifiers

BS EN 779:2002 Particulate air filters for general ventilation. Determination of the filtration

performance BS EN 810:1997 Dehumidifiers with electrically driven compressors. Rating tests, marking,

operational requirements and technical data sheet BS EN 814-1:1997 Air conditioners and heat pumps with electrically driven compressors. Cooling

mode. Part 1 Terms, definitions and designations BS EN 814-2:1997 Air conditioners and heat pumps with electrically driven compressors. Cooling

mode. Part 2 Testing and requirements for marking BS EN 814-3:1997 Air conditioners and heat pumps with electrically driven compressors. Cooling

mode. Part 3 Requirements PAS 57:2003 Cellar cooling equipment. Procedure for determining performance and

calculating energy efficiency


2.6.9 Mechanical Ventilation Units The 400 kV and 132 kV GIS Rooms and Cable Basements shall be mechanically ventilated utilizing 100% fresh air to:

(a) Always overpressure the room to exclude dust.

(b) Reduce the build up of excessive heat.

Supply air units shall be installed to maintain an overpressure within rooms/area as follows:

- 400 kV Switchgear

- 132 kV Switchgear

- Cable Basements The above units shall air at a minimum rate of 1AC/h. Units serving Switchgear Rooms shall be free discharge type with supply air grilles in discharge plenum sections. Units serving Cable Basements shall have supply ductwork as required, to each compartment. Provide relief vents as required for the Cable basement.

Supply air units shall be installed to provide mechanical ventilation to the following rooms to avoid the build up of heat:

- 132 kV Switchgear

- 400 kV Switchgear

The above units shall be selected to maintain a temperature not exceeding 50oC with an ambient conduit of 46oC, 4 deg C, temperature difference. Axial extract fans shall be provided, and interlocked with the supply air.

All fresh air supply units shall be of sectionalised construction having factory built low velocity filter section and centrifugal fan section, complete with the following:

• Sand louvre with insect screen;

• Washable metallic pre-filter - 50 mm thick;

• Cleanable high efficiency after filter having an average synthetic dust arrestance efficiency not less than 95% to ASHRAE 52-76. ;

• Centrifugal fan section;

• Channel base frame;

• Manometers and differential pressure switch across filter assembly with alarm facility. This alarm will be relayed to the control room.

The ventilation supply air unit shall be arranged to connect supply air duct. One ducted axial fan complete with back pressure damper and external louvre shall be provided for air extraction.


Fresh air ventilation unit shall be connected to a ducted non-insulated air supply system which shall be complete with air grilles. Air extraction fan shall be connected to a ducted non-insulated air extraction system which shall be complete with air grilles.

Amount of supplied ambient air shall be that to reduce the building up of in building temperature over the 50oC. Amount of air extracted shall be less than amount supplied at least for 1 air change per hour in order to enable overpressure of the building.

The over pressurization unit shall operate constantly 24 h a day all year around except when the ventilation unit is running.

Ventilation units (supply and extraction) shall start only when inside temperature exceed 45oC and if, in that moment, outside temperature is lower than inside. If outside temperature higher, then ventilation unit shall not start but over pressure supply air unit will be kept running. The above supply air units will be controlled by a differential temperature thermostat.

The following remote indications of all ventilation units status and faults shall be provided on the Control Panel as minimum:

• Power On (3 phase)

• Room temp. high

• Filter block (pre/final/F.A. Intake)

• Emergency stop button

• Reset

• Fans (ON/OFF/FAULT)

• Sand storm

• Fire shut-down

• Main Isolator

2.6.10 Extract Fans 2.6.10.1 Axial Fans General extract fans shall be of the axial-flow type, single stage long casing with adjustable pitch aerofoil blades. Unless otherwise agreed, fan speed shall not exceed 25 revs/sec.

Each fan and motor shall be completed housed in a heavy galvanised mild steel casing with flanged ends for duct connections. Fan casings shall be complete with access door, extended lubricators and terminal block. Casings shall be truly circular to maintain throughout a maximum blade to casing mean tip clearance of 0.25% of casing diameter. Adjustable pitch impellors shall be galvanised, and fixed to the extended shaft of the drive motor.


2.6.10.2 Battery Room Fans Battery rooms shall be extract ventilated to give a maximum residual hydrogen concentration in the room air of 1 percent by volume under battery boost charge conditions.

Two (duty/stand-by) explosion proof bifurcated two-speed fans shall be installed complete with extract insulated ductwork, grilles and louvres. The fans shall be with the additional fitting of a spark minimising impeller track and suitable for Group II gases (Battery room applications). The entire system shall be proofed against corrosive gases. The fans shall be interlocked with the battery charger systems so that during normal trickle charge a single fan will operate at slow speed and at high speed during boost charge. During boost charge the additional air supply requirements will be met by wall mounted electrically powered ON-OFF damper with external/sand louvre all mounted at semi-low level in an external wall. Damper actuator shall be interlocked with the battery charger system.

Air flow/pressure switches shall be provided across the battery room extract fans to monitor their performance and provide automatic changeover in the event of supply fan failure.

2.6.10.3 Toilet Extract Toilets shall be provided with exhaust ventilation to provide 8 AC/h.

Fans for toilets within the main building shall be packaged duty/standby units within a common casing, with backdraught shutters and automatic changeover in the event of failure of the duty fan. Units shall be provided with a wall mounting control box, with facility for fault indication to the central control panel.

Fans for toilets within the Guard Room shall be standard PVC fans for wall mounting, with speed controllers.

Electricity supply: 220V, 50Hz, SP & N.

2.6.11 Control Systems 2.6.11.1 General The specified faults shall be indicated in the control panel in the sub-station and shall also be relayed to the Substation Control System (SCS), and thence on to the National Control Centre (NCC).

The following faults and conditions shall be relayed to the SCS:

(a) Packaged A.C. unit stopped (2 No)

(b) Switchgear/cable basement fan(s) stopped (all)

(c) Battery Room extract fan failure (2 No)

(d) Filter assembly blocked (all)

(e) Fire/smoke detector energised (all).


(f) Return air temperature high

(g) Sandstorm monitor warning

Master control panels shall be located within dedicated control rooms for added security and weather protection.

The Contractor shall furnish a full set of control systems for each and every system, packaged unit or component part.

Control systems shall be designed to be compatible within any system, between systems and with control equipment and within the environment in which they function. Control systems shall be designed to achieve the desired conditions without excessive complexity or response. Wherever possible systems shall be provided with a manual intervention and override facilities.

The position of control devices and equipment shall take into account the need for access for adjustment and maintenance purposes.

Wherever control equipment is mounted within occupied areas the control panels and equipment shall be designed to prevent unauthorised interference.

All control systems shall be arranged so that in the event of power failure or other abnormal operating conditions the entire plant and equipment will revert to a fail-safe condition, give indication of the fault condition and recycle to the start-up mode.

The positioning of detectors and sensing elements shall take account of the building usage patterns, local conditions and be truly representative of the sensed conditions.

All grouped controls shall be enclosed within a purpose made ventilated panel rigidly constructed from folded mild steel sheet having a minimum thickness of 2.5 mm. Panels shall be finished smooth without sharp edges and exposed screw/bolt heads. Panels that are to be floor mounted shall be complete with matt black galvanized metal plinth provided with holding down lugs. Floor mounted panels shall also be complete with lifting eyes. All panels shall be designed to be dirt and dust proof and complete with anti-condensation heaters.

Panel doors shall be hinged, lockable and provided with an interlocked door isolator.

The panels shall be internally painted with a semi gloss white finish and externally semi-gloss stove enamel to an agreed colour.

Motor starters and controllers for mounting within the panels shall comply IEC 60439, IEC 60529 and IEC 60292 with enclosure dust and damp protection.

Where a high prospective fault current is indicated equipment shall comply with IEC 60439-1. Panels shall be sectionalised to segregate essential, duty/stand-by and main plant from minor and non-essential equipment. The segregation shall permit routine maintenance and multi-functions to be rectified in any one compartment irrespective of the status of the other sections.


Internal power wiring shall be coded to BS 6346. Control circuits and other wiring shall be identified by means of number slip on ferrules at each end of every termination.

Cable ends shall be secured by means of purpose made clamps or crimped cable tags. Grouped terminal blocks shall be provided for all cables leaving the panel.

The cabling within the panels shall be routed within PVC ventilated trunking of adequate size to retain at least 50 percent free cross-sectional area when fully cabled. Power and control circuits shall be segregated and not routed within the same trunking. Cartridge fuses to BS 88 shall be grouped and mounted to be readily accessible.

All items and components both internal and external to panels shall be suitably identified and agreed with the Engineer.

All live terminals and components within a panel and fixed to the panel doors shall be fully protected and surrounded to prevent personal contact.

A brass earthing lug shall be provided with all control panels.

Control panels shall be fully manufactured, equipped, wired and tested with test certificates approved and stamped before delivery to site. A functional test simulating full operation shall be performed and witnessed at works.

The panels shall be finally despatched from works suitably protected to prevent damage or deterioration during transit and to give site protection until finally commissioned.

Wiring diagrams and panel design and construction shall be agreed with the Engineer before commencement of manufacture.

The following remote indication on A/C system status and faults shall be provided on the control panel as minimum:

(i) Packaged A/C units status (Run/Stop/Fault)

(ii) Power On (3 Phases)

(iii) Pre/high efficiency / F.A Intake filter block

(iv) Package A/C 1 & 2 selector switch

(v) No air flow

(vi) High temperature

(vii) Smoke detected

(viii) Reset buttons (Airflow/Temperature)

(ix) Main Isolator


(x) Motorized damper open/close

(xi) Ammeters for Package A/C unit

(xii) OFF-COOL-AUTO switches for each unit

(xiii) Selector switch for Ammeter

Earth loop impedance, conductor, insulation and voltage tests shall be applied to each and every length of completed cable.

2.6.12 Ductwork 2.6.12.1 Ductwork Requirements Ductwork shall be installed in accordance with the UK Heating and Ventilating Contractors Association Code DW/144 (specification for Sheet metal Ductwork) and tested in accordance with the procedures laid down within DW/143 (Ductwork Leakage Testing).

For general duct systems, ductwork shall be constructed from hot-dipped galvanised steel to IEC 10142: Grade D x 51D + Z, coating type Z275. Battery room extract ductwork shall be constructed from stainless steel, grade 304515 – new designation 1.4301, mill finish type 2D. All ductwork shall be designed and constructed to the appropriate pressure classification, noting that minimum permitted gauge thickness shall be 0.7 mm.

The Contractor shall submit to the Engineer for approval before commencement of ductwork manufacture, schedules nominating for each size of duct the proposed construction and fastening requirements. A section of ductwork incorporating a tee fitting and running joint shall be offered to the Engineer for approval before commencement of manufacture of the main ductwork. This ductwork section shall then be retained by the Engineer as a sample of the minimum acceptable site standard for the installation.

Should the ductwork not comply in the opinion of the Engineer then the Contractor shall remove the rejected sections from site and re-manufacture to the approval of the Engineer and at the Contractors own cost.

Ductwork one metre either side of fire dampers shall be constructed from a minimum gauge thickness of 1.20 mm.

Ductwork passing through the building structure(s) where no fire damper is required shall be sleeved half a metre either side of the structure with 1.20 mm thick ductwork and the annular stemmed with 1 000°C fire grade mineral wool.

2.6.12.2 Ductwork - General A complete range of supply and extract ducting, including plant connections shall be supplied.

All ductwork shall be complete with dampers, bends, branch connections, tapers, transformations, inspection openings and any special pieces necessary to complete the system. All positions of


ducting and plant shall be checked on site and detailed working drawings shall be submitted to the Engineer for approval before manufacture is commenced.

Bends and take-offs shall be designed to keep resistance to air flow to a minimum, and where fittings having a mean radius ratio of less than 1:1 are unavoidable, internal guide vanes of approved design shall be provided. Transformation or taper pieces shall, where possible, be constructed so that the angle for any one side does not exceed 15° to the axis of a duct. Rectangular bends and take-offs are not permitted.

Multi-leaf volume, control and isolating dampers shall be supplied and fixed wherever necessary and shall be complete with lockable operating lever quadrant and open/shut indicator plate. After final regulation and balancing the position of the damper lever shall be marked on the damper quadrant in the red paint and locked in position.

Except where fire dampers are built into the structure, ductwork passing through floors, walls, etc. shall be provided with 1.20 mm thick galvanized steel sleeves flanged to the building structure, the annular fully packed and tightly compressed with slag wool 1000°C grade, to provide a fire stop and to eliminate movement of air between the duct and the sleeve and transmission of noise from one area to another. Duct shall not come into direct contact with the fabric of the building and shall maintain adequate clearance with other services to permit full insulation and vapour sealing.

All nuts and bolts shall be sherardized. The fastening of electrical cables (other than equipotential bonding) and other equipment to ductwork will not be permitted.

Test holes shall be provided in the ducting system at all main and branch ducts and wherever necessary to ensure satisfactory commissioning of the system, and these holes shall be provided with suitable permanent covers. Rubber plugs or taped sealers will not be accepted. Holes required for thermometer bulbs and thermostats, etc. shall also be provided complete with sliding union collar fixture.

All joints and connections throughout the ducting systems shall be airtight to the requirements of HVCA/DW144. Branch connections shall be supplied with gaskets and all joints shall be packed with suitable fire resistant sealing compound of approved make.

Flexible duct joints shall be provided at inlet and outlet of each fan and packaged unit. The joint material shall be flame retardant.

All ductwork entering and leaving the plant room(s)/areas shall be provided with an airtight/firestop periphery sealing plate and angle.

No ductwork shall be insulated or concealed within the building structure until satisfactory tests have been carried out and the Engineer has indicated his approval.

2.6.12.3 Low Velocity Ductwork All the supply and extract galvanized ductwork shall be designed for low velocity and except where specified otherwise, shall be constructed and stiffened to standards contained in the Heating and Ventilating Contractors Association (Ductwork Group) Specification DW/144 and the Practical Guide DW/143.


Each and every section of ductwork shall be provided with an earth bonding and equipotential brass stud or studs and cable fixing to suit the earthing systems.

All ductwork shall be adequately stiffened where necessary by external angle iron or cross-breaking, and large ducts internally by bracing arranged to present minimum resistance to air flow. Internal bracing to ducts shall be of similar material to the ducting.

Approved slip joints may be used but sufficient flange joints shall be provided to facilitate the stage by stage erection and where sections of ductwork have to be installed in advance to accommodate the building programme. the Engineer shall reserve the right to decide where flange joints are required. All joints shall be sealed in an approved manner.

Access doors to the ductwork shall be fitted where necessary for cleaning and where called for in the Specification. They shall be of the wing nut bolted-on type except where hinge types are indicated. Access doors and door openings in the ductwork shall be adequately stiffened and made airtight with a neoprene gasket. Access doors installed to systems required to be insulated shall be of the double skin pre-insulated type, with thermal resistance of insulation to match the adjacent duct insulation.

Duct connections to builders work duct and openings shall be provided with suitable angle frames to stiffen the ducts and ensure that the connections remain airtight.

Bends and off-sets shall have a throat radius equal to the width of the duct. Where short radiused elbows are indicated or are agreed by the Engineer as necessary due to site limitations, the dimensions and internal vanes shall be in accordance with HVCA (Ductwork Group) specification DW/144.

Supports shall comply generally with HVCA specification DW/144. Where cantilever brackets or other special forms of support are indicated they shall be structurally strong enough to take the load and to transfer the load to the building structure without distortion. The final position of the ductwork and the proposed method and material for supports must be shown on the working drawings submitted for approval and coordinated with all other services in conjunction with the Main Contractor before submission to the Engineer.

Any part of galvanized ductwork where the galvanizing is damaged during manufacture or erection shall be painted with two coats of aluminium, zinc rich corrosion resisting paint to the satisfaction of the Engineer.

Sizes of ducting indicated upon the contract drawings shall be the clear airway internal dimension.

Grilles shall be provided with boot neck sections to keep the grille and associated damper clear of the duct air stream in all cases.

2.6.13 Ductwork Accessories 2.6.13.1 Access To Ducts Access openings shall be provided in the ductwork for purposes of cleaning and inspection and shall be positioned to the approval of the Engineer.


Unless otherwise approved each access point shall have a minimum clear opening of 450 mm x 450 mm or equivalent area to suite the duct section.

Openings shall have rubber edge lip seals and be fitted with covers having turned down edges, and be secured with bolts and wing nuts into tapped holes unless hinged covers are to be provided.

Covers and openings shall be adequately stiffened and shall be airtight.

Inspection openings with cover plates shall be provided each side of all fit treatment devices, exchangers, adjacent to all dampers and all items of plant requiring periodic inspection, cleaning and for maintenance purposes. No inspection opening shall be more than 10 metres apart.

Where ducts are to be thermally insulated, it is a requirement that the access door frame be extended beyond the face of the duct by a measurement at least equal to the thickness of the insulation and be so arranged that the insulation and finish can be dressed into the frame thereby ensuring that the opening is not concealed and that the edges of the insulation are protected from accidental damage. The access door should be double skinned and filled with insulation of the same thermal resistance as the duct insulation.

2.6.13.2 Ducting Dampers Volume control, isolating and balancing dampers shall be provided where required for balancing and regulation purposes and as deemed necessary.

Dampers shall be opposed-blade multi-leaf type with double skin aerofoil section blades constructed in galvanized sheet steel, or aluminium and securely fixed to a central spindle. The blades shall be stiffened to prevent flutter. Spindles shall be carried in non-ferrous nylon or bronze bearings. Quadrants shall be made out of metal casting.

All dampers shall incorporate neoprene rubber blade edges and leakage pass the dampers when fully closed shall be minimal.

Damper frames shall be constructed from 16 mm gauge thick galvanized channel.

Multi-leaf dampers shall be used in rectangular ducts having a short side in excess of 300 mm. No damper blade shall exceed 1200 mm width and where dampers are required for the greater width the damper sections shall be constructed in multiple frames. Individual damper blades shall not exceed 175 mm in height. Multi-leaf dampers shall operate on the opposed blade principle and provision shall be made for linkages to connect the multiple extended spindles and a suitable indicating device shall be provided on the outside of the damper section.

Double skin blades shall be made out of minimum 22 gauge galvanized sheet steel. Single blade dampers with single skin blade section may be used for damper size up to 300 mm x 150 mm. Single skin blades shall be fabricated from 18 gauge galvanized steel sheet. The frame shall be of 16 gauge galvanized steel sheet.

All multi-leaf dampers shall be constructed in demountable ductwork sections and all dampers shall, where possible, be installed in accordance with the HVAC Code of Practice.


Motorized dampers and main regulating dampers shall be supplied by approved manufacturers and be complete with all necessary levers, linkages, motor brackets and micro-switches to indicate damper open or closed position.

The Contractor shall ensure and prove to the satisfaction of the Engineer that the motorized damper mechanisms and driving motors are adequate for the imposed torques.

2.6.13.3 Ducting Fire Dampers Fire dampers shall be installed in all ducts passing through the fire walls of the rooms and other fire boundaries, and shall be of a suitable fire rating for these boundaries. Fire dampers shall comply with UL 555.

Fire dampers shall be multiblade spring operated type with frame and blades made of galvanized steel sheet of 18 gauge and 22 gauge respectively and shall have 2 hour rating. The steel curtain dampers shall not exceed 1000 mm square and where ducts exceed any one dimension two smaller dampers shall be installed to a mild steel angle frame secured within the ducting.

Steel curtain damper blades shall not exceed 50 mm in width and have rolled edges interlocking to form full length hinges upon which blades pivot when released. The steel blades shall fold completely upon themselves and be stacked at one end of the damper to allow a completely free unobstructed opening. The blades shall be retained by a fusible link, set to fuse at 72°C. The damper frame shall be a continuous channel enclosing the blades and the frame shall act as a continuous stop on both sides of the damper. The overall depth of the casing and damper shall be 100 mm and suitable for the type of arrangement.

The fire damper frames shall be retained within a fire resistive sealing frame designed to accommodate thermal expansion of the damper unit and prevent jamming of the fire damper assembly under fire conditions.

The damper outer frames shall be designed suitable for building into ducts or within the building structure. Detailed drawings shall be submitted for approval before manufacture is commenced.

The Contractor shall install fire dampers correctly orientated to the direction of air flow.

Access doors or panels shall be provided in the ductwork adjacent to both sides of the dampers for inspection and the replacement of fusible links.

2.6.13.4 Ducting and Plant Supports All necessary hangers, brackets, steel bearers for plant and supporting structure shall be supplied by the Contractor for this installation.

All ductwork hangers and brackets shall be of an approved design and spaced to ensure adequate support and the ducting shall be erected to form a rigid and uniform structure free from swaying. Fixing of brackets and supports to concrete beams and structures by drilling into these shall only be allowed at the discretion the Engineer. Rawlbolt or similar anchor type fixing to concrete ceilings or beams shall be allowed at the discretion of the Engineer, provided no damage is incurred to the structure.


Rawlbolt or similar anchor type bolt fixings shall be installed to the manufacturer's instructions, to expand the sleeve correctly inside the drilled hole to ensure maximum holding power to the concrete, and used to secure angle channel or "Unistrut" sections to the concrete which in turn shall carry the individual duct supports. Direct screwed rod fixing into the anchor bolts shall not be allowed unless these anchor bolls are of a type approved for that purpose. The Contractor shall allow for drilling all holes. Hanger rods to be fully threaded galvanized type.

Ceiling supports for fans etc., intervals on long duct runs as called for by the Engineer, shall wherever possible, be of long bolts fixed through the ceiling slabs to suitable backplates which shall be bolted and screeded over. These supports shall be connected to angle or channel iron sections which in turn shall carry the individual components.

All necessary floor support stands and mild steel roof trimmers shall be provided by the Contractor, unless otherwise stated.

Where rod type hangers are used these shall be not less than 13 mm diameter and be supplied with nuts, locknuts and washers.

The Engineer reserves the right to call for a weight test on any brackets or fixing and may call for any additional supports to the ducting and equipment it deemed necessary.

Supports shall generally be provided at a maximum of 3 metre intervals and where practicable at each joint and shall be made of galvanized steel.

To prevent ducting noise due to expansion and other causes, felt pads secured with suitable adhesive shall be provided between supports and ducting. Ducting shall be internally stiffened and spaced from structure to prevent drumming.

Supports and brackets shall take into account the spacing requirements for insulated and continuously vapour sealed ductwork.

Approval must be obtained from the Engineer for all plant supports, brackets, etc. and failure to comply with these requirements will be at the Contractor’s risk both as regards cost and building programme.

2.6.13.5 Provision for Instrumentation & Commissioning All necessary screwed bosses, pockets etc on ductwork for thermometers, detectors, pressure gauges etc shall be extended beyond the thickness of insulation.

Test holes shall be provided as necessary in ductwork to facilitate accurate measurement of airflow using pilot tube traverses. Test hole filling shall have at least 25 mm dia bore complete with an effective removable seal. Locations of test points shall be clearly marked on the surface of any insulation applied to the duct.

2.6.14 Grilles And Diffusers (Supply And Extract) Grilles and diffusers shall be designed to prevent draughts, air noise and staining of walls and ceilings.


All duct mounted air supply diffusers shall be complete with an opposed blade volume control damper and designed to give the desired air pattern. The general air-flow pattern shall be fixed by the air diffuser, but means shall be provided to adjust the final air-flow pattern and direction of throw.

Extract grilles shall be mounted direct to the ducting and shall be of the fixed blade type with blades set at an angle of approximately 45° complete with a opposed blade damper behind the grille.

Transfer grilles shall be of the non-vision type designed to pass the required air volume with a minimum of resistance. Transfer grilles shall be provided with two matching flanges and gaskets, one for each side of the door/wall structure. Where transfer grilles are fitted into fire doors they shall be complete with a purpose designed fire damper to match the door thickness and give the desired fire rating.

Unless otherwise stated all grilles and diffusers shall be constructed of aluminium with a standard satin aluminium finish. They shall be fixed into wood frames with cadmium plated wood screws to match or by other proprietary securing devices. As an alternative, extruded aluminium with powder coated painting for the grills/diffusers may be considered.

The air velocity through the supply air grilles and diffusers shall be the minimum to provide the necessary duty at the throw and with the minimum noise level which must be at least 5 dB below the room design noise level.

Grills and diffusers shall not be positioned above the switchgears or control/relay panels.

2.6.15 Air Filters Filters shall be provided for fresh air and for mixed fresh and return air. For both the applications the filters shall be 50 mm thick permanent metallic washable type having efficiency not less their 80% average synthetic dust weight arrestance in accordance with ASHRAE standard 52-68. Filter media thickness shall be not less than 45 mm. This pre-filter shall be placed downstream of the main supply fan and the cooling coil.

Cleanable high efficiency after filters shall be having an average synthetic dust arrestance efficiency not less then 95% to ASHRAE 52-76 standard. Filters shall be as listed by Underwriters Laboratories as class 2. The filter media shall be of high-density microfine synthetic, pleated extended surface washable type.

Fresh air intakes shall be as remote as possible from concentration of surface or roof dirt and positioned to avoid intake of fumes or odours.

Fresh air inlets shall be positioned at least 1.2 m above ground level provided with sand trap louvres with wire mesh bird/insect screen and volume control damper. Goose-neck connections shall be provided to prevent ingress of rain water.

All ducts shall be clean and free from builder's rubble and dust before filters are installed.


2.6.16 External Louvres All fresh air inlet and exhaust louvres shall be designed to prevent rain and excess deposit entry at the operating velocities of the flesh air inlet louvres. All construction joints shall be fully weather sealed.

Unless otherwise indicated all louvres in the external walls of the building required for exhaust or fresh air inlets to the systems shall be of mild construction heavily galvanized after manufacture and finally degreased, etched, printed and painted two coats of paint to approved colour. The blades shall be formed from not less than 1.63 mm thick sheet plate carried in a robust galvanized mild steel channel frame suitable for fixing direct to the building structure. The bottom channel of the frame shall be drilled at each end to receive a small bore copper weep pipe. The maximum length of louvre blade shall not exceed 1.0 metre without intermediate bracing supports.

Bird and vermin proof wire guards shall be fitted behind each louvre.

The louvres shall be designed for a maximum free area and designed to pass the required air volume with a minimum pressure drop.

Sand louvres shall be manufactured in galvanized steel enclosed within a galvanized flanged holding frame. Louvres shall be complete with insect screen and sand collection gravity chamber. Sand louvres shall have an efficiency of 97 percent when tested particles between 150 to 450 microns. Face velocities shall not exceed 1.5 m/s. Wherever possible louvre sub-frames shall be vertically hinged to permit ease of cleaning.

2.6.17 Instruments & Detectors 2.6.17.1 Manometers Manometers and differential air-flow pressure switches shall be installed to measure the pressure drop across each and every air filter. The proposed type of manometer by the Contractor shall be submitted to the Engineer for approval.

The manometers shall be equipped with electrical contacts to allow transmission of dirty filter signals to the Substation Control Centre.

The clean and dirty filter static pressures shall be indelibly marked adjacent to the gauges for reference by maintenance personnel.

2.6.17.2 Thermometers The Contractor shall include for the supply and fixing of four duct-mounting thermometers at each sub-station. The thermometers shall be mounted at positions to be agreed with the Engineer.

Thermometers shall be 150 dia dial, mercury in steel, scaled 0-50oC or 0-100oC, chromium plated case.

2.6.17.3 Smoke Detectors Duct-mounting smoke detectors shall be provided in the main return air duct from air-conditioned areas, and the main exhaust ducts from the 400 kV and 132 kV GIS rooms.


The smoke detectors shall be of the photo-electric obscuration type, and be interlocked with the appropriate plant for shut-down in the event of smoke detection. The detectors shall be suitable for 220V 50Hz SP & N supply, have two volt-free contacts and be suitable for manual re-set only. Operation of a duct mounted smoke detector shall be indicate on the substation fire alarm panel. The detector shall be fully monitored and fault indications shall be provided on the substation fire alarm panel.

2.6.17.4 Sandstorm Monitor A sandstorm monitor shall be provided to shut off all ventilation units and close fresh/exhaust air dampers at a pre-set wind speed. The unit shall have automatic reset facilities at lower wind speeds after a pre-set time delay.

2.6.18 Insulation Work 2.6.18.1 General Requirements Insulation shall be installed neatly and to a high standard by skilled and experienced tradesmen.

All thermal insulation shall be non-corrosive to the insulated surface, water repellent and fire retardant.

All metal, surfaces shall be thoroughly cleaned and treated with approved corrosion inhibitor before applying insulation. Inhibitor coating shall not be required for galvanised surfaces.

All duct flanges, stiffeners and inspection doors etc shall be insulated in accordance with the recommended practice and to the Engineer's approval.

Inspection door insulation thermal resistance shall match that of the surrounding ducts.

All openings in roof slabs and walls for passing ducts shall be suitably weather proofed. Metal sleeves shall be provided where ducts pass through masonry walls or partitions. All openings in roof, ceiling or walls made for purpose of Air Conditioning installation shall be sealed to prevent ingress of rodents, insects, dust, moisture and water. Openings in equipment casing shall be sealed likewise.

All duct insulation shall be covered with fibreglass or cotton canvas cloth and vapour sealed. The cloth shall be soaked in approved weather proofing compound and wrapped carefully to provide a smooth surface, free from wrinkles and gaps. There shall be at least 50mm overlap at transverse and longitudinal cloth joints. Second coat of vapour seal shall be applied after drying of the first coat. The vapour barrier finish shall be carried over the load bearing inserts out of location of supports or hangers without discontinuity or punctures. The vapour seal material shall be fire resistant, non-toxic, weather resistant and anti-fungus quality. Bitumen based products shall not be used.

No insulation tests have been completed until the installation has been approved by the Engineer.

Variation in thickness and concentricity shall be limited to 5 mm at any point and the Engineer reserves the right to remove any sample he chooses for analyses. Replacement of these samples shall be at the Contractor's expense.


The Contractor shall clear all building surfaces, equipment, supports etc after completion of the insulation work to the satisfaction of the Engineer.

2.6.18.2 Rectangular Ductwork Insulation All rectangular supply and return ductwork shall be insulated with rigid fibreglass slab covered with reinforced aluminium foil. The slabs shall be free from shot or coarse and have density of not less than 48kg/m3 and thermal conductivity not more than 0.037 W/m″K. The slabs shall be fixed applying approved adhesive material of high quality to entire surface of both the ductwork and insulation slabs and fixed in place immediately. The adhesive shall be applied to both the edges of slab also. All joints shall be seated using 75 mm wide self adhesive tape.

All ductwork external to the building shall be insulated with 50 mm thick fibreglass slab and covered with fibreglass cloth of 200 gm/sq m quality.

All ductwork within the building, except plant rooms shall be insulated with 25 mm thick fibreglass slab and covered with high quality canvas of 200 gm/sg m quality.

All ducts shall be insulated in same manner as ductwork external to the building, but with canvas covering.

Fresh air and exhaust air ducts shall be suitably insulated wherever possibility of external or internal condensation exists.

Hardwood battens shall be provided between the ducts and the supports. Wood shall be treated for protection from fungus and termite.

Plastic insulation hangers shall be provided as additional support to the insulation of rectangular ducts with a side dimension in excess of 600 mm. Hangers shall be fixed to the bottom and sides of the ducts using blind rivets spaced 300-400 mm apart.

Battery room exhaust ducting shall be insulated to avoid condensation on the external surface of the ducts.

2.6.19 Civil & Builders Work All necessary civil and attendant builders work for the installations shall be included in the tender price.

2.6.20 Construction Standards All equipment to be incorporated into the works shall conform to British or equivalent Standards as previously given.

The equipment offered must be approved for use in Iraq and that Local Agent should be available to provide complete after sales service including the supply of spares.


2.6.21 Equipment Approvals The submission of details to the Engineer for approval shall not relieve the Contractor of his Contractual obligations nor be considered as a reason to delay the works through untimely submission. Part submission of proposals (unless otherwise agreed with the Engineer) shall be rejected.

2.6.22 Product Selection Product compliance selected against the design and specification requirements shall be the sole responsibility of the Contractor.

All ventilation fans selected shall be able to perform at 110 percent of their nominal rated values.

In particular, primary plant items shall not be selected at the Iimits of their performance characteristics unless approved by the Engineer. Attention is drawn to the following requirements:

(a) The selection from certified performance data,

(b) Acoustic performance restrictions,

(c) The local availability and long term supply of spare parts and maintenance support,

(d) The extended guarantees against product failure,

(e) The safety and reliability aspects,

(f) The noise and vibration limits,

(g) The fire and smoke hazards,

(h) The degree of stand-by due to either product failure or to meet the maintenance requirements,

(j) The environmental impact upon plant and equipment,

(k) Local mandatory registration and regulations,

(m) The methods of construction, delivery, storage and physical space requirements,

(n) Packaged units selected at design conditions shall be able to perform satisfactory at 50°C ambient without tripping or overload and shall include 20 percent reserve capacity,

(p) The standards and quality of unit construction,

(q) Field proven performance of plant and equipment,

(r) The ability to thoroughly cleanse and disinfect plant and equipment.


2.6.23 Product Handling & Storage The contractor shall ensure that all plant and equipment is adequately protected before despatch from the manufacturers works and both before, during and after installation.

The Contractor shall also ensure that no damage is sustained to the materials and work of other trades.

Any damage shall immediately be made good or replacements obtained at no cost to the contract and to the satisfaction of the Engineer.

All plant and equipment shall be maintained corrosion and dirt free and “open” components shall be suitably sealed during construction to exclude debris and contamination of the systems.

The consequence of non-compliance with this clause (which may require substantial disassembly) shall be to the cost of the Contractor.

2.6.24 Noise Levels All plant chosen for installation shall be selected for quiet operation and the Contractor shall provide information to the Engineer for approval, giving sound power levels at the required octave bands, including also the expected break-out through the plant casing, for the various items of plant in the plant rooms/areas before placing any official order with the manufacturer. Attenuators shall be provided in supply and return air ducts, should it become necessary to achieve the specified noise levels.

2.6.25 Positioning Of Plant The Contractor shall set out the work involved and take all measurements and dimensions required for the erection of plant of Site making any modification in detail as found necessary during progress of the work.

The Contractor shall ascertain on site before submission of working drawings that the installation will not foul other services, structures equipment or furniture and any work requiring alteration due to negligence in this respect will be at the Contractor's expense.

2.6.26 Foundation Bolts & Alignment The Contractor shall supply and install all foundation and holding down bolts of the correct length and diameter complete with washers and locking devices and shall be responsible for the correct positioning of those bolts.

The Contractor shall align and level each item of equipment using steel shims.

2.6.27 Plant Bases & Anti-Vibration Mountings Each piece of plant shall be situated on a suitable base and adequately supported. Rotating or moving machinery such as fans and motors shall be mounted upon anti-vibration mountings.

Packaged units shall be mounted on anti-vibration units in the form of multi layer rubber pads.


Multi layer pads shall be composed of rubber sheets, preferably with square grid pattern on both sides, and steel sheet inserts of 16 gauge. The composite pad thickness shall be selected to suit the equipment, but shall be not less than 32 mm.

AV pads shall contain counter-bored holes and fitted with suitable rubber grommets to permit free passage of foundation bolts without making contact with the equipment.

Care shall be taken to prevent any anti-vibration devices being loaded beyond their safe limits during erection of machinery.

Flexible duct joints shall be provided at inlet and outlet of each fan, air handling unit and packaged unit. The joint material shall be flame retardant.

Flexible electrical conduits shall be provided for final connection to vibrating equipment.

Suitable rubber grommets shall be incorporated in the suspension arrangements. Large suspended units shall be provided with vibration isolation arrangement to the Engineer’s approval.

Care shall be exercised to ensure that anti-vibration mounts are not "bridged-out" by direct contact between the equipment and building structure through foundation bolts, hangers, rigid pipe or cable connections, rigid clamping of equipment body to any element of the building or through bottomed mounting springs. All shipping bolts and stoppers must be removed before commissioning.

2.6.28 Connection of Equipment The Contractor shall be responsible for ensuring that the service connections conform with the items of equipment to which connections are to be made under this Contract. Details of operation, working pressures and temperatures of equipment shall be checked and written confirmation obtained from the manufacturers before any service is first operated.

2.6.29 Cutting and Drilling of Structural Frames, etc. No cutting or drilling of structural frames, beams, etc. will be permitted without written approval of the Engineer. Where such cutting or drilling is required, application in writing, complete with sketch drawings, must be made to the Engineer.

2.6.30 Machine Guards The Contractor shall supply and fix wire guards over all drives and moving parts of all machinery included in this Contract. The guards shall be of substantial construction to the approval of the Engineer and to the requirements of the appropriate section of the Factories Act. All guards shall be removable and provision shall be made to allow easy access to the motor and shafts as well as making observation of the belts possible without removal of the guards. Guards shall not contact any moving or rotating parts of the equipment.

Vee-belt drive guards shall be of wire mesh construction, the mesh spacing not greater than 13 mm.

Vee-belt guards exposed to the weather shall be constructed from 1.60 mm galvanised sheet steel and suitably weatherproofed and ventilated.


Suitable guards shall be provided to the inlets or outlets of all fans not connected to ductwork.

2.6.31 Painting & Identification All external ductwork supports shall be etch primed and painted with two coats of approved primer, and finished with two coats of chlorinated rubber based paint on all external faces.

A protective finish shall be applied to all mild steel internal ductwork sections (flanges, stiffeners, hangers, supports, etc.) before fixing, consisting of two coats of red oxide or zinc chromate paint.

All externally located equipment, i.e. air handling plant, and fan units, shall be finished with a factory applied epoxy resin or chlorinated rubber paint system to the paint manufacturer’s recommendations.

All rotating plant shall be complete with 150 mm long arrows indicating the correct direction of rotation.

Arrows shall be situated in a position where they can easily be seen and not on the "blind" side of plant. This requirement shall also apply to plant identification labels and plates.

Letters and identification symbols shall be pro-coloured plastic, adhesive backed and purpose-made for the application.

Ductwork shall be identified with black or yellow PVC symbols in accordance with HVCA Code of Practice DW/144.

Ductwork within plant rooms areas shall be identified at 6 metre intervals and at all “T 'junctions, mixing zones and terminations.

Ductwork external to plant rooms shall be identified as above but at maximum intervals of 15 metres, at all access points and where deemed necessary by the Engineer.

All major plant and equipment shall be fitted with a screw-fixed non-corrosive identification label. The label(s) shall be engraved with all relevant data applicable to the plant/equipment installed, together with the plant reference number. All identification and labelling shall be lettered in both the Arabic and English language.

2.6.32 Handover All plant and systems shall be thoroughly cleaned before handover to the satisfaction of the Engineer.

The Contractor shall change the entire filters with the new ones at the time of final handing over of the installation.

Apart from the above, the Contractor shall supply one complete replacement of high efficiency filters as spare for future maintenance.

When all documentation is complete in all respects and acceptance sheets issued by the Engineer approving the Test and Commissioning results, record drawings, operating and maintenance manuals


then a meeting will be arranged with the users/operators to familiarise them with the plant and systems.

Upon satisfactory completion a formal meeting will be arranged with the owners to handover the plant and systems.

2.6.33 Testing & Commissioning Before testing and commissioning is undertaken the entire system(s) shall be thoroughly cleaned to the satisfaction of the Engineer. The Contractor shall submit to the Engineer for approval at least one month before testing and commissioning is undertaken, a comprehensive work plan for the testing and commissioning activities together with pro-forma pre-commissioning and testing sheets which shall identify the procedures and standards to be adopted.

The methods prescribed within the CIBSE commissioning codes shall be adopted together with any other tests required by the Engineer to ensure the system(s) performance.

The Contractor shall test all specialist equipment, fans, filters, etc. as determined by and to the satisfaction of the Engineer in accordance with the accepted Standard.

All site tests shall be witnessed by the Engineer or his authorized representative. Commissioning tests shall generally be in accordance with the British Standard Code of Practice and the CIBSE Series Codes for commissioning procedure.

Prior to testing of ductwork systems, all duct and other materials shall be removed from ductwork and grilles and specialist equipment removed from the ductwork installation. If necessary, the Contractor shall demonstrate to the Engineer by dismantling sections of ductwork or provide access as deemed necessary by the Engineer.

Before commencement of any tests, the Contractor shall obtain and schedule a list of commissioning information requirements which shall include the following:

• Full pre-commissioning check lists for all plant and equipment,

• All fan speeds and duties,

• All design air flow rates and pressures within ductwork systems,

• All supply and extract air design volumes,

• All room temperature, humidity and air pressure requirements,

• Sound levels in selected areas,

• Design static pressure losses across air heater/cooler batteries, air filters and silencers, etc.,

• Power demands, starting currents, running currents and control logics,

• Manufacturer's setting to work and operating instructions,


• All other details necessary to identify the performance of the plant and equipment installed.

The HVAC equipment shall not be started until preliminary checks have been made on the correct rotation and installation of all plant, and control system(s) have been correctly wired and are fully operational.

Where deemed necessary by the Engineer, plant and equipment shall be tested in sections to suit the building construction rate.

From agreed date of handover/acceptance to the Engineer, the Contractor shall monitor the performance of all plant, equipment and systems for a period mutually agreed by the Engineer and the Contractor. During this period, the Contractor shall assess the performance against the original test and commissioning data and carry out adjustments to ensure performance compliance.

2.6.34 Special Equipment and Tools Works to be done under this section include the delivery of special equipment and tools for erection, installation, maintenance, setting to work and other purposes.

2.6.35 Spare Parts Works to be done under this section include the provision of spare parts.

2.6.36 Packaging, Shipping and Transport Packing, shipping and transport shall be arranged by the Contractor.

2.6.37 Training Works to be done under this section include training of M.O.E’s personnel to operate and maintain equipment efficiently and safely. .

2.6.38 Documentation The Contractor shall provide all necessary drawings, design specifications, design details, operation and maintenance manuals and other required.

2.6.39 Documentation With Tender The Tender shall contain at least the following information and documents:

(a) General arrangement, construction and overall dimension drawings of the air conditioning and ventilation systems;

(b) Schematic diagrams of the air conditioning and ventilation systems;

(c) General arrangement drawings of the main equipment items;

(d) Manufacturing specification of the air conditioning and ventilation systems;


(e) Catalogues, literature and reference lists of proposed equipment;

(f) Quality Management System Manual and ISO Certificate of the equipment manufacturer.

2.6.39.1 Documentation after Award of Contract All documents required for the Engineer’s approval shall be submitted by the Contractor in accordance with the contract conditions.

In addition, the Operating and Maintenance manuals shall be produced in sufficient details to enable inexperienced operatives to maintain and adjust the plant and systems.

They shall be written in a clear concise technical style.

Operating and maintenance manuals shall contain the following:

(a) A description of the buildings to which services are applied stating their duty and functions,

(b) A listing and description of the services as installed,

(c) Functional diagrams for the main and sub-systems showing fluid flow rates as finally adjusted.

(d) Details of the manufacturers installation, operating and maintenance requirements that must be edited or otherwise reproduced to be specific for the installation.

(e) A detailed list of equipment supplied, manufacturer, address, telephone number and official order number/date,

(f) A schedule detailing the regular maintenance requirements with space for remarks and service history,

(g) A fault tree analysis of the system(s),

(h) A copy of the "As fitted" record drawings,

(j) Copies of all test and commissioning data including pre-commissioning check lists,

(k) A schedule giving the finally adjusted set points for plant, equipment and controls,

(m) A detailed listing of all spare parts giving part number and description, typical cost and availability,

(n) Any item deemed necessary by the Engineer to clearly identify to the use/operator the function and intended performance of the plant and system.

MINISTRY OF ELECTRICITY IRAQ SUPERGRID PROJECTS 400/132 kV SUBSTATIONS CONTRACT NO VOLUME 3 SUBSTATION PLANT TECHNICAL SCHEDULES AUGUST 2005

Volume 3 - 400 kV Schedules Issue 3 August 05

LIST OF REVISIONS

Current Rev.

Date Page affected

Prepared by


Checked by (quality

assurance)

Approved by

1 2 3

19.11.04 18.03.05 Aug 05

ALL ALL ALL

SSA JK/MH

JK

JW JK/MH JK/MH

JW JW JW

JW JW JW

REVISION HISTORY

3 Aug 05 ALL Updated with MOE comments and general alignment across volumes.


CONTENT SHEET



CONTENTS

Page No.

SCHEDULE A - MILESTONES FOR THE PURPOSE OF PAYMENT AND HANDOVER TO THE CLIENT ............................................................................................. A.1

SCHEDULE B - TIME PERIODS FOR PROCUREMENT, DESIGN, MANUFACTURE, INSPECTION, TESTING, DELIVERY, INSTALLATION, COMMISSIONING AND HANDOVER ........................................................................................... B.1

SCHEDULE C - MANUFACTURERS AND PLACES OF MANUFACTURE, TESTING AND INSPECTION ..................................................................................................C.1

SCHEDULE C1 – 400 KV GAS INSULATED SWITCHGEAR ......................................................C.1

SCHEDULE C2 – 400 KV AIS OUTDOOR SWITCHGEAR..........................................................C.1

SCHEDULE C3 – 132 KV GAS INSULATED SWITCHGEAR ......................................................C.1

SCHEDULE C4 – 132 KV AIS OUTDOOR SWITCHGEAR..........................................................C.1

SCHEDULE C5 – 11 KV METALCLAD SWITCHGEAR ...............................................................C.1

SCHEDULE C6 - TRANSFORMERS REACTORS AND AUXILIARY PLANT .............................C.1

SCHEDULE C7 - LV SERVICES EQUIPMENT...........................................................................C.1

SCHEDULE C8 - CABLES ..........................................................................................................C.1

SCHEDULE C9 - SUBSTATION CONTROL AND PROTECTION SYSTEMS` ...........................C.1

SCHEDULE D – TECHNICAL PARTICULARS ..........................................................................D.1

SCHEDULE D1 – 400 KV GAS INSULATED SWITCHGEAR ......................................................D.1

SCHEDULE D2 – 400 KV OPEN TERMINAL SWITCHGEAR .....................................................D.1

SCHEDULE D3 – 132 KV GAS INSULATED SWITCHGEAR ......................................................D.1

SCHEDULE D4 – 132 KV OPEN TERMINAL SWITCHGEAR .....................................................D.1

SCHEDULE D5 - 11KV METALCLAD SWITCHGEAR ................................................................D.1

SCHEDULE D6 - CRANE FOR GIS BUILDING ..........................................................................D.1

SCHEDULE D7 – 400/132KV POWER TRANSFORMERS .........................................................D.1

SCHEDULE D8 - SHUNT REACTORS .......................................................................................D.1

SCHEDULE D9 – EARTHING AUXILIARY TRANSFORMERS ...................................................D.1

SCHEDULE D10 – CAPACITORS .................................................................................................D.1

SCHEDULE D11 – LVAC SWITCHGEAR......................................................................................D.1

SCHEDULE D12 – DC SYSTEM ...................................................................................................D.1

SCHEDULE D13 - 220 V AC UNINTERRUPTIBLE POWER SUPPLY .........................................D.1

SCHEDULE D15 - LV CABLES.....................................................................................................D.1

SCHEDULE D16 - PROTECTION SYSTEM .................................................................................D.1


SCHEDULE D17 - SUBSTATION CONTROL SYSTEM................................................................D.1

SCEHDULE D18 - CONTROL, OPERATION, INDICATION AND ALARM CIRCUITS ..................D.1

SCHEDULE D19 - BUSHINGS......................................................................................................D.1

SCHEDULE E - TECHNICAL DOCUMENTATION/DRAWINGS AND OPERATING AND MAINTENANCE INSTRUCTIONS................................................................... E.1

SCHEDULE E1 - DRAWINGS ISSUED WITH THE TENDER..................................................... E.1

SCHEDULE E2 - DRAWINGS REQUIRED WITH TENDER ....................................................... E.1

SCHEDULE E3 - CONTRACT DRAWING REQUIREMENTS..................................................... E.1

SCHEDULE E 4 - CONTRACTOR’S SUBMITTALS - DRAWING AND DESIGN DATA............... E.1

SCHEDULE E5 – INSTALLATION AND MAINTENANCE INSTRUCTIONS ................................ E.1

SCHEDULE E6 - FINAL RECORDS ........................................................................................... E.1

SCHEDULE F - DEVIATIONS FROM THE TECHNICAL SPECIFICATION.............................. F.1

SCHEDULE G – QUANTITIES AND PRICES ............................................................................G.1

SCHEDULE J1 - RECOMMENDED SPARES ...........................................................................J1.1

SCHEDULE J2 - SPECIAL TOOLS, TEST EQUIPMENT..........................................................J2.1

SCHEDULE J3 - TRANSFORMERS AND REACTORS QUANTITIES AND PRICES FOR SPARE PARTS ..............................................................................................J3.1

SCHEDULE K - BUILDING SERVICES .................................................................................... K.1

SCHEDULE L - HEATING, VENTILATION AND AIR CONDITIONING..................................... L.1


SCHEDULE A

MILESTONES FOR THE PURPOSE OF PAYMENT AND HANDOVER TO THE CLIENT

Sch A.1 Volume 3 - 400 kV Schedules Issue 3 August 05

SCHEDULE A - MILESTONES FOR THE PURPOSE OF PAYMENT AND HANDOVER TO THE CLIENT

(Information to be provided with Tender) The Tenderer is to indicate all milestones identified within the programme for the works as defined in this Project Specification. The milestones should align with those included in the priced (fixed sum) activity schedule.

Item No

Description Section


SCHEDULE B

TIME PERIODS FOR PROCURMENT, DESIGN, MANUFACTURE, INSPECTION, TESTING, DELIVERY, INSTALLATION, COMMISSIONING AND HANDOVER

Sch B.1 Volume 3 - 400 kV Schedules Issue 3 August 05

SCHEDULE B - TIME PERIODS FOR PROCUREMENT, DESIGN, MANUFACTURE, INSPECTION, TESTING, DELIVERY, INSTALLATION, COMMISSIONING AND

HANDOVER

(Information to be provided with Tender. All time periods are weeks from date of Notice to Proceed)

Description

Time within which:

1. All arrangement and equipment drawings shall be submitted for approval

2. All schemes and functional drawings shall be submitted for approval

3. All wiring and cable diagrams / schedules shall be submitted

4. Plant shall be available for final inspection / test in manufacturer’s works

5. Plant shall be delivered to site

6. Plant shall be installed

7. Overall works are commissioned

8. Overall works are handed over to client


SCHEDULE C

MANUFACTURERS AND PLACES OF MANUFACTURE, TESTING AND INSPECTION

Sch C.1 Volume 3 - 400 kV Schedules Issue 3 August 05

SCHEDULE C - MANUFACTURERS AND PLACES OF MANUFACTURE, TESTING AND INSPECTION

(Information to be supplied with Tender)

SCHEDULE C1 – 400 KV GAS INSULATED SWITCHGEAR

Item

Manufacturer

Place of manufacture

Place of testingand inspection

400 kV GIS:

Current transformers

Voltage transformers

Surge arresters

Circuit breaker operating mechanisms

Circuit breaker operating mech. motors

Disconnector/earth switch drive motors

Support insulators

Expansion bellows

Bursting discs

Gaskets

Conductors

Enclosures

SF6 Gas handling plant

SF6 Gas

Partial discharge capacitive couplers

Transducers

Local control cubicles

Indicating instruments

Control switches

Status indicators

Any deviation from this Schedule shall be notified as soon as possible for the Engineer's approval.


SCHEDULE C - MANUFACTURERS AND PLACES OF MANUFACTURE, TESTING AND INSPECTION – CONT

SCHEDULE C2 – 400 KV AIS OUTDOOR SWITCHGEAR

Item

Manufacturer



400 kV AIS Circuit breakers

400 kV AIS Current transformers

400 kV AIS Voltage transformers

400 kV AIS Surge arresters

400 kV AIS Disconnector/earth switches

Steel Structures

Conductor

Support insulators

Connectors

SCHEDULE C3 – 132 KV GAS INSULATED SWITCHGEAR

Item

Manufacturer



132 kV GIS:



Surge arresters


Circuit breaker operating mech. motors

Disconnector/earth switch drive motors



SCHEDULE C3 – 132 KV GAS INSULATED SWITCHGEAR - Cont

Item

Manufacturer



SF6 Gas handling plant

SF6 Gas

Partial discharge capacitive couplers

Local control cubicles

GIS Switchroom Crane


SCHEDULE C4 – 132 KV AIS OUTDOOR SWITCHGEAR

Item

Manufacturer



132 kV AIS Circuit breakers

132 kV AIS Current transformers

132 kV AIS Voltage transformers

132 kV AIS Surge arresters

132 kV AIS Disconnector/earth switches

Steel Structures

Conductor

Support insulators

Connectors



SCHEDULE C5 – 11 KV METALCLAD SWITCHGEAR

Item

Manufacturer



Metalclad enclosures

Circuit breakers


Interrupters



Earthing switches

Low voltage equipment


SCHEDULE C6 - TRANSFORMERS REACTORS AND AUXILIARY PLANT

Item

No

Description

Manufacturer


Place of testing and inspection

1 400/132 kV Transformer

2 Transformer Tap Changer

3 400 kV Shunt Reactor

4 250 kVA 11/0.4 kV Auxiliary Transformer

5 Earthing Transformer

6 11 kV Capacitor Bank

7 Series Reactor for Capacitor Bank



SCHEDULE C6 - TRANSFORMERS AND AUXILIARY PLANT - Cont

Item

No

Description

Manufacturer


Place of testing and inspection

8 11 kV Shunt Reactor

SCHEDULE C7 - LV SERVICES EQUIPMENT

Item

Manufacturer



LVAC Equipment

DC Equipment

Batteries

UPS Equipment

Standby Diesel Generator


SCHEDULE C8 - CABLES

Item

Manufacturer



132 kV power cable

11 kV power cable

LV multicore / multipair cable

Cable glands

Cable trays

Cable ladder racks




SCHEDULE C9 - SUBSTATION CONTROL AND PROTECTION SYSTEMS`

Item

Manufacturer



SCS Substation Computer

SCS Operator Workstations / HMI

Operator Desk and Chair

SCS Colour Visual Display Units

SCS Substation LAN

SCS Printers

SCS Bay Control Unit BCU

SCS I/O Cards for BCU

SCS Software Engineering

SCS Database Engineering

Protection Relays



SCHEDULE D

TECHNICAL PARTICULARS

Sch D1.1 Volume 3 - 400 kV Schedules Issue 3 August 05

SCHEDULE D – TECHNICAL PARTICULARS

SCHEDULE D1 – 400 KV GAS INSULATED SWITCHGEAR

UNIT DATA Required Offered

1. GENERAL

1.1. Manufacturer & Place of manufacturing

1.2. Type designation

GIS

1.3. Type

Metal enclosed, gas insulated GIS- indoor

1.4. Standards

IEC IEC 60517, 60694, 60270, 60376, 60480

1.5. Rated voltage

kV 420

1.6 System Voltage

kV 400

1.7. Rated frequency

Hz 50

18. Rated lightning impulse withstand voltage

- Phase to earth KVp 1425 - Across the isolating distance kVp 1665

1.9. Rated power frequency withstand voltage

- Phase to earth kV 670 - Across the isolating distance kV 670 - Phase to earth at SF6 pressure of 1 bar kV 1.1 U phase

1.10. Rated short-time withstand current (1 s)

kA 40

1.11. Rated peak withstand current

kA 100

1.12. Type of busbars

Breaker and Half

1.13. Type of enclosure

Single phase encloses

1.14. Material of enclosure for:


SCHEDULE D – TECHNICAL PARTICULARS – CONT

SCHEDULE D1 – 400 KV GAS INSULATED SWITCHGEAR - Cont


- Circuit breaker Al/St - Busbars Al/St - Other compartments Al/St

1.15. Material of HV conductor

Al/Cu

1.16. Material of contacts (indicate bi-metallic where used)

1.17. Type of contact

Tulip

1.18. Minimum subdivision of switchgear:

- Busbars Yes - Busbar disconnect Yes - Circuit breaker Yes - Circuit disconnect Yes - Cable box Yes - Voltage transformer Yes

1.19. Method of compensation of expansion and contraction

- For busbars - For enclosure

1.20. Type of pressure relief device

Bursting disk

1.21. Rupturing pressure

bar

1.22. Type of filter employed for moisture absorption

Molecular Sieve

1.23. Design lifetime of moisture absorbent

Years 10

1.24. Total mass of switchgear (average per bay)

kg

1.25. Mass of heaviest single component to be handled during erection

kg

1.26. Total mass of SF6 gas (average per bay)

kg

1.27. Density of gas in:

- Circuit breaker compartment (g/l) - Other than circuit breaker compartments (g/l)





1.28. Nominal working gas pressure at 15oC in:

- Circuit breaker compartment bar - Other than circuit breaker compartment bar

1.29. Nominal working gas pressure at 50oC in:


1.30. Design maximum pressure for:


1.31. Maximum leakage rate for any gas compartment

per annum

Less than 1%

1.32. Maximum leakage rate for the whole switchgear

per annum

Less than 1%

1.33. Minimum operating period without total replacement of SF6 gas

years 10

1.34. Minimum thickness of enclosure

mm

1.35. Minimum enclosure puncturing time due to internal arc fault at short-time withstand current

ms Greater than 500

1.36. Minimum factors of safety for switchgear

- Busbars or other connections based on elastic limit

2.5

- Complete insulators based on electro-mechanical test

2.5

- Insulator metal fittings based on elastic limit 2.5 - Steel structures based on elastic limit of

tension members and on crippling loads of compression members

2.5

- Foundations for structures against overturning or uprooting under maximum simultaneous working loadings

2.5

1.37. Seismic factor





2. CIRCUIT BREAKER



2.3. Type

Single pressure puffer, SF6

2.4. Standards

IEC 60517, IEC 62271-100, 61233, 60694, 60427, 60376,

60480

2.5. Rated voltage kV 420

2.6a. Rated Current – Busbars, Bus Section and Bus Coupler

- at 40 0C A - at 50 0C (Contractor to confirm by calculation)

A 2000

2.6b. Rated Current – Transformer/Transformer Feeder


A

2.6c. Rated Current – Incoming Feeder


A


Hz 50

2.8. Rated lightning impulse withstand voltage

- Phase to earth KVp 1425 - Across the isolating distance KVp 1665


- Phase to earth kV 670 - Across the isolating distance kV 670






kA 40


KAp 100

2.12. Rated operating sequence

O -0.3 sec- CO -3 min - CO

2.13. Auto reclosing


2.14. Rated making current

KAp 100

2.16. Rated breaking current (asymmetrical)

KA To IEC 62271-100

- %dc

%dc

2.17. Rated breaking current under out-of-phase conditions

kA

2.18. First phase to clear factor

1.5

2.18a Transient Recovery Voltages

TRVs To IEC 62271-100

Rated capacitive breaking current To IEC 62271-100

Rated line charging breaking current A Rated cable charging breaking current A

2.19.

Rated Single/Back to Back Capacitor bank breaking current

A

2.20. Rated small inductive/reactor breaking currents of:

To IEC 61233

- small inductive A - reactor A

2.21. Maximum overvoltage factor on any switching duty

pu 2.5

2.22. Maximum overvoltage factor when interrupting rated line/cable/capacitor bank charging currents

pu 2.5

2.23. Maximum overvoltage factor when switching small inductive/reactor currents

pu 2.5

2.24. Maximum total break time (trip initiation to final arc extinction)

ms 60





2.25. Opening time (trip initiation to contact separation)

- Without current ms - With 100% rated breaking current

ms

2.26. Maximum time interval between opening of first and last phase of three phase circuit breakers

ms 3

2.27. Maximum time interval between opening of interrupters of one phase

ms

2.28. Closing time from energisation of close coil to latching of circuit breaker in fully closed position

ms

2.29. Making time (energisation of close coil to contact touch)

- Without current ms - 100% making current ms

2.30. Maximum time interval between closure of first and last phase of three phase circuit breaker

ms 3

2.31. Maximum time interval between closure of interrupters of one phase

ms

2.32. Minimum time from extinction of main arc to contact make during auto-reclosing duty

ms

2.33. Mechanical life of circuit breaker and mechanism in No. of operations

10,000

2.34. Electrical contact life in number of operations at:

- Rated current - 2000 A - Fault current - 40 kA 15 to 20 - Cumulative ampere rating

2.35. Number of current interrupting break units in series per phase

two





2.36. Type of operating mechanism

Spring-charged or hydraulic

2.37. Type of power device (motor charged)

- For closing Spring or hydraulic

- For opening

Spring or hydraulic

2.38. Hand operating facility

yes

2.39. Hand charging facility

yes

2.40. Manual spring release

yes

2.41. Mechanical on/off indicator

yes

2.42. Mechanical spring charge / discharge indication

yes

2.43. Charging time

s

2.44. Number of trip coils

2

2.45. Number of close coils

1

2.46. Nominal control and operating voltage

V 110 DC

2.47. Nominal heater voltage

V 220 AC

2.48. Rated power of trip coil

W

2.49. Rated power of close coil

W

2.50. Rated motor power

W

2.51. Total load of heaters for circuit breaker

W

2.52. Mass of circuit breaker complete (three pole)

kg

2.53. Mass of single phase circuit breaker

- - -

2.54 Emergency Trip Facility during failure of DC supply

yes

3. DISCONNECTS

3.1. Manufacturer & Place of Manufacturing







Motor

3.4. Standards

IEC 62271-102, IEC 60694,

61128, 60517, 60265

3.5. Rated voltage

kV 420

Rated normal current - Busbars, Bus Section and Bus Coupler / Incomer / Feeder

- Required current at 40oC A 4000

3.6.

- Required current at 50oC (Contractor to confirm by calculation)

A


Hz 50


- Phase to earth KVp 1425 - Across the isolating distance KVp 1665


- Phase to earth kV 670 - Across the isolating distance kV 670

3.10 Rated short time withstand current (1 s)

kA 40


KAp 100

3 .12. Maximum capacitive current that can be interrupted by the isolator

A

3.13. Total time from initiation of opening operation to isolator in fully open position

s

3.14 Time from contact separation to extinct of capacitive arc

s

3.15 Total time from initiation of opening operation to time when isolator gap can withstand phase voltage

s





3.16 Hand operating facility

yes

3.17 Locking arrangement in on/off position

yes

3.18 Nominal control and operating voltage

V 110 DC

3.19 Automatic isolation of control supplies when lock off

yes

3.20. Accessibility to operating mechanism from ground level or catwalk

yes


V 220 AC

3.22. Rated power of operation coil

W


W

3.24. Total load of heaters for isolator

W

3.25. Total mass of three phase isolator complete

kg

3.26 Mass of single phase isolator

kg

3.27. Contact type

Tulip

4. EARTHING SWITCH

4.1. Manufacturer & place of manufacturing



Motor

4.4. Standards

IEC 62271-102, IEC 60694,

60517

4.5. Rated voltage

kV 420


Hz 50

4.7. Rated lightning impulse withstand voltage phase to earth

KVp 1425

4.8. Rated power frequency withstand voltage phase to earth

kV 670





4.9. Rated short time withstand current (1 s)

kA 40


kA 100


yes

4.12. Locking arrangement in on/off position

yes


V 110 DC

4.14. Automatic isolation of control supplies when lock off

yes

4.15 Accessibility to operating mechanism from ground level or catwalk

yes


V 220 AC

4.17. Rated power of operating coil

W


W

4.19. Total load of heaters for earthing switch

W

4.20. Total mass of earthing switch complete

kg

5. HIGH SPEED EARTHING SWITCH




Motor-spring

5.4. Standards

IEC 62271-102, IEC 60694,

61129, 60517

5.5. Rated voltage

kV 420


Hz 50


KVp 1425


kV 670






kA 40


KAp 100

5.11. Rated short-circuit making current

KAp 100

5.12. Rated capacitive symmetrical breaking current

A

5.13. Rated inductive symmetrical breaking current

A

5.14. Total time from initiation of opening operation to earth switch in fully open position

ms

5.15. Time from contact separation to extinction of arc when interrupting rated breaking current

ms

5.16. Making time

ms

5.17. Charging time

s


yes


yes


V d.c. 110


yes


yes


V 220 AC


W


W


W


kg





6. CURRENT TRANSFORMER


6.2. Type

Toroidal, GIS enclosed or

external

6.3. Standards

IEC 60694, 60044-1

6.4. Rated voltage GIS kV 420 Cores V


GIS kVp 1425 Cores kVp


GIS kV 670 Cores kV 3 kV (EK < 2kV) kV 5 kV (EK ≥ 2kV)

6.7. Rated power frequency voltage between secondaries

kV 3

6.8. Inter-turn test M/P type kV peak 4.5 Class PX To IEC 60044-1


Hz 50

6.10. Rated continuous thermal current at 50oC

A


kA 40

6.12. Rated dynamic current

kAp 100

6.13. Are earthed metal screens fitted between primary and secondary windings

6.14. Is current transformer housed in a separate gas compartment





6.15. Details of all current transformers are to be provided by the Contractor post contract award

- Number of cores - Rated extended primary current - Ratio (TR = turns ratio)

• I core A • II core A • III core A • IV core

A

- Class

7. VOLTAGE TRANSFORMERS


7.2. Type designation for

- Line transformer – 3 phase

- Busbar transformer – 3 phase

7.3. Type

Inductive, SF6 gas insulated,

enclosed

7.4. Standards

IEC 60186,60694,

60517, 60044-2

7.5. Rated voltage

kV 420


Hz 50

7.7. Rated lightning impulse phase to earth

KVp 1425


kV 670

7.9. Maximum permissible partial discharge level Um

pC 10

7.10. Maximum permissible partial discharge level 1.2Um /√3

pC 5





7.11. Maximum capacitive current discharge rating

A

7.12. Method of suppressing ferroresonance phenomena

7.13. Line bay voltage transformer

- Number of secondaries - Rated transformation ratio kV - Rated accuracy class

• I secondary • II secondary

- Rated output

• I secondary VA • II secondary

VA

- Mass of single/three phase voltage transformer

kg

7.14. Busbar voltage transformer

- Number of secondaries - Rated transformation ratio kV - Rated accuracy class

• I secondary

- Rated output (Burden to be 25-100% rated burden)

VA

• I secondary


kg

8. SURGE ARRESTERS

8.1. Type

8.2.

Standard IEC 60099-4, 60099-1 60099-5,

60694





8.3. Rated/system voltage

kV

420/400

- Maximum overvoltage factor on the system due to any switching duty

pu 2.5

8.4. Rated system frequency

Hz 50

8.5. Condition of system neutral

Solid

8.6. Nominal Discharge current

KA crest

8.7. Energy capability as per IEC 60099-4 KJ/kV

8.8. Rated voltage - MOA

kV

8.9. Long duration discharge class as per IEC 60099-4

Class 3

8.10. Maximum Continuous Operating Voltage (COV)

kV

8.11. TOV capability for

- 1 sec kV - 10 sec kV

8.12. Maximum residual voltage with current wave

- Switching Surges - 1kA / 2kA kV - 8/20 µs - 5kA kV - 8/20 µs - 10kA kV

8.14. Discharge current withstand strength

- High current (4/10 µs) KAp - Low current 2000A

Ap

8.15. Pressure relief capability

- High current (0.2 s) kA - Low current

8.16. Rating of earth connections

KA/sec 40/1

8.17. Surge counter provided

Yes





9. CABLE BOX (WHEN APPLICABLE).


9.2. Type of designation

9.3. Standards

IEC 60859

9.4 Cable HV test withstand capability

kV

9.5. Rated normal current at 40oC

A

9.6. Required current at 50oC (Contractor to confirm by calculation)

A

9.7. Rated short time withstand current (1s)

kA 40


kA 100

9.9. Total mass of three phase cable box complete

kg

10. MANUFACTURER QUALITY SYSTEM IN ACCORDANCE TO ISO 9000, 9001, 9002, 9003 AND 9004

Yes

10.1 Date of issue

Latest

10.2 Validity

Valid Certificates -Yes

11. TYPE TEST CERTIFICATE TO BE ISSUED BY INDEPENDENT LABORATORY OR INDEPENDENTLY WITNESSED TYPE TEST CERTIFICATE TO BE SUBMITTED

Yes



SCHEDULE D2 – 400 KV OPEN TERMINAL SWITCHGEAR


1. GENERAL

1.1. Standards

IEC IEC 62271-100, 62271-102, 60694,

60233, 60044, 60186, 60383,

60815

1.2. Rated voltage

kV 420

1.3. System Voltage

kV 400


Hz 50


Phase to earth KVp 1425 Across the isolating distance kVp 1665

1.6. Rated power frequency withstand voltage Phase to earth kV 630 Across the isolating distance kV 630


kA 40


kA 100

1.9. Rated Current – Cable Feeder at 50 oC (Contractor to confirm by calculation) A


Aluminium

1.11. Material of contacts

Bi-metallic


Busbars or other connections based on elastic limit

2.5

Complete insulators based on electro-mechanical test

2.5

Insulator metal fittings based on elastic limit

2.5

Steel structures based on elastic limit of tension members and on cripping loads of compression members

2.5



SCHEDULE D2 – 400 KV OPEN TERMINAL SWITCHGEAR - Cont


Foundations for structures against overturning or uprooting under maximum simultaneous working loadings

2.5

1.13. Creepage distance (based on Um)

mm/kV 31

1.14 Seismic factor

As UBC

2. CIRCUIT BREAKER


2.2. Type

SF6

2.3. Standards

IEC 62271-100, 61233, 60694, 60427, 60376,

60480



2. 5 Auto reclosing


2.6 Rated making current

KAp 62.5

2.7 Rated breaking current kA 40 Rated breaking current (asymmetrical)

KA To IEC 62271-100

%dc

%dc

2..8 Rated breaking current under out-of-phase conditions

kA

2.9 First phase to clear factor

1.5

2.10 Transient Recovery Voltages


2.11. Rated capacitive breaking current To IEC 62271-100

Rated line charging breaking current A Rated cable charging breaking current A Rated Single/Back to Back Capacitor bank

breaking current A





2.12. Rated small inductive/reactor breaking currents of:

To IEC 61233

small inductive A reactor A


pu 2.3


pu 2.3


pu 2.3


ms 60


Without current ms With 100% rated breaking current ms


ms 3


- - -

2.20 Closing time from energisation of close coil to latching of circuit breaker in fully closed position

ms

2.21 Making time (energisation of close coil to contact touch)

Without current ms 100% making current ms

2.22 Maximum time interval between closure of first and last phase of three phase circuit breaker

ms 3

2.23 Maximum time interval between closure of interrupters of one phase

- - -






ms N/A.

2.25 Mechanical life of circuit breaker and mechanism in No. of operations

10,000

2.26 Electrical contact life in number of operations at:

Rated current –1600 A Fault current - 40 kA

15 to 20

Cumulative ampere rating

2.27 Number of current interrupting break units in series per phase

One

2.28 Type of operating mechanism

Motor charged spring operated

2.29 Type of power device (motor charged)

For closing Spring or hydraulic For opening

Spring or hydraulic


Yes

2.31 Manual spring release

Yes

2.32 Mechanical on/off indicator

Yes

2.33 Mechanical spring charge / discharge indication

Yes

2.34 Charging time

s

2.35 Number of trip coils

2

2.36 Number of close coils

1


V 110 DC

2.38 Nominal heater voltage

V 220 AC

2.39 Rated power of trip coil

W





2.40 Rated power of close coil

W

2.41 Rated motor power

W

2.42 Total load of heaters for circuit breaker

W

2.43 Mass of circuit breaker complete (three pole)

kg

2.44 Mass of single phase circuit breaker

- - -

2.45 Emergency Trip Facility

Yes

3. ISOLATORS

3.1 Type designation


Motor

3.3 Standards

IEC 62271-102, IEC 60694, 61128,

60265

3.4 Maximum capacitive current that can be interrupted by the isolator

A

3.5 Total time from initiation of opening operation to isolator in fully open position

s


s


s

38 Hand operating facility

Yes


Yes


V 110 DC


Yes

3.12. Accessibility to operating mechanism from ground level

Yes






V 220 AC

3.14 Rated power of operation coil

W


W

3.16 Total load of heaters for isolator

W

3.17 Total mass of three phase isolator complete

kg


kg

3.19 Contact type

3.20 Type of interlocking

4. EARTHING SWITCH



Hand

4.3 Standards

IEC 62271-102, 60694


Yes


Yes


V 110 DC


Yes

4.8 Accessibility to operating mechanism from ground level

Yes


V 220 AC

4.10 Total load of heaters for earthing switch

W

4.11 Total mass of earthing switch complete

kg


5.1 Type

Post





5.2 Standards

IEC 60694, 60044-1

5.3 Rated continuous thermal current at 50oC

Rated extended primary current

Note: All Cl PX CTs shall be ISN 1.2 A

5.4 Cable feeder bays current transformer

To suit specific requirements

Number of cores Rated extended primary current Ratio (TR – turns ratio) I core A II core A III core A IV core A

Class I core II core III core IV core Knee point voltage (Ek) I core V II core V III core V IV core V Exciting current (IE) at Ek I core mA II core mA III core mA IV core mA Rated output (burden to be 25-100% rated

burden)

I core VA II core VA

III core VA IV core

VA

Total mass of single phase current transformer complete

kg

5.5 Bus coupler and bus section bays current transformer

To suit specific arrangement

Number of cores 120%





6. CAPACITIVE VOLTAGE TRANSFORMERS

6.1. Type

Capacitive

6.2. Standards

IEC 60186, IEC/PAS 60044-

5:2002


pC 10


pC 5


6.6. Line voltage transformer

6.7. Number of secondaries

2

Rated transformation ratio kV 132/√3 / 0.11/√3 /0.11/√3

Rated accuracy class I secondary 3P/1.0 II secondary 3P Rated output (burden to be 25-100% rated

burden)

I secondary VA II secondary VA Mass of single phase voltage transformer

kg

7. BUSBARS AND CONNECTIONS

7.1 Type (flexible or tubular)

7.2 Material

7.3 Short-circuit current rating / duration

KA/s

7.4 Normal current rating at 40oC at 50oC

A A





7.5 Maximum continuous current rating

A

7.6 Flexible conductors stranding nominal cross-sectional area outer diameter no. of conductors per bundle spacing between conductors

mm2

mm

mm

7.7 Tubular conductors nominal cross-sectional area outer diameter inner diameter

mm2

mm

mm

7.8 Maximum stress at surface of flexible conductor

kV/mm

7.9 Radio influence voltage level measured at 1.1 times Us/√3 at 1 MHz

µV

7.10 8 POST TYPE INSULATORS


8.2 Insulator material

8.3 Number of units in complete post insulator

8.4 Length of each unit

mm

8.5 Mass of complete post insulator

kg

8.6 Maximum cantilever working load (complete post insulator)

N

8.7 Minimum cantilever breaking load, upright (complete post insulator)

N

8.8 Power frequency withstand voltage dry: wet

kV

8.9 Basic insulation level

kVp





8.10 Minimum dry/wet switching surge withstand level

kVp


µv

9 TENSION AND SUSPENSION INSULATORS



9.3 Number of units in string

mm

9.4 Greatest diameter of units

mm

9.5 Distance between centres of units

mm

9.6 Length of string, overall

mm

9.7 Mass of string complete with all fittings

kg

9.8 Maximum working load

N

9.9 Power frequency withstand voltage of complete string

kV

9.10 Basic insulation level of complete string

kVp

9.11 Minimum wet switching surge withstand level of complete string

kVp

9.12 Radio influence voltage measured at 1.1 times Us/√3 at 1 MHz

µv



SCHEDULE D3 – 132 KV GAS INSULATED SWITCHGEAR


1. GENERAL



GIS

1.3. Type

Metal enclosed, gas insulated GIS-

indoor

1.4. Standards

IEC IEC 60517, 60694, 60270, 60376, 60480

1.5. Rated voltage

kV 145

1.6 System Voltage

kV 132


Hz 50

18. Rated lightning impulse withstand voltage

- Phase to earth KVp 650 - Across the isolating distance kVp 750

1.9. Rated power frequency withstand voltage - Phase to earth kV 275 - Across the isolating distance kV 315 - Phase to earth at SF6 pressure of 1 bar kV 1.1 U phase


kA 40


kA 80


Double

1.13. Type of enclosure

Single/Three phase enclosed

1.14. Material of enclosure for: - Circuit breaker Al/St - Busbars Al/St - Other compartments Al/St


Al/Cu

1.16. Material of contacts (indicate bi-metallic where used)

1.17. Type of contact

Tulip


SCHEDULE D – TECHNICAL PARTICULARS - CONT



1.18. Minimum subdivision of switchgear:

- Busbars - Busbar isolator

- Circuit breaker Yes - Circuit isolator - Cable box - Voltage transformer Yes

1.19. Method of compensation of expansion and contraction

- For busbars - For enclosure


Bursting disk

1.21. Rupturing pressure

bar

1.22. Type of filter employed for moisture absorption

Molecular Sieve

1.23. Design lifetime of moisture absorbent

Years 10


kg

1.25. Mass of heaviest single component to be handled during erection

kg

1.26. Total mass of SF6 gas (average per bay)

kg

1.27. Density of gas in: - Circuit breaker compartment (g/l) - Other than circuit breaker compartments (g/l)

1.28. Nominal working gas pressure at 15oC in: - Circuit breaker compartment bar - Other than circuit breaker compartment bar

1.29. Nominal working gas pressure at 50oC in: - Circuit breaker compartment bar - Other than circuit breaker compartment bar

1.30. Design maximum pressure for: - Circuit breaker compartment bar - Other than circuit breaker compartment bar

1.31. Maximum leakage rate for any gas compartment

per annum

Less than 1%





1.32. Maximum leakage rate for the whole switchgear

per annum

Less than 1%

1.33. Minimum operating period without total replacement of SF6 gas

years 10

1.34. Minimum thickness of enclosure

mm

1.35. Minimum enclosure puncturing time due to internal arc fault at short-time withstand current

ms Greater than 500

1.36. Minimum factors of safety for switchgear - Busbars or other connections based on elastic

limit 2.5

- Complete insulators based on electro-mechanical test

2.5

- Insulator metal fittings based on elastic limit 2.5 - Steel structures based on elastic limit of

tension members and on crippling loads of compression members

2.5

- Foundations for structures against overturning or uprooting under maximum simultaneous working loadings

2.5


2. CIRCUIT BREAKER



2.3. Type

Single pressure puffer, SF6

2.4. Standards

IEC 60517, IEC 62271-100, 61233, 60694, 60427, 60376,

60480

2.5. Rated voltage kV 132

2.6a. Rated Current – Busbars, Bus Section and Bus Coupler

- at 40 0C A - at 50 0C (Contractor to confirm by calculation) A





2.6b. Rated Current – Transformer/Transformer Feeder - at 40 0C A - at 50 0C (Contractor to confirm by calculation) A

2.6c. Rated Current – Incoming Feeder - at 40 0C A

- at 50 0C (Contractor to confirm by calculation)

A


Hz 50

2.8. Rated lightning impulse withstand voltage - Phase to earth KVp 650 - Across the isolating distance KVp 750

2.9. Rated power frequency withstand voltage - Phase to earth kV 275 - Across the isolating distance kV 315


kA 40


KAp 80



2.13. Auto reclosing



KAp 80


KA To IEC 62271-100

- %dc %dc 2.17. Rated breaking current under out-of-phase

conditions

kA

2.18. First phase to clear factor

2.18a Transient Recovery Voltages


Rated capacitive breaking current To IEC 62271-100 Rated line charging breaking current A Rated cable charging breaking current A

2.19.

Rated Single/Back to Back Capacitor bank breaking current

A

2.20. Rated small inductive/reactor breaking currents of: To IEC 61233

- small inductive A - reactor A






pu 2.5


pu 2.5


pu 2.5


ms 60


- Without current ms - With 100% rated breaking current

ms


ms 3


- - -


ms


- Without current ms - 100% making current ms


ms 3

2.31. Maximum time interval between closure of interrupters of one phase

- - -


ms 300

2.33. Mechanical life of circuit breaker and mechanism in No. of operations

10,000





2.34. Electrical contact life in number of operations at: - Rated current - 2000 A - Fault current - 40 kA 15 to 20 - Cumulative ampere rating

2.35. Number of current interrupting break units in series per phase

one


Spring-charged or

hydraulic

2.37. Type of power device (motor changed)

- For closing Spring or hydraulic

- For opening

Spring or hydraulic


yes


yes

2.40. Manual spring release

yes

2.41. Mechanical on/off indicator

yes

2.42. Mechanical spring charge / discharge indication

yes

2.43. Charging time

s


2


1


V 110 DC


V 220 AC


W


W


W


W

2.52. Mass of circuit breaker complete (three pole)

kg





2.53. Mass of single phase circuit breaker

- - -

2.54 Emergency Trip Facility during failure of DC supply

yes

3. DISCONNECTS




Motor

3.4. Standards

IEC 62271-102, IEC 60694,

61128, 60517, 60265

3.5. Rated voltage

kV 145

Rated normal current - Busbars, Bus Section and Bus Coupler / Incomer / Feeder

- Required current at 40oC A

3.6.

- Required current at 50oC (Contractor to confirm by calculation)

A


Hz 50

3.8. Rated lightning impulse withstand voltage - Phase to earth KVp 650 - Across the isolating distance KVp 750

3.9. Rated power frequency withstand voltage - Phase to earth kV 275 - Across the isolating distance kV 315

3.10 Rated short time withstand current (1 s)

kA 40


KAp 80

3 .12. Maximum capacitive current that can be interrupted by the isolator

A

3.13. Total time from initiation of opening operation to isolator in fully open position

s


s






s


yes


yes


V 110 DC


yes


yes


V 220 AC


W


W

3.24. Total load of heaters for isolator

W

3.25. Total mass of three phase isolator complete

kg


kg

3.27. Contact type

Tulip

4. EARTHING SWITCH




Motor

4.4. Standards

IEC 62271-102, IEC 60694, 60517

4.5. Rated voltage

kV 145


Hz 50


KVp 650


kV 275






kA 40


kA 80


yes


yes


V 110 DC


yes

4.15 Accessibility to operating mechanism from ground level or catwalk

yes


V 220 AC

4.17. Rated power of operating coil

W


W


W


kg

5. HIGH SPEED EARTHING SWITCH




Motor-spring

5.4. Standards

IEC 62271-102, IEC 60694,

61129, 60517

5.5. Rated voltage

kV 145


Hz 50


KVp 650


kV 275






kA 40


KAp 80

5.11. Rated short-circuit making current

KAp 80

5.12. Rated capacitive symmetrical breaking current

A

5.13. Rated inductive symmetrical breaking current

A

5.14. Total time from initiation of opening operation to earth switch in fully open position

ms

5.15. Time from contact separation to extinction of arc when interrupting rated breaking current

ms

5.16. Making time

ms

5.17. Charging time

s


yes


yes


V d.c. 110


yes


yes


V 220 AC


W


W


W


kg



6.2. Type

Toroidal, GIS enclosed

6.3. Standards

IEC 60694, 60044-1





6.4. Rated voltage GIS kV 145 Cores V 720


GIS kVp 650 Cores kVp


GIS kV 275 Cores kV 3 kV (EK < 2kV) kV 5 kV (EK ≥ 2kV)

6.7. Rated power frequency between secondaries 3 kV

6.8. Inter-turn test M/P type 4.5 kV peak Class PX To IEC 60044-1


Hz 50




kA 40


kAp 80


6.14. Is current transformer housed in a separate gas compartment

6.15. Transformer bays current transformer: To suit specific

- Number of cores arrangement - Rated extended primary current - Ratio (TR = turns ratio) • I core A • II core A • III core A • IV core A • V core A

- Class • I core • II core





• III core • IV core • V core - Knee point voltage (Ek) • I core V • II core V • III core V • IV core V • V core V - Exciting current (IE ) at Ek • I core mA • II core mA • III core mA • IV core mA • V core mA - Rated output (Burden to be 25-100% rated

burden)

• I core VA • II core VA • III core VA • IV core VA • V core VA

6.16 Line bays current transformer

To suit specific

- Number of cores arrangement - Rated extended primary current - Ratio (TR = turns ratio) - Knee point voltage (Ek)

6.17. Bus Section & Bus Coupler CT No.1

To suit specific

- Number of cores arrangement - Rated extended primary current - Ratio (TR = turns ratio)

6.18. Bus Section & Bus Coupler CT No. 2 (at the other

side of circuit breaker)

To suit specific

- Number of cores arrangement - Rated extended primary current - Ratio (TR = turns ratio)

7. VOLTAGE TRANSFORMERS


7.2. Type designation for

- Line transformer – 3 phase





- Busbar transformer – 3 phase

7.3. Type

Inductive, SF6 gas insulated, enclosed

7.4. Standards

IEC 60186,60694, 60517, 60044-2

7.5. Rated voltage

kV 145


Hz 50


KVp 650


kV 275


pC 10


pC 5

7.11. Maximum capacitive current discharge rating

A TBA


7.13. Line bay voltage transformer - Number of secondaries

- Rated transformation ratio kV - Rated accuracy class • I secondary • II secondary - Rated output • I secondary VA • II secondary VA - Mass of single/three phase voltage

transformer kg

7.14. Busbar voltage transformer

- Number of secondaries - Rated transformation ratio kV

- Rated accuracy class • I secondary





- Rated output (Burden to be 25-100% rated burden)

VA

• I secondary


kg

8. SURGE ARRESTERS

8.1. Type

8.2.

Standard IEC 60099-4, 60099-1 60099-5,

60694

8.3. Rated/system voltage

kV

145/132

- Maximum overvoltage factor on the system due to any switching duty

pu 2.5

8.4. Rated system frequency

Hz 50

8.5. Condition of system neutral

Solid

8.6. Nominal Discharge current

KA crest

8.7. Energy capability as per IEC 60099-4 KJ/kV

8.8. Rated voltage - MOA

kV

8.9. Long duration discharge class as per IEC 60099-4 Class 8.10. Maximum Continuous Operating Voltage (COV)

kV

8.11. TOV capability for - 1 sec kV - 10 sec kV

8.12. - Maximum residual voltage with current wave

- Switching Surges - 1kA / 2kA kV - 8/20 µs - 5kA kV - 8/20 µs - 10kA kV

8.14. Discharge current withstand strength - High current (4/10 µs) KAp - Low current 2000A Ap

8.15. Pressure relief capability - High current (0.2 s) kA

- Low current As per IEC





8.16. Rating of earth connections

KA/sec 40/1

8.17. Surge counter provided

Yes

9. CABLE BOX



9.3. Standards

IEC 60859

9.4. Rated voltage

kV 145


kVp 650


kV 275

9 .7. Cable HV test withstand capability

kV


Hz 50

9.9. Rated normal current at 40oC

A

9.10. Required current at 50oC (Contractor to confirm by calculation)

A

9.11. Rated short time withstand current (1s)

kA 40


kA 80

9.13. Total mass of three phase cable box complete

kg

10. MANUFACTURER QUALITY SYSTEM IN ACCORDANCE TO ISO 9000, 9001, 9002, 9003 AND 9004

Yes

10.1 Date of issue

Latest

10.2 Validity

Valid Certificates –Yes

11. TYPE TEST CERTIFICATE TO BE ISSUED BY INDEPENDENT LABORATORY OR INDEPENDENTLY WITNESSED TYPE TEST CERTIFICATE TO BE SUBMITTED

Yes



SCHEDULE D4 – 132 KV OPEN TERMINAL SWITCHGEAR


1. GENERAL

1.1. Standards

IEC IEC 62271-100, 62271-102, 60694,

60233, 60044, 60186, 60383,

60815

1.2. Rated voltage

kV 145

1.3. System Voltage

kV 132


Hz 50


Phase to earth KVp 650 Across the isolating distance kVp 750

1.6. Rated power frequency withstand voltage Phase to earth kV 275 Across the isolating distance kV 315


kA 40


kA 62.5

1.9. Rated Current – Cable Feeder at 50 oC (Contractor to confirm by

calculation) A 1600 (or to suit)


Aluminium


Bi-metallic


Busbars or other connections based on elastic limit

2.5

Complete insulators based on electro-mechanical test

2.5

Insulator metal fittings based on elastic limit 2.5

Steel structures based on elastic limit of tension members and on cripping loads of compression members

2.5

Foundations for structures against overturning or uprooting under maximum simultaneous working loadings

2.5





1.13. Creepage distance (based on Um)

mm/kV 31


N/A

2. CIRCUIT BREAKER


2.2. Type

SF6

2.3. Standards

IEC 62271-100, 61233, 60694, 60427, 60376,

60480



2. 5 Auto reclosing


2.6 Rated making current

KAp 62.5

2.7 Rated breaking current

kA 40

Rated breaking current (asymmetrical)

KA To IEC 62271-100

%dc

%dc

2..8 Rated breaking current under out-of-phase conditions

kA 6.25

2.9 First phase to clear factor

1.5

2.10 Transient Recovery Voltages


2.11. Rated capacitive breaking current To IEC 62271-100

Rated line charging breaking current A 125 Rated cable charging breaking current A 250 Rated Single/Back to Back Capacitor bank

breaking current A 400

2.12. Rated small inductive/reactor breaking

currents of:

To IEC 61233

small inductive A 10, 20, 50 and 100 reactor A 306


pu 2.3






pu 2.3


pu 2.3


ms 60


Without current ms With 100% rated breaking current ms


ms 3


- - -

2.20 Closing time from energisation of close coil to latching of circuit breaker in fully closed position

ms

2.21 Making time (energisation of close coil to contact touch)

Without current ms 100% making current ms

2.22 Maximum time interval between closure of first and last phase of three phase circuit breaker

ms 3

2.23 Maximum time interval between closure of interrupters of one phase

- - -


ms N/A.

2.25 Mechanical life of circuit breaker and mechanism in No. of operations

10,000

2.26 Electrical contact life in number of operations at:

Rated current –1600 A Fault current - 40 kA 15 to 20




UNIT DATA Required Offered Cumulative ampere rating

2.27 Number of current interrupting break units in series per phase

One


Motor charged spring operated

2.29 Type of power device (motor charged)

For closing Spring or hydraulic For opening

Spring or hydraulic


Yes

2.31 Manual spring release

Yes

2.32 Mechanical on/off indicator

Yes

2.33 Mechanical spring charge / discharge indication

Yes

2.34 Charging time

s

2.35 Number of trip coils

2

2.36 Number of close coils

1


V 110 DC


V 220 AC

2.39 Rated power of trip coil

W

2.40 Rated power of close coil

W


W

2.42 Total load of heaters for circuit breaker

W

2.43 Mass of circuit breaker complete (three pole)

kg

2.44 Mass of single phase circuit breaker

- - -

2.45 Emergency Trip Facility

Yes





3. ISOLATORS



Motor

3.3 Standards

IEC 62271-102, IEC 60694, 61128,

60265

3.4 Maximum capacitive current that can be interrupted by the isolator

A

3.5 Total time from initiation of opening operation to isolator in fully open position

s


s


s

38 Hand operating facility

Yes


Yes


V 110 DC


Yes

3.12. Accessibility to operating mechanism from ground level

Yes


V 220 AC

3.14 Rated power of operation coil

W


W

3.16 Total load of heaters for isolator

W

3.17 Total mass of three phase isolator complete

kg


kg

3.19 Contact type

3.20 Type of interlocking





4. EARTHING SWITCH



Hand

4.3 Standards

IEC 62271-102, 60694


Yes


Yes


V 110 DC


Yes

4.8 Accessibility to operating mechanism from ground level

Yes


V 220 AC

4.10 Total load of heaters for earthing switch

W

4.11 Total mass of earthing switch complete

kg


5.1 Type

Post

5.2 Standards

IEC 60694, 60044-1

5.3 Rated continuous thermal current at 50oC


Note: All Cl PX CTs shall be ISN 1.2 A

5.4 Cable feeder bays current transformer

To suit specific requirements

Number of cores Rated extended primary current Ratio (TR – turns ratio) I core A II core A III core A IV core A




UNIT DATA Required Offered Class

I core II core III core IV core Knee point voltage (Ek) I core V II core V III core V IV core V Exciting current (IE) at Ek I core mA II core mA III core mA IV core mA Rated output (burden to be 25-100% rated

burden)

I core VA II core VA

III core VA IV core VA Total mass of single phase current

transformer complete

kg

5.5 Bus coupler and bus section bays current transformer

To suit specific arrangement

Number of cores 120%

6. CAPACITIVE VOLTAGE TRANSFORMERS

6.1. Type

Capacitive

6.2. Standards

IEC 60186, IEC/PAS 60044-

5:2002


pC 10


pC 5


6.6. Line voltage transformer





6.7. Number of secondaries 2 Rated transformation ratio kV 132/√3 /

0.11/√3 /0.11/√3

Rated accuracy class I secondary 3P/1.0 II secondary 3P Rated output (burden to be 25-100% rated

burden)

I secondary VA II secondary VA Mass of single phase voltage transformer kg

7. BUSBARS AND CONNECTIONS

7.1 Type (flexible or tubular)

7.2 Material

7.3 Short-circuit current rating / duration

KA/s

7.4 Normal current rating at 40oC at 50oC

A A

7.5 Maximum continuous current rating

A

7.6 Flexible conductors stranding nominal cross-sectional area outer diameter no. of conductors per bundle spacing between conductors

mm2

mm

mm

7.7 Tubular conductors nominal cross-sectional area outer diameter inner diameter

mm2

mm

mm

7.8 Maximum stress at surface of flexible conductor

kV/mm


µV

7.10





8 POST TYPE INSULATORS



8.3 Number of units in complete post insulator

8.4 Length of each unit

mm

8.5 Mass of complete post insulator

kg

8.6 Maximum cantilever working load (complete post insulator)

N

8.7 Minimum cantilever breaking load, upright (complete post insulator)

N

8.8 Power frequency withstand voltage dry: wet

kV

8.9 Basic insulation level

kVp

8.10 Minimum dry/wet switching surge withstand level

kVp


µv

9 TENSION AND SUSPENSION INSULATORS



9.3 Number of units in string

mm

9.4 Greatest diameter of units

mm

9.5 Distance between centres of units

mm

9.6 Length of string, overall

mm

9.7 Mass of string complete with all fittings

kg

9.8 Maximum working load

N





9.9 Power frequency withstand voltage of complete string

kV

9.10 Basic insulation level of complete string

kVp

9.11 Minimum wet switching surge withstand level of complete string

kVp

9.12 Radio influence voltage measured at 1.1 times Us/√3 at 1 MHz

µv



SCHEDULE D5 - 11KV METALCLAD SWITCHGEAR


1. GENERAL



1.3. Type of Switchgear

Metal clad - air insulated, indoor switchgear with Vacuum Circuit

Breaker

1.4. Standards

IEC 60298, 62271-100,

60694, 60529

1.5. Number of years equipment of identical design has been in service

Years

1.6. Rated voltage

kV 12

1.7. Rated normal current -At 40oC − Incoming bay, busbar & bus-section bay A 4000 − Outgoing bay A 1600/600 to suit . - At 50oC (contractor to confirm by calculation) − Incoming bay, busbar & bus-section bay A − Outgoing bay A


Hz 50

1.9. Rated lightning impulse withstand voltage − Phase to earth kV 95 − Across the isolating distance kV 110

1.10. Rated power frequency withstand voltage − Phase to earth kV 38 − Across the isolating distance kV 45

1.11. Partial discharge test voltage

kV IEC 60270

1.12. Rated short-time withstand current (1s)

kA 50


kA 125


Single



SCHEDULE D5 - 11KV METALCLAD SWITCHGEAR - Cont


1.15. Method of earthing − Busbars side − Line side

1.16. Minimum subdivision of cubicles at compartments

Busbar/ CTs/ Circuit Breaker/

Cable/ VTs/Relay compartment.

1.17. Are busbars segregated − Between phases Yes − Between cubicles Yes

1.18. Material of cover

Metallic

1.19. Material of partitions

Metallic

1.20. Material of shutters

Metallic/Earthed

1.21. Busbars and joints fully encapsulated

Yes

1.22. Busbar and feeder shutters lockable with individual manual and automatic features

Yes

1.23. Protection class − General IP41 − Busbars, cable compartment, internal partitions IP3XD − Circuit breaker compartment

• Door closed • Door open

IP41 IPXX

− LV compartment IP41 − Shutters and spouts

− Pressure relief device/flaps IP4X

IP 5X

1.24. The way of securing (opening/closing of doors)

Hinged doors


Copper


Silver-plated copper


1.28. Method of personnel protection in case of operation of pressure relief device


kg





1.30. Minimum factors of safety for switchgear (minimum 2.5)

− Busbars or other connection based on elastic limit

2.5

− Complete insulators based on electro-mechanical test

2.5

− Insulator metal fittings based on elastic limit 2.5 − Steel structures based on elastic limit of tension

members and on crippling loads of compression members

2.5

− Foundations for structures against overturning or uprooting under maximum simultaneous working loading

2.5

1.31. Manufacturer quality assurance according to ISO

9000, 9001, 9002, 9003 and 9004

Yes

1.32. Type test certificate to be issued by Independent laboratory or independently witnessed type test certificate available

Yes

1.33 Emergency manual trip facility (during failure of DC supply)

Yes

2. CIRCUIT BREAKER



2.3. Type

Vacuum, Truck mounted,

withdrawable

2.4. Fully encapsulated

Yes

2.5. Standards

IEC 60298, 62271-100,

60694, 60427

2.6. Rated voltage

kV 12

2.7. Rated normal current at 40oC (Incomer/bus section; Feeder)

A 4000/1600/630

2.8. Required current at 50oC (Incomer/bus section; Feeder) (Contractor to confirm by calculation)

A


Hz 50





2.10. Rated lightning impulse withstand voltage − Phase to earth KVp 95 − Across the isolating distance

kVp 110

2.11. Rated power frequency withstand voltage − Phase to earth

kV 38

− Across the isolating distance

kV 45


kA 50


kAp 125


O-0.3 sec - - CO - 3 min - CO


kA 125

2.16. Rated breaking current (symmetrical)

kA 50


kA To IEC 62271-100

2.18. Rated breaking current under out of phase conditions

kA

2.19. First pole to clear factor

2.20. Rated line charging breaking current

A

2.21. Rated cable charging breaking current

A

2.22. Rated small inductive breaking current of - unloaded transformer - reactor

A


pu <2.5

2.24. If the Overvoltage factor above, is in excess of 2.5 pu, then detail steps taken to protect the system from overstressing, by the use of suitable Metal-Oxide surge arresters

2.25. Maximum peak value of switching overvoltage when interrupting capacitive currents

kV

2.26. Maximum peak value of switching over-voltage when interrupting low inductive and reactor currents

kV






ms 60

2.28. Opening time (trip initiation to contact separation) − Without current ms − With 100% rated breaking current ms


ms

3


ms


− Without current ms − With 100% rated current ms


ms 3

2.34. Mechanical life of CB and Mechanism in number of operations

min 5000

2.35. Electrical contact life at rated current in No. of operations

2.36. Electrical contact life at 100% fault current in No. of operations

10

2.37. Internal arcing tests in the switchgear enclosure to IEC 60298 – Annex AA

Adjacent compartments

are not affected

2.38. Mechanical means for withdrawal

yes


3 pole

2.40. Manual spring discharge facility

Yes

2.41. Interlock facilities complying with requirements of specification

Yes

2.42. Type of power device − For closing Motor-Spring − For opening Spring


Yes





2.44. Charging time

s


1


1


V 110 DC


V 220


W


W


W

2.52. Does earthing of truck remain effective until fully withdrawn

Yes


W

2.54. Mass of circuit breaker complete (three pole set)

kg


kV IEC 60270

2.56. Manufacturer quality assurance according to ISO 9000, 9001, 9002, 9003 and 9004

Yes

2.57. Type test certificate to be issued by independent laboratory or independently witnessed type test certificate available

Yes

3. BUSBARS

3.1. Rated current at 50oC − Manufacturer’s Standard A − Corresponding site rating A

3.2. Maximum temperature rise

oC

3.3. Cross Section

mm2

3.4. Material of barriers between units

3.5. Insulation of Busbars:

− Material − Maximum working temperature oC






Yes

4. EARTHING SWITCH

4.1. Manufacturer & Place of Manufacturing − at busbar side − at line side

4.2. Type designation − at busbar side − at line side


Manual

4.4. Standards

IEC 62271-102

4.5. Rated voltage

kV 12


Hz 50


kV 110


kV 38

4.9. Rated short time (1 s) current

kA 50

4.10. Peak Current

kAp 125

4.11. Total mass of three phase complete earthing switch − at busbar side kg − at line side kg

4.12. Type of contacts − Moving Copper − Fixed Copper

4.13. Moving contacts are directly connected to earthing system via copper connectors

Yes

4.14. Continuous running earth bar has been provided

Yes







5.2. Type

Cast-resin multi-core, multi-ratio

indoor

5.3. Type of primary winding (e.g. bar, wound, etc.)

5.4. Standards

IEC 60044-1

5.5. Rated voltage

kV 12


kV 110


kV 38


kV IEC 60270


Hz 50




kA 50


kA 125


5.14 Details of all current transformers are to be provided by the Contractor after contract award

- Type designation - Number of cores - Rated extended primary current in percentage of

rated primary current

- Ratio (TR – turns ratio) • I core A • II core A • III core A





6. VOLTAGE TRANSFORMERS (3-phase sets to be provided)


6.2. Type designation for − Line transformer − Busbar transformer − Power transformer bay

6.3. Type

Inductive cast - resin single pole

insulated

6.4. Standards

IEC 60044-2

6.5. Rated voltage

kV 12


Hz 50


kV 110


kV 38


kV IEC 60270

6.10. Type of primary isolation

Drawout

6.11. Line voltage transformer & Busbar Voltage Transformer

− Number of secondaries − Rated transformation ratio kV − Rated accuracy class − Rated output VA − Total mass of three phase voltage transformer

complete kg

7. Manufacturer quality system in accordance with

ISO 9000, 9001, 9002, 9003 and 9004

Yes

8. Type test certificate to be issued by independent laboratory or independently witnessed type test certificate available.

Yes



SCHEDULE D6 - CRANE FOR GIS BUILDING


1. Manufacturer 2. Type

Overhead

travelling

3. Capacity t 4. Test load, dynamic % 5. Operating speed: - Hoist m/min - Trolley travel m/min - Bridge travel m/min

6. Operating power source and terminal voltage - Voltage V 380/220 - Frequency Hz 50

7. Dimensions - Span m - Length of runway m - Total lift of hook m

8. Crane drive motors - Manufacturer - Type

9. Trolley drive motors - Manufacturer - Type

10. Operator/Maintenance cage provided with trolley

yes

11. Enclosed current collector

yes

12. Hoist - Manufacturer - Type - Type of control Pendant or

infrared

13. Total required power kW 14. Weights

- Bridge complete t - Trolley complete t - Runway complete t

15. Reference Standards BS 466, 2573 16. Manufacturer's Quality Assurance

ISO 9000 to

9004

17. Type Test Certificates (to be issued by independent laboratory or independently witnessed type test certificate)

yes



SCHEDULE D7 – 400/132KV POWER TRANSFORMERS

Item Description Data No Required Provided 1 Description of transformers

Transmission

autotransformer

2 Type of transformers:

2.1 Indoor or outdoor

Outdoor

2.2 Shell or core

2.3 Auto or separate windings

Auto

2.4 Three phase or single phase units

Single

2.5 Cooling (IEC letter symbols)

OFAF/ONAF/ONAN

3 Site Conditions

3.1 Altitude above sea level m

Less than 1000m

3.2 Air temperature minimum °C

-10

3.3 Air temperature maximum °C

+55

4 IEC ratio power at terminals of:

4.1 HV winding MVA

250

4.2 LV winding MVA

250

4.3 Tertiary winding MVA

75

5 Continuous maximum ratings at winding terminals according to tapping position when operating under site conditions:

5.1 HV winding MVA

250

5.2 LV winding MVA

250

5.3 Tertiary winding MVA

75

6 Maximum ONAN and ONAF ratings of winding terminals irrespective of tapping position, when operating under site conditions

6.1 ONAN ratings:



SCHEDULE D7 – 400/132KV POWER TRANSFORMERS - Cont

Item Description Data No Required Provided 6.1.1 HV winding MVA

150

6.1.2 LV winding MVA

150

6.1.3 Tertiary winding MVA

45

6.2 ONAF ratings:

6.2.1 HV winding MVA

150

6.2.2 LV winding MVA

150

6.2.3 Tertiary winding MVA

45

7 Rated voltage corresponding to principal tapping

7.1 HV kV

400

7.2 LV kV

132

7.3 Tertiary kV

11

8 System highest voltage:

8.1 HV kV

420

8.2 LV kV

145

8.3 Tertiary kV

12

9 Method of system earthing

9.1 HV system

Solid

9.2 LV system

Solid

9.3 Tertiary system

Earthing transformer

10 Method of earthing of transformers

10.1 HV winding

Solid

10.2 LV winding

Solid

10.3 Tertiary winding

Earthing transformer




Item Description Data No Required Provided 11 Rated frequency Hz

50

12 IEC rated lighting impulse withstand level

12.1 HV winding kVp

1425

12.2 LV winding kVp

650

12.3 Tertiary winding kVp

110

13 Switching surge withstand level

13.1 HV winding kVp

1050

13.2 LV winding kVp

-

13.3 Tertiary winding kVp

-

14 Maximum system symmetrical rms fault current (1 phase or 3 phase) at the terminals of the transformer which the windings must be capable of withstanding

14.1 HV terminals kA

40

14.2 LV terminals kA

40

14.3 Tertiary terminals kA

50

14.4 Asymmetrical crest factor

2.55

15 Phase connections

15.1 IEC vector group symbols

YNyn0d11

15.2 Whether links are required for alternative IEC vector group

No

15.3 Alternative vector group required

-

16 Windings

16.1 Common winding

Graded

16.2 Series winding

Graded




Item Description Data No Required Provided 17 Whether one winding is a stabilising

winding only

If so, whether the winding is to be brought out to If so, whether the winding is to be brought out to separate bushing insulator(s) or cable box terminals for test purposes (For earthing see Item 10)

No -

18 Whether `on-load' or `off-circuit' tap changing equipment or links are required

On load

19 Tapping quantities transformer designation

HV LV

19.1 Minimum voltage ratio 366.6 145.2

19.2 Maximum current tapping (HV) 382.6 145.2 19.3 Maximum current tapping (LV) 400 125.4 19.4 Principal tapping 400 138.6 19.5 Maximum voltage tapping (LV) 400 145.2

19.6 Maximum voltage ratio 400 118.8 See note below

220 Tapping steps:

20.1 Approximate size per cent

1

20.2

Approximate number 20

21 Excess of continuously applied voltage over tapping voltage for any tapping when transformer is delivering tapping power

5%

22 Whether tappings are preferred on any particular winding

22.1 On common winding

Yes

22.2 IEC category of voltage variation

CFVV




Item Description Data No Required Provided 22.3 On series winding

No


-

22.5 On Tertiary winding

No


-

23 Whether on-load tap changing equipment shall be suitable for supervisory control and indication

Yes

24 Remote tap change control panel

24.1 Whether required

Yes

24.2 Exterior finish

To match existing plant

25 Automatic voltage control equipment

25.1 Whether required

Yes

25.2 Whether to be suitable for remote adjustment of setting

Yes

26 Whether equipment shall be provided to permit automatic synchronised operation of on-load tap changing equipment in parallel with similar transformers

Yes

27 Whether gas and oil actuated relay shall be fitted to each tap selector compartment

Yes

28 Bushing insulators or cable boxes for line terminals

28.1 HV and LV

Oil/SF6 bushing or Oil/Air as applicable

28.2 Tertiary

Cable box*

28.3 Filling medium for cable boxes

Air




Item Description Data No Required Provided 29 Whether disconnecting chambers are

required

Yes

30 Bushing insulator or cable box for neutral terminals, if any:

30.1 HV

Bushing

30.2 LV

Bushing

30.3 Tertiary -

31 Whether accommodation for current transformers shall be provided on:

31.1 HV terminals

Yes

31.2 LV terminals

Yes

31.3 Common winding neutral end

Yes

31.4 Tertiary terminals

Yes

32 Whether tapping shall be brought out from each capacitance graded type bushing insulator to a separate terminal for power factor testing on site, on:

32.1 HV bushings

N/A (Unless Oil/air supplied)

32.2 LV bushings

N/A (Unless Oil/air supplied)

32.3

Tertiary bushings No

33 Whether pressure relief device is to be fitted

Yes

34 Whether first filling of oil shall be supplied for the transformer and its associated oil filled equipment

Yes

35 Whether transformer shall be transported filled with oil or with a suitable gas

Gas




Item Description Data No Required Provided 36 Minimum capacity of conservator

between highest and lowest visible levels, as percentage of total cold oil volume of the transformer

7.5%

37 Whether marshalling unit shall be provided IF SO:

Yes

37.1 Whether free-standing kiosk or transformer mounted cabinet

Free standing

37.2 Whether metalclad heater to be provided

Yes

38 Type of dehydrating breather:

38.1 Silica Gel

No

38.2 Automatic of the repetitive cycle type (Dehydrating)

Yes

39 Whether wheels shall be provided If so:

Yes

39.1 Whether plain or flanged

To be agreed with M.O.E.

39.2 Whether required to turn through 90°

Yes

39.3 Gauge of track

To be agreed with M.O.E.

40 Whether winding or oil temperature indicators are required

Yes

40.1 HV winding wti

Yes

40.2 LV winding wti

Yes

40.3 Tertiary winding (wti)

Yes

40.4 Oil temperature indicator

Yes

41 Whether winding temperature indicator remote repeaters are required

No




Item Description Data No Required Provided 42 Whether the forced cooling equipment

is to be operated automatically from contacts on the winding temperature indicator

Yes

43 Whether electrical energy will be provided on site for erection purposes IF SO: Maximum available power kVA

To be agreed with M.O.E

44 Supply voltage for transformer auxiliaries V

380/220

45 Whether control and instrument wiring shall conform to specified colour code

Yes

46 Impulse tests: (state whether "type" or "routine")

Routine

46.1 Whether recurrent surge oscillograph tests are to be carried out

Yes

46.2 Whether HV winding to be directly impulse tested

Yes

46.2.1 Whether chopped waves to be included

Yes

46.2.2 For tests of HV winding impedance to earth from:

Other HV terminals LV terminals Tertiary terminals

Earthed Earthed except tested

phase Resistance earthed

46.3 Whether LV winding to be directly impulse tested

Yes


Yes




Item Description Data No Required Provided 46.3.2 For tests on LV winding, impedance to

earth from: Other LV terminals HV terminals Tertiary terminals

Earthed Earthed except tested

phase Resistance earthed

46.4 Whether tertiary winding to be directly impulse tested

Yes


No

46.4.2 For tests on tertiary winding, impedance to earth from: Other tertiary terminals HV terminals LV terminals

Earthed Earthed except for

tested phase Earthed except for

tested phase

47 Dielectric tests on windings with Um » 300 kV, non-uniform insulation:

47.1 Whether tests shall be conducted in accordance with Method 1 or Method 2, to IEC 60076-3

Method 1

47.2 If Method 2, voltage level U2 at which partial discharge measurements shall be made

48 Whether zero phase sequence impedance test required

Yes

49 Vacuum test level m bars (a)

25

50 Maximum temperature rise above ambient at IEC rated power

51.1 Of windings:

51.1.1 Hot spot °C

51.1.2 Average (by resistance) °C

51.2 Of oil:




Item Description Data No Required Provided 15.2.1 Top of oil °C

51.2.2 At inlet to cooler °C

51.2.3 At outlet from cooler °C

52 Maximum flux density in iron at rated voltage and power frequency and at rated voltage ratio

52.1 Wound limbs T

52.2 Unwound limbs T

52.3 Yokes T

52.4 Shields T

53 Maximum flux density in iron under the most onerous voltage conditions and at power frequency:

53.1 Wound limbs T

53.2 Unwound limbs T

53.3 Yokes T

53.4 Shields T

54 Maximum current density in windings at IEC rated power:

54.1 HV A/mm2

54.2 LV A/mm2

54.3 Tertiary A/mm2

54.4 Tapping A/mm2

55 Magnetising current (HV winding)

55.1 At 90% rated voltage A

55.2 At 100% rated voltage A




Item Description Data No Required Provided 55.3 At 110% rated voltage A

55.4 At the maximum voltage equivalent to the value quoted in Schedule D Part I A

56 No load losses at rated voltage ratio:

56.1 At IEC rating kW

56.2 Input to cooling plant kW

57 Load losses at 75°C and rated voltage ratio:

57.1 HV winding at IEC rating kW

57.2 LV winding at IEC rating kW

57.3 Tertiary winding at IEC rating kW

57.4 At ONAN rating kW

58 Total losses at 75°C and rated voltage ratio and with all windings loaded at:-

58.1 At IEC rating kW

58.2 At ONAN rating kW

58.3 Proportion of sum of fixed and load losses at rated power which will be supplied during the temperature rise test per cent

59 Impedance voltage at 75°C on principal tapping - per cent on primary winding rating (including all tolerances)

MAX/MIN MAX/MIN

59.1 Between HV and LV windings

59.2 Between HV and tertiary windings




Item Description Data No Required Provided 59.3 Between LV and tertiary windings

60 Impedance voltage at 75°C at each end of tapping range - per cent on primary winding rating (including all tolerances)

MAX/MIN MAX/MIN

60.1 Between HV and LV windings At maximum voltage ratio At minimum voltage ratio

60.4 Connecting leads from winding to tap changer

60.5 Tertiary windings

61 Calculated thermal time constant:

61.1 Natural cooling s

61.2 Forced cooling s

62 Oil circulation (i.e. natural/partially directed/directed)

62.1 To the windings:

62.1.1 HV

62.1.2 LV

62.1.3 Tapping

62.1.4 Tertiary

62.2 Through the windings:

62.2.1 HV

62.2.2 LV

62.2.3 Tapping

62.2.4 Tertiary




Item Description Data No Required Provided 63 Core construction

63.1 Taped/banded/bolted limbs

63.2 Taped/banded/bolted yokes

63.3 Taping/banding material

63.4 Number of limbs

63.5 Number of limbs wound

64 Type of joint in magnetic core (90% butt, overlap, mitre etc)

64.1 Whether tank or other flux shields are incorporated

64.2 Type of core steel

64.3 Specific loss of core steel at 1.5 tesla W/kg

65 Voltage rating of neutral bushing or cable box:

65.1 HV neutral kV

65.2 LV neutral kV

65.3 Tertiary neutral kV

66 Type of on-load voltage control equipment:

66.1 Single or double compartment type etc

66.2 Manufacturer's type designation

67 Tappings

67.1 Arrangement of tappings (Linear, Coarse/fine, Reversing)

67.2 Which winding is tapped and where (e.g. neutral end)




Item Description Data No Required Provided 67.3 Size of step as percentage of winding

rated voltage

67.4 Number of steps

68 Minimum thickness of tank base plate Base plate

Side plate Base plate

Side plate

68.1 With flat base 19 6 Length not exceeding 2500mm 19 6 Length exceeding 2500mm not

exceeding 7500mm 25 9

Length exceeding 2500mm

32 16

68.2 With fabricated underbase Length not exceeding 2500mm 9 6 Length exceeding 2500mm 12 9 68.3 Top mm

69 Material of transformer tank

70 Thickness of radiator plates and/or cooling tubes mm

71 Number of coolers or cooler banks per transformers

72 Rating of each cooler or cooler bank kW

73 Total oil required (including cooling system) litres

74 Filling medium of transformer tank for shipment

75 Total volume of conservator litres

76 Volume of oil in conservator between the highest and lowest visible levels litres

77 Mass of core and windings tonnes

78 Mass of copper required in the complete transformer kg




Item Description Data No Required Provided 79 Mass of core laminations kg

80 Total mass of complete transformer including cooling gear, voltage regulating equipment, all fittings and oil tonnes

81 Mass of transformer as arranged for transport (heaviest part) tonnes

82 Maximum noise level (`A' weighting) dB

83 Dimensions of transformer arranged for transport:

83.1 Height m

83.2 Width m

83.3 Length m

84 Time for which transformer can safely withstand 30 per cent over-voltage s

85 Whether any reactors, capacitors, linear or non-linear resistors are immersed in the oil of the transformer or tap changer tank

86 Transformer magnetising characteristics (on nominal tapping), and allowable duration:

86.1 250 MVA TRANSFORMER VOLTAGE

ph-ph kV rms 360 400 440 480 520 560 600

MAGNETISINGCURRENT current/ph(A rms/ph) (s)




Item Description Data No Required Provided 87 Flux-current (B-H curve for the

transformers):

88 Confirm that the life of the transformer will not be significantly reduced if subjected to the overvoltages specified in Schedule D Part I

YES/NO YES/NO

(Delete as applicable)



SCHEDULE D8 - SHUNT REACTORS

Item Description Data No Required Provided 1 Description of reactor

1.1 Indoor or outdoor installation Outdoor

1.2 Shell or core construction

1.3 Gapped core or coreless type

1.4 Three phase or single phase units

Three or single

2 Site conditions

2.1 Altitude above sea level m Less than 1000m

2.2.1 Air minimum °C -10

2.2.2 Air maximum °C +55

3 Continuous maximum rating (CMR) when operating under site conditions:

50MVA

4 Rated frequency Hz 50

5 Rated voltage kV 420

6 Nominal voltage kV 400

7 Vector group symbol YN

8 Method of system earthing Solid - Effective

9 Method of earthing the reactors Not applicable

10 Type of cooling ONAN

11 Impulse withstand level (full wave 1.2/50 microsecond) under site conditions kVp

1425

12 Whether star connected winding shall be fully insulated or graded

Graded

13 Bushing insulators or cable boxes or sealing ends for:

13.1 Line terminals Oil/SF6 bushing or Oil/Air as applicable



SCHEDULE D8 - SHUNT REACTORS - Cont

Item Description Data No Required Provided 13.2 Neutral end terminals Bushing

14 Whether accommodation for current transformers shall be provided on:

14.1 Line terminals Yes

14.2 Neutral end terminals Yes

15 Whether tapping shall be brought out from each capacitance graded type bushing insulator to a separate terminal for power factor testing on site

N/A (Unless Oil/Air Supplied)

16 Whether pressure release device is to be fitted

Yes

17 Whether first filling of oil shall be supplied for the reactor and its associated oil filled equipment

Yes

18 Whether reactor shall be transported filled with oil or a suitable gas

Gas

19 Minimum capacity of conservator between highest and lowest visible levels, as percentage of total cold oil volume of the reactor

7.5%

20 Whether marshalling kiosk or reactor mounted cabinet

Marshalling kiosk

21 Type of dehydrating breather:

21.1 Silica Gel No

21.2 Automatic of the repetitive cycle (Dehydrating)

Yes

22 Whether wheels are required If yes:

Yes

22.1 Whether plain or flanged To be agreed with M.O.E

22.2 Whether required to turn through 90° Yes




Item Description 1.1.1.1.1 Data No Required Provided 22.3 Gauge of track To be agreed with

M.O.E

23 Whether oil temperature indicator is required

Yes

24 Vacuum test level m bars (a)

25

25 IEC rated power MVAr

26 IEC rated lightning impulse withstand voltage kVp

27 Maximum temperature rise above ambient at IEC rated power

27.1 Of windings

27.1.1

Hot spot °C

27.1.2

Average (by resistance) °C

27.2 Of oil

27.2.1

Top oil °C

27.2.2

At inlet to cooler °C

27.2.3

At outlet to cooler °C

28 Maximum flux density in iron at rated voltage and power frequency

28.1 Cores T

28.2 Yokes T

28.3 Shields T

29 Maximum current density in winding at IEC rated power A/mm²

30 Total losses at 75°C and rated voltage kW

31 Impedance at 75°C at IEC rated voltage and IEC rated power




Item Description 1.1.1.1.2 Data No Required Provided 32 Resistance of windings at 75°C

ohms/phase

33 Type of winding

34 Conductor material (e.g. copper, work hardened copper etc.)

35 Conductor insulation

36 Calculated thermal time constant s

37 Type of joint in magnetic core (90° butt, overlap, mitre etc.)

37.1 Whether tank or other flux shields are incorporated

37.2 Type of core steel

37.3 Specific loss of core steel at 1.5 tesla W/kg

38 Voltage rating of neutral bushing or cable box kV

39 Minimum thickness of tank base plate Base plate

Side plate Base plate

Side plate

39.1 With flat base 19 6 39.2 Length not exceeding 2500mm 19 6 Length exceeding 2500mm not

exceeding 7500mm 25 9

Length exceeding 2500mm

32 16

With fabricated underbase Length not exceeding 2500mm 9 6 Length exceeding 2500mm 12 9 39.3 Top mm

40 Material of reactor tank

41 Thickness of radiator plates and/or cooling tubes mm

42 Number of coolers or cooler banks per reactor




Item Description Data No Required Provided 43 Rating of each cooler or cooler bank

kW

44 Total oil required (including cooling system) litres

45 Filling medium of reactor tank for shipment

46 Total volume of conservator litres

47 Volume of oil in conservator between the highest and lowest visible levels litres

48 Mass of core and winding tonnes

49 Mass of copper required in the complete reactor kg

50 Mass of core laminations kg

51 Total mass of complete reactor including control gear, all fittings and oil tonnes

52 Mass of reactor as arranged for transport (heaviest part) tonnes

53 Maximum noise level (‘A’ weighing) dB

54 Dimensions of reactor arranged for transport

54.1 Height m

54.2 Width m

54.3 Length m

55 Departure from linearity of voltage/current characteristic at following percentages of rated voltage

55.1 110 per cent A




Item Description Data No Required Provided 55.2 120 per cent A

55.3 130 per cent A

55.4 Whether above values will be demonstrated by test



SCHEDULE D9 – EARTHING AUXILIARY TRANSFORMERS

UNIT DATA

Required Offered

1 EARTHING/AUXILIARY TRANSFORMER 11/0.380KV; WITH 250 KVA AUXILIARY WINDING

1.1 Manufacturer & Place of manufacturing


1.3 Type

Three phase, oil immersed,

core type

1.4 Standards

IEC 60076-1, -2, -3, -5, -10,

60296 NEMA TR1

1.5 Mounting Outdoor, wheel

1.6 Rated voltage ratio

kV 11/0.380

1.7 Rated frequency

Hz 50

1.8 Vector group

ZNyn11

1.9 Cooling

ONAN

1.10 Method of earthing 1.10.1 HV winding Solid 1.10.2 LV winding Solid

1.11 Type (graded/non-graded) of windings

1.11.1 HV winding Non-graded 1.11.2 LV auxiliary winding Non-graded

1.12 Rated voltage of windings

1.12.1 HV winding kV 11 1.12.2 LV auxiliary winding kV 0.380

1.13 Highest voltage for equipment

1.13.1 HV winding kV 12 1.13.2 LV auxiliary winding kV 0.420



SCHEDULE D9 – EARTHING AUXILIARY TRANSFORMERS - Cont

UNIT DATA

Required Offered

1.14 Rated lightning impulse withstand voltage at HV Terminal

kV 75

1.15 Rated power frequency withstand voltage at 1.15.1 HV terminal kV 28 1.15.2 LV terminal

kV 3

1.16 HV neutral terminal kV 28

1.17 Rated power at site conditions

kVA 250

1.18 Maximum temperature rise at rated power at: 1.18.1 Windings K 55 1.18.2 Hot spot of windings K 68 1.18.3 Top oil K 50 1.18.4 Oil at inlet of cooler K 1.18.5 Oil at outlet of cooler K 1.18.6 Core K

1.19 Temperature rise of winding due to short circuit

duration of 2 s and HV side short circuit current of 25 kA

1.20 No load losses at rated voltage and rated frequency

kW

1.21 Load losses at 75°C, and rated frequency, rated power and principal tapping:

1.22 Maximum current density at rated power: 1.22.1 HV winding A/mm2 1.22.2 LV auxiliary winding A/mm2

1.23 Symmetrical short circuit withstand current (duration 2

s) at:

1.23.1 HV terminal kA 31 1.23.2 LV auxiliary terminal kA

1.24 Magnetising current (HV winding)

1.24.1 At 90% rated voltage A



SCHEDULE D9– EARTHING AUXILIARY TRANSFORMERS - Cont

UNIT DATA

Required Offered

1.24.2 At 100% rated voltage A 1.24.3 At 110% rated voltage A

1.25 Maximum flux density in core at rated voltage, power

frequency and principal tapping

T

1.26 Type of tap changing

Off-load

1.27 Type designation of off-load tap changer

1.28 Tapped winding

HV

1.29 Tapping range

+5% -5%

1.30 Tapping step

2.5%

1.31 Number of steps (positions)

4 (5)

1.32 Limitation and withstanding of fault current in neutral for 10s

A 1000

1.33 Impedance voltage range at 75°C and principal tapping: 1.34 At principal tapping > 4%

1.34.1 At maximum voltage ratio >4% 1.34.2 At minimum voltage ratio >4%

1.35 Resistance of winding at 75°C and principal tapping:

1.35.1 HV side Ω/phase 1.35.2 LV auxiliary side Ω/phase

1.36 Zero phase sequence impedance of inter-star windings

at 75°C (LV windings open-circuit)

Ω/phase

1.37 Zero phase sequence impedance of LV windings at 75°C (inter-star windings open-circuit)

Ω/phase




UNIT DATA

Required Offered

1.38 Terminal connection 1.38.1 HV terminal Air-filled cable

box

1.38.2 LV terminal Air-filled cable box

1.38.3 HV neutral terminal Air-filled cable box

1.38.4 LV neutral terminal Air-filled cable box

1.39 Isolating link for test purposes (not required if separable connector allows testing)

1.39.1 HV terminal Yes 1.39.2 LV terminal No

1.30 Mounting of current transformer at

1.30.1 HV terminal In tank 1.30.2 Neutral terminals In tank or box

1.31 Current transformers To suit

HV Line Number of cores Rated extended primary current Ratio (TR = turns ratio) I core A Class I core Knee point voltage (Ek) I core V Exciting current (IE ) at Ek I core mA Rated output (Burden to be 25-100% rated burden) I core VA HV Neutral Number of cores Rated extended primary current Ratio (TR = turns ratio) I core A




UNIT DATA

Required Offered

II core A Class I core II core Knee point voltage (Ek) I core V II core V Exciting current (IE ) at Ek I core mA II core mA Rated output (Burden to be 25-100% rated burden) I core VA II core VA LV Line (Only AIS connections) Number of cores Rated extended primary current Ratio (TR = turns ratio) I core A Class I core Knee point voltage (Ek) I core V Exciting current (IE ) at Ek I core mA Rated output (Burden to be 25-100% rated burden) I core VA LV Neutral Number of cores Rated extended primary current Ratio (TR = turns ratio) I core A Class I core Knee point voltage (Ek) I core V




UNIT DATA

Required Offered

Exciting current (IE ) at Ek I core mA Rated output (Burden to be 25-100% rated burden) I core VA All class PX CTs shall have a rated secondary current,

ISN

A

1.32 Oil:

1.32.1 Manufacturer 1.32.2 Type designation 1.32.3 Standards IEC 60296 1.32.4 Minimum flash point oC 1.32.5 Viscosity

At 20oC mm2/s At 50oC mm2/s At 80oC mm2/s

1.32.6 Maximum dielectric strength for 1 min kV 1.32.7 Dielectric factor 1.32.8 Acidity (neutralization value) mgKOH/

g

1.33 Type of dehydrating breather (Non-sealed

transformers)

Silicagel – automatic

recharge type

1.34 Conductor material (e.g. copper, work hardened copper, etc.):

1.34.1 HV windings 1.34.2 LV windings

1.35 Conductor insulation:

1.35.1 HV winding 1.35.2 LV winding

1.36 Calculated thermal time constant

min

1.37 Thickness of transformer tank 1.37.1 Sides mm




UNIT DATA

Required Offered

1.37.2 Bottom mm 1.37.3 Top mm

1.38 Material of transformer tank

1.39 Thickness of radiator plates

mm

1.40 Total volume of conservator

litres

1.41 Masses of transformer 1.42 Core and coils kg 1.43 Total mass excluded oil kg 1.44 Oil mass • in tank kg

• in radiators kg • total kg

1.45 Total mass kg

1.46 Mass of transformer as arranged for transport (heaviest part)

kg

1.47 Dimensions of transformer arranged for transport

Height m Width m Length m

1.48 Maximum noise level (to NEMA TR1)

dB 56

1.49 Vibration test (Y/N) N 1.50 Conservator vessel, radiators, fan grilles, control boxes

or cubicles and pipework anticorrosion protection

Hot dip galvanized and painted

1.51 Tank anticorrosion protection

1.52 Control/Protection voltage

V 110 DC

1.53 Manufacturer quality assurance Yes According to ISO 9000, 9001, 9002, 9003 and 9004




UNIT DATA

Required Offered

1.54 Type test certificates to be issued by: Independent Laboratory or independently witnessed

type test certificate Yes



SCHEDULE D10 – CAPACITORS

UNIT DATA Item No Description Required Offered

1.1 Assigned rated current

A

1.2 Assigned rated voltage

kV

1.3 Assigned rated output MVAr

1.4 Whether complete 3-phase bank is star or delta connected

1.5 Rated frequency

Hz

1.6 Temperature category to IEC 60871

1.7 Nominal capacitance:

1.7.1 For each element

µF

1.7.2 For each capacitor unit

µF

1.7.3 Capacitance of single phase bank

µF

1.8 Dielectric embodied in elements:

1.8.1 Whether paper and/or plastic film

1.8.2 Thickness of each: a. Paper b. Film

µm µm

1.8.3 Number per layer: Of paper Of film

1.9 Element foils thickness

µm

1.10 Method of making connections to element foils

1.11 Details of impregnating medium:

1.11.1 Trade name

1.11.2 Chemical compound

1.12 Nominal rated voltage of elements

V



SCHEDULE D10 – CAPACITORS – Cont


1.13 Design maximum dielectric stresses:

a. Paper b. Film

V/µm V/µm

1.14 Minimum rms breakdown voltage of individual elements

V

1.15 Connection of elements per capacitor unit:

1.15.1 Number in parallel

1.15.2 Number in series

1.16 Rated voltage UN of capacitor unit

kV

1.17 Rated current of unit

A

1.18 Rated output of unit

MVAr

1.19 Connection of capacitors:

1.19.1 Number of units in parallel per phase

1.19.2 Number of unit groups in series per phase

1.20 Details of fusing arrangement and whether internal or external

1.21 Losses in capacitor unit determined as described in IEC 60871 at dielectric temperatures of: 20 °C 75 °C

W/kWAr W/kVAr

1.22 Variation of losses due to temperature variation over the ambient temperature range for the temperature category stated in Item 1.6 W/kVAr at °C W/kVAr at °C

W/kVAr W/kVAr

1.23 Variation of capacitance due to temperature variation over the ambient temperature range for the temperature category stated in Item 1.6

%





1.24 Maximum operating surface temperature

rise of container - (above an ambient temperature of 50°C)

°C

1.25 Maximum internal hot spot temperature rise (above ambient stated in Item 1.24)

°C

1.26 Weight of complete unit capacitor including all fittings and impregnating medium

kg

1.27 Total weight of complete 3-phase capacitor bank arranged for transport

kg

1.28 Thickness of container:

mm

1.28.1 Top

mm

1.28.2 Sides

mm

1.28.3 Bottom

mm

1.29 Type of connector provided at HV terminals of capacitor bank

1.30 Type of connector provided at neutral ends of capacitor bank

1.31 Minimum ambient temperature at which a capacitor bank at this temperature may be energised at rated voltage and frequency without damage to, or loss of life of, unit capacitors or deterioration of associated fuses

°C

1.32 Details of discharge device:

1.32.1 Type

1.32.2 Connection

1.32.3 Number of devices (per element, of group of elements)

1.32.5 Voltage rating/device

V





1.32.6 Current rating/device

mA

1.32.7 Total loss per device at rated current

W

1.32.8 Total loss per unit capacitor at rated current

W

1.32.9 Estimated times for discharge down to the voltage limit specified in IEC 60871:

a. For a unit capacitor

Minutes

b. For the complete single phase bank

Minutes



SCHEDULE D11 – LVAC SWITCHGEAR

DATA UNIT Required Offered

A. LVAC SWITCHGEAR (380/220 V, 50 Hz)

1. GENERAL

1.1. Rated voltage V 380

1.2. Rated frequency Hz 50

2. LVAC SWITCHBOARD

2.1. Manufacturer


2.3. Type of switchboard Metal-clad withdrawable type,

multi-tier

2.4. Standards IEC 60439

2.5. Number of years equipment of identical

design has been in service

2.6. Rated current of busbars at 50°C ambient

temperature A

2.7. Busbar cross section mm2

2.8. Busbar insulation material

2.9. Busbar insulation maximum working

temperature °C

210. Temperature rise on continuous operation at

rated current at 50°C

2.11 Rated short-time withstand current (1 s) kA 50

2.12 Rated peak withstand current kA 125

2.13 Test voltage (1 min) V 2500

2.14. Impulse Withstand Voltage kVp

2.15. Type of internal barriers, shutters, etc.

Metallic

2.16. Degree of protection

IP51



SCHEDULE D11 – LVAC SWITCHGEAR - Cont


2.17. Overall dimensions per cubicle − Width mm − Depth mm

− Height mm − Weight

kg

2.18. Method of circuit breaker withdrawal manual

3. CIRCUIT BREAKER

3.1. Manufacturer


3.3. Type Air, withdrawable

3.4. Number of poles 3

3.5. Standard IEC 60947-2

3.6. Rated current at 50°C A

3.7. Rated short-time withstand current (1 s) kA 50

3.8. Rated peak withstand current kA

3.9. Rated symmetrical breaking current kA

3.10. Rated making current kA

3.11. Breaking time s

3.12. Material of: − moving contacts − fixed contacts

3.13. Design of: − moving contacts − fixed contacts

3.14. Operating mechanism − Motor rated power W − Motor operating voltage V

3.15. Weight of draw-out unit

kg

3.16. Type tests





3.16.1. Temperature Rise Test

Have heating tests at continuous rated normal current been carried out ?

− report number − date

3.16.2. Basic Impulse Voltage Type Test:

Has B.I.V test been completed?

− circuit breaker − report number

− date

3.16.3 Life Test:

Has 2000 operating life test at no load (de-energised) been carried out?

− report number − date

4. MOULDED CASE CIRCUIT BREAKERS (MCCBs)

4.1. Manufacturer


4.3. Withdrawable MCCBs type yes

4.4. Number of poles 3

4.5. Standards IEC 60947-2

4.6. Rated current at 50°C A

4.7. Rated short-time withstand current (1 s) kA

4.8. Rated peak withstand current kA

4.9. Rated breaking current kA

4.10. Remote signalling yes

4.11. Operating mechanism

4.12. Mass





5. CURRENT TRANSFORMERS

5.1. Manufacturer

5.2. Type

5.3. Type of primary winding (e.g. bar, wound, etc.)

5.4. Standards IEC 60044-1

5.5. Rated voltage

kV


kV


kV

5.8. Partial discharge test voltage kV


Hz 50



kA


kA

5.13. Line current transformer

5.13.1. Type designation

5.13.2. Number of cores

5.13.3. Rated extended primary current

%

5.13.4. Ratio (TR = turns ratio) • I core • II core

A A

5.13.5. Class • I core • II core

5.13.6. Knee point voltage (EK) • I core • II core

V V

5.13.7. Exciting current (IE) at EK • I core • II core

A A





5.13.8. Rated output (burden to be 25-100% rated burden) • I core • II core

VA VA

6. INSTRUMENTS

6.1. Manufacturer

6.2. Standards

IEC 60051

6.3. Type designation − Ammeter

− Voltmeter

6.4. Total scale range − Ammeter − Voltmeter

6.5. Dimensions

mm

6.6. Accuracy

7. PROTECTION RELAYS

7.1. Earth Fault Protection

7.1.1. Manufacturer

7.1.2. Type reference

7.1.3. Relay design (electromechanical, static, microprocessor-based, numerical)

7.1.4. Range of current settings, percent of current rating

%

7.1.5. Range of time multiplier setting

7.1.6. Current at which relay resets, percent of current setting

%

7.1.7. Current at which relay picks-up, percent of current setting

%

7.1.8. Self-checking facility

7.1.9. CT’s requirements

7.1.10. Tripping contacts ratings





7.2. Restricted Earth Fault Protection

7.2.1. Manufacturer


7.2.3. Relay design (electromechanical, static, microprocessor-based, numerical)

7.2.4. Estimated minimum faults setting (% of CT rating)

%

7.2.5. Operating time at 5 x setting

ms

7.2.6. Maximum primary out-of-zone fault current at which protection is stable

A

7.2.7. State principle of operation, i.e. H - high impedance L - low impedance

H

7.2.8. Current transformer requirements: − Required knee point voltage, Vk − CT maximum winding resistance − Magnetising current at Vk

V Ω A

7.2.9. Self monitoring

yes

7.2.10. Self checking

yes

7.2.11. Tripping contacts rating

7.3. Undervoltage / Overvoltage Relay

7.3.1. Manufacturer


7.3.3. Relay design (electromechanical, static)

7.3.4. Total scale range

V

7.3.5. Operate time at instantaneous voltage change for undervoltage / overvoltage relay

ms

7.3.6. Reset ratio overvoltage / undervoltage

%

7.3.7. Self monitoring





7.3.8. Self checking

8. Manufacturer quality system in accordance with ISO 9000, 9001, 9002, 9003 and 9004

yes

9. Type test certificate to be issued by independent laboratory or independently witnessed type test certificate available

yes



SCHEDULE D12 – DC SYSTEM

DATA LV SERVICES UNIT Required Offered

1. 110 V D.C SYSTEM - SUBSTATION SERVICES SUPPLY

1.1. 110 V Battery Units

1.1.1 Manufacturer

1.1.2 Type designation

1.1.3 Number of battery units

2

1.1.4 Type of cell

Nickel-Cadmium

1.1.5 Operating voltage per cell

V

1.1.6 Number of cells

1.1.7 Standard * IEEE 1115 for calculation

* IEC 60623, 60478, 60439 for

equipment

1.1.8 Discharge capacity:

− 10 hour rate Ah min. 250 (to be confirmed by calculation)

− 5 hour rate Ah − 3 hour rate Ah − 1 hour rate Ah − 30 minute rate

Ah

1.1.9 Final cell voltage after discharge:

− 10 hour rate V − 5 hour rate V − 3 hour rate V − 1 hour rate V

− 30 minute rate V

1.1.10 Ampere hour efficiency:

− 10 hour rate %

− 5 hour rate %

− 3 hour rate %



SCHEDULE D12 – DC SYSTEM - Cont


− 1 hour rate

%

1.1.11 Watt hour efficiency:

− 10 hour rate % − 5 hour rate % − 3 hour rate % − 1 hour rate % − 30 minute rate %

1.1.12. Maximum charging voltage per cell

V

1.1.13. Normal charging rate range

A

1.1.14. Maximum charging rate range

A

1.1.15. Float charging rate

A

1.1.16. Boost charging rate

A

1.1.17. Normal voltage across battery on float charge

V

1.1.18. Voltage per cell on float charge

V

1.1.19. Normal voltage across battery on boost charge

V

1.1.20. Voltage per cell on boost charge

V

1.1.21. Overall dimensions of one cell

mm

1.1.22. Quantity of electrolyte per cell

Litres

1.1.23. Overall dimensions of each stand

mm

1.1.24. Number of stands

1.1.25. Number of tiers

1.1.26. Material and cross section of connections: − between cells − between tiers − between stands − to battery fuse box

mm2 mm2

mm2 mm2





1.1.27. Method of treating copper connection against corrosion

1.1.28. Method of protecting copper connections against accidental short circuiting

1.1.29. Estimated short circuit current from fully charged battery

A

1.1.30. Anticipated life of electrolyte under actual operating conditions

Years

1.1.31. Anticipated life of electrolyte under actual operating conditions

Years

1.1.32 Operating temperatures: − Normal operation maximum minimum

°C °C

− Emergency discharge − maximum minimum

°C °C

1.2 110 V D.C Battery Chargers

1.2.1. Manufacturer


1.2.3. Degree of protection

IP 51

1.2.4. Number of chargers

2 x 100% for each battery

1.2.5. Type

Thyristor Controlled

1.2.6. Charging characteristic

1.2.7. Input voltage

V 3 Phase, 380

1.2.8. Input frequency and range

Hz 50

1.2.9. Input power

kVA

1.2.10. Minimum working power factor





1.2.11. Rated output power

kW

1.2.12. Output voltage range:

− float charge V − boost charge

V

1.2.13. Continuous output current range:

− float charge A − boost charge

A

Accuracy of output voltage

%

1.2.14. Overload range

%

1.2.15. Voltage ripple

%

1.2.16. Ripple frequency

Hz

1.2.17. Means of adjusting output

1.2.18. Details of any forced cooling equipment for chargers

1.2.19. Ambient temperature range

°C

1.2.20. Ambient relative humidity range

%

1.2.21. Mean time between failure (MTBF)

Years

1.2.22. Overall dimensions (shall be a separate free-standing panel/cubicle)

mm

1.2.23. Weight

kg

1.2.24. Boost charge maximum permitted constant potential per cell

V

1.2.25. Boost charge maximum permitted current as percentage of 5 hour capacity

%

1.2.26. Time to be re-charge to 90% capacity at maximum permitted voltage and current

hrs





1.3. Battery Fuse Boxes

1.3.1. Manufacturer



IP 51

1.3.4. Fuse rated current at 50oC

1.3.5. Remote signalling

yes

1.4. 110 V D.C. Switchboards

1.4.1. Manufacturer



IP 51

1.4.4. Standards

IEC 60439

1.4.5. Rating voltage

V 110

1.4.6. Rated current of busbars at 50oC ambient temperature

A

1.4.7. Busbar cross section

mm2

1.4.8. Busbar insulation material

1.4.9. Number of circuits

1.4.10. Main isolator rating

A

1.4.11. Main fuse rating

A

1.4.12. Single line diagram number

Arrangement drawing number





1.4.13. Details of Contactors:

− Manufacturer

− Type designation

− Type

− Site current rating (at 50°C)

A

− Rated breaking capacity

kA

− Short time current (1 s)

kA

− Maximum operating time

• opening msec • closing

msec

− Voltage / power coil rating

V/W

− Typical circuit diagram number

1.4.15. Details of Earth Fault Protection:

− Manufacturer

− Type Designation

− Brochure number

1.4.16. Details of Undervoltage / Overvoltage Protection:

− Manufacturer

− Type Designation

− Brochure number





1.4.17. Instruments

− Manufacturer

− Voltmeter (type)

− Ammeter (type)

− Instruments

Details of Moulded Case Circuit Breakers (MCCBs)

− Manufacturer − Type designation − Number of poles − Standards − Rated current at 50°C − Rated short-time withstand

current (1 s) − Rated breaking capacity − Remote signalling

A

kA

kA

Yes

1.4.18 Details of Miniature Circuit Breakers (MCBs)

− Manufacturer


− Number of poles

− Standards

A Yes

− Rated current at 50°C

kA

− Rated short-time withstand current (1s)

kA





− Breaking capacity at

− Remote signalling

Manufacturer quality system in accordance with ISO 9000, 9001, 9002, 9003 and 9004

Yes

Type test certificate to be issued by independent laboratory or independently witnessed type test certificate available

Yes



SCHEDULE D13 - 220 V AC UNINTERRUPTIBLE POWER SUPPLY

DATA

UNIT Required Offered

1. GENERAL

The uninterruptible power supply (UPS) shall consist but not be limited to the following items:

− 10 V DC / 220 V AC inverters

yes

− static interrupters and transfer switches

yes

− 220/220 V single phase isolating by-pass transformer

yes

− manual by-pass switch

yes

− UPS distribution board yes

2. INVERTER

2.1. Manufacturer



IP51

2.4. Rated output power VA min 1200 (to be confirmed by calculation)

2.5. Rated input voltage and range

V±%

2.6. Rated input current

A

2.7. Rated output voltage

V

2.8. Steady state voltage variation

%

2.9. Rated output current

A

2.10. Rated output frequency

Hz

2.11. Steady state frequency variation

%

2.12. Total harmonic distortion

%



SCHEDULE D13 - 220 V AC UNINTERRUPTIBLE POWER SUPPLY - Cont

DATA


2.13. Rated output power factor

2.14. Maximum harmonic distortion:

− at any single frequency

%

− at all frequencies

%

2.15. Radio frequency interference (RFI) classification

2.16. Output voltage rise time on turn-on

ms

2.17. Output voltage decay time on turn-off

ms

Maximum transient voltage variation after full load acceptance or rejection for:

− 1 cycle % − 0.1 s % − 1 s

%

2.18. Method of cooling

2.20. Ambient temperature range

°C

2.21. Maximum temperature rise (inside)

°C

2.22. Ambient relative humidity

%

2.23. Method of protecting inverters against high intensity D.C voltage surges

2.24. Mean time between failure (MTBF)

Years

2.25. Dimensions

mm

2.26. Weight

kg

3. STATIC SWITCH

A detailed description of offered static switch with data and diagram to be provided




DATA


4. ISOLATION BY-PASS TRANSFORMER

4.1. Manufacturer

4.2. Standard applied


4.4. Maximum continuous capacity

VA

4.5. Number of phase

1

4.6. Rated voltage under full load

V

4.7. Protection class

IP

Dimensions overall

mm

Total weight kg 5. MANUAL BY-PASS SWITCH

5.1. Manufacturer


5.3. Rated current at 50°C

A

6. DISTRIBUTION BOARD

6.1. Manufacturer



IP 51

6.4. Busbar insulation material

6.5. Number of circuits

6.6. Details of Miniature Circuit Breakers (MCBs)

− Manufacturer





DATA


− Number of poles

− Standards

− Rated current at 50oC

A

− Rated breaking capacity

kA

− Remote signalling

Manufacturer quality system in accordance with ISO 9000, 9001, 9002, 9003 and 9004

yes

Type test certificate to be issued by independent laboratory or independently witnessed type test certificate available

yes



SCHEDULE D14 – 132/11 KV POWER CABLES

132 KV POWER CABLES UNIT DATA Required Offered

1. GENERAL

1.1 Name of manufacturer

1.2 Place of manufacture

1.3 Manufacturers type or drawing reference number

1.4 Circuit rating required

MVA

1.5 Constructional and Testing standards Standard(s) to which cable complies

1.6 General description of cable Voltage designation Uo/U(Um) kV Number of cores one Conductor size mm2 Conductor material aluminium Type of insulation XLPE Type of metal screen/sheath lead Type of armour Type of oversheath

MDPE

1.7 Year of first commercial operation of cable type 2 CONSTRUCTIONAL FEATURES

2.1 Conductor Material aluminium Nominal cross-section mm2 800 Type of conductor Overall diameter mm Waterblocking method Semiconducting binder tape yes/no

2.2 Conductor screen Type of material Extruded semi

conductive, cross-linkable, fully bonded

Nominal thickness mm

2.3 Insulation Material XLPE Thickness: Minimum average mm Thickness: Minimum at a point mm Nominal overall diameter mm



SCHEDULE D14 – 132/11 KV POWER CABLES - Cont


2.4 Insulation screen

Type of material Extruded semi conductive,

cross-linkable


2.5 XLPE Manufacturing Methods - Extrusion line type e.g. CCV - Single pass, triple extrusion yes/no - Curing method - Cooling method

2.6 Bedding (if applicable) Type and material

2.7 Metallic screen on each core Type and material copper wire or

tape

Nominal thickness mm Nominal diameter over the screen mm

2.8 Bedding layer Type and material Nominal thickness mm Minimum thickness mm

2.9 Armour Nominal diameter under the armour mm Type and material Armour wire diameter or dimensions of strip mm

2.10 Protective anti-corrosion external sheath covering

Type and material MDPE Colour Nominal thickness mm Minimum thickness mm Termite resistant yes/no yes Type of anti-termite protection

2.11 Nominal overall cable diameter mm





2.12 Weight of completed cable kg/m

3 CURRENT RATINGS

3.1 Maximum continuous rating, direct-buried, assuming: Ground temperature at burial depth of 35oC Soil thermal resistivity of 2.5K.m/W Depth of laying 0.8m Thermally independent of other cable circuits trefoil touching (solid bonded) A flat formation spaced at one cable diameter (single

point bonded) A

Calculation Method

IEC 60287

3.2 Maximum continuous rating, in single way ducts, assuming:

Ground temperature at burial depth of 35oC Soil thermal resistivity of 2.5K.m/W Depth of laying 0.8m Thermally independent of other cable circuits trefoil touching (solid bonded) A flat touching formation (single point bonded) A Calculation Method

IEC 60287

3.3 Maximum continuous rating, in-air, assuming: Air temperature (in shade) of 50 oC Thermally independent of other cable circuits trefoil touching (solid bonded) A flat formation spaced at one cable diameter (single

point bonded) A

Calculation Method

IEC 60287

3.4 Maximum permissible conductor temperature for continuous operation

oC

3.5 Conductor short circuit capacity Short circuit current kA 40 Duration s 3 Permissible maximum temperature

oC 250

3.6 Screen / armour short circuit capacity Short circuit current kA Duration s 3 Permissible maximum temperature oC 200 4 ELECTRICAL CHARACTERISTICS

4.1 DC resistance of conductor at 20˚C Ω/m





4.2 AC resistance of conductor at 50 Hz and maximum conductor temperature

Ω/m

trefoil touching (solid bonded) Ω/m flat formation (single point bonded)

Ω/m

4.3 Positive Sequence Resistance of cable at 50 Hz Ω/m trefoil touching (solid bonded) Ω/m flat formation (single point bonded)

Ω/m

4.4 Positive Sequence Reactance of cable at 50 Hz Ω/m trefoil touching (solid bonded) Ω/m flat formation (single point bonded)

Ω/m

4.5 Zero Sequence Resistance of cable at 50 Hz in trefoil touching formation (solid bonded)

Ω/m

4.6 Zero Sequence Reactance of cable at 50 Hz in trefoil touching formation (solid bonded)

Ω/m

4.7 Capacitance per core pF/m 5 LOSSES

5.1 Total losses per three phase circuit when operating at nominal voltage and 50Hz and at the current ratings stated in Item 2 :

W/m

laid direct in trefoil touching (solid bonded) W/m laid direct in flat formation (single point bonded)

W/m

in ducts in trefoil touching (solid bonded) W/m in ducts in flat touching formation

(single point bonded) W/m

in air in trefoil touching (solid bonded) W/m in air in flat formation (single point bonded) W/m 6 INSTALLATION DATA

6.1 Minimum cable bending radius when laid: During installation mm Adjacent to joints and terminations mm

6.2 Minimum internal diameter of pipes or ducts

mm

6.2 Maximum permissible pulling force of total cable

kN

7 COMMISSIONING TESTS

7.4 Recommended tests after all terminating and jointing has been completed but before connection to the system.





1. GENERAL

1.1 Name of manufacturer

1.2 Place of manufacture

1.3 Manufacturers type or drawing reference number

1.4 Circuit rating required

MVA

1.5 Constructional and Testing standards Standard(s) to which cable complies

1.6 General description of cable Voltage designation Uo/U(Um) kV Number of cores one Conductor size mm2 Conductor material copper Type of insulation XLPE Type of metal screen/sheath Type of armour Type of oversheath

1.7 Year of first commercial operation of cable type 2 CONSTRUCTIONAL FEATURES

2.1 Conductor Material Copper Nominal cross-section mm2 Type of conductor Overall diameter mm Waterblocking method Semiconducting binder tape yes/no

2.2 Conductor screen Type of material Extruded semi

conductive, cross-linkable, fully bonded


2.3 Insulation Material XLPE Thickness: Minimum average mm Thickness: Minimum at a point mm Nominal overall diameter mm





2.4 Insulation screen

Type of material Extruded semi conductive,

cross-linkable


2.5 XLPE Manufacturing Methods - Extrusion line type e.g. CCV - Single pass, triple extrusion yes/no - Curing method - Cooling method

2.6 Bedding (if applicable) Type and material

2.7 Metallic screen on each core Type and material copper wire or

tape

Nominal thickness mm Nominal diameter over the screen mm

2.8 Bedding layer Type and material Nominal thickness mm Minimum thickness mm

2.9 Armour Nominal diameter under the armour mm Type and material Armour wire diameter or dimensions of strip mm

2.10 Protective anti-corrosion external sheath covering

Type and material MDPE Colour Nominal thickness mm Minimum thickness mm Termite resistant yes/no yes Type of anti-termite protection

2.11 Nominal overall cable diameter mm





2.12 Weight of completed cable kg/m

3 CURRENT RATINGS

3.1 Maximum continuous rating, direct-buried, assuming: Ground temperature at burial depth of 35oC Soil thermal resistivity of 2.5K.m/W Depth of laying 0.8m Thermally independent of other cable circuits trefoil touching (solid bonded) A flat formation spaced at one cable diameter (single

point bonded) A

Calculation Method

IEC 60287

3.2 Maximum continuous rating, in single way ducts, assuming:

Ground temperature at burial depth of 35oC Soil thermal resistivity of 2.5K.m/W Depth of laying 0.8m Thermally independent of other cable circuits trefoil touching (solid bonded) A flat touching formation (single point bonded) A Calculation Method

IEC 60287

3.3 Maximum continuous rating, in-air, assuming: Air temperature (in shade) of 50 oC Thermally independent of other cable circuits trefoil touching (solid bonded) A flat formation spaced at one cable diameter (single

point bonded) A

Calculation Method

IEC 60287

3.4 Maximum permissible conductor temperature for continuous operation

oC

3.5 Conductor short circuit capacity Short circuit current kA 50 Duration s 1 Permissible maximum temperature

oC 250

3.6 Screen / armour short circuit capacity Short circuit current kA Duration s 3 Permissible maximum temperature oC 200 4 ELECTRICAL CHARACTERISTICS

4.1 DC resistance of conductor at 20˚C Ω/m





4.2 AC resistance of conductor at 50 Hz and maximum conductor temperature

Ω/m

trefoil touching (solid bonded) Ω/m flat formation (single point bonded)

Ω/m

4.3 Positive Sequence Resistance of cable at 50 Hz Ω/m trefoil touching (solid bonded) Ω/m flat formation (single point bonded)

Ω/m

4.4 Positive Sequence Reactance of cable at 50 Hz Ω/m trefoil touching (solid bonded) Ω/m flat formation (single point bonded)

Ω/m

4.5 Zero Sequence Resistance of cable at 50 Hz in trefoil touching formation (solid bonded)

Ω/m

4.6 Zero Sequence Reactance of cable at 50 Hz in trefoil touching formation (solid bonded)

Ω/m

4.7 Capacitance per core pF/m 5 LOSSES

5.1 Total losses per three phase circuit when operating at nominal voltage and 50Hz and at the current ratings stated in Item 2 :

W/m

laid direct in trefoil touching (solid bonded) W/m laid direct in flat formation (single point bonded)

W/m

in ducts in trefoil touching (solid bonded) W/m in ducts in flat touching formation

(single point bonded) W/m

in air in trefoil touching (solid bonded) W/m in air in flat formation (single point bonded) W/m 6 INSTALLATION DATA

6.1 Minimum cable bending radius when laid: During installation mm Adjacent to joints and terminations mm

6.2 Minimum internal diameter of pipes or ducts

mm

6.2 Maximum permissible pulling force of total cable

kN

7 COMMISSIONING TESTS

7.4 Recommended tests after all terminating and jointing has been completed but before connection to the system.



SCHEDULE D15 - LV CABLES

DATA LV CABLES UNIT Required Offered

1. 380 VOLT POWER CABLES

1.1. Manufacturer

1.2. Cable type

Cu/XLPE/ SWA/LSOH

1.3. Standards

IEC 60189, 60227, 60228, 60287, 60724, 60811,

60885. BS 6724, BS EN 50265

1.4. Rated voltage

V 600/1000

1.5. Test voltage (1 min)

VAC/min 4000

1.6. Conductor − Cross sectional area − Material: copper − Design (stranded, sectoral, etc.) − Overall dimensions − No. of Cores

mm2

mm

min 2.5

Cu Stranded

1.7. Insulation

XLPE

1.8. Fillers − Material: polypropylene

1.9. Armour bedding − Type − Nominal thickness

mm

1.10. Armour − Type of wire − Number of wire − Diameter of wire

No. mm

1.11. Outer covering − Material − Minimum average thickness

mm

LSOH

1.12. Completed cable − Overall diameter − Weight per metre − Maximum drum length

mm kg m

*

1.13. Cable drums − Overall diameter − Width − Weight loaded

m m kg

*



SCHEDULE D15 - LV CABLES - Cont


1.14. Continuous current carrying capacity based on the conditions specified: Laid in the ground − One Circuit − Two Circuits − Three Circuits Drawn into ducts − One Circuit − Two Circuits − Three Circuits In air − One Circuit at 50°C

A A A

A A A

A

*

1.15. Maximum conductor temperature

oC

90

1.16. Conductor short circuit current Carrying capacity for one second, cable loaded as above prior to short circuit and final conductor

Temperature of

KA

oC

1.17. Minimum radius of bend around which cable can be laid − Laid direct − In ducts − In air

m m m

1.18. Ducts − Nominal internal diameter of pipes or

ducts through which cable may be pulled

mm

1.19. Maximum DC resistance − Per km of cable at 20oC of conductor

ohm

*

1.20. Maximum AC resistance − Of conductor per km of cable at

maximum conductor temperature

ohm

*

1.21. Insulation resistance − per km of cable per core

Megaoh

m


* The tenderer may provide a table of data for each of the cables offered.






2. MULTICORE CONTROL CABLES

2.1. Manufacturer

2.2. Cable type

2.3. Standards

IEC 60189, 60227, 60228, 60287, 60724, 60811,

60885. BS 6724, BS EN 50265

2.4. Rated Voltage

V 600/1000

2.5. Test voltage (1 min)

V AC/min 4000

2.6. Cores − Number of cores

No

2, 3, 4,7, 12, 19,

27, 37

2.7. Conductor − Cross sectional area: annealed copper− Material

mm2

2.8. Insulation − Thickness nominal − minimum

mm mm

XLPE

2.9. Armour bedding − Type: − Nominal thickness

mm

LSOH

2.10. Armour − Number of wire: − Diameter of wire

No. mm

2.11. Outer covering − Material: − Minimum average thickness

mm

LSOH

2.12. Completed cable − Overall diameter − Weight per metre − Maximum drum length

mm kg m

* * *





2.13. Mean electrostatic capacity − of each conductor to earth per km − of each core at 20°C

pF

*

2.14. Maximum DC resistance − per km of each core at 20°C max.

− 1.5mm2 − 2.5mm2

ohm

2.15. Minimum radius of bend round which cable can be laid

mm



* The tenderer may provide a table of data for each of the cables offered.



SCHEDULE D16 - PROTECTION SYSTEM

GENERAL PROTECTION REQUIREMENTS UNIT DATA Required Offered

1 OPERATING PERAMETERS

1.1 Auxiliary voltage range (Vn = 110Vdc) Vdc 77→150

1.2 Input frequency range (50Hz nominal) Hz 47.5→52.5

2 2. TYPE TESTS

2.1 Atmospheric Environment

Operation -25C and 55C for 96hrs, IEC 60068-2-1 Yes

Transport/storage -25C and 70C for 96hrs, IEC 60068-2-2 Yes

2.2 Relative Humidity

Operation at 93% Yes

Tested to IEC 60068-2-78 with severity class 56 days Yes

2.3 Enclosure

IEC 60529 IP50 Yes

2.4 Mechanical Environment

Vibration IEC 60255-21-1 Yes

Shock and bump IEC 60255-21-2 Yes

Seismic IEC 60255-21-3 Yes

2.5 Insulation

Rated insulation

1000 V high impedance protection CT inputs

250 V for other circuits Yes

1000 V open contact withstand Yes

Dielectric Tests

IEC 60255-5 – Series C of table 1 Yes



SCHEDULE D16 - PROTECTION SYSTEM - Cont

GENERAL PROTECTION REQUIREMENTS UNIT DATA Required Offered

Impulse voltage

IEC 60255-5 test voltage 5kV Yes

2.6 Electromagnetic Compatibility

1 MHz Burst disturbance tes

IEC 60255-22-1 severity class III

Yes

Electrostatic Discharge IEC 60255-22-2 severity class III

Yes

Radiated Electromagnetic Field Disturbance

IEC 60255-22-3 severity class III

Test method A, 27MHz through 500MHz

Yes

Electromagnetic Emissions

IEC 60255-25

Yes

Fast Transient Disturbance

IEC 60255-22-4 severity level IV

As appropriate




DISTANCE PROTECTION UNIT DATA Required Offered

1 MANUFACTURER

2 TYPE REFERENCE

3 RELAY DESIGN (MICROPROCESSOR BASED, NUMERICAL)

Numerical

4 DISTANCE PROTECTION REQUIREMENTS

4.1 3 zone ph-ph & ph-E Yes

4.2 Phase fault & Earth fault characteristic shapes (Mho, Quad)

4.3 Operating time <30ms

4.4 Switch On To Fault Yes

4.5 Power swing blocking (depending on relaying point in the power system)

Yes

4.6 Voltage transformer supervision Yes

4.7 Time delays for all zones Yes

4.8 Zone enable/disable for all zone Yes

4.9 Teleprotection modes PUR/POR/Block (Selectable) Yes

4.10 DEF plain & Blocking modes (Selectable) Yes

4.11 Z1 min and max operating time (mid zone) ms <30

5 OTHER REQUIREMENTS

5.1 Thermal overload, (49) Yes

5.2 Circuit breaker failure. 50BF- (dependent on application) Yes

2.2 5.3 Event recording function Yes

5.4 Disturbance recording function Yes

5.5 Fault locator function Yes




DISTANCE PROTECTION UNIT DATA Required Offered

5.6 Integral operator interface for local interrogation

Yes

2.3 5.7 Programmable scheme logic Yes

2.4 5.8 User-friendly HMI, Windows based software for relay setting, relay configuration and event, disturbance and fault record management.

Yes

2.5 5.9 Tripping contacts rating Carry continuous 5A Make 30A maximum for 0.2s Break dc 50W resistive 25W inductive(L/R40ms)

Yes

5.10 Self checking facility

Yes

5.11 Integral intertrip send and receive, with external input interface Intertrip send and receive operate time

Yes

6 COMMUNICATIONS

6.1 Protection

Direct optical fibre 1300nm single mode Others (please list)

Yes

6.2 Control

Communication ports (Front/rear etc) Physical links (RS485/Fibre optic) Protocols supported IEC 60870-5-103 Yes others

6.3 TYPE TEST CERTIFICATE PROVIDED

Yes




FEEDER DIFFERENTIAL PROTECTION UNIT DATA Required Offered

1 MANUFACTURER

2 TYPE REFERENCE


Numerical

4 FEEDER DIFFERENTIAL PROTECTION REQUIREMENTS

4.1 Fault settings (% of relay rating)

4.2 Minimum current at one feeder end for relay operation at that end:

1. Phase faults 2. Earth faults

4.3 Minimum current at one feeder end for relay operation at both feeder ends:

1. Phase faults 2. Earth faults

4.4 Effect of load current on settings given in 3.5, 3.6 above

4.5 Operating time at 5 x setting

45ms

4.6 Maximum primary out-of-zone fault current at which protection is stable

4.7 Insulation level between pilot wires and relay equipment 15 kV

5 PILOT WIRE REQUIREMENTS:

5.1 Number of cores

5.2 Insulation level between cores

5.3 Insulation level between cores and cable sheath

5.4 Any other requirements




FEEDER DIFFERENTIAL PROTECTION UNIT DATA Required Offered

6 PILOT WIRE SUPERVISION Check Relay (Setting ranges - Ph F 0.4In – 2.0In, EF 0.2In –0.8In)

Yes

Yes

7 TWO WAY INTERTRIP FUNCTION

Yes

8 TRIPPING CONTACTS RATING Carry continuous 5A Make 30A maximum for 0.2s Break dc 50W resistive 25W inductive (L/R40ms)

9 SELF-MONITORING

10 TYPE TEST CERTIFICATE PROVIDED

Yes




MAIN TRANSFORMER BIASED DIFFERENTIAL PROTECTION UNIT DATA Required Offered

1 MANUFACTURER

2 TYPE REFERENCE


numerical

4 BIASED DIFFERENTIAL FUNCTION

4.1 Operation time at 5 times setting

ms <25

4.2 Adjustable bias characteristics

Yes

4.3 Differential current stage Id >>

Yes

4.4 Magnetisation inrush restraint

Yes

4.5 “5th” Harmonic inrush restraint

Yes

4.6 Maximum through fault current for which relay remains stable (multiple of rating)

4.7 CT ratio and vector group compensation

5 RESTRICTED EARTH FAULT FUNCTION

5.1 HV REF

Not used

5.2 LV REF

Not used

5.3 Principle of operation High impedance/Low impedance

High

5.4 Metrosil requirements

5.5 Operation time at 5 times settings

ms <30


6.1 Phase overcurrent function 50/51 (requirement depending on application)

6.2 Earth fault protection 51N (requirement depending on application)




MAIN TRANSFORMER BIASED DIFFERENTIAL PROTECTION UNIT DATA Required Offered


Yes

6.4 Programmable scheme logic

Yes

6.5 User-friendly HMI, Windows based software for relay setting, relay configuration and event, disturbance and fault record management.

Yes

6.6 Tripping contacts rating Carry continuous 5A Make 30A maximum for 0.2s Break dc 50W resistive 25W inductive (L/R40ms)

6.7 Event recording function

Yes

6.8 Disturbance recording function

Yes

6.9 Fault recording function

Yes

6.10 Self monitoring and alarm facility

6.11 Integral intertrip send and receive

7 COMMUNICATIONS

7.1 Control

7.2 Communication ports (Front/rear etc)

7.3 Physical links (RS485/Fibre optic)

7.4 Protocols supported

• IEC 60870-5-103 Yes • others


Yes




LOW IMPEDANCE BUSBAR PROTECTION INCLUDING BREAKER FAILURE PROTECTION

UNIT DATA

Required Offered 1 MANUFACTURER

2 TYPE REFERENCE

3 RELAY DESIGN (MICROPROCESSOR-BASED, NUMERICAL)

Numerical

State principle of operation, i.e. low impedance

Low Z

4 LOW IMPEDANCE BUSBAR PROTECTION INCLUDING BREAKER FAILURE PROTECTION FUNCTIONS

4.1 Integral check zone feature (state principle of operation)

Yes

4.2 Distributed Bay Modules and Central Unit (Y/N)

Yes

4.3 Maximum number of Bays

4.4 Isolator replica

4.5 CT saturation detector and stabilisation

4.5 Integral CT supervision

4.6 CT matching functions

4.7 Phase segregated protection

4.8 Sensitivity

1. Phase faults A sec’y 2. Earth faults

A sec’y

4.9 Operating time at 5 x fault setting

ms 30

4.10 Two stage Circuit Breaker Failure Adjustable current setting Adjustable time delays per stage

Yes



Yes




LOW IMPEDANCE BUSBAR PROTECTION INCLUDING BREAKER FAILURE PROTECTION

UNIT DATA

Required Offered 5.2 Tripping contacts rating

Carry continuous 5A Make 30A maximum for 0.2s Break dc 50W resistive 25W inductive (L/R40ms)


Yes


Yes

5.5 Self monitoring and alarm facility

6 COMMUNICATIONS

6.1 Bay to central Module communication

f.o.


Yes

7 CONTROL






Yes




MULTI-FUNCTIONAL OVERCURRENT & EARTH FAULT PROTECTION

UNIT DATA


2 TYPE REFERENCE


Numerical

4 MULTI-FUNCTIONAL OVERCURRENT & EARTH FAULT PROTECTION FUNCTIONS

4.1 Number of phase CT inputs

4.2 Number of earth fault CT inputs

4.3 Standard, Very and Extreme Inverse and definite time characteristics curves conforming to IEC 60255

Yes

4.4 Number of inverse overcurrent functions (per phase)

4.5 Number of high set overcurrent functions (per phase)

4.6 Number of low set overcurrent functions (per phase)

4.7 Number of inverse earth fault functions

4.8 Number of high set earth fault functions

4.9 Number of low set earth fault functions

4.10 Number of group settings

4.11 Earth fault element suitable of high impedance REF (with external resistor)

Yes

4.12 Operating time at 5 x setting when configured for REF

ms 30

4.13 Suitable for Blocked Overcurrent busbar protection scheme

Yes

5 OTHER FUNCTIONS PROVIDED • Thermal overload 49 Y/N • Directional OC&EF Y/N




MULTI-FUNCTIONAL OVERCURRENT & EARTH FAULT PROTECTION

UNIT DATA

Required Offered 5.1 Number of output relays

• Rated for tripping • Rated for control and alarm

5.2 Integral metering functions

Yes

5.3 Opto-isolator inputs

Yes


Yes

5.5 Event and Fault recording functions

5.6 Self-monitoring facility


Yes


6 COMMUNICATIONS


Yes

7 CONTROL






Yes




MULTI-FUNCTIONAL DIRECTIONAL OVERCURRENT & EARTH FAULT PROTECTION

UNIT DATA


2 TYPE REFERENCE


Numerical

4 MULTI-FUNCTIONAL DIRECTIONAL OVERCURRENT & EARTH FAULT PROTECTION FUNCTIONS

4.1 Number of phase CT inputs

4.2 Number of earth fault CT inputs

4.3 Three phase VT input

Yes

4.4 Method of determining zero sequence voltage • Broken delta VT input (Y/N) • Derived mathematically (Y/N) •

4.5 Standard, Very and Extreme Inverse and definite time characteristics curves conforming to IEC 60255

Yes

4.6 Number of inverse DOC overcurrent functions (per phase)

4.7 Number of high set DOC functions (per phase)

4.8 Number of low set DOC functions (per phase)

4.9 Number of inverse DEF functions

4.10 Number of high set DEF functions

4.11 Number of low set DEF functions

4.12 Number of group settings

5 OTHER FUNCTIONS PROVIDED

5.1 • Non-directional overcurrent 50/51 (Y/N)

5.2 • Non-directional earth fault 50 N/51 N (Y/N)

5.3 • Thermal overload 49 (Y/N)

5.4 • Suitable for Blocked Overcurrent busbar protection scheme


MULTI-FUNCTIONAL DIRECTIONAL OVERCURRENT & EARTH FAULT PROTECTION

UNIT DATA

Required Offered 5.5 • Earth fault element suitable of high impedance REF

(with external resistor)

5.6 Number of output relays • Rated for tripping • Rated for control and alarm

5.7 Integral metering functions

Yes

5.8 Opto-isolator inputs

Yes


Yes

5.10 Event and Fault recording functions

5.11 Self-monitoring facility


Yes


6 COMMUNICATIONS


Yes

7 CONTROL




• IEC 60870-5-103 Yes • others 8 TYPE TEST CERTIFICATE PROVIDED

Yes




DIFFERENTIAL PROTECTION AND BACK-UP DISTANCE UNIT DATA Required Offered

1 MANUFACTURER

2 TYPE REFERENCE


Numerical

4 DIFFERENTIAL PROTECTION REQUIREMENTS

4.1 Phase segregated protection

Yes

4.2 Ratio and Vector correction for CTs

Yes

4.3 Adjustable biased differential protection characteristic

Yes

4.4 Sensitivity: - For phase faults - For earth faults

4.5 Operating time

ms <30

5 DISTANCE PROTECTION REQUIREMENTS

5.1 2 zone ph-ph & ph-E 3

Yes

5.2 Phase fault & Earth fault characteristic shapes (Mho, Quad)

5.3 Operating time

<30ms

5.4 Switch On To Fault

Yes

5.5 Power swing blocking (depending on relaying point in the power system)

Yes

5.6 Voltage transformer supervision

Yes

5.7 Time delays for all zones

Yes

5.8 Zone enable/disable for all zones

Yes


6.1 Thermal overload, 49 – (requirement if cable over-temperature unsuitable for tripping)

Yes




DIFFERENTIAL PROTECTION AND BACK-UP DISTANCE UNIT DATA Required Offered

6.2 Circuit breaker failure. 50BF- (dependent on application)

Yes


Yes


Yes

6.5 Fault locator function

Yes


Yes


Yes


Yes

6.9 Tripping contacts rating Carry continuous 5A Make 30A maximum for 0.2s Break dc 50W resistive 25W inductive(L/R40ms)

Yes

6.10 Self checking facility

Yes

6.11 Integral intertrip send and receive, with external input interface

Yes

7 COMMUNICATIONS

7.1 Protection

Direct optical fibre 1300nm single mode

Yes

7.2 Control

Communication ports (Front/rear etc) Physical links (RS485/Fibre optic)

Protocols supported IEC 60870-5-103 Yes others 8 TYPE TEST CERTIFICATE PROVIDED

Yes




RESTRICTED EARTH FAULT PROTECTION UNIT DATA Required Offered

1 MANUFACTURER

2 TYPE REFERENCE

3 RELAY DESIGN (MICROPROCESSOR-BASED, NUMERICAL, E-M)

Numerical

4 RESTRICTED EARTH FAULT PROTECTION FUNCTIONS

4.1 Estimated minimum fault setting (% of CT rating)

%

4.2 Operating time at 5 x setting

ms

4.3 State principle of operation,

• H = high impedance • L = low impedance

4.4 Metrosils provided

4.5 Self monitoring (excluding EM)

Yes



4.8 Communications (numerical relays)


Yes

5 CONTROL






RESTRICTED EARTH FAULT PROTECTION UNIT DATA Required Offered


• IEC 60870-5-103 • others

Yes

6 TYPE TEST CERTIFICATE PROVIDED Yes




TRIP CIRCUIT SUPERVISION UNIT DATA Required Offered

1 MANUFACTURER

2 TYPE REFERENCE

3 RELAY DESIGN (MICROPROCESSOR, BASED NUMERICAL)

Numerical

4 3. TRIP CIRCUIT SUPERVISION FUNCTIONS

4.1 Operating time

ms

4.2 Supervision of the whole trip circuit with CB open and closed.

Yes

4.3 Relay operated indicator

Yes


Yes




MULTI-CONTACT TRIPPING RELAYS UNIT DATA Required Offered

1 MANUFACTURER

2 TYPE REFERENCE

3 MULTI-CONTACT TRIPPING RELAYS FUNCTIONS

3.1 Operating time

ms <12

3.2 Is relay mechanically latched or self resetting?

3.3 Method used to reset latched relay (hand or electrical)

3.4 Burden at rated voltage

3.5 Minimum voltage at which reliable operation occurs


3.7 Relay operated indicator type


Yes



SCHEDULE D17 - SUBSTATION CONTROL SYSTEM

SUBSTATION CONTROL SYSTEM UNIT DATA

Required Offered

1.0.0 SUBSTATION CONTROL SYSTEM Yes

2.0.0 MASTER CONTROL UNIT

2.1.0 Substation Computer

2.1.1 Manufacturer Yes

2.1.2 Model Yes

2.1.3 Processor

2.1.4 Type

2.1.5 Word length Bits

2.1.6 Clock speed (minimum) MHz

2.1.7 Memory size

2.1.8 Supplied (minimum) Mb

2.1.9 Supportable/expandable Gb

2.1.10 Hard disk size

2.1.11 Supplied (minimum) Gb


2.1.13 Optical Storage Yes

2.1.14 Operating system

2.1.15 Software supplied

2.1.16 Operating temperature range °C

2.1.17 Maximum relative humidity %

2.1.18 Nominal voltage V ac

2.1.19 Operating frequency Hz

2.1.20 Starting current A

2.1.21 Power requirement W

2.1.22 Mean time between failure h

2.1.23 Mean time to repair h



SCHEDULE D17 - SUBSTATION CONTROL SYSTEM - Cont


Required Offered

2.2.0 Gateway


2.2.2 Model Yes

2.2.3 Processor

2.2.4 Type



2.2.7 Memory size






2.2.13 Communication Protocols To Control Centre(s)

2.2.14 NCC Main IEC 60870-5-101 Yes

2.2.15 NCC Alt IEC 60870-5-101 Yes

2.2.16 NCC TCP/IP Intranet Yes

2.2.17 DCC Main IEC 60870-5-101 Yes

2.2.18 DCC Alt IEC 60870-5-101 Yes

2.2.19 NCC IEC 60870-5-104 Yes

2.2.20 DCC IEC 60870-5-104 Yes

2.2.21 Communication Protocols in Substation

2.2.22 NCC IEC 60870-5-103 Yes

2.2.23 DCC IEC 60870-5-103 Yes

2.2.24 NCC IEC 60870-5-101 Yes

2.2.25 DCC IEC 60870-5-101 Yes

2.2.26 List other operating Protocols





Required Offered

2.2.27 Data Communications Interface

2.2.28 V.35 interface at 64Kb/s Yes

2.2.29 X.21 / V.11 interface at 64Kb/s Yes




2.2.33 Nominal voltage V dc






2.3.0 Operator Workstations / HMI


2.3.2 Model Yes

2.3.3 Literature reference for principle of operation Yes

2.3.4 Processor

2.3.5 Type



2.3.8 Memory size






2.3.14 Optical Storage Yes





Required Offered

2.3.15 Pointer Device


2.3.17 Operator interface screens









2.3.26 Operator Desk Yes


2.3.28 Type of construction

2.3.29 Finish and material of working surfaces

2.3.30 Method of mounting VDUs

2.3.31 Number

2.3.32 Operator Chairs

2.3.33 Manufacturer

2.3.34 Type of construction

2.3.35 Type of upholstery

2.3.36 Number

2.4.0 Colour Visual Display Units (VDUs)


2.4.2 Model Yes


2.4.4 Screen size across diagonal mm





Required Offered

2.4.5 Usable display area mm

2.4.6 Resolution (minimum) pixels

2.4.7 Dot pitch mm


2.4.9 Operating relative humidity range %





2.4.14 Approximate lifetime of monitor under continuous use h



2.5.0 Substation Local Area Network (LAN)

2.5.1 Architecture and Technology Yes


2.5.3 Transmission medium (e.g. optical fibre) and physical specification

2.5.4 Protocols

2.5.5 IEC 60870-5-101

2.5.6 IEC 60870-5-104

2.5.7 IEC 61850

2.5.8 List all other protocols

2.5.9 Data transmission rate(s) Mbps

2.5.10 Physical arrangement - Identify all main elements in the supply including hubs, concentrators, bridges, routers, gateways switches etc. and the number of each

Yes

2.5.11 For each element of the LAN indicate the

2.5.12 No and type of ports

2.5.13 % of spare for each type of port





Required Offered

2.5.14 Management software package, functions and facilities, and hardware platform

2.5.15 % Loading under various system activity scenarios including

2.5.16 normal loading for performance testing %

2.5.17 high loading for performance testing %

2.5.18 system power up %

2.5.19 main server fail-over and database resynchronisation

2.5.20 Overall availability %

2.6.0 Individual Elements

2.6.1 For each element of the LAN equipment provide the following information

2.6.2 Manufacturer

2.6.3 Type

2.6.4 Nominal voltage

2.6.5 Power requirements V ac

2.6.6 Range of ambient temp. and max relative humidity for continuous reliable operation W

2.6.7 Mean time between failures oC

2.6.8 Mean time to repair %RH

2.7.0 Printers

2.7.1 Logging Printer Yes

2.7.2 Manufacturer

2.7.3 Model

2.7.4 Literature reference for principle of operation

2.7.5 Number

2.7.6 Mounting arrangement

2.7.7 Method of printing (e.g. ink jet)

2.7.8 Print speed ppm

2.7.9 Paper feed mechanism

2.7.10 Number of columns (minimum)





Required Offered






2.7.16 Max noise level at 1 m dB(A)



2.7.19 Colour Printers


2.7.21 Model Yes


2.7.23 Number

2.7.24 Mounting arrangement

2.7.25 Print speed (minimum) ppm

2.7.26 Technology

2.7.27 Resolution dpi

2.7.28 Paper size

2.7.29 Sheet feed paper tray capacity Sheets

2.7.30 Internal memory (minimum) Mb






2.7.36 Max noise level at 1 m dB(A)





Required Offered






BAY CONTROL UNIT HARDWARE UNIT DATA

Required Offered

3.0.0 BAY CONTROL UNIT HARDWARE

3.1.0 General Yes


3.1.2 Module designation Yes


3.1.4 Power supply V dc 110

3.1.5 Power requirements W

3.1.6 Maximum Number of expansion modules

3.1.7 Mean-time to repair for each type of RTU H

3.1.8 Mean-time between failure for each type of RTU H

3.1.9 Local LCD Display

3.1.10 Operating temperature range °C 0 – 50

3.1.11 Operating relative humidity range

3.2.0 BCU Enclosure

3.2.1 Manufacturer

3.2.2 Module designation

3.2.3 Literature reference for enclosure

3.2.4 Weight

3.2.5 Dimensions

3.2.6.0 Degree of protection

3.2.6.1 Flush Mounted housing

3.2.6.2 Surface mounted housing

3.3.0 IEC Standards ( Or Equivalent )

3.3.1 EMC Type tests (Provide Class/Level or Severity rating)

3.3.2 EMC Compliance IEC 60255-22-3

3.3.3 Dielectric withstand test IEC 60255--5

3.3.4 High Voltage impulse test IEC 60255-5





Required Offered

3.3.5 Fast transient disturbance test IEC 61000-4-4 and 60255-22-4

3.3.6 Oscillatory transient IEC 61000-4-12

3.3.7 Radiated immunity test IEC 61000-4-6 and 60255-22-3

3.3.8 Electrostatic discharge test IEC 61000-4-2 and 60255-22-2

3.3.9 1 MHz Burst disturbance test to IEC 60255-22-1

3.3.10 Electromagnetic emissions to IEC 60255-25

3.3.11 Emitted interference test IEC 61000-4-3

3.3.12 Mechanical test Compliance

3.3.13 Vibration test IEC 60255-21-1

3.3.14 Shock test IEC 60255-21-2

3.3.15 Seismic test IEC 60255-21-3

3.3.16 Temperature rise test IEC 60068-2-1 and 2-2

3.3.15 Relative humidity test 60068-2-78

3.3.16 Enclosure test to IEC 60529 IP50

3.4.0 BCU Functions

3.4.1 The monitoring functions include:

3.4.2 Switching status monitoring (breakers)

3.4.3 Indication & alarm status monitoring

3.4.4 Analogue measurements (currents, voltages, etc.)

3.4.5 Resolution of time tagging ms 1

3.4.6.0 The control functions include:

3.4.6.1 Close / open of circuit breakers

3.4.6.2 Close / Open of isolators / disconnectors

3.4.6.3 Transformer Automatic tap change control

3.4.6.4 Breaker Voltage Synchronisation Check Control

3.4.6.5 Bay interlocking facilities

3.4.7.0 The reporting functions include:





Required Offered

3.4.7.1 Sequence of Events recording

3.4.7.2 Post – Mortem Review / Fault waveform capture

3.4.7.3 Tenderers to state memory capacity and functionality of Sequence of events and fault waveform capture

3.5.0 BCU Configuration

3.5.1 Number of processors

3.5.2 Main processor

3.5.3 Secondary processors

3.5.4 Communication processor (module)

3.5.5 Type of communication between processors

3.5.6.0 LCD Display and selector Buttons on front of BCU Yes

3.5.6.1 Functionality to include

3.5.6.2 Full control of circuit bay

3.5.6.3 Status of bay plant

3.5.6.4 Circuit active line diagram

3.5.6.5 Power system Measurements

3.5.6.6 Display alarms and events

3.6.0 Processing Units

3.6.1 Main CPU

3.6.2 Manufacturer



3.6.5 Mean - time between failure h


3.6.7 Type of processor

3.6.8 Word length bit

3.6.9 Clock speed MHz





Required Offered

3.6.10.0 Kinds of memory used:

3.6.10.1 Type, size and extension capabilities KByte

3.6.10.2 Type, size and extension capabilities Kbytes


3.7.0 Secondary CPU

3.7.1 Manufacturer



3.7.4 Mean - time between failure h



3.7.7 Word length bit

3.7.8 Clock speed MHz

3.7.9.0 Kinds of memory used:




3.8.0 Communications




3.8.4 Number of communications channels


3.8.6 Word length

3.8.7 Clock speed bit

3.8.8 Type and size of memory MHz

3.8.9 Line interface to communication channel





Required Offered

3.8.10 Kinds of memory used: B/s

3.8.11 Number and type of communication ports

3.8.12 Meantime between failure h


3.8.14.0 Communication Interfaces

3.8.14.1 IEC60870-5-101 direct to Control Centre(s)

3.8.14.2 IEC60870-5-103 interface to protection IED

3.8.14.3 IEC61850 interface to substation LAN

3.8.14.4 IEC60870-5-101 for remote downloading of BCU data

3.8.14.5 List all Protocols available at BCU

3.8.15 Local interface for Laptop Computer

3.8.16.0 IED interface

3.8.16.1 List of manufactures the BCU has interfaced Yes

3.8.16.2 Standard communication protocols available Yes

3.8.16.3 Optional communication protocols available Yes

3.9.0 Power Supply Module



3.9.3 Maximum number of modules per processor

3.9.4 Nominal Input voltage VDC

3.9.5 Operating voltage range


3.9.7 Isolation







Required Offered

3.10.0 Digital Input Module




3.10.4 Input voltage V dc

3.10.5.0 Is contact input type configurable as

3.10.5.1 Status and alarms

3.10.5.2 Sequence of events

3.10.5.3 BCD or parallel inputs

3.10.5.4 Pulse accumulator

3.10.5.5 Or any combination of these

3.10.6.0 Standard number of inputs per module:

3.10.6.1 double position

3.10.6.2 single position

3.10.7 Type of input circuit isolation

3.10.8 Input galvanic separation

3.10.9 Impulse voltage withstand kV

3.10.10 Scan time ms

3.10.11 Minimal pulse duration ms

3.10.12 Input impedance ohm

3.10.13 Filter time constant ms



3.11.0 Pulse Counting Module

3.11.1 Is this facility incorporated into the digital input module?







Required Offered


3.11.5 Type of counter

3.11.6 Maximum count

3.11.7 Storage and resetting under control of external clock?

3.11.8 Number of inputs per module

3.11.9 Input current mA


3.11.11 Signal range : pulse widths ms



3.12.0 Command Output Module




3.12.4.0 Contact ratings

3.12.4.1 Switched voltage V

3.12.4.2 Switched power VA max

3.12.4.3 Switched current A

3.12.4.4 Range of duration of command output S

3.12.5 Number of two position output channel per module

3.12.6 Are outputs activated by select-check-actuate procedure?

3.12.7 Are welded contacts checked prior to command output?

3.12.8 Are the outputs fused and fuse status monitored?








Required Offered

3.13.0 Digital Output Module



3.13.3 Number of outputs per module


3.13.5 Maximum output current mA

3.13.6 Maximum switched output voltage V


3.13.8 Type of protection against back EMF kV

3.13.9 Command duration adjustable in the range s



3.14.0 Analogue to digital conversion module





3.14.5 Resolution bits

3.14.6 Accuracy %

3.14.7 Common mode noise rejection dB

3.14.8 Normal mode noise rejection dB

3.14.9 Conversion time ms

3.14.10 Scanning time (per channel) ms

3.14.11 Meantime between failures h






Required Offered

3.15.0 Analogue Input Module




3.15.4 Scanning resolution bits

3.15.5 Accuracy %

3.15.6 How are overflow and conversion failures dealt with?

3.15.7 Conversion time

3.15.8 Input filter attenuation at 50 Hz dB

3.15.9 Input signal types (e.g. 4-20 mA)

3.15.10 Method of isolation


3.15.12 Input impedance ohm

3.15.13 Type of ADC switching

3.15.14 Standard number of inputs per module



3.16.0 Analogue Output Module



3.16.3 Number of outputs per module


3.16.5 Output voltage range V

3.16.6 Output current range mA

3.16.7 Type of isolation

3.16.8 Load resistance range ohms

3.16.9 Maximum error over-current ranges %





Required Offered


3.17.0 Direct AC Connection Voltage



3.17.3 Maximum number of modules processor


3.17.5 Input voltage ranges V ac


3.17.7 Burden on instrument transformer circuit VA



3.17.10 Accuracy %

3.17.11 What calculations are supported?



3.17.14 Impulse voltage withstand kV kV

3.18.0 Direct AC Connection Current



3.18.3 Maximum number of modules processor


3.18.5 Input current ranges A





3.18.10 Accuracy %





Required Offered

3.18.11 What calculations are supported?



3.18.14 Impulse voltage withstand kV kV




BCU SOFTWARE UNIT DATA

Required Offered

4.0.0 BCU SOFTWARE

4.1.0 General Requirements

4.1.1 Program structure

4.1.2 System software

4.1.3 Standard functions programs

4.1.4 User functions programs

4.2.0 Capability of:

4.2.1 BCU program downloading from Control Centre

4.2.2 Application configuration from Control Centre

4.2.3 Remote selection of processing parameters

4.2.4 Selection of communication protocols

4.2.5 Selection of operation modes (cyclic, polled, etc.)

4.2.6 Appropriate protection of software against power failure

4.2.7 Automatic BCU re-start without software down-loading

4.3.0 SYSTEM SOFTWARE

4.3.1 Operating System (Monitor) Functions and capabilities

4.3.2 Calendar Program Type, Functions and capabilities

4.3.3 Time Synchronization Program Functions and capabilities

4.3.4 Database Updating Program Functions and capabilities

4.3.5 Testing and Diagnostics Programs Functions and capabilities

4.4.0 Standard Functions Programs

4.4.1 Data Communication Programs: Functions and capabilities

4.4.2 Capability of communication protocol selection





Required Offered

4.4.3 Capability of operating modes selection

4.5.0 Analogue Measurements, Scanning and Transmission Programs

4.5.1 Capabilities of adjustments

4.5.2 Transducers constants

4.5.3 Periodic transmission/transmission by exception

4.5.4 Automatic checking of A/D-conversion accuracy

4.5.5 Smoothing

4.5.6 Threshold values

4.5.7 Limits

4.5.8 Scan duration (range)

4.5.9 Cycle duration (range) s

4.5.10 Priority of transmission s

4.5.11 Digital Input Data Scanning and Transmission Program

4.6.0 Functions and capabilities

4.6.1 Capability of adjustments

4.6.2 Scan duration (range) ms

4.6.3 Transient time of status information (range)

4.6.4 Cycle duration (range) ms

4.6.5 Debouncing filter s

4.6.6 Suppression of intermediate status information

4.6.7 Time tagging

4.6.8 Transmission mode

4.6.9 Priority of transmission

4.7.0 Alarm and Event handling

4.7.1 Grouping of alarms and events

4.7.2 Maximum number of groups





Required Offered

4.8.0 Supervisory Control Programs: Functions and capabilities

4.8.1 Select before execute

4.8.2 Target check

4.8.3 Cancelling control after adjustable time delay

4.8.4 Capability of adjustments:

4.8.5 Duration of output (range) s

4.8.6 Allowed duration of execution (range) s

4.8.7 Sequence of Events programs

4.8.8 Minimal sequence of events time resolution ms

4.8.9 Sequence of events memory capacity

4.8.10 Events time resolution (adjustable range)

4.8.11 Priority of transmission

4.8.12 Post - Mortem Review / Program

4.8.13 Selection of analogues for post-mortem review

4.8.14 Short interval time resolution (adjustable range) s

4.8.15 Long interval time resolution (adjustable range) s

4.9.0 Data processing programs: Functions and capabilities

4.9.1 Required minimum data processing:

4.9.2 Logic functions

4.9.3 Arithmetical functions (MW , Mvar etc )

4.9.4 Limiting functions s

4.9.5 Comparative functions

4.9.6 Time functions




GATEWAY SOFTWARE UNIT DATA

Required Offered

5.0.0 GATEWAY SOFTWARE

5.1.0 General Requirements

5.1.1 Database management application

5.1.2 Alarm and Event Grouping

5.1.3 Alarm and Event Separation for NCC and DCC

5.1.4 Alarm and Event storage and remote / local access

5.2.0 Capability of:

5.2.1 Gateway program downloading from Control Centre

5.2.2 Application configuration from Control Centre

5.2.3 Remote selection of processing parameters

5.2.4 Selection of communication protocols

5.2.5 Selection of operation modes (cyclic, polled, etc.)

5.2.6 Appropriate protection of software against power failure

5.2.7 Automatic re-start without software down-loading

5.3.0 System Software

5.3.1 Operating System (Monitor) Functions and capabilities

5.3.2 Calendar program Type, functions and capabilities

5.3.3 Time Synchronization Program Functions and capabilities

5.3.4 Data Base Updating program Functions and capabilities

5.3.5 Testing and Diagnostics Programs Functions and capabilities




TRANSDUCERS UNIT DATA

Required Offered

6.0.0 TRANSDUCERS

6.1.0 Current transducer.

6.1.1 Manufacturer

6.1.2 Type reference

6.1.3 Number

6.1.4 Principle (e.g. 3 phase, 3 wire, unbalanced)

6.1.5 Output range mA

6.1.6 Input ranges available A


6.1.8 Insulation level kV

6.1.9 Impulse withstand level kV peak

6.1.10 Minimum accuracy over working range %

6.1.11 Response time (0 to 90%) ms

6.1.12 Mounting details


6.1.14 Operating humidity range %

6.1.15 Auxiliary supply if required

6.1.16 Voltage range V

6.1.17 Power requirements VA

6.1.18 Frequency Hz

6.1.19 Type of overload protection

6.1.20 Permissible continuous input overload %A

6.2.0 Voltage transducer

6.2.1 Manufacturer

6.2.2 Type

6.2.3 Number






Required Offered

6.2.5 Input ranges available V









6.2.14 Auxiliary supply

6.2.15 V range V


6.2.17 Frequency Hz


6.2.19 Permissible continuous input overload %V

6.3.0 Active Power MW

6.3.1 Manufacturer


6.3.3 Number



6.3.6 Input ranges available

6.3.7 Voltage V

6.3.8 Current A

6.3.9 Burden on instrument transformer circuit

6.3.10 Current Transformer (CT) VA

6.3.11 Voltage Transformer (VT) VA





Required Offered








6.3.19 Auxiliary supply if required



6.3.22 Frequency Hz


6.3.24 Permissible continuous input overload

• Voltage %V

• Current %A

6.4.0 Reactive Power MVArs

6.4.1 Manufacturer


6.4.3 Number




6.4.7 Voltage V

6.4.8 Current A







TRANSDUCERS UNIT DATA Required Offered











6.4.22 Frequency Hz



• Voltage %V

• Current %A

6.5.0 Frequency

6.5.1 Manufacturer

6.5.2 Type

6.5.3 Number

6.5.4 Measurement range Hz


6.5.6 Input ranges available V ac

6.5.7 Burden on instrument VT circuit VA









TRANSDUCERS UNIT DATA Required Offered





6.5.17 Frequency Hz


6.5.19 Permissible continuous input overload %V %

6.6.0 Power Factor

6.6.1 Manufacturer

6.6.2 Type

6.6.3 Number

6.6.4 Measurement range


6.6.6 Input ranges available V ac

6.6.7 Burden on instrument VT circuit VA










6.6.17 Frequency Hz






Required Offered

6.6.19 Permissible continuous input overload %

• Voltage %V

• Current %A

6.7.0 Combined active and reactive power

6.7.1 Manufacturer

6.7.2 Type

6.7.3 Number

6.7.4 Measurement range


6.7.6 Voltage V ac

6.7.7 Current A








6.7.15 Number of analogue outputs

6.7.16 Analogue output range mA

6.7.17 Calculations available

6.7.18 Serial output protocol










Required Offered

6.7.24 Frequency Hz



• Voltage %V

• Current %A



SCEHDULE D18 - CONTROL, OPERATION, INDICATION AND ALARM CIRCUITS

Item No Device Function Operating supply voltage

Required Provided

1 Gas And/Or Oil Actuated Relay

a. Alarm b. Trip

48 V dc 110 V dc

Yes Yes

2 Winding temperature indicator

Alarm Trip Cooler Control

48 V dc 110 V dc 220/380 V ac

HV Yes LV Yes Tertiary Yes

3 Winding temperature indicator remote repeater

Indication HV No LV No Tertiary No

4 Oil temperature indicator

Alarm Trip

48 V dc 110 V dc

Yes Yes

5 Tap-changing equipment

Control Indication

220/380 V ac 48 V dc

Yes Yes

6 Fan failure Alarm 48 V dc Yes

7 Oil flow failure

Alarm 48 V dc Yes

8 Remote electrical indicator to show if units of a group of transformers are in parallel on different tappings

Indication Alarm

48 V dc -

Yes No

9 Transformer “tap change in progress” remote electrical indication

Indication Alarm

48 V dc -

Yes No

10 Transformer “voltage ratio” remote electrical indication

Indication

48 V dc

Yes



SCHEDULE D19 - BUSHINGS

Item No

Description Required

Provided

1 Nominal voltage (UN) kV

380 132 11

2 Site altitude above sea level for which bushings are to be suitable where this exceeds 1000 m

Less than 1000m

3 Minimum nominal specific creepage distance in mm per unit of system highest voltage mm/kV

31

4 Impulse withstand level (full wave 1.2/50 microsecond) under site conditions kVp

1425 650 110

5 Switching surge withstand level kVp

1050 - -

6 Arcing horns or rings

Yes Where Oil/Air Bushings provided

7 Radio influence voltage measured at 110 per cent of the maximum line to ground operating voltage and at 1000 kHz, shall be less than µV

500

8 Maximum symmetrical fault current kA

40 31.5 50


SCHEDULE E

TECHNICAL DOCUMENTATION/DRAWINGS AND OPERATING AND MAINTENANCE INSTRUCTIONS

Sch E.1 Volume 3 - 400 kV Schedules Issue 3 August 05

SCHEDULE E - TECHNICAL DOCUMENTATION/DRAWINGS AND OPERATING AND MAINTENANCE INSTRUCTIONS

This Schedule details the requirements for drawings, documents, operating and maintenance instructions, samples and models as may be required to describe the Works. SCHEDULE E1 - DRAWINGS ISSUED WITH THE TENDER

The drawings listed below form an integral part of this specification and are to provide a guide regarding the system electrical connection, location and arrangement.

Drawing

Title

1 IQ 18284 Typical 400/132kV GIS Substation - Single Line Diagram of 400kV Switchgear

1 IQ 18285 Typical 400/132kV GIS Substation - Single Line Diagram of 132kV

Switchgear 1 IQ 18286 Typical 400/132kV GIS Substation - Single Line Diagram of 400kV

Substation Protection 1 IQ 18287 Typical 400/132kV GIS Substation - Single Line Diagram of 132kV

Substation Protection 1 IQ 18518 Typical 400/132kV AIS Substation - Single Line Diagram of 400kV

Switchgear 1 IQ 18519 Typical 400/132kV AIS Substation - Single Line Diagram of 132kV

Switchgear 1 IQ 18520 Typical 400/132kV AIS Substation - Single Line Diagram of 400kV

Substation Protection 1 IQ 18521 Typical 400/132kV AIS Substation - Single Line Diagram of 132kV

Substation Protection 1 IQ 18288 Typical 400/132kV Substation - Single Line Diagram of LVAC Supplies 2 IQ 18289 Typical 400/132kV Substation - Single Line Diagram of 110V DC

Supplies 2 IQ 18290 Typical 400/132kV Substation - Single Line Diagram of 48V DC

Supplies 3 IQ 18291 Typical Substation Diagrams - Symbols List 1 IQ 18292 Typical 400/132kV GIS Substation - General Arrangement of Buildings

and Roads 1 IQ 18293 Typical 400/132kV Substation - Layout and Elevation of 400kV GIS

Switchgear Building 1 IQ 18294 Typical 400/132kV Substation - Layout and Elevation of 132kV GIS

Switchgear Building


Drawing

Title

1 IQ 18295 Typical 400/132kV Substation - Layout of Control and Relay Building 1 IQ 18296 Typical 400/132kV Substation - Layout and Elevation of Substation

Store, Workshop and Car Port 2 IQ 18297 Typical Guard House 1 IQ 18298 Typical 400/132kV Substation - Layout of Staff Housing 2 IQ 18303 Typical Arrangement of Control Desk 1 IQ 18304 Typical Outdoor Open Terminal 400/132/33/11/6.6kV Electrical Safety

Clearances

SCHEDULE E2 - DRAWINGS REQUIRED WITH TENDER

The Contractor shall submit with this Tender full details to describe the proposal and as a minimum shall include the following information:

(a) General arrangement of the switchyard showing general equipment layout, overall dimensions of equipment bays, and phase-phase and phase-earth clearances where applicable.

(b) Outline drawings of switchgear bays, circuit breakers, disconnect switches, earthing switches and other main plant showing overall dimensions and weights, including details for shipping.

(c) Typical drawings of protection equipment, relay panels, and associated equipment enclosures

(d) General arrangement for transformers and reactors.

(e) Bushings or cable termination details for transformers.

(f) Descriptive information and drawings dealing with tank, core and winding arrangements including type of coils, insulation, use of grading, on-load tap-changing equipment and location of all ancillary devices.

(g) Evidence of Type testing on similar switchgear and transformer units.

The contractor shall include any other drawings, catalogues, descriptions and photographs necessary to present a clear picture of the type and class of equipment being submitted.


SCHEDULE E - TECHNICAL DOCUMENTATION/DRAWINGS AND OPERATING AND MAINTENANCE INSTRUCTIONS - CONT

SCHEDULE E3 - CONTRACT DRAWING REQUIREMENTS

Following award of Contract the Contractor shall submit for approval drawings, which shall be in sufficient detail to show:

1 Substation General Arrangement and Single Line Diagrams

(a) General arrangement at each substation. (These drawings shall give the principal dimensions and positions of the circuit breakers, disconnecting switches, etc.)

(b) Single line diagram of the main high-voltage connections, showing protection and metering circuits.

2 Switchgear and Associated Control and Protection

(a) Section drawings of circuit breakers showing general details of construction.

(b) General arrangement of control and indicating panels.

(c) General arrangement of relay panels.

(d) Typical diagrams of unit protective equipment and busbar zone protection.

(e) General arrangement of battery charging equipment.

(f) General arrangement of auxiliary switchgear.

(g) General arrangement, details and schematic diagram of oil filtering and storage equipment (if any are required).

(h) General arrangement and details of isolating switches and earthing blades.

(j) General arrangement, details and schematic diagram of compressed air system, if required.

(k) Details of bushing, post and suspension insulators.

(m) General arrangement and details of surge arresters and associated surge counters.

(n) Sectional elevation drawings of each type of circuit breaker bay showing positions of current transformers and other apparatus forming an integral part of each unit.

(p) Details and schematic diagram of interlocking.

(q) Complete schematic diagrams of:

(i) Direct current tripping connections;



SCHEDULE E3 - CONTRACT DRAWING REQUIREMENTS – Cont

(ii) Direct current control and indication connections;

(iii) Current transformer connections;

(iv) AC voltage connections for protective equipment, indication and synchronizing;

(v) Connections of electrical interlocking equipment;

(vi) Connections of busbar zone protective equipment.

(r) Complete wiring diagrams.

(s) Details of protective relays, accessories and current transformers including particulars of wiring and drilling dimensions.

(t) Details and arrangements of auxiliary plant and kiosks.

(u) Details of circuit breakers handling equipments.

(v) Details of instrument scales.

(w) Material lists.

(y) Layout and schedule of multi-conductor cables.

(z) Details of transformer fire protection equipment (if any are required).

3 Transformers

(a) The general arrangement and dimensions of the equipment to be supplied under the Contract.

(b) Detail drawings showing core clamping, winding arrangements, tank and wheel detail dimensions, cooler details and control cubicle details.

(c) The weight of each part on all detail drawings.

(d) The nature of the material from which the various parts are to be made and their surface finishes.

(e) The weld details and machining and assembly tolerance of all assemblies.

(f) The manner in which such parts are designed to function.

(g) Name plate details.

(h) Wiring diagrams and catalogue numbers of all electrical equipment.



SCHEDULE E3 - CONTRACT DRAWING REQUIREMENTS – Cont

(j) Complete electrical wiring diagrams.

(k) Complete electrical wiring diagrams.

(m) Material lists of all ancillary equipment - starters, fans, relays, bushings etc.

(n) The location of checks, anchors, grout pockets and the like in structures constructed by others. Such drawings shall be provided not less than six months prior to the scheduled start of construction of the structure effected.

(p) Final issues of all applicable drawings

(q) Drawings, submitted by the Contractor shall be in sufficient detail to show:

(i) The general arrangement and dimensions of the parts and the size of each major part of the equipment to be supplied under the contract.

(ii) The weight of each major part on all detail drawings. The shipping weight and dimensions shall also be given.

(iii) The nature of the material and surface finish from which the various parts are to be made.

(iv) The weld details and machining and assembly tolerance of all assemblies.

(v) The manner in which such parts are designed to function.

(vi) Wiring diagrams and catalogue numbers of all electrical equipment

4 Civil, architectural and building services

Submittals required for are required to fully detail all substation buildings, roads, drainage equipment foundations building serves and air conditioning equipment as specified.

SCHEDULE E 4 - CONTRACTOR’S SUBMITTALS - DRAWING AND DESIGN DATA

The Contractor shall submit all drawings, samples and models for approval in sufficient time to permit modifications to be made if such are deemed necessary, and the drawings and samples and models to be re-submitted without delaying the initial deliveries or completion of the Contract Works. The time allowed for the Employer to review and comment on drawings, samples and models shall be agreed.

If the Contractor requires early review of any drawing in order to avoid delay in the completion of the Contract Works, he shall advise the Engineer to such effect when submitting the drawing.



SCHEDULE E 4 - CONTRACTOR’S SUBMITTALS - DRAWING AND DESIGN DATA - Cont

The drawing format and the indexing system, will be agreed at the first Contract meeting between the Contractor and the Engineer. The number of copies of each drawing or of any subsequent revision to be submitted to the Engineer for review shall be advised to the Contractor by the Engineer.

Drawings, samples and models submitted by the Contractor and approved by the Engineer shall not be departed from without the instruction in writing of the Engineer.

The Engineer reserves the right to request any further additional information that may be considered necessary in order fully to review the Contractor’s drawings.

Any drawing modified from a previously submitted drawing shall bear a new version number. Revised drawings reissued for review shall have at least one copy clearly marked indicating the amendments to the drawing. Revision boxes must be provided giving the date, revision letter and brief description of each drawing.

Any drawing or document submitted for information only shall be indicated as such by the Contractor. Drawings submitted for information only will not be returned to the Contractor unless the Engineer considers that such drawings do need to be reviewed, in which case they will be returned suitably stamped with comments.

Following final review, further copies of the reviewed drawing shall be marked “Issued for Construction” and shall be supplied to the Engineer for distribution and to Site.

All drawings shall be drawn to one of the preferred scales quoted in Table 7 of BS Publication PD6031 and on paper of the appropriate size from the International Series of A sizes.

Except as otherwise specifically approved, all drawings shall be of size not greater than A0 (normally 841 mm x 1189 mm) nor smaller than A4 (normally 210 mm x 297 mm).

All drawings shall be accurately drawn to scale on sheets of specified size and shall be legible. Wording on drawings shall be in English. All units and dimensions shall be in the metric (S.I) system. Symbols shall be in accordance with approved standards. Drawings submitted for approval shall be to scale not less than 1:20. All important dimensions shall be given and the material of which each part is to be constructed shall be indicated.

The Contractor shall be responsible for any discrepancies or errors in or omissions from the drawings, whether such drawings have been approved or not by the Engineer. Approval given by the Engineer to any drawing or sample shall neither relieve the Contractor from his liability to complete the Contract Works in accordance with this Specification and the Conditions of Contract nor exonerate him from any of his guarantees, or relieve the Contractor of responsibility for correctness, nor for results arising from errors or omissions nor for failure in the matter of guarantee, which may become evident during erection or subsequent operation.



SCHEDULE E 4 - CONTRACTOR’S SUBMITTALS - DRAWING AND DESIGN DATA - Cont

All drawings, samples and models shall be submitted in accordance with the provisions of this Specification and shall become the property of the Employer.

If revisions are required after a drawing has been submitted, the Contractor shall resubmit the specified number of reproductions to the Engineer.

All drawings submitted by the Contractor shall have the following particulars in the lower right hand corner in addition to the Contractor’s name, date, scale, number and title of the drawing, contract number, substation title and equipment description.

Ministry of Electricity

Baghdad, Iraq

SCHEDULE E5 - INSTALLATION AND MAINTENANCE INSTRUCTIONS

The Contract Price shall be deemed to include illustrated installation and maintenance instructions written in English.

The instructions are to be as simple and clear as possible, fully illustrated with drawings and diagrams as necessary and detailed with part numbers for ordering of replacements. Two copies are required for use of the Engineer during erection work.

A further 6 copies are to be reproduced as a book or books of approximately A4 size and bound into strong black durable imitation leather covers inscribed upon the front generally in the form of the title page to this document except that the references to Specification, Conditions of Contract, drawings, etc, will be replaced by “Installation and Maintenance Instructions”.

The name of the main Contractor, but not that of any subcontractor, may also be inscribed upon the cover after the description of the plant. The name of the Ministry of Electricity shall be inscribed upon the spine.

SCHEDULE E6 - FINAL RECORDS

After completion of work on Site all Contract drawings shall be revised where necessary to show the equipment as installed and two copies of revised drawings shall be submitted for review. A complete set of reviewed records shall be provided comprising, one full size reproducible copy and one full size print. Record drawings shall be endorsed “As Constructed” and shall be correctly titled and carry the Engineer’s review number, Contractor’s drawing number and where appropriate the Ministry of Electricity’s number allocated to the item.



SCHEDULE E6 - FINAL RECORDS - Cont

After final review of the “As Constructed” record drawings the Contractor shall submit two complete sets of records on compact discs, one of which is for the Ministry of Electricity. Electronic copies of the drawings shall be in CAD 2002 format suitable for reproduction on paper using the Engineer’s preferred software packages. Each disc shall provide a comprehensive drawing list containing the drawing number, sheet, revision and title of every drawing. Each single file drawing record shall be self-supporting, complete with unique title and drawing number, without referencing other files. Non-standard items such as fonts, line types, etc should not be used. If compression techniques are applied to files then any software necessary to decompress the files shall be included on the discs. The Contractor shall ensure that all information contained on the discs has been checked for virus contamination. Each compact disc shall be supplied suitably encased and accompanied with printed documentation describing the contents of the compact discs, the formats and software used to compile the discs and the print hardware required to reproduce the record drawings.

Final record copies shall be handed over before the issue of the Taking Over Certificate.


SCHEDULE F

DEVIATIONS FROM THE TECHNICAL SPECIFICATION

Sch F.1 Volume 3 - 400 kV Schedules Issue 3 August 05

SCHEDULE F - DEVIATIONS FROM THE TECHNICAL SPECIFICATION

(Information to be provided with Tender) The Tenderer shall set out below a tabulated statement showing clearly section by section compliance and departures from the Specification and details of alternative proposals. The Tenderer will be deemed to have complied with the Specification in all respects and as written unless qualified in this Schedule.

Section Departure from the requirements of the Project Specification

with details of alternative proposals


SCHEDULE G

QUANTITIES AND PRICES

Sch G.1 Volume 3 - 400 kV Schedules Issue 3 August 05

SCHEDULE G – QUANTITIES AND PRICES

PREAMBLE

The prices inserted in Schedule G shall include all the requirements in the Invitation to Tender. The quantities, rates and prices in Schedule G shall include all design, testing, inspection, plant, labour, supervision, materials, erection, maintenance, transportation, handling, storage, supply and use of Contractor’s equipment, temporary works, insurance, profit; together with all general risks, liabilities and obligations set out or implied in the Contract.

The cost of items against which the Tenderer has failed to enter a price shall be deemed to be covered in the Tender price. The whole cost of complying with the provisions of the Invitation to Tender shall be included in the items provided in Schedule G and where no items are provided, shall be deemed to be distributed among the rates and prices for related items of work.

Sch G.2 Volume 3 - 400 kV Schedules Issue 3 August 05

SCHEDULE G - QUANTITIES AND PRICING - CONT

(Information to be provided with Tender)

This Schedule shall be completed for the Proposal as per the Specifications

Item no.

Description

Qty

Supply, delivery and insurance to

site

Installation, commissioning

and insurance at site

Total Price


SCHEDULE J1

RECOMMENDED SPARES

Sch J1.1 Volume 3 - 400 kV Schedules Issue 3 August 05

SCHEDULE J1 - RECOMMENDED SPARES

(Information to be provided with Tender) The Tenderer is required to provide a list of recommended spares for a 5-year period from the end of the Defect Liability Period for the Work. All unit prices quoted shall be valid for any spare parts ordered by the Client in this period.

Main equipment type Part no/description Quantity Unit price


SCHEDULE J2

SPECIAL TOOLS, TEST EQUIPMENT


SCHEDULE J2 - SPECIAL TOOLS, TEST EQUIPMENT

(Information to be provided with Tender)

Details of all special tools and test equipment required should also be provided. All unit prices quoted shall be valid for tools and test equipment ordered by the Client during the Contract Period.

The work to be done under this section consists of the supply, delivery to site and guarantee of all tools and equipment for operation and maintenance of the substations. All tools shall be of the best quality and of the class most suitable for working under the conditions specified. All material used in the tools and equipment shall be new. These shall include, but not necessarily be limited to, the items listed in the following sections.

A lump sum shall be quoted in the Schedule of Prices for all Tools and Equipment, except where separate prices are specifically requested.

Main equipment type Part no/description Quantity Unit price

Heavy Equipment

(a) Supply two mobile cranes with jib length and lifting capacity suitable for maintenance of all switchgear equipment; in the substation. Provide an optional separate price for this equipment.

(b) Supply two mobile aerial buckets, suitable for inspection and washing of 400 kV substation insulators. Provide an optional separate price for this equipment.

(c) Supply one mobile oil filter plant, suitable for filtration of the main system 400 transformer oil. Provide an optional separate price for this equipment.

(d) At each substation, supply one set of jacking devices suitable for use in installation or removal of the main system transformers as applicable


SCHEDULE J2 - SPECIAL TOOLS, TEST EQUIPMENT - CONT

Main equipment type Part no/description Quantity Unit price Workshop Equipment

(a) Steel work benches, approximately 10 square metres of working surface.

(b) Distilled water plant.

(c) Drill Press complete with 2 sets of assorted drills.

(d) Bench Grinder, fine and coarse wheels, complete with spare wheels.

(e) Electric Welder, complete with assorted rods.

(f) Moisture absorbing material drying oven

Industrial vacuum cleaner.

(g) Tool racks and boxes as required.

(h) Assorted slings and lifting tackle.

(j) Vices. Hand Tools

(a) Two sets of flat spanners, in sixes suitable for the equipment supplied.

(b) Two sets of socket spanners, in sizes suitable for the equipment supplied.

(c) Inspection lamps.

(d) Assorted screwdrivers.

(e) Electricians knives.

(f) Hammers

(g) Hacksaws.

(h) Pliers.

(j) Files



Main equipment type Part no/description Quantity Unit price (k) Blow torch

(l) Soldering Iron.

(m) One set of taps and dies, in sizes suitable for the equipment supplied.

Special Tools

(a) Earthing and Safety Equipment

(b) 4 sets - 132 kV insulated earthing rods,

(c) 2 sets - 11 kV insulated earthing rods,

(d) Earthing connections with suitable clamps

(e) One - 132 kV neon indicator,

(f) One - 11 kV neon indicator

(g) One - 33 kV neon indicator.

(h) 2 pairs - Rubber gloves,.

(j) 6 - Safety hats,

(k) 6- pairs -. Safety glasses

(l) 2 - Lineman's safety belts

(m) 50 - Warning plates.

(n) 4 - First aid kits.

(p) Sufficient length of white rope to rope off two maintenance areas in the substation.



Main equipment type Part no/description Quantity Unit price Test Equipment

(a) One set of Oil Testing Equipment, suitable for sample testing of transformer, reactor and circuit breaker oils.

(b) One AV Primary injection test set

(c) One 5000 Volt, motor-driven Megger insulation tester.

(d) One set of Meters to cover all tanks of substation maintenance (V meter, Ammeter, W meter, AC and DC).

(e) One AC Secondary injection test set.

(f) One Double Beam oscilloscope, complete with trolley.

(g) Two AVO multimeters, in ever-ready cases.

(h) One 50 C Volt hand driven Megger insulation tester.

(i) One 1000 Volt hand-driven Megger insulation tester.

(k) Test equipment for protection with necessary transformers, wires, tools, etc.


SCHEDULE J3

TRANSFORMERS AND REACTORS QUANTITIES AND PRICES FOR SPARE PARTS


SCHEDULE J3 - TRANSFORMERS AND REACTORS QUANTITIES AND PRICES FOR SPARE PARTS

This Schedule shall be completed by the Tenderer. Each Tenderer shall in addition to the specified spares, provide details of additional items recommended by him. These items are optional and shall only be included in the definite work on written instructions from the Engineer.

Description Recommended Number for 10 year maintenance period

Price

Autotransformers

400 kV bushings

132 kV bushings

Neutral Air/oil bushings

Set of autotransformer gaskets, complete (400MVA transformer)

Fans with motors, complete

Gas/oil relay (main unit) if similar type otherwise one of each type.

Gas/oil relay (tap changer) if similar type otherwise one of each type.

Oil level gauges if similar type otherwise one of each type.

Oil temperature indicator if similar type otherwise one of each type.

Winding temperature indicators if similar type otherwise one of each type.

Dehydrating breathers

Set of tap changer spares: details of spares offered including diverter switch, motor drive etc to be specified.

Tap position indicators

AVC relay


SCHEDULE J3 - TRANSFORMERS AND REACTORS QUANTITIES AND PRICES FOR SPARE PARTS - CONT

Description Recommended Number for 10 year maintenance period

Price

Fan motor protection relays

Pressure relief device

Contactors of each type

MCBs complete with bases and holders of each rating

Cubicle heaters

Thermostats

400 kV Reactor

400 kV bushings

Sets of shunt reactor gaskets complete

Gas/oil relay

Oil level gauge

Silicon gel breather

Oil temperature indicator

Earthing Transformers

Set of gaskets, complete

Gas/oil relay

Pressure relief device


SCHEDULE K

BUILDING SERVICES

Sch K.1 Volume 3 - 400 kV Schedules Issue 3 August 05

SCHEDULE K - BUILDING SERVICES

DATA BUILDING SERVICES

Required Manufacturer Offered

The Tenderer is to provide the name of the Manufacturer on this sheet against the item of Plant/Equipment to be provided; and provide full details of the Plant/Equipment appended to the Tender.

1. LIGHTING AND SMALL POWER

1.1 Distribution Boards:

1.2 Main Switches:

1.3 Luminaires Type / Weather proof outside

1.4 Luminaires Type / For emergency lighting

1.5 Luminaires Type / Explosion proof for battery room

1.6 Columns:

1.7 Earthing and Bonding Materials:

2. FIRE DETECTION SYSTEM

3. FIRE FIGHTING SYSTEM

3.1 Portable Extinguisher CO2 type

3.2 Portable Extinguisher, Dry powder type

3.3 Mobile Extinguisher, Foam Type (Outdoor)


SCHEDULE L

HEATING, VENTILATION AND AIR CONDITIONING

Sch L.1 Volume 3 - 400 kV Schedules Issue 3 August 05

SCHEDULE L - HEATING, VENTILATION AND AIR CONDITIONING

DATA HEATING, VENTILATION AND AIR CONDITIONING

Required Manufacturer Offered

The Tenderer is to provide the name of the Manufacturer on this sheet against the item of Plant/Equipment to be provided; and provide full details of the Plant/Equipment appended to the

Tender.

1. Split unit air conditioning

2. Battery room axial flow fans

3. Twin fan toilet extract units

4. Switchgear room supply and extract ventilation for high ambient temperature control

5. Switchgear room fresh air supply over pressurization unit

6. Extraction fans

7. Low velocity supply, return, exhaust and fresh air duct of required thickness including all hangers, supports and required accessories

8. Insulation to sheet metal ductwork thickness and type of materials

9. Grilles and diffusers supply, return, all as described in the specification

10. Weather louvres

11. Exhaust louvres

12. Sand filters louvers factory assembled

13. Fire dampers, size, material and type

14. Volume control dampers type and material

15. Filters for fresh air intakes and ahu

16. Automatic control system complete for a/c and ventilating system including control panel

IRAQ TYPICAL SUBSTATION SPECIFICATION DRAWING LIST

Type Scope Number Title Sht Rev Number Title Sht Rev Number Title Sht Rev

Swgr Single Line GIS 1 IQ 18284 Typical 400/132kV GIS Substation - Single Line Diagram of 400kV Switchgear 1 CSwgr Single Line GIS 1 IQ 18285 Typical 400/132kV GIS Substation - Single Line Diagram of 132kV Switchgear 1 BSwgr Single Line GIS 1 IQ 18320 Typical 132/33/11(6.6)kV GIS Substation - Overall Single Line Diagram 1 BProt Single Line GIS 1 IQ 18286 Typical 400/132kV GIS Substation - Single Line Diagram of 400kV Substation Protection 1 C

Prot Single Line GIS 1 IQ 18287 Typical 400/132kV GIS Substation - Single Line Diagram of 132kV Substation Protection 1 C 1 IQ 18522 Typical 132/33/11(6.6)kV GIS Substation - Single Line Diagram of 132kV Substation Protection(Replaces drawings 3 IQ 18322, 18323, 18324, 18325, 18326, 18327 and 18328)

1 A

Substation GA 1 IQ 18292 Typical 400/132kV GIS Substation - General Arrangement of Buildings and Roads 1 C 1 IQ 18336 Typical 132/33/11(6.6)kV GIS Substation - General Arrangement of Buildings and Roads

Building Layout GIS 1 IQ 18293 Typical 400/132kV Substation - Layout and Elevation of 400kV GIS Switchgear Building 1 C

Building Layout GIS 1 IQ 18294 Typical 400/132kV Substation - Layout and Elevation of 132kV GIS Switchgear Building 1 B 1 IQ 18529 Typical 132/33/11(6.6)kV GIS Substation - Layout of 132/33/11(6.6)kV Combined Switchgear and Auxiliary Building -

Building Layout GIS 1 IQ 18530 Typical 132/33/11(6.6)kV GIS Substation - Elevations of 132/33/11(6.6)kV Combined Switchgear and Auxiliary Building -

Swgr Single Line AIS 1 IQ 18518 Typical 400/132kV AIS Substation - Single Line Diagram of 400kV Switchgear 1 ASwgr Single Line AIS 1 IQ 18519 Typical 400/132kV AIS Substation - Single Line Diagram of 132kV Switchgear 1 ASwgr Single Line AIS 1 IQ 18321 Typical 132/33/11(6.6)kV AIS Substation - Overall Single Line Diagram 1 BProt Single Line AIS 1 IQ 18520 Typical 400/132kV AIS Substation - Single Line Diagram of 400kV Substation Protection 1 A

Prot Single Line AIS 1 IQ 18521 Typical 400/132kV AIS Substation - Single Line Diagram of 132kV Substation Protection 1 A 1 IQ 18523 Typical 132/33/11(6.6)kV AIS Substation - Single Line Diagram of 132kV Substation Protection- (Replaces drawings 3 IQ 18322, 18323, 18324, 18325, 18326, 18327 and 18328)

1 A

Substation GA AIS 1 IQ 18524 Typical 400/132kV AIS Substation - General Arrangement of Buildings and Roads 1 IQ 18336 Typical 132/33/11(6.6)kV AIS Substation - General Arrangement of Buildings and Roads

Substation GA AIS 1 IQ 18525 Typical 400/132kV AIS Substation - General Arrangement of 400kV SwitchgearSubstation GA AIS 1 IQ 18526 Typical 400/132kV AIS Substation - General Arrangement of 132kV SwitchgearSubstation GA AIS 1 IQ 18527 Typical 400/132kV AIS Substation - Elevations of 400kV SwitchgearSubstation GA AIS 1 IQ 18528 Typical 400/132kV AIS Substation - Elevations of 132kV Switchgear 1 IQ 18339 Typical 132/33/11(6.6)kV AIS Substation - Elevations of 132kV SwitchgearBuilding Layout AIS 1 IQ 18531 Typical 132/33/11(6.6)kV AIS Substation - Layout of 33/11(6.6)kV Combined Switchgear and

Auxiliary BuildingBuilding Layout AIS 1 IQ 18532 Typical 132/33/11(6.6)kV AIS Substation - Elevations of 33/11(6.6)kV Combined Switchgear

and Auxiliary Building

Prot Single Line GIS/AIS 1 IQ 18329 Typical 132/33/11(6.6)kV Substation - Single Line Diagram of 33kV Substation Protection 1 C

Prot Single Line GIS/AIS 1 IQ 18330 Typical 132/33/11(6.6)kV Substation - Single Line Diagram of 11(6.6)kV Substation Protection 1 C

Prot Single Line 132/33/11 3 IQ 18331 Typical 132/33/11(6.6)kV Substation - Single Line Diagram of MW Max Demand Indication and Recording

1 B

Aux Supplies GIS/AIS 3 IQ 18289 Typical 400/132kV Substation - Single Line Diagram of 110V DC Supplies 1 B 3 IQ 18233 Typical 132/33/11(6.6)kV Substation - Single Line Diagram of 110V DC Supplies 1 BAux Supplies GIS/AIS 3 IQ 18290 Typical 400/132kV Substation - Single Line Diagram of 48V DC Supplies 1 B 3 IQ 18234 Typical 132/33/11(6.6)kV Substation - Single Line Diagram of 48V DC Supplies 1 BAux Supplies GIS/AIS 1 IQ 18288 Typical 400/132kV Substation - Single Line Diagram of LVAC Supplies 1 B 2 IQ 18332 Typical 132/33/11(6.6)kV Substation - Single Line Diagram of LVAC Supplies 1 BBuilding Layout GIS/AIS 1 IQ 18295 Typical 400/132kV Substation - Layout of Control and Relay Building 1 BBuilding Layout GIS/AIS 1 IQ 18296 Typical 400/132kV Substation - Layout and Elevation of Substation Store, Workshop and Car

Port1 B

Building Layout 400 & 132kV 1 IQ 18297 Typical Guard House 1 B 1 IQ 18297 Typical Guard House 1 BBuilding Layout 400KV 1 IQ 18298 Typical 400/132kV Substation - Layout of Staff Housing 1 BClearances ALL 1 IQ 18304 Typical Outdoor Open Terminal 400/132/33/11/6.6kV Electrical Safety Clearances 1 C 1 IQ 18304 Typical Outdoor Open Terminal 400/132/33/11/6.6kV Electrical Safety Clearances 1 CSymbols List All 3 IQ 18291 Typical Substation Diagrams - Symbols List for (Replaces 3 IQ 18335) 1 B 3 IQ 18291 Typical Substation Diagrams - Symbols List for (Replaces 3 IQ 18335) 1 BControl Desk 400 & 132kV 2 IQ 18303 Typical Arrangement of Control Desk 1 A 2 IQ 18303 Typical Arrangement of Control Desk 1 A

33/11KVSingle Line 33/11 1 IQ 18278 Typical single Line diagram 33/11kV Substation with 2 x 31.5MVA Transformers 1 BSingle Line 33/11 1 IQ 18279 Typical single Line diagram 33/11kV Substation with 2 x 16MVA or 10MVA Transformers 1 B

Aux Supplies 33/11 2 !Q 18283 Typical single Line diagram of LVAC Supplies for 33/11kV Substation 1 ASubstation GA 33/11 1 IQ 18280 Layout of Typical 33/11kV Substation with 2 x 31.5MVA Transformers. 1 ASubstation GA 33/11 1 IQ 18281 Layout of Typical 33/11kV Substation with 2 x or 10MVA MVA Transformers. 1 ACivil Details 33/11 1 IQ 18282 Layout of Typical 33/11kV Substation Civil Details 1 A

Existing drawing being modifiedNew drawing being prepared

33/11kV

GIS

AIS

COMMON GIS/AIS

400/132kV 132/33/11(6.6)kV

Typical Substation Specification Drawing List 24 Aug 05 Date Printed 10/2/2005 11:58 AM