sp-1080 electrical desing criteria

8/10/2019 SP-1080 Electrical Desing Criteria

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ABU DHABI MARINE OPERATING COMPANY

Document Ref.:

SP-1080Control Sheet

ADMA-OPCO STANDARD ENGINEERING DOCUMENTSPAGE

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DESIGNATION SP-1080DO

C

UM

E

N

T

TITLESPECIFICATIONFOR

ELECTRICAL DESIGN CRITERIA

AUTHORITY NAME TITLEB.UNIT/

DIVSIGNATURE DATE

TECHNICAL

CUSTODIANThenarasu S. Muthu SEE

P&E/

DED

TECHNICAL Michael J. Lyon CEETLP&E/

DED

STANDARDS M. Khalid Elshobary ESQASLP&E/

DED

APPROVAL Hisham Awda MDE(A)P&E/

DED

ENDORSEMENT Ali Al-JarwanAGM(P&E)

ActingP&E

CONTROL STAMP

0 02-08 Issued For Implementation

REV. DATE DESCRIPTION/TEXT AFFECTED

The soft copy of this document onADMA-OPCO Web is

Controlled.When printed, it is considered

Uncontrolled

SF / General / 001 Rev.0 sheet 1 of 1

COPYRIGHT ABU DHABI MARINE OPERATING COMPANY - ADMA-OPCO

All rights reserved. The information contained in this document is regarded as confidential. Recipient(s) other than ADMA-

OPCO's employees undertake both during the continuance of their services to ADMA-OPCO and after termination to maintainin safe custody and not to use any such information for any purpose other than a purpose falling within the scope of the

Agreement or Contract under which this document was supplied. Recipient(s) further agree not to dispose of, make copies, inwhole or in part of such information or permit the use or access of the same by any Third Party unless the prior written

permission of ADMA-OPCO Manager Facilities Engineering is obtained.


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Rev Date Description / Text Affected


ADMA-OPCO SP-1080PAGE

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Liability for utilization by personnel/organizations outside ADMA-OPCO

Whilst every effort has been made to ensure the accuracy of this document,neither ADMA-OPCO nor its employees will assume liability for any applicationor use outside ADMA-OPCO premises/assets.


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TABLE OF CONTENTS

1. INTRODUCTION....................................................................................................................... 5

1.1 OBJECTIVE................................................................................................................................51.2 SCOPE ........................................................................................................................................51.3 COVERAGE ..............................................................................................................................51.4 EXCLUSION .............................................................................................................................51.5 REFERENCES...........................................................................................................................61.6 ABBREVIATIONS.....................................................................................................................71.7 DEFINITIONS...........................................................................................................................71.8 USE OF LANGUAGE...............................................................................................................71.9 UNITS ........................................................................................................................................71.10 LESSONS LEARNT..................................................................................................................71.11 ENVIRONMENTAL CONDITIONS........................................................................................8

2. QUALITY ASSURANCE .......................................................................................................... 9

2.1 QUALITY ASSURANCE SYSTEM.........................................................................................92.2 QUALITY PLAN.....................................................................................................................102.3 INSPECTION AND CERTIFICATION REQUIREMENTS ..................................................10

3. BASIS OF DESIGN.................................................................................................................. 11

4. POWER SUPPLY SYSTEM...................................................................................................14

4.1 GENERAL ................................................................................................................................144.2 SYSTEM CONFIGURATION .................................................................................................154.3 DISTRIBUTION SYSTEM ......................................................................................................184.4 EQUIPMENT RATING/SIZING..............................................................................................184.5 SUPPLY VOLTAGE, FREQUENCY AND SUPPLY WAVEFORM.....................................194.6 SYSTEM POWER FACTOR ...................................................................................................204.7 STANDARD VOLTAGES AND TOLERANCES...................................................................204.8 ELECTRICAL DESIGN STUDIES..........................................................................................214.9 SYSTEM PROTECTION AND METERING ..........................................................................25

4.10 INTERTRIPPING AND INTERLOCKING.............................................................................264.11 POWER MANAGEMENT SYSTEMS (PMS).........................................................................274.12 EARTHING & LIGHTNING PROTECTION SYSTEMS.......................................................29

5. CLASSIFICATION OF HAZARDOUS AREA ................................................................... 31

5.1 GENERAL ................................................................................................................................31

6. SUBSTATIONS......................................................................................................................... 32

6.1 GENERAL ................................................................................................................................326.2 MINIMUM CLEARANCES IN SUBSTATIONS ...................................................................34


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7. EQUIPMENT AND MATERIALS ........................................................................................34

7.1 GENERATORS.........................................................................................................................347.2 HV SWITCHGEAR..................................................................................................................357.3 TRANSFORMER ....................................................................................................................357.4 LV SWITCHGEAR AND MOTOR CONTROL CENTRES...................................................367.5 MOTORS ..................................................................................................................................367.6 UPS SYSTEMS.........................................................................................................................377.7 BATTERIES .............................................................................................................................38

7.8 CAPACITORS..........................................................................................................................397.9 LOCAL MOTOR CONTROL STATIONS..............................................................................397.10 CABLES AND ACCESSORIES ..............................................................................................407.11 LIGHTING................................................................................................................................427.12 SOCKET OUTLETS.................................................................................................................457.13 PORTABLE LAMPS................................................................................................................46

8. ELECTRICAL HEAT TRACING.........................................................................................46

9. INSTRUMENTATION INTERFACES.................................................................................46

10. NON-INDUSTRIAL BUILDINGS .........................................................................................47

11. MISCELLANEOUS ................................................................................................................. 48

11.1 ELECTRICAL WORKSHOP AND SAFETY KITS................................................................48

12. SPECIFIC REQUIREMENTS FOR OFFSHORE INSTALLATIONS ........................... 48

12.1 POWER SUPPLY.....................................................................................................................4812.2 PLATFORM SUPPLY SOCKET .............................................................................................4812.3 JETTIES ....................................................................................................................................4912.4 WELLHEAD TOWERS ...........................................................................................................49

13. EQUIPMENT AND CABLE NUMBERING SYSTEM...................................................... 51

14. DRAWINGS AND DOCUMENTS.........................................................................................51

14.1 GENERAL ................................................................................................................................5114.2 REQUIREMENTS FOR DRAWING AND DOCUMENTATION .........................................52

APPENDIX-A1: ILLUMINATION LEVELS ................................................................................54

APPENDIX-A2: TYPICAL SCHEMES..........................................................................................57

APPENDIX-A3: ELECTRICAL LOAD SCHEDULE (FORMAT)............................................ 64

APPENDIX-B: ABBREVIATIONS .................................................................................................65

APPENDIX-C: DEFINITIONS ........................................................................................................ 67

APPENDIX-D: REFERENCED DOCUMENTS ...........................................................................71


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1. INTRODUCTION

1.1 Objective

The objective of this Specification is to provide Electrical Design Criteria for

ADMA-OPCO Projects/Works.

This document stipulates the design and selection criteria for electrical equipment

and system design in accordance with the latest international rules, regulations andindustrial practices.

1.2 Scope

This Specification specifies the minimum requirements for Design and Engineering

of Electrical Facilities for ADMA-OPCO offshore and onshore operational areas.

This Specification is intended to define the basic requirements to be followed by the

Contractor. Nothing in this Specification shall be construed to relieve the

Contractor of his contractual obligations. Any deviation from this Specificationrequires written approval from ADMA-OPCO.

Within this Specification the basic technical features are outlined and general

requirements are given. In case special requirements exist for particular locations/

applications over and above the requirements as stated in this Specification, they

will be provided separately as part of the project specifics.

1.3 Coverage

This Specification covers the design criteria for electrical system design, selection

of equipment and materials, layout, earthing and lightning protection for new aswell as existing facilities for ADMA-OPCO projects. It also includes requirements

for safety, flexibility and reliability of the installations.

1.4 Exclusion

This Specification excludes installation and field commissioning which is covered

in ADMA-OPCO Specification SP-1083 & GDL-006. It also excludes power

sources from external utility (i.e. other than ADMA-OPCOs own generation).

For the electrical design and equipment requirements associated with the external

utility supplies, reference is made to the rules and regulations as stipulated by theapplicable utility supplier (e.g. ADWEA).


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1.5 References

1.5.1 General

The latest edition (at the time of the contract award) of the standards and

amendments as listed in Appendix-D shall, to the extent specified herein, represent

part of this Specification.

The latest edition/revision of ADMA-OPCO Standards Engineering Documents

shall be utilized as indicated in the Status List SL-001.

1.5.2 Equivalent Standards

Standard Documents equivalent to those referred to herein shall not be substituted

without written approval from ADMA-OPCO. Approval of equivalent Standard

Documents will not, in any way, remove responsibility from the Contractor to meet

the best practices and/or requirements of the Standard Engineering Documents

referred to herein, in the event of conflict.

Where differences and/or conflicting issues occur between the referenced

documents themselves or the requirements of this document, the requirements of

this document shall overrule unless otherwise advised by ADMA-OPCO. However

major conflicts shall be reported in writing to the ADMA-OPCO Standards

Authority/Technical Custodian appearing in the front sheet of this Procedure for

arbitration/resolution.

The following hierarchy of adherence to standards shall be followed:

a. Whenever ADMA-OPCO Standard Engineering Documents (SEDs) relevant

to the system and/or equipment design are available, the same shall be utilizedfirst for the purpose of design.

b. Shareholder (BP) RPs/GPs (tailored to suit ADMA-OPCO needs) shall be

utilized next in the hierarchy, if the relevant subject is not covered by ADMA-

OPCO standards.

c. National or International standards (tailored to suit ADMA-OPCO needs) shall

be utilized, if the required subject is not covered either by ADMA-OPCO or

Shareholder SEDs.

The Contractor shall equip himself with copies of all the referenced Standard

Engineering Documents referred in Appendix-D of this Specification and shallmake them readily available to all ADMA-OPCO, or nominated representative,

personnel involved in the work.


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1.6 Abbreviations

The abbreviations used in this Specification are listed in Appendix-B.

1.7 Definitions

The definitions used in this Specification are listed in Appendix-C.

1.8 Use of Language

Throughout this document, the words will, may/can, should and shall/must,

when used in the context of actions by ADMA-OPCO or others, have specific

meanings as follows:

a. Will is used normally in connection with an action by ADMA-OPCO and / or

nominated representative, rather than by a Contractor or Vendor.

b. May / Can is used where alternatives / action are equally acceptable.

c. Should is used where provision is preferred.

d. Shall / Must is used where a provision is mandatory / vital.

1.9 Units

Unless otherwise specified by ADMA-OPCO, SI units should be used in

accordance with ISO 1000. However, Imperial units versus SI units should be

quoted between brackets e.g. 30C (86 F).

1.10 Lessons Learnt

Upon completion of works related to the scope of this document, lessons learntshall be made available by the contractors/consultants/job officer and shall be

provided to ADMA-OPCO Lessons Learnt system as appropriate.


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1.11 Environmental Conditions

Following parameters shall be considered for installation works:

Parameter Description

General conditions:

Minimum ambient temperature: 5 CMaximum ambient temperature: 48 C

Design ambient temperatures:

a) For Indoor Installations: 40 C

b) For Outdoor Installations: 50 C

Temperature

(Note: All components shall be capable of withstanding storage

and transport temperature of 85 C.)

Humidity

The relative humidity is high throughout the year, averaging

about 70 % and reaching 95 % or more in the early morning

hours, although in winter the humidity may fall below 50 %temporarily during a Shamal.

Design relative humidity: 95 %

Altitude Sea level

Atmosphere

Salipherous and corrosive, often containing fine dust and

pollutant, in particular traces of carbon dioxide and hydrogen

Sulphide.

Dust storms

Dust storms are commonly associated with Shamals.

This fine dust has extremely high mobility and can penetratenormally dustproof enclosures. All measures shall be taken to

protect such ingress of dust and prevent subsequent

accumulation within equipment and cause malfunction.

Rainfall

Relatively rare and amounts are small.

Measurable rainfall usually occurs on an average of about 10

days per year.


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2. QUALITY ASSURANCE

2.1 Quality Assurance System

2.1.1 All activities & services associated with the scope of this Specification shall be

performed by Contractors/ Vendors approved by ADMA-OPCO.

2.1.2 The Contractor/Vendor shall operate a Quality Management System (QMS) within

his organization, which ensures that the requirements of this Specification are fullymet.

2.1.3 The Contractor/ Vendors quality management system shall be based on ADMA-

OPCO Specification SP-1009 or the latest issue of ISO 9001 Series and accredited

by an international certifying agency.

The Contractors quality manual shall provide details for the preparation of a

quality plan, which shall include provisions for the QA/QC of services activities.

Where an approved Contractor/ Vendor revises their Quality Management Systemthat affect the ADMA-OPCO approved Quality / Inspection & Test Plan, then the

revised Quality Plan / Inspection & Test Plan shall be submitted for ADMA-OPCO

approval before initiating any service activities.

2.1.4 The effectiveness of the Contractors quality management system may be subject to

monitoring by ADMA-OPCO or its representative and may be audited following an

agreed period of notice.

2.1.5 The Contractor/ Vendor shall make regular QA audits on all their Sub-contractors/

Vendors. Details of these audits shall be made available to ADMA-OPCO when

requested.

2.1.6 The Contractor/ Vendor shall maintain sufficient Inspection and Quality Assurance

staff, independent of the service provider management, to ensure that the QMS is

correctly implemented and that all related documentation is available.

2.1.7 Using Sub-contractors is not allowed for services/functions carried out by the

Contractor without the approval from ADMA-OPCO.


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2.2 Quality Plan

2.2.1 Contracted activities associated with the scope of this specification shall be

performed in accordance with an approved Quality Plan.

2.2.2 The level of detail required in the Quality Plan shall be commensurate with the

scope of services provided.

2.2.3 The quality of works is an essential factor in carrying out all services & activities

covered by this document.

2.2.4 During services/activities, quality assurance/quality control issues are the

responsibility of the Contractor, and shall be approved and certified by TPA.

2.2.5 Conflicts between contractor & TPA shall be reported in writing to ADMA-OPCO

for resolution.

2.3 Inspection and Certification Requirements

For all major equipment like generators, variable speed drive systems, switchgear,

transformers and UPS systems, the VENDOR shall submit type test reports of the

equipment at the tendering stage of an enquiry.

Furthermore, certificates or declarations of conformity for equipment in hazardous

areas shall be required.

All equipment and devices sourced from European Vendors and installed in

hazardous area shall be as per ATEX directives.

Details of tests to be performed on electrical equipment are covered in respectiveequipment standards.

The VENDOR of such equipment shall ensure that these Inspection and

certification requirements for material shall be certified to ADMA-OPCO CP-102

and BS EN 10204.


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3. BASIS OF DESIGN

3.1 The particular project design shall commence with project specific design criteria,

which shall be prepared by the Contractor and submitted for ADMA-OPCO

approval.

3.2 The design and engineering of the electrical installation shall satisfy all relevant

ADMA-OPCO Standards, Safety Codes and Practices and when applicable statutory

requirements of any local authorities and the requirements included in thisdocument.

3.3 The design of the electrical systems shall be based on the following key aspects:

a. Safety of personnel and equipment during operation and maintenance.

b. Reliability of supply of primary electrical power source and distributionsystem.

c. Accessibility.

d. Simplicity of operation.

e. Voltage regulation throughout the distribution system.

f. Frequency stability.

g. Flexibility to expand and adapt.

h. Cost effective.

3.4 The power distribution system planning and design shall consider the following:

a. Electrical load definition, load forecasting and locations of major equipment.

b. Appropriate power distribution philosophy, utilization voltages, maximum

continuity of supply to users, protection, monitoring and control,communication etc.

c. Provide reliable power sources for essential/emergency loads.

d. Allow operation and maintenance of the system safely without unduly

affecting the production of the plant and remote operation from a centralized

control room, or technical room.

3.5 The loads shall be classified as: Vital, Emergency, Essential, Normal and

temporary, as per following definitions:

a. Vital / very essential loads: Loads affecting the safety management systemssuch as Fire and Gas, Public address, Emergency Shutdown Systems, High

Integrity Protection Systems and critical telecommunication systems. The Vital

loads shall be supplied by means of battery back-up UPS systems.


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b. Emergency loads: Loads affecting personal safety, means of escape and

emergency response capabilities, whether directly or indirectly and a risk of

major damage to installation or equipment. These loads shall include but not be

limited to:

b1. Emergency lighting.

b2. Aeronautical equipment (e.g. Non Directional beacon).

b3. Black start utilities (in case no Essential generator is provided).

b4. One supply to the AC or DC UPS system.

b5. Critical HVAC loads, such as Control room HVAC systems.

b6. Food cold stores.

b7. Supply to battery back-up systems for critical communication systems.

b8. Radar systems.

b9. Life boat battery chargers.

b10. Fire water main and jockey pumps (if electrically driven).b11. Battery systems for run down lub oil pumps (please note that in case an

Essential generator is available, this load shall be fed from the Essential

system).

b12. Ventilation systems for battery rooms.

b13. HVAC systems for UPS rooms.

b14. Emergency generator and switchgear room ventilation and air

conditioning.

b15. Man overboard search lights.

b16. Instrument air compressor (in case of 2 * 100 % instrument air

compressors, one shall be supplied from the emergency generator and

one from the normal power generation).

b17. Potable water systems for living quarters.

b18. Battery chargers for portable hand lamps.

In case the emergency generator is adequately sized and relatively close to the main

gas turbine generator starter motors, there will be no need to include a separate

essential generator within the design.


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c. Essential loads: Loads involved in the restarting of the installation in case the

emergency generator has insufficient capacity to energize the main gas turbine

starter motors or in case the emergency generator is too remote to allow the

transfer of energy to the main gas turbine starter motors. The essential

generator shall be automatically started on loss of normal supply. It shall be

possible to select auto mode (automatic start) or manual mode (operator start)

by means of a selector switch. The essential loads shall include but not be

limited to:

c1. HVAC for switchgear rooms.

c2. Black start utilities (in case the Emergency generator is inadequate or too

remotely located).

c3. Lighting systems required for start-up.

c4. Battery systems for run down lub oil pumps.

d. Normal loads: Loads, which have no effect either on the safety or the safeguard

of installation or equipment.

e. Temporary loads: Loads which have no effect on the normal production or

safety, but are intended to supply the loads for temporary services during

Onshore or Offshore construction activities or during operations. Normally

these loads shall be supplied, by temporary generators which shall be located in

non-hazardous areas.

For offshore telecommunication applications and navigational aids dedicated

battery back-up supply systems shall be provided in accordance with SOLAS

regulations.

For all types of load the load schedule as provided in Appendix-A3 shall be applied,

clearly indicating the type of load in the heading.


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4. POWER SUPPLY SYSTEM

4.1 General

The design and construction of the electrical systems shall take into consideration

potential alternatives for the supply of electricity such as ADMA-OPCOs own

generation systems and outside supplies through local utility suppliers. A

combination of these two alternatives shall be considered to provide the most

economical and reliable solution.

4.1.1 Power Supply required for the ADMA-OPCO onshore facilities and offshore is

presently by dedicated power generation. Reference is made to the typical offshore

and onshore Key One line diagrams (See Figs.1&2, Appendix-A2). Please note that

referenced typicals are indicative and shall be adapted to project specific

requirements on a case to case basis, subject to ADMA-OPCOs approval.

4.1.2 The firm capacity of normal electrical power system shall be capable of supplyingcontinuously 120 % of peak load, without exceeding the specified voltage limits,

frequency limits and equipment ratings.

4.1.3 For offshore application the power generation system shall follow a N-1philosophy, meaning that N generators minus the largest generator can continuously

supply 120 % of the peak load.

4.1.4 For onshore application the power generation system shall follow a N-2 philosophy,meaning that N generators minus the two largest generator can continuously supply

120 % of the peak load.

4.1.5 The number and size of generators selected will be a result of a joint technical and

economical study by the Contractor and ADMA-OPCO.

4.1.6 For subsea cables a spare capacity of 20 % peak load shall be taken into account.

4.1.7 If the sole source of power for the production and utilities is derived from a subseapower cable, the subsea power cable shall be redundant. Each subsea cable shall be

routed via a different route so that no single event can cause the loss of both the

subsea cables.

4.1.8 For general considerations of prevention of installation interference between subseacable and subsea pipelines reference is made to ADMA-OPCO SP-1048, and SP-

1056.


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4.1.9 For subsea cable installation, pre-installation surveys shall be performed to checkthe status of the desired route. For installation, appropriate vessels and equipment

such as motorized rim reel drive, tensioner, bend restrictors, sand bags, etc. shall be

applied. As a standard requirement, sand bags shall be used to protect the cable

against vortex shedding induced vibrations. Post lay surveys shall be performed to

check the status of the cable after installation and also to confirm distances between

cable and the existing infield pipelines.

4.1.10 The subsea cable and associated equipment and installation methods shall be in

accordance with the project specific requirements and subject to ADMA-OPCO

approval.

4.2 System Configuration

The principle system design shall comprise of a HV and LV Normal, Essential

Emergency and Vital (UPS) generation and distribution system as shown in

Appendix-A2 (fig. 1&2). The UPS system and distribution panels shall be designed

in such a way that maintenance can be performed in a safe manner on one side of

the system while the other side remains live without disruption of UPS power toconsumers.

4.2.1 H V System

a. The main HV switchboard is connected directly or through unit transformers to

the local generation units.

b. HV switchgear with at least two power supplies shall have two bus-sections

and a bus-tie rated for the total load on the switchgear including a minimum

spare margin of 20 %. In order to increase the availability, redundant

equipment shall be judiciously split between the two bus-sections. The HV

switchboard shall normally operate with the bus-tie closed; however duringmaintenance activities one section might be out of service while one section is

maintained life, therefore both sections have to operate independently.

4.2.2 Emergency Power System

The emergency generator system can be utilized to provide both the emergency and

black start services. In case the required black start power supply and other essential

demands are such that a dedicated essential generator and associated equipment

proves a necessity, the requirements as stipulated below shall both apply to the

essential as emergency generation system. However in case of offshore application,

the emergency generator and associated systems and the installations shall be

certified by a certifying authority as per ADMA-OPCO approved TPA list.

a. The emergency generator(s) shall receive a start signal upon loss of voltage at

the emergency service switchboard and automatically feed the emergency

loads with minimum interruption.


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b. For normal power recovery, synchronization between the main and the

essential sources shall be provided. Upon restoration of the main generation,

the generator shall be stopped manually.

c. Provisions shall also be made to test periodically the start up and loading of the

emergency generator. This will require synchronization of the generator with

the normal generation system at the emergency switchboard.

d. The Emergency and Essential generator shall have a primary and a secondary

start system. Each system with sufficient stored energy to provide a minimumof six starts equivalent to 180 seconds of cranking time at an ambient

temperature of 5 C. Thus providing a total of twelve consecutive starts with a

total cranking time of 360 seconds at an ambient temperature of 5 C.

e. The Emergency generator shall be equipped with a diesel day tank sized for

twenty four hours full load.

f. The Essential generator shall be provided with a diesel day tank sized in

accordance with the project specific requirements. The Essential generator

shall supply the diesel transfer pumps to guarantee a continuous flow of diesel

from the main diesel fuel storage tanks. In case no Essential generator is

required the fuel transfer pumps (or one of the fuel transfer pumps in case thesystem is configured as 2 * 100 %) shall be supplied from the emergency

diesel generator. This will only be applicable if the main normal power

generation system is suitable for dual fuel or includes diesel generator.

4.2.3 LV System

a. Low voltage switchgear and Motor Control Centres (MCCs) shall have two

incomers and one tie breaker. MCCs for turbo generator/ turbo compressor/

HVAC auxiliaries and LV switchgear where only one incomer is sufficient,

with specific notification to ADMA-OPCO, the same can be provided.

b. The two bus sections (A and B), and associated incoming breaker (A and B)

and bus-tie breaker (C) can be in the following configurations:

b1. Incoming circuit breakers A and B closed and the bus-tie C open.

b2. Incoming circuit breaker A and the bus-tie C closed, incoming B open.

b3. Incoming circuit breaker B and the bus-tie C closed, incoming A open.

The configuration b1.Represents the normal operating condition.

The configurations b2.and b3.may be used during maintenance on one of the

incoming feeder. Transfer from one configuration to another one, shall notcause any loss of supply to consumers, (make before break).


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c. The short-circuit rating of the switchboard however, is not required to be

calculated to cover for this condition as the risk of a fault occurring at the

instant when all three circuit breakers are closed is considered extremely

unlikely. In all cases, the three circuit breakers shall never be simultaneously

closed for more than one (1) second as described above. Key lockable switches

and clear instruction plates at the front of the switchboard shall be provided, to

prevent any miss operation.

d. For essential and process sensitive loads, as per project specific requirements,

separate LV switchboard/ MCCs shall be used with bus-tie closed to allow for

uninterrupted operation of the connected loads during failure of any single

source. In such cases the short-circuit current on the bus shall be calculated for

closed bus-tie and both incomers feeding the fault. The switchboard short-

circuit rating shall be calculated accordingly.

e. Note that after a complete shut down all battery supplies of the Vital system

might be drained, therefore ESD overrides shall be implemented allowing the

Emergency generator to start after a total outage. These overrides shall be key

operated with clear instruction plates and shall be executed suitable for Zone 1,IIB, T3 areas, in case these are located in battery rooms the classification shall

be Zone 1, IIC, T6.

f. HVAC drives may be fed in the following manner as specified in the project

scope, either:

f1. Starters integrated into Normal/Emergency switchgear.

f2. From a dedicated HVAC switchgear (with normal and essential sections).

Each section being fed by one feeder from a Normal switchboard and one

feeder from an Emergency switchboard.

f3. From separate dedicated normal and essential HVAC switchboards, each

being fed by one feeder from the respective electrical board.

4.2.4 Transformers

Each power transformer shall be able to feed the total load of its downstream

switchboard. In normal configuration, the two transformers shall feed each half of

the bus section, each providing around 50 % of the load. Transformers shall have a

20 % spare capacity. Transformers shall comply with ADMA-OPCO STD-155.

4.2.5 Distribution Boards

Distribution boards (e.g. for lighting and small power) shall be normally fed by only

one feeder coming from an upstream board. For Vital loads (eg. DC and AC UPS),

two feeders shall be required as specified in the data sheet.


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4.3 Distribution System

4.3.1 Main Power distribution within the ADMA-OPCO onshore and offshore facilities is

High Voltage (HV) (11 kV and/or 33 kV (future)) unless otherwise specified or

indicated in single line diagrams.

4.3.2 On-site power generator circuits shall be connected at a common primary

substation, the common primary sub station shall be used as the main load

distribution center for the site facility.

4.3.3 Outgoing load circuits shall be connected to the bus sections in such a way, that

power flow across bus bar section switches is minimized and shall in addition

permit unscheduled and scheduled bus bar section outages with minimum

disturbance to the connected loads.

4.3.4 On-site power generators may be connected either directly to the primary power

supply bus bars or via generator/transformers.

4.3.5Different configurations of power supply schemes are existing in ADMA-OPCOonshore and offshore facilities. General schematic of the same are shown in

Appendix-A2 Figures 1&2 respectively.

4.3.6 11 kV bus bars in the Main Receiving Station/Sub-station shall be continuous with

bus section breakers in normally closed position.

4.3.7 Feeders to continuous process unit Sub-stations shall be radial type. Each unit Sub-

station shall have two 120 % rated 11 kV feeders terminating directly on a 11kV

switchgear or transformers, pending project specific requirement.

4.4 Equipment Rating/Sizing

4.4.1 Equipment sizing for each installation shall be such that all extensions known at

design phase shall be taken into account.

4.4.2 All components (e.g. bus bars, circuit breakers, contactors, switches, etc.) and

cables shall be rated for at least the fault rating of the equipment in which they are

installed.

4.4.3 In particular, the short-circuit rating of the generator switchgear shall be calculated

taking into account all generators running and connected simultaneously. Any

additional future contribution (e.g. future extra generators or incomers) shall bespecifically mentioned in the project specifics and taken into account accordingly.

4.4.4 The short-circuit rating of LV switchboards shall be determined with one

transformer in operation (bus-tie closed) and all the LV consumers in service.


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4.5 Supply Voltage, Frequency and Supply Waveform

a. Voltage at equipment terminals shall not deviate from the rated equipment

voltage by more than 5 %.

b. System frequency shall not deviate from the rated frequency (50Hz) by more

than 2 %, during transient conditions a maximum frequency deviation of 5

% is permitted for short periods of time (


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4.6 System Power Factor

The overall system power factor, inclusive of reactive power losses in transformers

and other distribution system equipment, shall not be less than 0.9 lagging at rated

load.

4.7 Standard Voltages and Tolerances

4.7.1 The selection of voltages shall be based on the following parameters:

a. Power to be delivered (based on the power balance established for each

consumer voltage level).

b. Short-circuits levels.

c. Existing systems and supplies.

d. Distributors supply voltage.

e. Distances between consumers and supplies.

4.7.2 The general electrical characteristics for electrical systems shall be as presented in

the following table.

VoltageOperational

range

Neutral

systemService

Allowable Voltage

Drop (%) at Terminals

33 kV 10 % NERInter connector

Unit Transformer5 %

Generator 5 %

Motor5 % running

15 % starting11 kV 10 % NER

Inter connector 5 %

6.6 kV 10 % NER 5 %

3.3 kV 10 % NER 5 %

415 V 10 % Solid 5 %

240 V 10 % Solid Lighting 2 %

240 V 10 % Solid Small power 2 %

110 VAC 10 % Solid Local I&C panels 5 %

DC

Systems

24, 48, 110

VDC

10 %See

Note 1

Navigational aids,

instruments, control &

monitoring systems

and, telecom.

2 %

Note 1: In principle the negative pole shall be grounded, however in special

application the positive pole might be grounded (e.g. telecommunication

equipment) or the system requires a fully floating. Therefore special consideration

shall be given to the earthing of DC systems and shall be evaluated on a case to case

basis.


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4.8 Electrical Design Studies

Electrical studies and calculations shall be performed by the Contractor/

Engineering Consultant to substantiate the selection and sizing of electrical

equipment such as generators, transformers, bus duct, switchgear, etc.

4.8.1 Electrical Consumer Lists and Load Balance

The Contractor shall prepare a load summary, which will list all electrical

consumers. This document shall include as a minimum:

a. Equipment tag numbers,

b. Driver equipment service,

c. Rated voltage,

d. Absorbed mechanical power,

e. Nameplate rating,

f. Efficiency,

g. Absorbed electrical power in kW and kVAR,

h. Diversity or cyclic factor,i. Power factor.

All the loads, including standby units, shall be listed under the switchboard/motor

control centre to which they are connected so that the load and size of each

switchboard/MCC can be determined.

The individual power transformer ratings and generator ratings shall also be

included in the summary.

The total design load is defined below:

Total design load = Continuous (emergency, essential and non-essential) load + 30

% of the intermittent load or the largest intermittent load (whichever is higher).

4.8.2 Load Assessment and Electricity Consumption

A schedule of the installed electrical loads, the maximum normal running plant load

and the peak load, expressed in kilowatts and kilovars and based on the plant design

capacity when operating under the site conditions specified, shall be prepared,

reference is made to Appendix-A3. This shall be completed and updated regularly

throughout the design stage of the project, and shall form the basis for provision of

the necessary electricity supply and distribution system capacity.


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Formula for determining the total electrical loads shall be as follows:

Considering

1) Sum of all Continuous loads : E

2) Sum of all Intermittent Loads : F

3) Sum of all Standby Loads : G

4) Diversity factor for Continuous loads : x

5) Diversity factor for Intermittent Loads : y

6) Diversity Factor Standby Loads : z

For load Calculation formulas:

Maximum normal running plant load : x (%) E + y (%) F

Peak load : x (%) E + y (%) F + z (%) G.

The values of the diversity factors x, y and z must take account of the individual

drives or consumers which make up the continuous, intermittent and stand-by loads,

respectively. For example, y (%) F cannot be less than the largest individual

intermittent drive or consumer.

a. The following default values shall be used for load assessments:

x = 100 % (By definition, at rated plant throughput all driven equipment

should be operating at its duty point. However, some diversity may need to be

applied to non-process loads, e.g. offices and workshop power and lighting

(typically 90 %).

y = 30 %

z = 10 %

b. A separate schedule shall be prepared for each switchboard, the total of all

switchboard loads being summarized as required to arrive at the maximumnormal running and peak loads for each substation and for the plant/facility

overall.

c. All loads to be shed during an under-frequency condition shall be identified as

such in the remarks column. All loads to be automatically restarted (in case

of specific process/ operational requirements) after a voltage dip at the bus bars

(


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4.8.3 Power System Studies

Power system studies shall be produced where specified in the project scope. The

number/type of studies and their timing of execution will depend on the size and

complexity of the installation.

The software to be used shall be ETAP, EDSA (latest version) or ADMA-OPCO

approved equivalent. Contractor shall provide the native file, including editable

Power System Model (without password protection) for each submittal of the

system study report to ADMA-OPCO.

A basic outline of study types is given below:

a. Load flow study (steady state conditions)

This study will be used to calculate voltages at any location in the network plus

currents in all branches thus giving MW/MVAR/MVA flows.

This information will allow adjustment of machine ratings, transformer and

cable sizes, etc. to ensure that steady state voltages are maintained within

acceptable limits and ensure that equipment will operate within desired ratings.

b. Motor Starting studies

Voltage drop will be studied during motor starting operations.

The maximum system transient impedance shall be used in calculating voltage

drops relating to motor starting, restarting and re-acceleration requirements.

The actual distribution of the allowable overall steady-state voltage drop across

the different parts of the electrical system will depend on the circuit

configurations and distances between circuit components.

The steady state voltage drop of each circuit shall be calculated on the premisethat the total load on the circuit is equal to the sum of the nameplate full load

amperes of all connected utilization devices that will be in operation under

normal conditions.

c. Short-circuit calculation

These studies shall be used to calculate fault data as follows:

c.1 Balanced short-circuit currents at any location e.g.:

Initial symmetrical short-circuit current, Ik and steady state short-circuit

current, k for thermal withstand of switchgear.c.2 Peak short-circuit current used for electro-dynamic stresses and the

making capacity of circuit breakers.

c.3 Symmetrical short-circuit breaking current used for breaking capacity of

circuit breakers.

c.4 Decaying (a-periodic) component of short-circuit current.


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c.5 Unbalanced short-circuit currents at any location e.g.:

c.5.1 Line to line.

c.5.2 Double line to earth.

c.5.3 Line to earth.

Short-circuit studies shall be carried out in accordance with IEC 60909.

d. Dynamic stability studies

Depending on the size and complexity, a particular electrical network dynamic

stability study may be required. It shall be required for installations with

internal electrical generation.

This study shows the dynamic response of an electrical power system and

monitors the ability of the network to give stable responses to transient

conditions and disturbances such as short-circuits, generator tripping and

starting of large motors.

The results will be used to:

d.1 Verify selection of equipment and system configuration.

d.2 Determine the need for load shedding following a fault and or loss of

generation and maximum acceptable load shed times.

d.3 Confirm the protection plan.

d.4 Confirm stability of the system and maximum acceptable fault clearance

times.

d.5 Verify motor starting capability.

d.6 Verify motor reacceleration and restart capability and develop restart

sequences.

e. Harmonic studies

For installations, which contain a significant percentage of non-linear loads

(e.g. variable speed drives, large thyristor controlled heaters, etc.), harmonic

studies shall be produced.

These studies shall verify that any harmonics on the system are in accordance

with acceptable limits taking full account of the various harmonic sources in

the network. Where required, action shall be taken either by equipment over-

sizing or by additional filtration to meet these limits.


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4.9 System Protection and Metering

4.9.1 Protection and metering scheme for the electrical distribution network shall be as

shown on single line diagrams. Typical protection schemes and minimum

requirements for various applications are included in Appendix-A2.

4.9.2 Unit type protection with overlapping zones shall be provided as primary protection

for the various elements of the power system. Graded time over current protection

shall be provided as backup protection.

4.9.3 All protective relays shall be microprocessor, intelligent type and shall be subject to

ADMA-OPCO approval based on existing installations and project specific

requirements.

4.9.4 Protection schemes for certain equipment /circuits not specified shall be developed

during the study in consultation with ADMA-OPCO.

4.9.5 For co-ordination of electrical system protective devices, ADMA-OPCO protection

philosophy is:

a. Time constant protection system shall be preferred. Time dependent protection

system may be considered.

b. Selectivity shall be preferably time graded.

c. Protection settings are based on minimum short-circuit values.

d. In case of protection failure, any electrical fault shall be tripped by the

upstream protection.

e. A lockout relay (86) shall be installed on all equipment to inhibit automatic

restart after a failure (except thermal overload (49), local reset only).

f. Protection settings shall not be changed through communication links, however

facilities shall be available in the relays for the same, to allow programming of

system parameters at the relay.

g. Differential protection shall be considered only for large/critical equipment

reference is made to Appendix-A2 Typical Schemes.

4.9.6 Preliminary protection and co-ordination diagrams shall be proposed when loads

are tentatively sized and before order placement of major equipment , to ensure that

all the HV, LV and DC systems will be ultimately selective.


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4.9.7 The final electrical co-ordination study shall include the following:

a. Detailed Electrical protection diagrams showing the protective devices and

associated current and potential transformers.

b. Vendors name, type, designation and ranges as applicable, for all protective

selected relay settings and setting range, circuit breaker trip settings and fuse

sizes.

c. Time-current diagrams showing the coordinated minimum and maximum

clearing time curves for the selected settings and sizes of the protection

devices.

d. Supporting data, such as motor starting and running currents, calculated fault

currents, equipment protection requirements, inrush currents and references

that were used in establishing the setting and sizes of the protective devices.

e. Copies of the Vendors characteristic curves for all relays, circuit breaker

trips and fuses used for equipment protection.

f. Vendors instruction manuals for all protective devices.

4.9.8 Final study shall be completed when the loads and electrical system are adequately

defined and the equipment types and ratings are firm.

4.9.9 Selectivity study and relay set reports for all systems including sets of curves with

settings, tripping time, etc. shall be prepared by the Contractor. Any discrepancies

or gaps in the systems fault discrimination during particular or general operating

scenarios shall be clearly highlighted in the study report.

4.10 Intertripping and Interlocking

4.10.1 Intertripping sequences and interlocking must be achieved by hardwired interlocks

via PMS/DCS shall be considered additional only.

4.10.2 Intertripping shall be provided, where applicable, between associated equipment to

correctly isolate faulty items and to leave the system in a predictable orderly state

after the operation of protection devices:

e.g.:

Normal opening or tripping by protection of HV breaker shall cause the opening of

the corresponding LV breaker.

4.10.3 Interlocking shall be provided, where applicable, to prevent incorrect operation of

equipment. This shall be achieved, depending on the particular equipment involved,

either electrically and/or by a system of locks and key switches as far as reasonable

and practical.


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e.g.:

Mechanical interlock between the earth switch of the generator incomer breaker and

the generator excitation control panel shall be provided.

Downstream breakers and tie breakers shall not be closed until upstream breakers

are closed.

Key interlocking shall be provided in order to prevent application of earthing

devices until all sources of supply are isolated (access to transformer terminals, HV

live parts in switchboard, etc.)

Mechanical interlocking shall prevent closing of an earthing switch on an energized

part of an HV circuit.

4.11 Power Management Systems (PMS)

4.11.1 General

a. Depending on the size, complexity and operating requirements of thedistribution system, the Power Management System (PMS) shall be

implemented to facilitate control, supervision and monitoring of the network.

b. The PMS functions however should only be an aid to the operation of the

network with the safety requirements being ensured by the normal direct acting

devices (e.g. protection relays acting on circuit breakers) which are not linked

to the PMS. In addition, the network shall remain in service should the PMS

fail. Manual facilities shall be provided to allow manual operation in case of

PMS failure.

c. Typical functions to be included are:

c.1 Control of power generation and distribution e.g. remote closing ofcircuit breakers from a central control point (which may be the control

room or an electrical technical room).

c.2 Provision, at the central control point, of a VDU based system to provide

animated display of power generation and distribution system, data

acquired and provide operator/machine interface.

c.3 Load shedding.

c.4 Motor re-acceleration/restarting.

c.5 Sources automatic transfer sequence.

c.6 Event recording and parameter trending.

c.7 Display of alarms.

c.8 Interface with Process Control System(s).


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4.11.2 Load Shedding

a. Depending on the power generation design and the load balance a load

shedding system may be required.

b. Loads to be shed, shall be selected in accordance with process priority.

c. Load shedding shall be achieved either by the Power Monitoring System (if

any) or by dedicated fast acting modules and providing a response time

suitable for successful operation (20ms maximum).

4.11.3 Restarting

In accordance with process requirements a restart scheme may be required for

motors.

4.11.4 Black Start Requirements

Black start is defined as the operational scenario from a total loss of power

including main UPS up till start/ running of the normal power generation plant.

The black start shall always be manually executed. A general requirement for

establishing a black start philosophy is listed below. A job specific black startphilosophy shall be established taking the specific operational and system

requirements into consideration.

A black start shall be possible from the emergency generator or from the essential

diesel generator.

For offshore applications the intention is to limit the size of the emergency

generator. The emergency generator is normally located in the Accommodation for

offshore applications. Therefore the emergency generator itself might not be

capable of providing sufficient power for a black start depending on the actual start-

up load required.

After a total loss of power, including UPS (emergency shutdown) the ESD trips on

the emergency generator will be manually overridden (rig saver, start battery circuit

breaker trip) and manually opening of emergency generator room fire dampers, the

emergency generator can be started. From the emergency distribution board the

feeder circuits to the main UPS system can be re-established (ESD overrides on

these feeder circuits). This will allow the ESD, F&G and DCS system to reboot.

The next action will be to start a diesel generator, it will be required to manually

open the fire dampers associated with the area where the diesel generators are

located, to establish the supply of combustion air. The diesel generators can inprinciple be started without seawater/ air primary cooling systems and can run

initially on there closed cool water system which will require a mechanically driven

pump and an electrically driven pump. If the diesel generator is started by means of

starting air (machinery starting air system required) a primary seawater service

pump of limited size can be started to facilitate the seawater flow through the closed

cooling water heat exchangers.


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From the diesel generator the closed cooling water circulation pumps associated

with the gas turbine generators can be started. The gas turbines will require

instrument air.

The fuel gas to the gas turbines has to be ensured by means of a fuel gas take off

lines before first stage separation or by applying dual fuel burners, which will allow

the gas turbines to start-up on liquid fuel.

The start motor and air supply fans of the gas turbines shall be powered from thediesel generators. After overriding any associated ESD trips on the gas turbines, the

normal power generation plant can be started.

The required equipment and associated steps to be taken shall be developed in detail

during the design stage and care shall be taken regarding the location of certain

equipment to facilitate the black start sequence. It shall be taken into account that

all batteries are drained (except for the generator start batteries). Each override shall

be provided with a status indication to the DCS.

a. Initial status

a.1 All sources of power are shut down and all batteries discharged and

switched off.

a.2 All electrical rooms are presumed to be filled with gas.

b. Purge of the emergency generator room (including all auxiliaries), or if

installed outdoors, make sure that there is no gas around or inside the package

enclosure. Open fire dampers. Room purge can be ensured by natural

ventilation (opening louvres, doors, etc) or by an independent portable fan

(suitable for hazardous areas).

c. When the atmosphere is recognized as safe, override any ESD/ Fire & Gas trip,

start the emergency generator. Start purging required equipment/ switchgearroom(s) to allow normal power generation start-up.

d. Energize the DC and UPS systems.

e. Remove ESD/ Fire & Gas trips.

f. Progressive starting of the main turbo generators.

g. Progressive supplying of all of the electrical equipment.

4.12 Earthing & Lightning Protection Systems

The main goals of system grounding are to minimize voltage and thermal stresseson equipment, provide personnel safety, reduce communication system interference,

and give assistance in rapid detection and elimination of ground faults.

For earthing and grounding practices BP GP-12-25 shall be followed.

Protection against lightning shall be in accordance with BS.EN 62305.


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4.12.1 High Voltage Systems Earthing

a. For an installation with its own power generation and electrically isolated from

any external network, high voltage neutral shall be earthed by low impedance.

Special attention shall be paid to the value of the Neutral Earthing Resistor

(NER) considering reliable earth fault tripping, limiting maximum earth fault

currents and circulation of harmonics.

b. Each generator shall operate with the neutral connected through a resistordirectly to earth.

c. Earthing resistors should be provided with insulation suitable for the phase-to-

phase voltage of the system to which they are connected as a minimum,

otherwise dictated by the system fault voltage.

d. The power rating of the Neutral Earthing Resistor shall be such that the resistor

can sustain the maximum earth current that can occur for a minimum of 10

seconds without any deteriorating effects and limiting the temperature rise to

760 C, (Hot Spot value).

e. The enclosure of the Neutral Earthing Resistors shall be suitably coated, in

such a way that high temperatures will have no deteriorating effects on the

coating.

f. Special attention shall be paid in case that unequal generator are running in

parallel as there could be a risk that third harmonic circulating current will flow

through the earthing resistor, causing false tripping of the ground fault

protection. Therefore the earth fault protection has to be set above the

circulating third harmonic current if no third harmonic filter is included in the

protection relay.

g. For earthing of networks or power supply branch lines fed by transformers a

neutral point resistor shall be installed on the secondary side of eachtransformer. Depending on the operating philosophy, a switching device shall

be provided.

h. In case electricity is derived from a utility supplier (e.g. ADWEA), the neutral

system and the relevant fault current values shall be limited as defined by the

utility company.


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4.12.2 Low Voltage Systems Earthing

In principle all Low voltage and small power circuits shall be solidly earthed,

except where indicated otherwise. The earth fault protection devices shall be fully

selective to each other.

a. Each outgoing 415 VAC feeder/ motor supply shall be provided with RCDs,

with a maximum trip setting of 150 mA.

b. LV generator and transformer incomers shall have an integral earth fault trip

relay with a maximum trip setting of 300mA.

c. Supplies to small power (240 V) lighting loops shall have a maximum RCD

trip setting of 100mA.

d. Supplies to small power/ UPS socket supply loops shall have a maximum RCD

trip setting of 30mA.

e. Individual small power supplies/ UPS shall have a maximum RCD trip setting

of 30 mA.

5. CLASSIFICATION OF HAZARDOUS AREA

5.1 General

5.1.1 The hazardous area classification and associated drawings shall be used for the

selection of electrical equipment, unless otherwise indicated (e.g. for

standardization purpose bulk material shall be standardized for use in hazardous

areas, regardless of the location)

5.1.2 Hazardous area shall be classified into Zones 0, 1, 2 in accordance with IEC 60079-

10.

5.1.3 In principle the ATEX directives can be followed, however equipment specified in

accordance with ATEX shall in addition fully comply with IEC 60079 standards to

ensure uniformity of design and application.

5.1.4 The area classification shall be conducted in accordance with IEC 60079-10, and

referenced as such in the applicable documentation, however the examples and

information provided in the latest edition of Part 15 of the Institute of Petroleum

model code of safe practice shall be utilized as design application guidance.

5.1.5 Grouping of various hazardous gases and vapors shall be as per IEC 60079.

5.1.6 Electrical equipment selection and installation for the classified area shall be in

accordance with IEC 60079, for specific motor requirements reference is made to

ADMA-OPCO STD-148 & STD-149. Please note that Ex(p) motors are not

permissible.


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5.1.7 In general the normal temperature classification for most applications shall be T3

(200 C), the gas group in most application shall be IIB, unless otherwise indicated

in this specification or in the project specific hazardous area documentation.

All electrical equipment used in classified area should be ATEX certified or

equivalent eg. (USA - UL, FM, ETL & Germany PTB, BVS etc.) subject to

specific approval from ADMA-OPCO.

The ingress protection shall be IP56 as a minimum.

5.1.8 Regardless of the hazardous area classification, the following considerations shall

be made for selection of equipment and materials:

a. Escape lighting systems, navigational aids, platform identification lights,

helideck lighting and public address system on offshore installations shall all

be suitable for a Zone 1 environment.

b. All electrical equipment in battery room shall be suitable for Zone 1, IIC, T6.

c. All bulk items such as junction boxes, light fittings, local control stations etc.

used in process areas shall be suitable for Zone 1 hazardous areas even inunclassified areas to have uniformity and minimizing of spares.

6. SUBSTATIONS

6.1 General

6.1.1 Electrical distribution equipment shall be normally located within dedicated

electrical rooms and in case of ONAN type of transformers they shall be located

outside in separated bays adjacent to the room. It is permissible to have dry type

transformers located in electrical switchgear rooms.

6.1.2 Substation location shall be as near as possible to the loads and outside hazardous

areas as far as possible.

6.1.3 Number of different types of transformers shall be limited as much as possible.

6.1.4 Dimensions of substations shall enable easy and safe operation and maintenance.

6.1.5 Provisions shall be taken to mitigate any wiring fire consequences (emission of

corrosive smoke leading to spurious trips with possible production losses). As far as

practical, low smoke, Halogen free material shall be used.

6.1.6 Substations shall be built from concrete for large onshore buildings, or of pre-

fabricated or modular construction for offshore and small onshore buildings.


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6.1.7 Only authorized personnel shall enter into the electrical substations. The electrical

substations shall be fitted with key locking doors and with at least one exit equipped

with an anti-panic system.

6.1.8 Electrical rooms shall be air-conditioned to provide clean and dry environment,

special attention shall be paid to humidity control and adequate numbers/ rating of

anti condensation heaters shall be incorporated in equipment design.

6.1.9 Appropriate room pressurization shall be provided in case of sand, wind, dusty

atmosphere or location in hazardous area, or in case rooms have to operate under

gas/ fire hazardous conditions and the supply air can be taken from a safe area.

6.1.10 The layout within the room shall be governed by the size and quantity of switchgear

and a reservation shall be made for extensions (e.g. at least 25 % extra space to be

provided for future phases unless otherwise specified).

6.1.11 For HV and LV switchgear, available space for one cubicle at each side shall be

provided as a minimum.

6.1.12 The layout will provide safe access and adequate space for operation, maintenanceand removal of each item of equipment.

6.1.13 Doors shall be provided such that an unobstructed exit route is available in case of

emergency.

6.1.14 One door shall be sized to allow entry of the largest single item of equipment.

Rooms shall be designed with raised floor (offshore, with minimum height of 600

mm) or technical void (onshore, minimum height of 1.80 m) for cable routing.

Cable penetrations in the buildings shall be by MCT (offshore) or by adequate

sealing method (onshore). One spare penetration for temporary cable entry shall be

provided. Bottom entry is preferred.

6.1.15 Process & Utility pipe works shall be avoided within electrical rooms. Cable trays

and ladders shall be used for cable routings in raised floors.

6.1.16 Floor finishing shall be designed for rolling of the heaviest load (circuit breaker on

its truck, etc) and tolerance (floor flatness shall be in accordance with switchgear

VENDOR requirements). Floors shall be coated with anti dust coating as per

ADMA-OPCO SP-1030.

6.1.17 Electrical rooms with concrete walls and ceiling shall be painted.

6.1.18 HV and LV equipment can be located in the same switchgear room (authorized

access only).

6.1.19 Substations in hazardous areas shall be pressurized as per hazardous areaclassification requirements and all equipment shall be also properly selected and

installed.


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6.1.20 Manual operated total flooding fire fighting systems, shall be provided inswitchgear rooms, transformer rooms (when stated in the project specific scope of

work) and emergency generator rooms (in case the emergency generator is equal or

larger than 500 kW), complying with all relevant codes and standards.

6.1.21 Gas, smoke detectors and fire dampers shall be installed as per fire & gas

requirements and ADMA-OPCO specification ADMA-OPCO SP-1134.

6.2 Minimum Clearances in Substations

Following figures are minimum values given as a general guidance, unless

otherwise specified by equipment / switchgear VENDOR.

Vertical from equipment to ceiling 450 mm

Front of operating side of high voltage switchgear 1400 mm

Front of operating side of low voltage switchgear 1000 mm

Switchgear from each end and non operating side 750 mm *

Other Equipment, at least on 3 sides < 250 mm (or) > 750 mm

*Note: In case of switchgear construction, which is such that it is designed to be

fully serviced from the front side, this requirement can be relaxed, subject to

ADMA-OPCOs approval. For cooling purposes a minimum distance from the wall

is required depending on Vendor requirements.

7. EQUIPMENT AND MATERIALS

The following are the general requirements for equipment and materials. Please note that indeluge protected areas, only cable entries from the bottom and the sides are allowed. In all

other areas side and bottom entries are preferred and top entries shall be prevented as much

as possible and are only allowed if unavoidable.

Additionally, all items to be used in hazardous areas shall comply with the specific

hazardous area classification requirements.

In general all electrical equipment rooms and generator enclosures shall be serviced by

redundant HVAC systems with auto-change over facilities.

7.1 Generators

7.1.1 Main generators shall either be gas turbine driven or steam turbine driven as

specified for the project. Generators shall comply with ADMA-OPCO Specification

(to be advised). Emergency and Essential generators shall be diesel driven and

designed in accordance with GP-12-85.


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7.1.2 Generator auxiliaries shall be supplied from a 415V switchboard fed from a

11kV/415V transformer directly connected to the generator output through a

breaker with necessary protection. This switchboard shall have a second feed from

the Emergency or Essential switchgear with suitable changeover arrangement for

start-up purposes.

7.1.3 Generators and associated equipment required for black start purposes shall beserviced by ventilation systems provided with black start key lockable fire and gas

overrides (suitable for Zone 1 operation), with status indication (to DCS), to allow

fire dampers to be opened and fans to be started to supply combustion air and

cooling air. Clear instruction plates shall be provided denoting the black start

operation instructions.

7.1.4 Black start facilities shall be provided/ensured for the generator if specified.

7.2 HV Switchgear

7.2.1 High Voltage switchgear up to and including 11kV shall comply with ADMA-OPCO STD-144.

7.2.2 All circuit breakers in the switchgear assembly shall be installed in single tier

formation. Double tier formation may be allowed if safe maintenance is proven and

economically attractive.

7.2.3 At least one fully equipped cubicle shall be provided as spare on each bus section, if

not specified elsewhere in construction documents.

7.3 Transformer

7.3.1 Power and distribution transformers shall comply with ADMA-OPCO STD-155 &

electrical reactor shall comply with ADMA-OPCO STD-154.

7.3.2 Rating of HV/LV distribution transformer shall be limited to 2500 kVA unless

specifically approved by ADMA-OPCO. The contractor shall review standard

ratings of transformers in ADMA-OPCO facilities and propose suitable new

transformers in accordance with site specific requirements. Contractor shall design

and supply transformers of ratings similar to existing to minimize type and spares.

7.3.3 Oil immersed distribution transformers/ electrical reactors shall be separated by

walls (onshore) or fences (offshore) and shall be protected against rainfall or directsunlight by a removable roof. Fencing and roof shall allow natural ventilation.

Adequate oil containment shall be provided around the transformer/ electrical

reactor to contain any leakage.

7.3.4 When required transformers/reactors located in offshore areas shall be separated

from process area by a firewall.


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7.3.5 In principle transformers/electrical reactors shall not be located in Hazardous areas.However if this is unavoidable, the transformers shall be ATEX Certified or

equivalent (minimum Zone2, IIB, T3). In case the required transformer(s)/reactor(s)

are not available as a certified type, pressurized equipment rooms can be

considered, including air locks, Zone 1 certified ventilation system, low pressure

and loss of pressure alarms and shutdowns. Special attention shall be paid to the

location of the air inlets of the equipment room, they shall be positions in such a

way that their intake is drawn from a safe area. Gas detectors and fire dampers shall

be included in the design as per Fire & Gas requirements.

7.3.6 The NERs shall be located in a safe area and as close as possible to the transformer

or generator.

7.4 LV Switchgear and Motor Control Centres

The following are the general requirements unless specified otherwise.

7.4.1Low voltage switchgear and control gear shall comply with ADMA-OPCO STD-143.

7.4.2 Switchboards/ MCCs for air conditioning system of all buildings (industrial as well

as non industrial) shall be with microprocessor based protection relays. These

switchboards shall be fed from the main 415 V switchboard. Auto or manual

changeover facility shall also be incorporated as per project specific requirements.

7.5 Motors

7.5.1 Electric motors shall comply with ADMA-OPCO STD-148 for LV motors & STD-

149 for HV motors.

7.5.2 As a general rule, motors up to 160 kW shall be Low Voltage; above 250 kW

motors shall be High Voltage. Motors between 160 and 250 kW shall be subject to

technical and economical study by Contractor if required as per project

requirements. LV motors rated above 160 kW may be acceptable in case provided

with reduced voltage (star delta), soft starter or VFD subject to ADMA-OPCO

approval for a specific project.

7.5.3 When required for certain critical auxiliaries of rotating machinery DC motors shall

be used. AC motors fed by AC UPS are not acceptable for such applications.


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7.6 UPS Systems

7.6.1 For detailed Specification for DC and AC UPS refer ADMA-OPCO STD-146 &STD-156.

7.6.2 Unless otherwise specified in the project particular specification the autonomy of

the UPS are defined in the following table:

Type of load EarthingSystem

Autonomy Voltage Remarks

Electrical Switchgear HV& LV (incomers and bus-tie), Protection & Control

Unearthed 90 minutes 110 V DC

LV Contactor Control shall be

derived directly from the bus throughindividual MCBs and control

transformers (where required).Voltage shall be 240V AC, 50 HZ,

1PH+N and shall be solidly earthed

Battery backed up

Emergency lightingN-Earthed 90 minutes

240 V AC,

50Hz,1ph+N

Power shall be derived from integral

battery packs, with status indicationlights

Offshore:-Instrumentation DCS,SCADA, F&G, ESD,Local Control Panels

Unearthed 90 minutes 110 V ACIn case 24 V DC is required it shallbe derived inside the control/instrument cabinet from the incomingAC UPS supply

Onshore:-Instrumentation

DCS, SCADA, ESD,Local Control Panels

Unearthed 90 minutes 110 V AC24V derived internally from AC UPS

supply

Onshore:- F&G Unearthed 90 minutes 240 V AC STOREX area with 110V AC UPS

Navigation aids Unearthed 96 hours12/24 V DCor 240 V AC

Telecom-PABX Unearthed

90 minutesunder

continuousalarm

48 V DCSupplied by service provider

(ETISALAT)

Post lube pump of

machine etc.

Vendorstandard

requirement

Vendorstandard

requirement

110 V (seenote under

Remarks)

Preferred voltage for minimizing thespares. Other standard voltage

subject to approval.


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7.7 Batteries

7.7.1 Battery shall be of the following type:

a. Nickel-Cadmium (Ultra low maintenance types, design life > 20 years).

b. Sealed Lead-acid (Reduced maintenance types, design life > 12 years).

Batteries associated with diesel starting arrangements shall be suitable for more

than 3000 cycles at an 80 % depth of discharge.

Batteries located in non-air conditioned rooms/ enclosures or on open decks, shall

be suitable to operate satisfactory at temperatures of 60 C.

7.7.2 Batteries shall in principle be installed in dedicated battery rooms. Installation in

cubicles shall be assessed on a case to case basis, depending on the application and

battery capacity (small c