20100719233500

FOR AUTHORISED USE ONLY

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GOVERNMENT OF MAHARASHTRA

WATER RESOURCES DEPARTMENT

KUMBHE HYDRO ELECTRIC PROJECT

(1 X 10 MW)

BIDDING DOCUMENT NO.

SEGEMC/KUMBHE/E & M/TGP/1/2010

FOR

DESIGN, DETAILED ENGINEERING, MANUFACTURING, SUPPLY, ERECTION,

TESTING, COMMISSIONING OF TURBINE, GENERATOR AND ASSOCIATED

EQUIPMENT.

VOLUME-I COMMERCIAL TERMS AND CONDITIONS OF CONTRACT

VOLUME-II TECHNICAL SPECIFICATIONS OF TURBINE, GENERATOR &

ASSOCIATED EQUIPMENTS

VOLUME-II

OFFICE OF THE

CHIEF ENGINEER (ELECT.)

HYDRO PROJECTS,

HSBC BANK BUILDING,

4TH

FLOOR, M.G.ROAD,

FORT, MUMBAI-400 001.

TEL. (022) 22670074, 22674867

FAX. (022) 22674996

INDEX

SECTION

NO.

DESCRIPTION PAGE NO.

I INTENT OF THE SPECIFICATIONS 1-18

II GENERAL REQUIREMENT 19-59

III SCHEDULE OF REQUIREMENTS 60-82

IV TECHNICAL SPECIFICATION OF

GENERATOR

83-163

V TECHNICAL SPECIFICATIONS OF TURBINE 164-214

VI TECHNICAL SPECIFICATION OF

SPHERICAL VALVE

215-235

VII TECHNICAL SPECIFICATIONS OF STATION

AUXILIARIES

236-260

VIII TECHNICAL SPECIFICATION OF

PROTECTION AND METERING

261-271

IX TECHNICAL SPECIFICATION OF

SUPERVISORY CONTROL AND DATA

ACQUISITION SYSTEM

272-298

X DRAWING 6 NOS.

1

SECTION- I

INTENT OF THE SPECIFICATIONS

Signature of Bidder Signature of Purchaser 2

SECTION- I


INDEX

Sr.no. Description Page no.

1.1 Intent of the specifications 3

1.2 Hydraulic data 5

1.3 Climatic and other conditions 5

1.4 Seismicity 6

1.5 Approach and transport limitation 6

1.6 Operational requirements 6

1.7 Rating requirements 7

1.8 Other design requirements 8

1.9 Layout constraints 10

1.10 Designs studies/calculations 10

1.11 Data sheets 13

1.12 Drawings and data to be submitted with bid 13

Annexure I-1 14


SECTION- I


1.1 INTENT OF THE SPECIFICATIONS:

The scope of work comprises of the following:

To undertake the complete engineering, design, manufacture, supply, onsite

erection, testing and commissioning, putting into commercial use and trail run for

90 days of the following hydro power plant and equipment. The brief details of

the power plant equipment shall be as follows:

Mechanical Lot

One no.: Horizontal Shaft Pelton Turbine directly coupled to Generator with

nozzle spear head, servo motor and deflector assembly etc. Turbine designed

for net rated head of 402.00 mtr. and discharge 3.12 m3/sec at rated head and

rated output capacity of 10.42 MW, 500 rpm, comprising of electronic Governor

with oil pressure unit, high pressure oil & water piping, valves, strainers, flow

meters, relays, limit switches, temperature gauges etc., complete.

One no.: Main O.P.U. type spherical valve of suitable size for 1000mm dia.

Penstock along with operating system, inlet/outlet pipes, control cabinet etc.,

complete. Valve shall be designed for a pressure of 700 m of water column.

One lot : Penstock pipes:-Matching pipes between i) penstock end and Spherical

valve( i.e. Penstock specials) ii) Spherical valve and Distributor pipe and Branch

pipes. Further lot shall comprise of stiffeners, supports and anchors for proper

embedment.

Lot :


i) Compressed air system for Governor, M.I.V., generator breaking and other

purpose shall include adequate nos. of compressors, air tanks and piping etc.,

complete.

ii)Drainage & dewatering system shall include adequate nos. of pumps, strainers,

valves, and piping etc.

iii) Cooling water system shall include adequate nos. of pumps, pressure

reducers, strainers, valves, and piping etc., complete.

Electrical lot:

One no.: Horizontal shaft synchronous generator salient pole, 3 ph, 50 Hz, 0.9 pf,

12.5 MVA, 11 kV rated voltage suitable for coupling to above mentioned turbine

with fully static excitation system including excitation transformer, grounding

cubicle, power cable for interconnection, DVR etc. Complete.

One Lot : Generator auxiliaries : comprising of S.S.G. unit, Local control boards ,

fire protection system, H.S. lubrication, LAVT, Bus Duct, 11 kV XLPE cable,

isolator, earthing switch, 11kV junction bus panel, power, control & measurement

cables, coolers, heaters, etc., complete.

One Lot: Protection:-Software based protection relay panels covering all required

electrical protections with back up protections of Turbine, Generator, step up

transformer, auxiliaries etc., complete

One no. SCADA system with Unit control board: SCADA system and Unit control

board for the operation of plant. This includes PLC based control system of

turbine generator unit, Synchronizing unit, alarm window, annunciation window.

Auto as well as manual control of the plant.

Lot : Mandatory Spares for above items.

Lot : Special Tools and Plants for erection, testing and commissioning.


The above work shall be carried out on totality basis including the incidental

services mentioned in clause No.3.15 and 4.7 of vol.1. Further the said work

shall be carried out in co-operation with the purchaser and suppliers of other

equipment in a business like manner with utmost speed so as to achieve overall

economy and efficiency.

1.2 HYDRAULIC DATA

The hydraulic data and the other data regarding water conductor system is as

follows:

LEVELS

A Minimum Draw Down level (m) 579.11 EL

B Full Reservoir water level (m) 602.00 EL

C Maximum tail water level 190.00 EL (tentative)

D Minimum tail water level 189.00 EL (tentative)

E Design discharge 3.12 m3/sec

F Nozzle level (m) 190.00 EL

G Total Head loss (m) 1.91

H Rated head (Design) (m) 402

The turbine shall be designed based on the hydraulic data

mentioned above.

1.3 CLIMATIC AND OTHER CONDITIONS


Kumbhe HEP is situated in hilly terrain of Sahyadri ranges. The general climatic

and isoseismic conditions are as stated under Section VII Annexure I of

Volume-1.

1.4 SEISMICITY :

Entire plant and equipment shall be designed to withstand forces due to

gravitational acceleration as stipulated in Section-VII Annexure I of Volume I i.e.

Commercial Terms and Conditions of Contract.

1.5 APPROACH AND TRANSPORT LIMITATION:

Bidders are requested to verify and ascertain limitations given under section –VII

Annexure I of Volume I i.e. Commercial Terms and Conditions of Contract. The

limitations are indicative and the bidder has to ascertain the actual limitation and

design the plant accordingly.

1.6 OPERATIONAL REQUIREMENTS:

The whole of the plant and equipment including auxiliaries shall be suitable for

trouble-free operations under varying operational conditions. The anticipated

operational requirements of the turbine and generator unit and associated

equipment are given below:

A. Operating mode:

Power generation at any load in the range between 9000 kW of power and

maximum power of 11000kW

B. Operating Duty:

1. No. of starts and stops per year 800 starts and 800 stops

2. Total time for starting

From standstill to Synchronising (Max.) < 300 Sec

3. Rate of loading


a) Normal loading a) About 2.0% of P max/sec

b) Fast loading b) About 6.25% of P max/sec.

c) Emergency loading c) About 6.25% of Pmax/sec.

4. The frequency and 47.5 to 51.5 Hz.

voltage range 0.9 Un to 1,1 Un

under which the

units shall be capable of

performing satisfactorily. where Un means rated voltage of

Turbine generator unit.

5. Load range between 9000 kW to 11000 kW

6. Network condition: 220kV±10%

The voltage and 47.5 Hz to 51.5 Hz

frequency variations

in system with which the unit

shall be synchronised and able

to deliver rated power continuously.

1.7 RATING REQUIREMENTS:

1) Output :

The Turbine shall be so designed that rated output of 10000 kW is developed

under the rated net head of 402mtr.

2) Turbine setting:

Turbine setting and other key dimensions of unit is the sole responsibility of the

bidder. The bidder shall design the turbine setting based on the hydraulic data

mentioned above. The Purchaser has tentatively chosen (Shown in study

drawing) the turbine setting as 0.375 m above the penstock center level. This is

only for study purpose. Further, the key dimensions / levels of the power house


are tentatively fixed based on the dimensions of turbine and generator. The

bidder shall examine this aspect and give his recommendations about the

precise requirements. The proposed setting shall provide adequate allowance

under all operating conditions considering power swing, shaft pressure pulsation,

cavitationless performance, minimum vibration and minimum noise, flooding level

of river etc.

3) Moment of inertia (GD²)

The moment of inertia shall be calculated and furnished. It shall includes the

maximum momentary speed rise, and maximum momentary pressure rise

specified under clause No.1.8 of this section (other design requirement).

1.8 OTHER DESIGN REQUIREMENTS

In addition to the operational requirement, mentioned in Clause no.1.6 of

this section, the following requirements shall be kept in view.

i) The whole of the plant including all auxiliaries shall be designed to give

satisfactory service with designed availability for a period of 50 (fifty)

years.

ii) Number of tripping (max.) : Ten (10) nos. per year

iii) Number of turbine : One (1) no. in five

Runway condition year’s life on an average.

iv) Closing of Spherical : Every time the unit is

valve (MIV) stopped and brought to standstill

position.

v) The rotating parts of the unit shall be mechanically designed so as to allow

the continuous operation and the stresses included in any part at

maximum runway condition shall not exceed 67% of the yield point of the

material of that part or 30% of the ultimate strength.


vi) The pressure containing parts of the unit for example the Spherical valve,

the Distributor and branch pipes, penstock specials, the nozzles,

deflectors, governing assembly, runner, buckets shall be designed from

consideration of fatigue stresses induced due to cyclic changes in

vii) pressure conditions. The nozzles, deflectors, regulating mechanism shall

be designed to have closing tendency and minimum of lost motion and

friction.

viii) The pulsation in power output in turbine operation shall not exceed ± 1.5%

at full load output and ± 5% at partial loads of actual rated power output.

ix) The maximum momentary pressure rise under most unfavorable transient

conditions accordingly to Clause 2.3.5.7 of IEC 41 shall not exceed 700 m.

x) The maximum momentary over speed under most unfavorable transient

conditions according to IEC 41(1991), sub-clause 2.3.4.14 will not exceed

1.50 times the rated operating speed.

xi) Whole of plant and equipment including the control and protective

equipment shall remain operative when maximum credible earthquake

occurs at site. Further, the plant should trip and safely come to standstill

when earthquake of large magnitude occurs.

Entire plant and equipment to operate : Horizontal direction aH = 0.3g

without malfunctioning upto seismic :Vertical direction aV=0.2g

conditions as project area is situated

in earthquake zone.

Entire plant and equipment to : Horizontal direction aH = 0.375g

to shut-off at seismic conditions : Vertical direction aV=0.25g


xii) The plant and auxiliaries shall be designed to operate continuously for 12

months period without any off-load maintenance and to achieve a high

start-up reliability.

xiii) The control scheme shall be so designed that in the event of a collapse of

the state grid system, The Kumbhe HEP shall be disconnected

automatically.

xiii) When unit is in operation, the noise level in the turbine housing 1 m away

from shaft measured shall not exceed 90 dB (A) .

xiv) The generator and turbine bearing shall be so designed to allow the unit to

be frequently and quickly started. Besides, the bearing shall be liberally

designed such that full power output is available even if oil cooler of any

bearing is blocked continuously. In addition, the volume of oil provided and

circulating system shall be such that none of the bearing would suffer any

damage during shutdown process in the event the unit is tripped due to

stoppage of cooling water / oil supply.

xv) Entire equipment shall be designed for maximum runaway speed for 15

minutes.

1.9 LAYOUT CONSTRAINTS :

The layout of power station is prepared with a view achieving over all

economy. The major layout constraints are given below:

i) Width of the power station 24.00m

ii) Overall length of power station 25.60m

1.10 DESIGNS STUDIES/CALCULATIONS:

The bidder and eventually the supplier shall have to undertake/conduct

special studies and calculation in order to establish that the design

requirements are achieved. The cost of such studies and calculations shall


be deemed to be included in the contract price. The following studies

and/or calculations are required to be completed.

A) Studies prior to bid submission.

1) Study of hydraulic Transients.

The study must be conducted considering worst operating conditions and

the results thereof must be submitted in the form of graphs, tables etc.

giving the values of maximum momentary pressure rise, maximum

momentary speed rise, water levels in the approach channel, surge well,

and tail race channel. The purchaser desires that the following conditions

are to be studied by the bidder.

i) Unit generating maximum power is tripped on mechanical fault.

ii) Unit generating maximum power is tripped and then attempt is made to

restart the unit in emergency.

iii) Unit generating maximum power and generator circuit breaker is tripped

due to electric fault.

The bidder may consider any other condition which may induce/provoke

more dangerous situation. In addition, the bidder should provide specific

comments regarding settings of intake and outfall structures.

2) Studies regarding critical speed of the shaft system.

B) After award of Contract:-

The Successful bidder (Supplier) shall be required to undertake the following

studies and / or calculations:

1. Optimisation of the turbine runner and the hydraulic passages.

2. Review studies and/or calculation mentioned above on the basis of data

obtained on completion of detailed design and supply the result.

3. Conduct FEM study to determine the stresses induced and the pattern of

concentration of stresses in major components of the unit such as turbine

runner, nozzles, Deflectors, Distribution pipes, generator stator frame and the

bearing brackets, shaft etc.

4. Computations of forces on overhangs, generator foundations, Bearings

supports etc. under most unfavorable conditions.


5. Dynamic analysis:

Studies to determine the dynamic behavior of the unit rotating parts, bearing

brackets and the forces which would be induced and transferred to civil

foundations shall be undertaken by computer simulations. The studies should

demonstrate the unit and the foundations are capable of withstanding without

damage the abnormal conditions during trip-outs and during runaway

conditions.

Dynamic analysis by computer simulation of the unit vibratory characteristics

should be carried out to determine the amplitude and frequency of the

hydraulically and mechanically excited vibrations originating within turbine,

generator and entire water passage system. The frequency of these

vibrations should be compared with each other and the natural frequency of

related components to determine whether or not there would be resonance.

The comparison should include critical speeds of major machinery

components, frequency and magnitude of vortex shedding from runner,

runner buckets, nozzles, deflectors, the unit dynamic imbalance, runner

hydraulic imbalance etc. All these natural frequencies shall be checked for

adequate margin against predominant frequencies to avoid resonance.

Studies carried out in this regard shall be furnished.

The supplier shall duly analyse all cases of possible interferences of

different resonance frequencies and must ensure that abnormal vibration

shall not occur when the unit operating at any load from 90% to 110% load

turbine. Besides, such an operation shall not provoke power pulsations at

generator terminals.

6. Dynamic analysis by computer simulations of the entire rotating system

should be carried out and determine the dynamic stability of the unit, main

shaft and bearings. These analyses should be sensitive to running

clearances, bearings spring constants, magnetic and hydraulic imbalances,

runaway speed, component centrifugal growth and critical speeds. These

analyses should demonstrate that the critical speeds, shaft run-outs, unit

bearings supports and bearing oil film are within safe limits for normal and

transient operating conditions. The maximum stresses induced under worst

conditions shall not exceed 2/3rd of yield point strength of material.


7. Dynamic stability studies both for large disturbances as well as small

perturbances shall be carried out to determine excitation characteristics and

determine necessity and type of damping, feedback signal for static excitation

system.

8. All the designs as per above requirements shall be validated on the basis of

studies carried out by the supplier and by mere calculations.

9. Model Test of Turbine:

The supplier shall manufacture a homologous model of the turbine and

perform the various tests to predict the performance and other operational

behavior of the prototype turbine. The tests to be conducted on the model

turbine are detailed in clause 5.5 of section V of this volume. Only after the

model tests are successfully performed and test report is approved by

purchaser, the manufacture of turbine shall be commenced. The model must

include geometrically similar water passages from the inlet of the turbine up to

end of hydraulic upto exit section. Besides, the model must be sensitive to the

running clearances.

10. EOT Crane: One no. of electricaly operated overhead traveling crane will be

provided in power house for handling the parts of the turbine and generator

and other equipment such as Spherical valve etc. Maximum load to be lifted

by EOT crane shall be given by bidder. Hook approaches, reaches end

clearances etc. of crane should be calculated by bidder and submit to the

Purchaser for necessary provisions.

1.11 DATA SHEETS

All data sheets appended to bidding documents must be completely filled in by

the bidder. The bidder shall specifically note that incomplete information or non

supply of important information may result in rejection of his bid.

1.12 DRAWINGS AND DATA TO BE SUBMITTED WITH BID


All drawing and data as per enclosed Annexure-I.1 shall be submitted along with

the bid. The drawing and data shall be sufficient enough to prove technical

compatibility of the bid and shall not be limited to the list of Annexure I.1.

ANNEXURE I-1

LIST OF DRAWING AND DATA TO BE SUBMITTED WITH BID

I- MECHANICAL LOT

DRAWING

(Power Station layout drawing specially prepared to scale and large enough to give

clear understanding regarding the provision of space for mounting various equipment,

cable galleries, pipe gallery etc.)

A) LAYOUT DRAWINGS PREFERRED SCALE

1. Cross section of Power Station.

The drawing must shown the limit

of supply on the upstream side and

on the downstream side, the turbine

Setting, the excavation level, turbine

level and generator level, Spherical

Valve gallery level, the hook lift

requirement above the service bay


level and the required capacity

of the power station crane …….1: 100

2. Plan of the station at Service bay level

showing the of equipment proposed provision …….1:100

3. Cross section of power station at turbine

generator level …….1:100

4. Cross section of power station showing station auxiliaries. …….1:100

5. Power station Control room Layout …….1:100

6. L section of power station at turbine generator level …1.100

B) MACHINE DRAWING

6. Cross section of the turbine showing clearly arrangement of shaft seal, bearing,

turbine housing and the access to these part during maintenance / operation; the

running clearance between labyrinths on the runner , runner and discharge , the

position of nozzles, deflectors, servomotors. The height of shaft flange above the

centre line of turbine and any other details desirable. ……..1:20

7 L section of the turbine showing clearly arrangement of shaft seal, bearing,

turbine housing and the access to these part during maintenance / operation; the


running clearance between labyrinths on the runner , runner and discharge , the

position of nozzles, deflectors, servomotors. The height of shaft flange above the

centre line of turbine and any other details desirable ……..1:20

8. Nozzle and Deflectors assembly:

Plan and sectional assembly drawing showing

the important dimension. The method of construction

and field welding joints. ……..1:20

9. Bearings

The drawing should shown in

sufficient details, the arrangement

of supporting the pads; method

of adjusting the pad clearance;

The minimum and maximum level

of oil, arrangement of cooling the

oil etc. …….1:20

10. Arrangement drawing of

Spherical valve & matching piece. …….1:20

11 Arrangement drawing of Distribution pipe, branch pipe. …….1:20

C) LIFTING ARRANGEMENT DRAWING FOR

Turbine runner and shaft,


Turbine housing,

Spherical Valve

Stator and Rotor

Bearings

D) SCHEMATIC DIAGRAMS OF

-Cooling water system

-Compressed air system

-Drainage system and Dewatering system

-Penstock dewatering system

-Pressure oil system of Governor and MIV

D. DESIGN CALCULATION /RESULT OF DESIGN STUDIES

1. Transient behavior

2. Adequacy of cooling water

3. Adequacy of dewatering and drainage pit.

4. Details of pump capacity, rating etc. for drainage &

dewatering system.

5. Details of water pressure reducer set with pressure reducer valve, stop valve,

safety valve and strainer etc. for cooling water system.

6. Requirement of DC supply voltage, Ampere capacity etc.


7. Requirement of AC Supply, voltage capacity etc.

II ELECTRICAL LOT

A. LAYOUT DRAWINGS:

1. Generator-turbine cross section showing important dimensions, levels etc.

2. General arrangement and overall dimensions of Turbine generator showing

position of main and neutral leads, bearing and bearings supporting

arrangements etc.

3. Excitation system

4. Protection scheme: single line diagram showing CT, PT, LAVT etc. and its rating.

5. 11 kV XLPE cable arrangement drawing.

B. Graphs, tables and charts

1. Graph showing the no load, short circuit and air gap line curves.

2. Excitation currents for 105%, 100%, 95% of rated output.

3. Power generation charts at 0.9—1.0—1.1 Un.

4. Table giving the various losses and calculated efficiency at various loads and power

factors.

19

SECTION – II

GENERAL REQUIREMENT

Signature of Bidder Signature of Purchaser

20

SECTION – II

GENERAL REQUIREMENT

INDEX


2.1 General requirements 21

2.2 Limits of contract 21

2.3 Project information 21

2.4 Interchangeability 21

2.5 Engineering data 21

2.6 Quality assurance plan 22

2.7 Safety and Compliance with rules regulations &

obtaining statutory approval

23

2.8 Inspection of works 24

2.9 Drawings 24

2.10 Supply of oils, grease/lubricants and other consumable 26

2.11 Manufacturing schedule and the progress reports 26

2.12 Design improvements 27

2.13 Erection-tools and tackles and spanners 27

2.14 Foundations and fixtures 27

2.15 Material and workmanship 27

2.16 Balancing 41

2.17 Electrical equipment 42

2.18 Earthing 48

2.19 Units 48

2.20 Protective guards 49

2.21 Storage at site 49

2.22 Rating plates, name plates and labels 49

2.23 Tests 49

2.24 Report of chemical analysis of water 55

2.25 Applicable standards 55


21

SECTION – II

GENERAL REQUIREMENT

2.1 GENERAL REQUIREMENTS :

The general requirements explained hereafter shall be applicable to the

equipment to be supplied.

2.2 LIMITS OF CONTRACT:

Equipment furnished shall be complete in every respect with all mountings,

fittings, fixtures provided with such equipments needed for erection,

completion and safe operation of the equipments and are deemed to have

been included. Further, these fittings, fixtures and accessories shall be of the

best standards and proven for use.

2.3 PROJECT INFORMATION

The data and information given in Bid Document are based on the information

available from project site authority. The Bidder shall satisfy himself about the

adequacy of the said data/information and interpretation there-of and if

necessary, carry out further investigation.

2.4 INTERCHANGEABILITY:

All parts shall be made to standard gauge in accordance with the normal

practice for the class of equipment concerned. All corresponding parts of

similar apparatus including spare parts shall be interchangeable.

2.5 ENGINEERING DATA:

The furnishing of engineering data by bidder shall be in accordance with the

provisions mentioned in the Technical specifications and the Data Sheets

annexed thereto. The review of these data by the purchaser will cover only

general conformity of the data to the specifications and documents interfaces

with the equipments provided under the specifications, external connections

and of the dimensions which might affect plant layout. This review by the

purchaser shall not be construed by the supplier, as limiting any of his

responsibilities and liabilities for mistakes, omissions and deviations from the


22

requirements, specified under these specifications. All engineering data

submitted by the supplier after final design including review shall form part of

the contract documents and the entire work covered under these

specifications shall be performed in strict conformity.

If the provisions made for the unit (e.g. jacks for rotor lifting, lifting

beam for rotor lifting, H.S. lubrication etc.,) by the Purchaser is not required,

the bidder shall clarify for the same in his bid.

2.6 QUALITY ASSURANCE PLAN

2.6.1 Quality Assurance Plan for Manufacturing Works

Four copies of Quality Assurance Plan giving details of inspection, tests and

customer witness / hold points shall be submitted with the bids. The quality

plan shall contain the details of inspection and tests to be carried out for each

major component of each functional assembly as recommended by the

manufacturer as per their standard practice. The tests will include material

composition and its properties, NDT, X-ray, hydraulic tests, leakage tests,

insulation, high voltage tests and functional tests etc. along with the applicable

standards and acceptance criteria.

The Supplier shall get the quality plans finalised and approved after the award

of the Contract. The approved quality plan shall form the basis for inspection

and acceptance of the equipment. The Engineer shall have the right to ask for

more relevant tests if the same could not be included in the quality assurance

plan at the time of their approval due to non availability of final design

drawings.

2.6.2 Quality Assurance Plan for Site Installation & Commissioning

Four copies of Quality Assurance Plan giving details of stage inspection

during installation, pre-commissioning and commissioning tests and customer

witness / hold points shall be submitted with the bids. The quality plan shall

contain the details of inspection and tests to be carried out for each major

component of each functional assembly as recommended by the

manufacturer as per their standard practice. Test Procedure shall be specified

giving for each test item (kind of test) a description, test method / standards,


23

used instruments, sample/routine test, test judgement.The tests will necessarily

include NDT, X-ray, hydraulic tests, leakage tests, insulation, high voltage tests and

functional tests etc. along with the applicable standards and acceptance criteria.

The Supplier shall get the quality plans finalised and approved after the award

of the Contract. The approved quality plan shall form the basis for inspection

and acceptance of the equipment at site. The Engineer shall have the right to

ask for more relevant tests if the same could not be included in the quality

assurance plan at the time of their approval due to oversight and/or non

availability of final design drawings.

2.7 SAFETY AND COMPLIANCE WITH RULES REGULATIONS & OBTAINING

STATUTORY APPROVAL

A Unit with respect to their location, layout, general arrangement and design

and equipment, structural design, etc. shall be safe to the personnel and

conform to the relevant safety rules and regulations / statutory requirement

issued by Government and the Central Government as well as to the following

Indian Electricity Rules

Indian Electricity Act

Indian Explosives Manual

Fire Protection Manual issued by Tariff Advisory Committee (India).

All equipment / materials shall be installed in accordance with the

requirement of relevant Standards, Indian Electricity Rules and Acts. The

successful bidder shall ensure that the electrical installation supplied and

erected by him shall be to the entire satisfaction of Chief Electrical Inspector,

Central Electricity Authority or any other statutory body having Jurisdiction in

the area and also to the purchaser / his authorized representative. Electrical

Inspectorate’s approval for the installation and commissioning shall be the

responsibility of the bidder. Preparation and submission of all necessary

drawings, calculations, tests certificate and relevant details to the Electrical

inspectorate and obtaining prior approval for commencing the work and for

the complete installation work done shall be done by the bidder. Any statutory

fee for inspection charge by Electrical inspectorate, shall be borne by the

bidder.


24

2.8 INSPECTION OF WORKS

During erection, re-assembly, commissioning and trial operation, the

Successful bidder shall perform at suitable intervals all inspections and tests

in the presence of the Engineer in order to prove the orderly execution of the

works in accordance with the Contract. Unless otherwise specified, all costs

for testing at site and of works and charges associated with it shall be borne

by the Bidder. Thus includes the measuring devices – properly calibrated, and

any pertinent accessories which shall be made available by the Successful

bidder for the entire duration of the tests. The successful bidder shall delegate

his experts to perform the tests at site. In case of disagreement between the

Engineer and Successful bidder on the test result, an independent expert

shall be appointed by Purchaser to whom both parties shall agree. If no

amicable settlement can be reached, the Arbitration Clause shall be applied.

2.9 DRAWINGS:

2.9.1 DRAWINGS AND DATA TO BE SUBMITTED WITH BID:

Drawings and other data which is required to be submitted with the bid is

stated in the Annexure-I-1 of section I of this Volume. These drawing shall

include sufficient details to demonstrate fully that the apparatus furnished

shall conform to the provision and intent of these specifications. Detail

drawings or design data for the purpose of checking the adequacy of the

supplier’s design by calculations shall not ordinarily be required but the

purchaser reserves the right to call for these in certain cases at his discretion.

These drawing shall show sufficient overall dimensions clearance etc.

required for assembling and dismantling and furnishing the space

requirements of all apparatus to enable the purchaser to determine the

design and layout of the installation and to decide the compatibility of the bid.

2.9.2 DRAWINGS AND DATA TO BE SUBMITTED AFTER AWARD OF

CONTRACT :

A) Drawings for approval :

The supplier shall furnish eight (8) copies of each of the drawings, the list

of which is given in respective specifications, for approval of the


25

purchaser. The methodology of submitting these drawings to the officers of

purchaser and or to consultants etc. shall be mutually agreed after award

of contract. The Purchaser and consultants as far as possible will review

the drawings submitted by the supplier within eight (8) weeks of their

receipt. During the process the purchaser shall have the right to call for

additional clarification or to suggest changes, which in the purchaser’s

opinion, are required to conform the equipment to the provision of the

specification. The drawings shall then be returned to the supplier along

with comments and/or modified drawing. The supplier shall account for the

comments and the suggested modifications and submit the revised

drawings for approval. The delay arising out of revision of drawings by the

supplier shall not cause any hold-ups related to site work or the

manufacturing schedule and eventually the completion of contract.

All the drawings pertaining to the plant and goods of Electro-

Mechanical works shall preferably be worked out on computers using

latest version of AutoCAD on maximum A1 size. Electrical drawings

including schematic drawings, block diagrams, flow diagrams, terminal

details, panel outline drawings, circuit diagrams etc. shall be worked out

on A3 size. All drawings shall have a uniform title-block as approved by

the Engineer. Beginning with the very first submittal to the Engineer, the

successful bidder’s drawings shall bear a serial number corresponding to a

drawing classification plan to be agreed upon by the Successful bidder

and the engineer. The drawings of bought out items shall also be preferred

in AutoCAD version, however, their scanned version will be allowed.

Catalogue sheets, illustration, printed specifications, etc., shall be checked

and prepared by the Successful bidder in such a way that the figures,

statements and data valid for the delivered sizes and types of the works

concerned are clearly marked. These documents also shall be stored on

CD and supplied to Department.

B) Revised drawings :

When revised drawings are submitted for approval, the changes for the

previous submissions shall be clearly identified on the drawings including

changes affected by supplier on his own from previous experience. Each

revision made shall be identified by revision number and the date and the


26

brief description of the revision. The drawings shall be clear and legible in

all respects. The revised drawings shall be again examined and if all the

comments are accounted, the drawing shall be ‘Approved’ and copy will

be returned to supplier.

Further work by the supplier shall be in strict accordance with such

approved drawings and no deviation shall be permitted without the written

approval of the purchaser.

All manufacturing and fabrication works in connection with the equipment

prior to the approval of the drawings shall be at the supplier’s risk and

cost. Approval of supplier’s drawing or work by the purchaser shall not

relieve the supplier of any of his responsibilities and liabilities under the

contract.

C) ‘As Built’ Drawings :

After the completion of the onsite erection work, the supplier shall furnish

ten (10) sets (including one copy on tracing cloth or in velograph i.e.

reproducible film) of the ‘As Built’ drawings showing changes, if made,

during erection for reference and record of the purchaser. These

Drawings also shall be stored on CD and supplied to purchaser.

2.10 SUPPLY OF OILS, GREASE/LUBRICANTS AND OTHER CONSUMABLE:

Sufficient quantity of oil, grease, lubricants and other consumable

required to put the whole of the plant including auxiliaries into successful

operation shall be supplied (i.e. deemed to be included in scope) without

extra charges.

The quality and the grade of the oils, grease and / or lubricants and

other consumable to be used shall be from the locally available suppliers.

2.11 MANUFACTURING SCHEDULE AND THE PROGRESS REPORTS:

The supplier shall submit to the purchaser his confirmed manufacturing and

delivery schedules for all equipments within thirty (30) days from the date of

Notification of award of contract. This schedule will not relieve the supplier

of the delivery and work completion obligations as offered by him with the

bid. The schedule shall be such as to meet the requirement of onsite

construction. This schedule may be updated, if required, and the changes, if


27

any, must be informed to the purchaser every quarter. The schedules shall

also include the materials and equipments purchased from outside. Every

quarter a report highlighting the delays, if any, and the actual progress

achieved shall be submitted. For substantiating the progress report, video

films and copies of the photographs (in duplicate) shall be supplied.

2.12 DESIGN IMPROVEMENTS:

The purchaser or the supplier may propose changes in the specifications of

the equipment or the quality thereof and if the parties agree upon any such

changes, the specification shall be modified accordingly.

2.13 ERECTION-TOOLS AND TACKLES AND SPANNERS:

A complete outfit of erection tools and tackles, gauges, slings, other lifting

devices, instruments and all other appliances required for the assembly,

erection, dismantling and maintenance of the plant shall be supplied.

Spanners and wrenches shall fit the nuts and bolts used in the plant.

2.14 FOUNDATION AND FIXTURES :

Foundations related to various equipment shall be prepared by the purchaser

on the basis of design data furnished by the supplier in line with civil

construction schedule. However, the supplier shall supply all fixtures

necessary for proper erection of embedded parts shall be supplied by the

supplier. If requested by the purchaser, the supplier shall assist the purchaser

involving special designs and criteria for civil foundation works of the turbine

and generator unit. All supports, fixtures etc. needed for assembly, erection,

testing and commissioning including that for field tests shall be prepared by

supplier at his cost.

2.15 MATERIAL AND WORKMANSHIP :

2.15.1 GENERAL

All parts shall be manufactured true to drawing dimensions. All tolerance shall

be designed on the suppliers drawings for both manufacturing and installation

purposes. Holes shall be drilled full size or under size and reamed during

shop assembly. Punched holes will only be permitted in plates 20 mm or less


28

in thickness provided all such holes are subsequently reamed full size during

shop assembly.

The materials used in the construction of the plan shall be new of high quality

and selected particularly to meet the duties required of them. The material

specification shall be indicated in supplier’s detailed drawings.

The use of materials liable to be attacked by termites or other insects shall not

be allowed. All workmanship shall be of the highest quality throughout to

ensure running smooth without vibration and noise under all possible

operating conditions. The design, dimensions and materials of all parts, shall

be so chosen that the stresses to which they may be subjected shall not

render them liable to distortion or damage under the most severe conditions

encountered in actual services.

Materials and workmanship shall conform to the latest editions of the relevant

standards.

2.15.2 PIPING :

All pipes and fittings (adequate number to be approved by the purchaser),

valves, drain plugs/cocks, test plugs, sight flow indicators, meters etc. shall be

provided so as to allow the operation and maintenance of the system with

ease.

All piping shall be clean inside and where ending in open connections for

other works, the piping shall have the ends capped for protection. Valves shall

be easily accessible and gauges and other operating or indicating devices

shall be located so that they can be conveniently operated or read from the

floor walkways. Valves shall be suitable for the services intended. Either a

blind end flange or a pipe shall be provided wherever necessary to protect

valves.

Where piping systems must be disconnected for servicing, flanges or

unions shall be provided and the piping, valves and joints shall be arranged

for minimum disturbance or interference with other parts during operation.

As far as possible, the pipes shall not be embedded but shall run in trenches

or shall be suitably supported by hangers, brackets, hooks, pedestals, or any

other support suited to the requirements, care being taken to avoid vibration

at the supports. An adequate allowance for the expansion of pipes under

service conditions shall be made. Each drain pipe shall be laid with suitable


29

slope to facilitate drainage. End pipe shall be suitably tagged or painted with

anticondensation paints where necessary. The material of piping for different

services shall be stated in the bid. Flexible pipe connections to apparatus

shall be provided wherever necessary. For ready identification or different

piping systems and their functions, each piping system shall be painted in

code colour (to be provided by the supplier and approved by the purchaser).

All operating points and also each separate section shall be painted with two

bands of approved code colours, the wide band twice the width or the narrow

one. An arrow showing the direction of flow shall also be marked. All

operating valves on a piping shall also be painted with the same code colour.

Each valve shall have, fitted to it, a suitable name plate indicating the function

of the valve.

2.15.3 FASTENINGS :-

Nuts, bolts, studs and washers for incorporation of plant shall conform to the

requirements of the appropriate standards. Where the contract includes nuts

and bolts of different standards, then the tools shall be provided in compliance

with that specification and shall be provided in compliance with that

specification and shall include spanners, taps and dies for these nuts and

bolts. Nuts and bolts for pressure parts shall be of the best quality bright steel,

machined on the shank.

All washers shall be included under the contract, including locking devices

and antivibration arrangements. Taper washers shall be fitted, wherever

necessary. Where there is a risk of corrosion, bolts and studs shall be finished

flush with the surface of the nuts. Bolts except for high strength friction grip

bolts shall be designed so that with the nuts fully tightened, the stress

intensity at the bottom of the thread shall not exceed half the yield point of the

material under all conditions. All bolts, nuts, and screws, which shall be

subjected to frequent adjustment on frequent removal in the course of

operation, shall be made of corrosion resistant steel or bronze.

Spring type washers will not be permitted where they may damage any

protective castings. Special tools, wrenches and devices found to be

necessary for the completion of the work shall also be provided under this

contract.


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2.15.4 FORGING :-

All highly stressed forgings shall be subjected to examination internally for the

detection of flaw and heat treatment for the relief of residual stresses.

Particulars of the heat treatment proposed for all forging shall be submitted to

the purchaser.

2.15.5 CASTINGS :-

The casting shall not contain damaging defects and shall be satisfactorily

cleared before use. The surfaces which are not machine finished and which

will be exposed after their final installation shall be such that grinding at the

site will not be required before painting. The presence of defective material

shall be determined and it shall be removed down to sound metal.

The cast parts shall be homogeneous and free from excessive non-metallic

inclusion. An excessive concentration of impurities or a separation of the alloy

elements in the critical points of a cast part shall be sufficient reason for its

rejection.

The casting of the main parts, including all those subject to hydraulic pressure

and all castings which undergo a major repair, shall be tested using

radiographic, ultrasonic, dye penetration, magnetic particle or any other

standard non-destructive test method. The expenses incurred on such tests

shall be to the suppliers account. In case of bus duct only 10 % radiography of

enclosure shall be done.

Minor defects or imperfections which definitely do not affect the strength or

utilization of the cast parts, may be repaired by welding, according to the

accepted practice for the repair of such parts.

Thickness and other dimensions of the cast parts shall agree substantially

with the dimensions shown on the drawing and shall not be reduced by shop

or casting practices to such extent that the effective strength of the cast parts

shall not be less than the stressed allowed by these specifications. Use of

cast iron for parts subjected to tension or impact shall not be permitted without

the approval of the purchaser.


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2.15.6 WELDING :-

Supplier shall specify clearly on all relevant drawings, the amount and type of

material for each type of weld, supplier shall also provide detailed drawings

showing joint preparation required for each type of welding to be carried out

on site and at supplier’s works.

The parts to be joined by electric welding shall be cut precisely to the correct

size by methods suitable for the type of weld to be used and to allow proper

penetration and good fusion on the weld with the base metal. The cut surface

shall not have visible defects such as scales, superficial defects caused by

shearing or torch cutting operation or any other damaging defects. The

surfaces of the edge to be welded shall be free from rust, oil, grease and

other foreign matter. All welds exposed to water flow shall be ground to a

smooth and even surface flush with the adjacent plate.

Supplier shall indicate on the detailed drawings, the type, sizes and material

of electrodes he proposes to use for shop and / or field welding. Unless

otherwise stated, all non destructive tests shall be carried out. All major

welding and all welding carried out on tanks and vessels, which will contain

liquid under pressure or compressed air shall subjected to 100 % radiographic

examination. In those cases where it is impossible to carryout radiographic

inspection, or otherwise state in specifications, it may be replaced by

ultrasonic examinations or any other non- destructive test systems.

2.15.7 SURFACE TREATMENT AND PAINTING :

1 GENERAL :

Where necessary the work shall be painted or treated with protective coating

to protect them from corrosion and to a neat and pleasing appearances. This

work shall comprise the surface treatment, priming and application of paint or

metallic coatings in the supplier’s workshops and at the site including all paint

repair work becoming possibly necessary. Every possible attempt shall be

made that the design of the equipment is such that all surfaces can be finish

coated or recoated after erection at the site. Unless otherwise specified, the

coating and painting shall be carried out in accordance with the latest

International Standard (Protective coatings for steel structures, directions) or

another equivalent approved standard. All priming and painting material shall


32

satisfactorily fulfill the requirements imposed by the site conditions

(considering also possibility extended periods of storage at site) as well as the

stresses to which the respective equipment is subjected during operation of

the works, Shades of the finishing coatings shall be as per the standard colour

tables at the choice of the purchaser. Each coat of primer and paintings shall

be compatible with the previous and subsequent coats. All pigmented primers

and paints, which will be used for priming and painting at the site shall be

delivered in original and sealed containers packed by the supplier. The

supplier shall supply full details regarding the extent by which sand blasting,

priming will be carried out in his workshops (or his sub-suppliers as the case

may be), at the site and after erection.

2 SURFACE PREPARATION :

Before the application of primers and paints the surfaces of steel or ferrous

equipment shall be properly cleaned up to the base metal in accordance with

ISO 8501-1 : 1988 or Swedish Standard SIS- SS05, 59.00. Wherever

practicable scale, rust and dirt shall be removed by abrasive blast cleaning

with quartz sand or corundum. The blast cleaned surfaces shall correspond to

standard gauges and the average surface roughness after sand blasting shall

not exceed 40 micrometers or minimum blast cleaning guide to BSA 2 ½ (ISO

8501 – 1 : 1988). All water passages, turbine and spherical valve shall be

prepared as follows:

Sand blasting to a minimum surface cleanliness or finish corresponding to

standard recommended grade. Sand shall be quartz sand, washed, clean and

dry and be gypsum and salt free. The practical size shall be between 0.7 mm

and 2.00 mm and the average peak to valley profile obtained shall be 40-60

micrometers. If grit blasting is used, it shall have good angularity of form with

sharp cutting edges and be free from ‘half rounds’. It shall be chilled iron on

hard steel grit with a particle size not greater than 0.9 mm. The maximum

peak to valley height thus obtained shall not normally exceed 100

micrometers. It is accepted that there will generally be isolated ‘rogue’ peaks

where the amplitude is abnormal, but no where shall these be greater than

150 micrometers. Parts, which cannot be blast-cleaned, shall be cleaned free

from rust and scale by power tool cleaning to the highest possible degree,

according to the above standards. The surface preparation for non-ferrous


33

materials shall be to the approval of the purchaser and or consultant and will

generally be required to conform to the recommendation of the coating

manufacturer. All working of the material (e.g. welding, drilling, grinding) shall

be completed and surface defects (e.g. weld splatter, burns, cracks, surface

laminations and pitting), likely to be detrimental to the protective coating shall

be removed before surface preparation begins. As regards welding joints,

these shall be covered with one coat of appropriate primer shortly after

welding wherever possible. Otherwise they must be cleaned with a steel

brush before applying the first primer coat.

3 PRIMER, FINISHER AND PAINT APPLICATION:

Before the application of the primer all sand blasted or otherwise mechanically

created surfaces shall be subject to thorough cleaning process during which

all dirt, dust, grease, moisture etc. is removed so that the primer is applied on

suitable surfaces. Clean cloth and pure dissolvent shall be used for this

process.

The primer may be applied by airless spray gun, roller or by brush. All

subsequent coats of paint shall be applied using airless spray equipment,

unless otherwise recommended by the paint supplier or approved by the

purchaser and or consultant. Where the use of airless spray equipment is

found impracticable, the supplier must be prepared to use brush application at

no additional cost to the purchaser, such application being to the approval of

the paint supplier and the purchaser. The paint supplier’s instructions shall be

followed implicitly with respect to the method of application of the paints, the

drying time between coats and the temperature of the material being painted,

where ambient temperature, relative humidity or dew point will affect the

drying or curing of paint, the manufacturer’s recommendations shall be

followed. Unless specifically recommended otherwise by the paint supplier or

approved by the purchaser, not less than 24 hours, not more than five days

shall lapse between priming and successive coats of paint. Each coat shall be

free from runs, drops, pin holes, waves, lops, sag and unnecessary brush

marks. Particular care shall be taken to provide adequate paint film cover on

corners and edges, nuts and bolt heads.

Equipment contained in cubicles, cabinets or similar enclosures shall be

painted as if is exposed to view and the inside surface of the enclosures shall


34

be painted semi-gloss white. In sheet metal enclosures where otherwise the

surface would not be protected against corrosion (e.g. between the surfaces

of spot welded joints and behind stiffening channels), such surfaces shall be

quoted before assembly with an approved spot welding primer after

preparation of the surface in accordance with the paint supplier’s instructions.

All paint shall be delivered to the point of use in unopened containers bearing

the manufacturer’s label which shall include, where appropriate for special

systems, date of manufacture, batch number and instructions. All paint shall

be supplied in the ready mixed condition and except to comply with the

supplier’s direction, mixing of paints by the supplier shall not be permitted.

Machinery paint may be thinned, if necessary to permit satisfactory

application, but the amount of thinner shall be kept to a minimum. Special

attention has to be given to the two pack coating. The application of these

materials is no problem if the specification is strictly followed. For a perfect

application the following important and generally valid conditions apply. The

prime coating should be applied immediately after or at least on the day of

blasting (exception only in air conditioned rooms). After the mechanical

treatment but before the top coating is applied, the prime coating has to be

cleaned (grease, oil and other impurities) with solvents and / or hot stream.

Application temperature for two pack epoxy resin coating at least 5 degrees C

Surface temperature minimum 5 degrees C above dew point. Maximum

atmospheric humidity: not higher than 75 %. The proportion of mixture for two

component products are to be strictly followed. Waiting times between

coatings to be observed according to specification. For multilayer it is

advisable to change the shade of colour (for later abrasion). Otherwise

abrasions have to be checked by measuring film thickness. Edges have to be

pre coated. Not to prime a strip of 150 mm beside the planned site welds

(especially important for zinc rich primers) Prior to the top coating, the prime

coating has to be repaired carefully.

4 GALVANISING:

All drilling, punching, tapping, cutting and bending of the parts shall be

completed and all burrs removed prior to galvanizing. Galvanising shall be

applied by the hot dipped process and shall consist of the smooth clean zinc

coating free from defects and of uniform thickness. Original blast furnace raw


35

– zinc ( minimum purity 98%) shall be used. The zinc coating shall weight not

less than 600 g/m2 of area covered. Sheardizing or other alternative process

shall not be used without the approval of the purchaser and / or consultant.

Material on which galvanizing has been damaged shall re-dipped unless, in

the opinion of the purchaser, the damage is local and can be repaired by

applying a coat of galvanizing repair paint where such repair is authorized the

damaged area shall be cleaned by wiping with clean rags saturated with

mineral spirits or xylene followed by wire brushing. After wire brushing, the

area shall be re-cleaned with solvent to remove residue and shall be given a

minimum of two coats of zinc primer containing not less than 98% (by weight)

of metallic zinc in the dry film which shall have a total thickness of not less

than 60 micrometers.

Galvanised surfaces should be kept apart in storage and transport. If this is

impossible, they should be treated by dipping in a 10 to 18% solution of

chromic acid, which should produce a coating of 12 micrometers. This

coating must be removed before any painting is attempted.

5 METAL SPRAYING :

Subject to the approval of the purchaser where an item is of a size or shape to

render hot-dip galvanizing impracticable, zinc spraying or other approved

method of coating may be adopted. Metal spraying of surfaces shall comply

with the following procedure:

Surface preparation prior to spraying shall be dry grit blasting to a

standard approved by the purchaser and/or consultant. Immediately after grit

blasting, the surface shall be cleaned of any traces of blast products on the

surface and in pockets, pits and corners by brushing with clean brush, blowing

with compressed air or vacuum cleaning.

The surface shall be coated with the metal spray before discoloration

occurs. In the event of the surface becoming contaminated e.g. with rust, oil

or dirt between blast cleaning and applying the metal spray, it shall be re-

cleaned by repeating the above procedures. Care shall be taken to have as

little roughness as possible on the sprayed surface.


36

6 NON METALLIC COATINGS :

Coatings in this category include sprayed or sheet linings, as applied to tanks,

vessels and pipes carrying aggressive fluids and wrappings as applied to

buried or immersed pipe work. The materials employed may be rubber, PVC

sheet, glass reinforced resin or plastic. Surface preparation and application of

the coating shall be strict in accordance with the approved instructions of the

coating supplier.

7 WETTED SURFACES CORROSIVE MATERIALS :

The material to be protected is usually under water and exposed to

constant flow. Erosion through water with a more or less high sand content is

one of the main strains for these parts. Therefore the coating has to be of high

quality, epoxy resin is best suited. In order to endure chemical aggression of

soiled water, the coating material is mixed with coal tar, which is also resistant

against bacteria, fungi and algae.

The coating system is set up as follows:

Prime coating: One layer of two pack high zinc pigmented epoxy primer. This

primer is an active corrosion protection, above all to avoid “under rusting” if

the top coat is damaged or porous.

Film thickness: 60 micrometers.

Top coating: Two pack modified epoxy coal tar. Depending on the application

place or the suitability of the part, there will be distinguish between two layers

of two pack modified epoxy coal tar containing solvents of 100-150

micrometers .

Colour : black or red.

This material can be applied by brushing or by airless spraying or the normal

use more than one coat is necessary.

Total film thickness: 260-360 micrometers. Or one layer of two coat modified

epoxy coal tar solvent free material of 300 micrometers.

Colour : black.

The material can only be applied with a special machine. Standard

applications are one coat. Because of the lack of solvents in the painting

material, there is no danger of pores. Total film thickness: 360 micrometers.


37

REMARK: Condensation zones where the colour is not visible from outside,

may be coated with epoxy coal tar.

8 NON-CORROSIVE MATERIALS:

Normally highly alloyed stainless steels, Ni : Cr, 4 : 13 (can be corrosive if

soiled) and bronze e.g. red brass are not to be coated. It is important,

however, that the contact areas stainless steel / normal steel are carefully

protected by coating, also a stripe of the non- corrosive material, otherwise an

amplified corrosion may occur (Contact corrosion). Machine with long rest

periods (e.g. pumps) are exposed to increased localised corrosion similar to

‘pitting’ (localised corrosion) usually on the base materials when the coating is

porous and damaged.

EXCEPTION: If a stainless steel part required a coating due to reasons

such as photographing or decoration, a water and oil resistant synthetic

resin primer should be applied. Such a coating has to be especially

required by the purchaser.

9 ZONES WETTED BY CONDENSATION :

The main strain for zones wetted by condensation is the permanent rewetting,

i.e. interchange : wetting – drying. The visible surfaces are less stressed.

However, surface quality and appearance (shade of colour) require a high

standard of material. Gloss and semi gloss finishes facilities cleaning. Due to

practical reasons visible and invisible (dry) surfaces are not differentiated. The

same applies for visible surface of stainless materials. The coating system is

set up as follows :

Prime coating :

One layer of two pack zinc rich epoxy primer to avoid ‘under rustings’ if the

top coat is damaged or porous.

Film thickness 60 micrometers.

Intermediate Coating :

One layer of two pack micaceous iron oxide epoxy paint (two coats if exposed

to condensation). The micaceous iron oxide in lamellar from embedded in the

epoxy oxide is a perfect pore protection and has excellent adherence

properties for the top coating.


38

Film thickness : 60 micrometers,

Top coating :

One coat :

Either polyurethane acrylpoiyol micaceous iron oxide coat of 60

micrometers (recommended for outdoor coating providing a mat glossy

surface ).

Or polyurethane top coating of 60 micrometers with a glossy surface, usually

applied for indoor coatings. The polyurethane based top coats have very good

abrasion and mechanical resistance in addition to a proven corrosion protection

and an excellent colour retention.

Total film thickness : 180-240 micrometers.

REMARK : Parts covered with epoxy coal tar on the water side should be

coated with the same material on the condensation water side if the shade of

colour is not important.

10. OIL WETTED SURFACES :

For oil tanks, bearing casings, servomotors etc. As a standard coat as a one

pack synthetic resin primer is sufficient. This coat is oil and water resistant

upto 150 degree C. The first primer is applied before the tightness test and

the second coat is applied after assembly.

The total film thickness : 80 micrometers.

11 COATING OF MACHINED SURFACES :

Machined surfaces require a two pack epoxy resin zinc chromate or zinc

phosphate pigmented prime coat to improve adhesion to the base material.

A standard top coating may then be applied, depending on the strain the

parts are exposed to total film thickness : 120-160 micrometers.

REMARK : Generally sand blasting after machining (if possible) is preferred

because of the adhesion of the paint. Sand blast surfaces may then be

coated in the normal manner.

12 BLANK SURFACES :

These surfaces are only to be protected for transportation and temporary

storage with a soluble lacquer.


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13. PIPEWORK

WATER PIPES

All such pipes, except those of corrosion resistant material shall be blast

cleaned and be coated by dipping in acid free hot bituminous compound to

give an acceptable finished coating thickness.

Ends of pipes and tubes subject to weld joining at the site shall be left

uncoated over a distance of approx. 100 mm. After site welding the erection

welds shall be coated with 2 layers of zinc – rich primer containing not less

than 95 % (by weight) of metallic zinc in the dry film, which shall have a total

thickness of not less than 60 micrometers. Finishing of the ends of pipes and

tubes interior shall be by a layer of zinc rich chlorinated rubber paint. The

exterior of small pipes shall be carefully cleaned and pickled and coated with

2 layers of zinc-rich chlorinated rubber paint. Exterior surfaces of pipes and

tubes, except those of corrosion resistant materials shall be primed with three

layers of red lead paint on chlorinated rubber / synthetic resin basis (total

minimum thickness of the dry film : 100 micrometers) .. Uninsulated and

unwrapped pipes and tubes shall receive two subsequent layer of finishing

paint on the same basis (total minimum thickness of the dried finishing coats

: 60 micrometers)

OIL PIPES

Both the interior and exterior shall be thoroughly cleaned and pickled and

rinsed very carefully to an approved method. The exterior surfaces shall

subsequently receive two layers each of oil resistant priming and finishing

varnish or enamel. The interior of fuel carrying pipes shall be protected by a

corrosion prevention compound.

AIR PIPES

Same treatment and painting as for the water carrying pipes. The purchaser

will decide on the finishing shades at a later date.

AIR DUCTS

External surfaces shall be coated with 2 layers each of priming and finishing

paint.


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14 CUBICLES AND CABINETS

FOR INDOOR INSTALLATION

After careful sand blasting all cubicles and cabinets shall be given two

priming and two finishing coats of varnish or enamel which in case of those

carrying oil or liable to oil vapour exposition shall be oil resisting. A minimum

dry film thickness shall be 100 micrometers in total.

The insides of cubicles and cabinets where condensation is liable to occur

shall be coated with four layers of an approved anti – condensation

composition. Other inside surfaces shall be coated with at least two layers of

varnish of semi glass white.

External surfaces of cubicles and cabinets shall be given to suppliers

standard primer and machinery enamel or appropriate enamel for cubicles

being used indoors for electrical equipment. All cubicles being located in one

row must be painted with the same shade.

FOR OUTDOOR INSTALLATION

These cubicles and cabinets shall be given after careful sand blasting and hot

dip galvanizing coat inside and outside. After etching these should receive two

layers each weather resisting varnish or enamel.

15 STEEL CONSTRUCTIONS

INDOOR

Same shall be thoroughly sand-blasted and provided with (two hours later)

three layers of red lead primer on chlorinated rubber / synthetic resin basis

(total minimum dry film thickness : 100 micrometers).

Finishing shall be by 2 respective coatings on the same basis (total

minimum dry Film thickness of finishers : 60 micrometers)

Areas subject to oil and grease shall receive four layers of oil resistant

priming and finishing varnish or enamel). This shall apply in particular to all

transformers.

OUTDOOR

After careful blast cleaning with an approved method and cleaning of the

surface after this process, all steel structures shall be heavily hot dip

galvanized.


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16 WORKSHOP EQUIPMENTS, PUMPS, COMPRESSORS ETC.

Treatment as per the supplier’s practice and coating with the supplier’s

standard primer and machinery plant.

17 PLATFORMS, HANDRAILS, COVER PLATES, TRENCH COVERS,

ACCESS LADDERS ETC.

All gratings shall be heavily hot-dip galvanized. Aluminum alloy chequered

plates need no treatment and protection. Ferrous chequered plates shall be

heavily hot dip galvanized. Handrails shall be heavily hot dip galvanized.

These should after etching receive 2 layers of oil resisting varnish or enamel.

18 PARTS IN CONCRETE

The surfaces shall be cleaned from mill scale, dirt, oil, greace and other

residues and shall be covered before leaving supplier’s premises with a

substantial coating of Portland cement wash or other proprietary coating. For

parts in concerete, it is important that the zone between visible surface and

zone in concrete a stripe of approx . 0.5 m of the concrete be coated, along

the visible surface.

Components under high pressure (penstocks or spiral cases) touching in

concerete should be sealed additionally.

2.16 BALANCING

For small rotating machinery all rotating parts and assemblies shall be well

balanced both statically and dynamically at the supplier’s works. The supplier

shall rectify any out of balance that may occur during erection at site. Over

dimensioned and heavy rotating machinery shall be statically and accurately

balanced at the point of installation.

2.16.1 DOWELLING

At all stages of assembly, where accuracy of fit has to be assured on site,

dowel holes shall be provided with dowels to assist reassembly and load

resisting if needed.


42

2.17 ELECTRICAL EQUIPMENT

2.17.1 GENERAL

The various auxiliaries and controls shall be suitable for operation on following

power supply mains.

i) 400 V, 3 phase, 50 Hz, A.C.

ii) 230 V, single phase, 50 Hz, A.C.

iii) 220 V D.C

The above power supply will be available with ±10 % for AC voltage and +

10% and – 15% for DC voltage and + 3% and -5% frequency variations for AC

supply. If any other voltage is needed, the supplier shall make his own

arrangement with suitable power converters, transformers etc. to derive the

required supply. The cost thereon is deemed to have been included in the bid.

Electricity for construction work will be supplied free of charge by purchaser.

2.17.2 PUMPS AND MOTORS:

Unless otherwise specified, oil pumps shall be directly coupled to driving

motors and their type, capacity and performances shall be best suited to the

requirements. The efficiency of the pumps shall be as high as practicable

consistent with good design. As far as possible, the pumps shall be of

standard size to facilitate replacement of parts. The pump shall be of the self

priming type, if however any external means of priming are employed these

shall be stated in bid and shall be subject to the approval of the purchaser.

Driving motors to which pumps are coupled shall confirm to the general

standards laid down in this specification. Gear motors, if employed shall be

subject to the purchaser’s approval.

The alternating current (A.C) motors of rating ≤ 120 kW shall be provided with

direct on line starter at supply voltage of 400 V and those of rating > 120 kW

shall be provided with star / delta starter. Rated power of motors shall be

guaranteed at 85 % rated voltage and 95 % of rated frequency with closed air

cooling according to IEC standard with interchangeable possibility.

The pump capacities and the rating of the driving motors shall have liberal

margin over the requirements. Motors shall be drip proof.


43

All pumps shall be designed and constructed to ensure quiet and satisfactory

operation without undue noise or vibration under all condition of discharge

and pressure. Centrifugal pump casings shall be designed to produce smooth

flow with gradual changes in velocities. In addition, the pumps shall be easily

removable and replaceable. Suitable gaskets shall be provided for all pipe

joints to ensure that they are leak proof. If any strainers are required with the

pumps, these shall be included in the bid and be duplex type or by pass to

enable periodic cleaning.

All pumps shall be complete with the necessary piping, both on the suction

and delivery sides and with all fitting suited to the size and duty of the pump.

Adequate number of valves as stated earlier shall be furnished with each

pumping units to suit its operation and maintenance. Where ever necessary,

pumps shall be provided with suitable flow meters or flow indicators and

pressure gauges to measure the discharge and the pressure delivered by the

pumps. Suitable eye bolts or lifting lugs shall be provided on each pumping

set to facilitate handling.

2.17.3 ELECTRIC MOTORS AND MOTOR CONTROL GEAR :

All motors furnished by the supplier, for driving the unit auxiliaries and other

apparatus shall be directly coupled to the apparatus driven and shall be

suitable for operation on purchasers power supply. All motors to be supplied

shall be energy efficient motors. The enclosure of each motor shall be of the

type best suited to the service conditions of the motor and shall be subject to

the approval of the purchaser in every case. The motor shall generally

conform to the relevant Indian or IEC or other equivalent standards. The

insulation shall be moisture, oil, oil vapour, drip proof and the motors shall be

entirely suitable for the operation in the tropical climate conditions prevailing

at site with 100 % humidity (degree of protection IP 54 or as applicable).

Motor shall be provided with varnish cambric or glass insulation class F and

shall be used for connections from the windings to the terminals. All motor

terminals shall be of stud type and totally enclosed.

The capacity, speed and torque characteristic of the motors shall be suitable

for the starting and operating requirements of the associated apparatus.


44

Necessary starting, protective and control gear shall be furnished by the

supplier with each motor. Instantaneous and thermal overload protection shall

be provided for the motors together with remote indication of the operation of

the protective gear, wherever necessary. In the case of essential motors

stoppage of which would result in serious damage the thermal overload

protection devices shall be arranged give alarm only, without disconnecting

the motors. Red and green indicating lamps shall be furnished for indication of

the closed and open positions respectively of motor contacts The control and

indication equipment shall be suitable for operation with 220 V DC supply.

Special type of motors, not adequately covered by the specification may be

offered for any special application, but these shall be subject to the approval

of the purchaser.

2.17.4 SMALL WIRING:

All small electrical wiring of various equipments, panels, etc. shall be

completed at the supplier’s work as far as possible. All small wiring shall be

arranged neatly into flat or rectangular groups and shall be adequately

supported with cleats etc. The small wiring shall be so arranged as to reduce

the number of bends or crossing to a minimum. There shall be no splices in

the wire and all connections shall made at the terminal studs or terminal

blocks. Similar circuit shall be arranged to terminate as far as possible on

adjacent terminals to facilitate grouping and to minimise the number of

interconnecting cables. Secondary or control wiring including leads from the

current transformers, temperature detectors, alarm contracts, speed and

pressure switches etc., shall be enclosed in conduits and shall be carried to

dust and water proof and oil tight cabinets located conveniently for connection

to the control cables.

Pressure circuits shall be suitably protected so that failure of one circuit shall

not cause the progressive failure of adjacent circuits. Alternating current

circuits, direct current circuits, shall be grouped separately and the wiring of

each of these group shall preferably be segregated.

For the purpose of easy identification, tracing and reconnection the wiring

shall be colour coded according to relevant international or IS standards and

shall be fitted near the terminals with ferrules or such other cup indelibly


45

marked with the identification number corresponding with that of the

associated terminal blocks. When an electrical circuit is extended to several

pieces of equipment necessitating sectionalising of circuit wiring at the

terminal blocks of the corresponding equipments common identification

numbers shall be used for the designation of the circuit at all the terminal

blocks and connections. The terminals and circuit designation for all wiring

shall be subject to the approval of the purchaser.

All small wiring shall be switchboard type, single conductor, tinned annealed

copper wire, PVC insulated cables as per relevant Indian or International

standards, insulated with varnished cambric, which has proved its utility in

tropical region against hot damp and moist climatic conditions and wiring

complying with the relevant international standards. All small wiring shall have

oil and oil vapour proof insulation. The sizes of the wiring for different circuits

shall be so chosen as to provide ample margin for the purposes intended and

shall subject to the approval of the purchaser.

2.17.5 TERMINAL BLOCKS:

Terminal blocks shall preferably be made of suitable moulded plastic material

and shall be provided with brass stud inserts for terminating the outgoing end

of the cubicle wiring and the corresponding wiring of the incoming end.

Provision shall be made on each block for holding 15% extra connections. All

blocks shall be shrouded by easily removable shrouds moulded from

transparent dielectric material. The terminal block shall be of disconnecting

type and suitable for max. 1000 V service and dielectric test of 2000 V.

Sufficient space for receiving the control cables inside the switch board at the

bottom of the switchboard cubicles and mounting arrangements for the

terminal glands shall be provided.

Terminal block compartment shall be separated from the remainder of the

equipment by oil and oil vapour proof barriers and scale, wherever necessary.

2.17.6 MEASURING INSTRUMENTS:

All instruments and meters shall be suitable for operation under the climatic

conditions prevailing at site. The instrument cases shall be dust proof, water

tight, vermin proof and specially constructed to adequately protect the

instruments against damages for deterioration due to high ambient


46

temperature and humidity, special care being taken in the protection of

instruments for indoor and outdoor services also. The dials, pointers etc.,

shall be designed to facilitate glare from instrument window and by providing

clear, bold, dial markings. The size of dial and length of the scales of

indicating instruments shall be subject to the approval of the purchaser in

each case. The scale of the indicating instruments which are to be mounted

on main control panel shall cover approximately size 48 x 48 mm. Supplier

can follow his standard practice for other instruments. The scale plates of

panel mounted indicating instruments shall have a permanent white matt

finish with black graduation. The pointer or the pointer indicating and contact

setting (in contact working instruments) shall be distinguished from the main

pointer by a distinct colour and/or shapes. Instruments mounted on panels

shall be of the semi-flush finish type and shall be back connected. All

instruments on a switchboard or instrument panel shall be of matching

pattern, shape and finish so as to present a pleasing appearance consistent

with the functional requirements. The finish of the instrument case shall be

subject to the approval of the purchaser. All instruments shall be designed for

accurate measurements of the quantity or state under all conditions of

operations and any error due to change in the ambient temperature, over the

entire range of temperatures obtainable at site, shall be kept to a minimum.

The instruments shall be provided with all the auxiliary appliances and any

special tools required for their maintenance.

MKS (meter-kilogram-seconds) units shall be used for marking the instrument

dials. The range shall generally be such that the normal operating values are

indicated in the middle third of the scale. All electrical instrument coils shall be

designed for continuous operation on at least 120 percent of the full rated

current and voltage of the instruments. The instrument coil rating shall be

coordinated with those of the associated instrument transformers. The VA

burden of instrument coils shall be as low as possible, consistent with the best

modern design.

Electrical indicating instruments shall comply generally with the requirements

of the Indian/IEC or any other International Standards and shall be of the

accuracy specified in relevant sections.

Recording instruments shall be of the strip chart type with chart scales having

a suitable width. The chart shall be gear driven by a self-starting synchronous


47

motor wound spring device having ample torque even at reduced voltage and

with at-least 8 hours spring reserve under all normal conditions of operation.

The recording instruments shall be of withdrawal type for easy access to

maintenance work. Sufficient number of chart rolls, recording ink for five

years of operation and any special tools required for the maintenance of the

instruments shall be furnished with each recorder.

Integrating watt and VAR hour meters shall comply generally with the

requirements of the international standards.

Instruments provided with contacts shall have contacts suitable for 230V,

A.C. or 220 V D.C. circuits.

All instruments shall have as high accuracy as possible consistent with best

modern design. The construction of instruments shall be mechanically sound

and shall ensure permanence in the accuracy. The limits of error for different

instruments shall be stated in the bid and their accuracy classification, where

otherwise not specified, shall be subject to the approval of the purchaser. All

instruments shall be tested in accordance with the requirements of the

standard, wherever specified. In cases where no specific standards are

mentioned, the supplier shall submit the list of the standards in accordance

with which the instruments are proposed to be manufactured and tested and

these shall be subject to the approval of the purchaser in every case.

The instruments shall be capable of withstanding the following tests viz.,

effect of shock, effect of vibration, effect of humidity and dielectric tests of

2000 V to ground for one minute in accordance with relevant standards.

2.17.7 FLOW RELAYS

Flow controllers, used throughout the works shall be equipped with adjustable

contacts suitable for 220V D.C.System designed to change position on a

decrease in flow below predetermined value.

2.17.8 LIMIT SWITCHES

Any limit switch shall be entirely suitable for its specific application. Particular

attention shall be paid to potentially harmful environmental conditions,

including water, oil, dust, dirt, temperature variations and differential

expansions, where switches operate through linkages. Precautions shall be


48

taken to eliminate variations of setting and incorrect operations resulting from

wear or tolerance. Operating voltage shall be 220V D.C.

2.17.9 CONSTRUCTIONAL REQUIREMENTS FOR CUBICLES AND PANEL

BOARDS

Switch boards, control, relay and metering panel shall be of robust, industrial

type design and manufacture, formed of a steel frame and covered with

smooth steel plate. The steel plate shall be sufficiently thick and properly

stiffened to prevent distortion. If required, flush mounted hinged steel doors

with latches shall be provided; doors shall be of the lockable type by means

of approved key locks. The key lock shall be of the same type for all panels.

All cubicles shall be fully enclosed and protected according to the protection

class given in the specification. The lowest degree of protection shall be IP

44. The frames of the cubicles shall be designed to permit firm anchoring on

the floor. The frames shall permit easy erection and allowance shall be made

for extension of the cubicles by additional similar ones. Supplier’s supply shall

include all necessary mounting brackets, framing, foundation bolts and

respective embedded metal to permit proper installation of the cubicles.

2.18 EARTHING

The Supplier shall provide earthing terminals on all the equipments supplied

under the contract and shall connect the earthing conductors (95-120mm²

copper) to these terminals as approved or directed by the purchaser.

The Supplier will provide the earthing conductors from the station

earthing bus to the equipment. Supplier shall do equipment earthing. The

Supplier shall provide suitable test terminals at convenient points of the

equipments being supplied to enable periodic testing of the receptivity and

insulation level of the equipments. Purchaser will provide earth mat and mild

steel flats. Supplier shall provide suitable earthing terminals with bimetal

clamps, washers, nut bolts, lug etc. suitable for both connections.

2.19 UNITS

According to the latest edition of the relevant Indian and/or IEC publications

shall be used for this contract. For the purpose of design/calculations, SI

Units shall be used.


49

2.20 PROTECTIVE GUARDS

Suitable guards shall be provided for protection of personnel on all exposed

rotating and/or moving machine parts. All such guards with necessary spares

and accessories shall be designed for easy installation and removal for

maintenance purpose.

2.21 STORAGE AT SITE

The supplier shall furnish complete instructions regarding the storage of the

equipment at site. If at any time after the receipt of equipment at site,

supplier or his representative desires to draw the attention of the purchaser to

the conditions of storage, which in his opinion might affect the state of the

equipment stored, he shall do so in writing to the purchaser. Periodical

inspection of stored items shall be the responsibility of supplier.

2.22 RATING PLATES, NAME PLATES AND LABELS

A rating plate of non-corrodible material metal sheets shall be attached to

major and auxiliary item of equipment supplied. This plate shall be

permanently engraved with the designed full load ratings, serial number, type,

number, date of manufacture and other identification deemed necessary.

Where necessary, diagram plates shall also be supplied. A name plate shall

be provided to identify the service of major items of plant supplied. The

purchaser shall approve the identifying description. Devices shall be

identified by name plate on both front and rear of all desks, panels, cubicles

etc. Names plates or labels shall be manufactured of stainless steel or

aluminum alloy with engraving of contrasting colour or alternatively for indoor

use of transparent plastic material with lettering engraved on the back and

filled with enamel. These shall be in English language only.

2.23 TESTS

In accordance with stipulations of General Conditions of Contract and Special

Conditions of Contract the test shall be performed. Brief details of tests are as

follows but shall not be limited to the same.


50

2.23.1 GENERAL

Inspection and testing of the equipment shall include all inspections, tests,

checks, procedures etc. Whether mechanical, hydraulic or electrical as

required to ensure that the equipment supplied meets the requirements of the

technical specifications.

The tests include, but are not limited to the following.

• Turbine model test

• Chemical analysis of materials

Destructive and non-destructive tests of materials

• Check and examination of welds

• Check of fits and assemblies

• Dimensional checks

Inspection of paints and coatings (thickness and porosity)

• Hydrostatic pressure and tightness tests

• Balancing tests

• Shaft run-out tests

• Electrical tests

Running tests (inclusive measurements of vibration and noise levels).

• Functional tests

• Performance tests

• Load and overload tests

• Load rejection and load taking-up tests

Acceptance tests (prototype output and efficiency tests)

• Type tests if specially required

The technique, equipment and instrumentation to be used for these tests,

checks, inspections, examinations etc. shall generally be in accordance with

the relevant internationally accepted standards, rules or codes mentioned in

except where specifically mentioned in the technical specification.

If in the purchaser’s and/or consultants opinion instruments, apparatus,

devices etc. used by the supplier (or sub supplier) need calibration or re-

calibration then such instruments, apparatus, devices etc. shall be calibrated

at the supplier’s cost by an independent authority or institute subject to

approval by the purchaser.


51

2.23.2 RANDOM SAMPLE TESTS

These tests are to be carried out on random samples from a lot of equipment,

parts or material. The purchaser and/or consultant shall do the choosing of

samples to be tested, parts etc. and the complete lot of equipment be

presented for this purpose. The number of samples taken will be either at the

discretion of the purchaser and/or consultant particularly for small lots, or

shall conform to the generally accepted rules and standards of statistical

testing. The whole lot, of which the samples have been taken, shall be

considered satisfactory if none of the sample tested has failed. Should any

one of the samples fail, even in any one test, the following shall apply.

a) SMALL LOTS: All pieces shall be fully tested.

b) LARGE LOTS: A second set of samples, identical in number to the first one,

shall be chosen and tested. If the set passes all tests satisfactorily, the lot

shall be considered to be accepted. If again one or more sample fails in the

tests, either the whole lot shall be rejected of all pieces of the lot be fully

tested individually. The decision as to which of the two alternatives shall be

adopted shall be with the purchaser.

Pieces of lots which have been declared non acceptable and samples which

have failed in test must be marked immediately and must not be presented

for test again.

2.23.3 TESTS AT SUPPLIER’S WORK

Before any material, equipment, aggregate, apparatus etc. is packed or

dispatched from the supplier or sub-supplier’s works, all tests, inspections,

checks, examinations etc. required by the relevant and international accepted

standards, rules or codes shall be carried out as far as practicable and

agreed in the specifications.

All equipment, materials, aggregates, apparatus and other parts of

components of the works to be tested, inspected, checked, examined, etc. at

the supplier’s or sub-supplier’s works shall be properly accessible for testing

and inspection work. There shall be no interference or disturbance from

other shop activities when conducting the tests and inspections.

It shall be understood that all equipment materials, aggregates, apparatus

and other parts or components will be adequately shielded and protected

against weather whilst being tested, inspected, checked and examined.


52

Parts and components shall be assembled to the fairest possible and agreed

extent and dimensional checks shall be performed on all major assemblies,

sub-assemblies, parts and components especially when close tolerance and

fits are being involved (tolerance of shafts, clearance between stationery and

moving parts, connecting dimensions for the assembly with other elements

and supplies, combined functioning of electrical equipment etc.)

Components and parts to be weld assembled at the site, shall be tag welded

in the shops to permit visual and dimensional check of the fits and

transmissions. All such components and parts shall be match marked

properly to ensure correct assembly and welding at the site.

If dimensional checks show discrepancies in measurements, which may

affect the fit transition clearance, assembly or dismantling of the respective

part or component, immediate, proper, and workman like correction or

modification is a must.

Such correction or modification shall, however, in no way lead to sacrifice

with respect to reliability of operation or inter-changeability and shall be

performed only after the agreement of the purchaser and/or consultant has

been obtained. If the correction or modification can not be carried out in

accordance with the terms mentioned above, the part or component

concerned may be subject to rejection.

Doubtful, used, weak and faulty materials or products will also become

automatically liable for rejection.

Shop testing shall also cover the hydrostatic pressure testing of equipment

which can be finish assembled in the supplier’s or his sub Supplier’s

premises.

Pumps, fans, compressors and apparatus shall be tested at the

manufacturer’s works. If two or more identical pumps, fans, compressors and

apparatus etc. are supplied a complete performance test is to be carried out

on the first unit only. Such performance test shall comprise the verification of

the discharge capacity against discharge pressure, power input and efficiency

and other performance data requested in the specification. The respective

test diagrams shall be provided. Subsequent units need to be tested only if

test results obtained from the first unit prove doubtful or unsatisfactory.

Evidence and diagrams of previous ‘type tests’ undertaken on identical

design of pumps, fans, compressors and apparatus may be acceptable


53

instead of further complete performance tests, but the purchaser’s approval

must be sought in each case. A test at the duty point will, however, in any

event be required. Particular requirements have also been set out in the

specifications.

As far as possible tests on pumps in the manufacturers works shall be carried

out with suction conditions as those after installation at the site.

Cubicles, cabinets and control boards shall, prior to their inspection and

testing, be completely definitely assembled, equipped and wired internally in

the supplier’s or his sub Supplier’s shops.

Shop testing shall include functional tests as the case may be part or

complete assemblies to the extent practicable and agreed. Such tests shall

be performed under, as far as possible in operation like conditions.

When requested by the purchaser the functional tests shall be repeated or

extended until proof has been obtained that the functioning of the assemblies

will comply with the requirements of the specification.

2.23.4 TESTS AT SITE

During erection and installation work at site, the equipment shall be subject to

tests which may include but not be limited to the testing, checking, inspection

and examination of all equipment assembled/welded and set up at the site.

The procedure may be confirmed upto final acceptance of the works.

The supplier shall provide at his cost, all competent personnel (including

those from sub-supplier) as well as all equipment, material and other services

required for the proper and the complete testing and putting into commercial

service of all equipment. If in the opinion of the Purchaser not sufficient

competent personnel have been delegated, the Purchaser may request the

Supplier to send additional appropriate competent personnel to the site.

Further to the tests, checks, examinations etc, stipulated in technical

specifications, the tests at the site shall comprise but not be limited to:

- Checks and examination of welds

- Hydrostatic pressure tests

- Tightness tests

- Dielectric tests

- Dry rotation tests (with clearance and run out checks)


54

- Functional checks (on protective devices, automatic and manual controls,

monitoring, supervisory equipment etc.)

- Running tests

- Reliability tests

- Performance tests and determination of characteristic data and tests in

particulars of the turbine and generator.

- Turbine acceptance tests (in accordance with IEC-Publication for “field

acceptance tests to determine the hydraulic performance of hydraulic

turbine”)

- Regulator acceptance tests (in accordance with the IEC Publication 308,

1970, “International Code for testing of speed governing systems for

hydraulic turbine”)

2.23.5 RELIABILITY TESTS

After the supplier has notified the purchaser and received his agreement that

the equipment is ready for commercial services, the generating units may be

operated continuously at rated speed and maximum output for a maximum

period compatible with site conditions.

After successful completion of such tests, the unit shall be operated under the

various conditions envisaged within the limits of maximum output either

continuously or intermittently, for a period of ninety (90) days with a view of

obtaining useful information and to verify if the interest of specifications are

met or otherwise.

The equipment will be operated by the purchaser’s staff with the assistance

and as per the advice of the supplier’s staff during the reliability test period.

The supplier may request any minor adjustments, which may be necessary

provided that such adjustments do not in any way, interfere with or prevent

the use of the equipment by the purchaser or result in reducing the output or

decreasing the efficiency.

If any failure or interruption occurs in any portion of the equipment covered by

the contract due to, or arising from faulty design or materials, or workmanship

(including construction at site) sufficient to prevent full use of the equipment,

all the reliability tests shall be repeated after the supplier has remedied the

cause of failure or interruption.


55

2.24 REPORT OF CHEMICAL ANALYSIS OF WATER

Source of water sample : Nirabai River , Date of sampling : 24/05/2010.

Sr. No. Parameters Results

1 Colour Clear

2 Odour Odour Free

3 pH 6.7

4 Suspended Solids 34 mg/lit.

5 Dissolved Solids 96 mg/lit.

6 Total Solids 130 mg/lit.

7 Turbidity 5.0 NTU

8 Alkalinity 66 mg/lit.

9 Chiorides (as Cl) 8.5 mg/lit.

10 Sulphate(as SO4) 9.5 mg/lit.

11 Flurides (as F ) 0.4 mg/lit.

12 Calcium (as Ca) 12 mg/lit.

13 Total Hardness

(as CaCO3) 76 mg/lit.

14 Iron (as Fe) 0.044 mg/lit.

15 Magnesium (as Mg) 11.18 mg/lit.

2.25 APPLICABLE STANDARDS

Unless otherwise specifically stated, the applicable standards would be the

latest revisions of the relevant IEC standards/codes or other standards, which

are equivalent to IS or IEC. The supplier is requested to get himself

acquainted with Indian Electricity Acts and Rules and follow those.

Generally applicable standards are as under but not limited to:

IEC standard for main turbine

IEC 193(1963) International code for model acceptance tests of hydraulic

turbines (code X) Amendment No.1 (1977) (code K)

IEC 193A (1972) First supplement (code P)


56

IEC 308(1970) International code for testing of speed governing system to

hydraulic turbine (code X)

IEC 497(1976) International code for model acceptance tests of storage pumps

(code X B)

IEC 41(1991) Field acceptance test to determine the hydraulic performance of

hydraulic turbine storage pumps and pump-turbines.(code XK)

IEC 545(1976) Guide for commissioning, operation and maintenance of

hydraulic turbines (Code S)

IEC 609(1978) Cavitations pitting & valuation in hydraulic turbines, storage

pumps & pump turbines (Code P)

IEC 994(1991) Guide for field measurement of vibration and pulsation in

hydraulic machines (turbine, storage pumps and pump-turbines)

(Code XB)

IEC 995(1991) Determination of prototype performance from model acceptance

tests of hydraulic machines with consideration of scale effects.

(Code V)

Note: IEC 198(1966) acceptance tests of pump turbines and IEC 609

(1978) Thermodynamic measurement are replaces to IEC 41

(1991) IEC standard for accessories of turbine.

ASME VIII,

ASME V

ASTMA 435

ASTMA 609, Welding materials

ASTMA 709 .

ASTMA A 388 and

IEC 404

ASME Boiler and pressure vessel code section VIII, Dim 2 Low cycle

fatigue.

IEC- 34.9 Noise limits for electrical machines.

ISO- 1996 Noise measuring.

VDI-2056 Vibration limit.

IEC 298(1990) A.C. metal enclosed switchgear and control gear for rated

voltage above 1 KV and up to and including 52 kV (code XA)

Amendment No.1 (1994) (Code K)


57

IEC 264 Packaging of winding wires 264.1, 264.2, 264.2.1, 264.2.2,

264.2.3, 264.3, 264.3.1, 264.3.2, 264.3.3, 264.3.4, 264.4,

264.4.1, 264.4.2.

IEC 502(1994) Extruded solid dielectric insulated power cables for rated voltage

from 1 kV up to 30 kV (code XA)

IEC 227 Polyvinyl chloride insulated cables of rated voltage up to and

including 450/750 V, 227.1(1993) (code S), 227.2(1979)(code

K), 227.3(1993) (code Q), 227.4(1992) (code H)-227.5(1979)

(code P), Amendment No.1 (1987) (code B), Amendment No.2

(1994) (code D), 227-6(1985) (code L).

IEC 228(1978) Conductors of insulated cables (code M) Amendment No.

1(1993) (code D)

IEC 228 A (1992) First supplement, Guide to the dimensional limits of circular

conductors (code E)

IEC 287(1982) Calculations of the continuous current rating of cables (100%

load factor) (code XB)

Amendment No. 1 (1988) (code G)

Amendment No.2 (1991) (code E)

Amendment No 3(1993) (code L)

IEC 287.1.2(1993) Part 1: Correct rating equations (100% load factor) and

calculations of losses - Section 2 Sheath eddy current loss

factor for two circuit in flat formation. (Code U)

IEC 287.2-1(1994) Part 2: Thermal resistance section 1: and calculation of

thermal resistance.(Code V)

IEC 947-2(1989) Part 2: Circuit breaker (This publication Supersedes IEC 157-1

(Code XB)

Amendment No.1 (1992) (code U)

Amendment No.2 (1993) (code S)

IEC 947-4-1(1990) Part 4 contactors and motor starters Section 1 Electro

mechanical Suppliers and motor - starter (code XD) (This

publication supersets IEC 158-1(1970) and its Amendment

(1983) and 158-1c.

IEC 269 Low voltage fuses


58

269-1 (1966)Part 1 General requirements (code XB)

Amendments No.1 (1994) (code B)

269-2(1986) Part 2 Supplementary requirements for fuses for

use by authorized persons (fuses mainly for industrial

application) (code G)

269.2.1. (1987) Part2 Supplementary requirements for fuses for use by

authorised persons (code D)

Amendment No. 1 (1993) (code F)

Amendment No.2 (1994) (code B)

269-3 Part 3 Supplementary requirements for fuses for uses by unskilled

persons (code L)

269-3.1Part 3 Supplementary requirements for fuses for uses by unskilled

persons (code XD)269-4 (1986) Part - 4 Supplementary

requirements for fuse links for protection of semiconductor

devices (code U)

IEC 357 IEC 947 - 5 - 1

IEC 364 Electrical installation of buildings

IEC 508 Methods for measuring the performance/electric ironing

machines for semi conductor IEC 147

IEC 408 IEC 947 - 3

IEC 439 Low voltage switchgear and control gear assemblies.

439 - 1, 439-2, 439-3, 439-4.

IEC - 51 Direct acting indicating analogue electrical measuring I

instruments and their acessories.51-1 to 51-9

IEC 145(1963) VAR hour meters. (Code R)

IEC 52(1988) Class 0.5.1 and 2 alternating current watt hour meter (code w)

IEC – 255 Electrical relays 255 - 1.00 to 255-23.

IEC 72 Dimensions and output series for rotating electrical machines 72

-1 to 72 -3.

IEC 404 Magnetic materials

404-1, 404-2, 404-3, 404-4, 404-5, 404-6, 404-7, 404-8, 404 -

8.1, 404-8.2, 404-8.3, 404-8.4, 404-8.5, 404-8.6, 404-8.7,

404.8.8, 404-8.9, 404-8.10, 404-9, 404-10, 404-11, 404-12.

IEC 34-9(1990) Part 9 Noise limit for rotating, electrical machines (code K)


59

IEC 34 Rotating electrical machines 34-1, 34-2A, 34-3, 34-4, 34-5,

34-6, 34-7, 34-8, 34-9, 34-10, 34-11, 34-11-2, 34-11-3, 34-12,

34-13, 14-14, 14-15, 34-16-1, 34-16-2, 34-17, 34-18-1, 34-18-2,

34-183.

IEC – 76 Power transformers 76-1 (1993) - 76-2 (1993), 76-3 (1980), 76-

3-1 (1987), 76-5 (1976).

IEC 56(1987) High voltage alternating current circuit breakers (code XH)

Amendments No.1 (1992) (Code M)831,871,931


60

SECTION III

SCHEDULE OF REQUIREMENTS


61

SECTION III

SCHEDULE OF REQUIREMENTS INDEX


I MECHANICAL LOT

3.1 Turbine 62

3.2 Governor 64

3.3 Spherical valve 65

3.4 Station auxiliaries 65

3.5 Spares 66

II ELECTRICAL LOT

3.6 Generator and static excitation equipment 70

3.7 11 kV XLPE cable and 12 kV Bus Duct 72

3.8 Isolator, earthing switch, magnetic voltage transformer,

current transformer

73

3.9 Protective and Metering System 75

3.10 Supervisory control and data acquisition system 76

3.11 Spares 79


62

SECTION III

SCHEDULE OF REQUIREMENTS

I MECHANICAL LOT

3.1 TURBINE

1 No. Horizontal shaft Pelton turbine.

Turbine shall be capable of developing maximum continuous output

of at least 11000 kW at rated net head of 402 m. Turbine shall

consist of:

1 No. Pipes between Penstock and Spherical valve (i.e. penstock

special), between Spherical valve and Distribution pipes of the

turbine including stiffeners. installation material etc. complete with

pipes, duplex valve systems. Valve shall be suitable for operations

from Spherical valve gallery.

1No. Turbine housing

1No. Pelton runner with adequate no. of buckets

1No. Turbine shaft (Runner mounting on extended generator shaft may

be allowed, if offered by bidder)

1No. Turbine bearing (Drive end side) with H. S. lubrication (if required),

oil coolers, Resistance temperature detector (R.T.D.’s), Dial type

thermometers (D.T.T.’s) etc. with piping, valves etc.

2Nos Jet deflectors (interlinked) with deflector servomotor


63

2Nos. Nozzles each with needle servomotor and needle operating device,

regulating apparatus, servomotor double acting type etc. complete

with locking device, oil pipelines, valves, pressure gauges, limit

switches etc.

1Set Brake jet assembly including necessary piping, valves etc.

1Set. Oil pressure unit and oil pipe lines

1 Set Penstock drainage system

1 Set. Expansion joint, air release valve

Lot Thermometers, thermal relays, all level gauges and relays, water

pressure gauges and relays etc. Gauges, temperature indicators

etc. to be mounted on unit control board covered under electrical

lot. Supplier of Mechanical and Electrical lot shall co-ordinate to

include all interfaces suitable for local/remote and auto operations

of the system.

1 Set Oil leakage system if needed (requirement shall be justified at

bidding stage) complete with tank, motor-pump sets, pipes, valves,

level switches, gauges etc.

1 Set Velocity measuring devices before Spherical valve.

1 Set Water level measuring devices.

1 Set Mechanical over speed device

Lot Control and Power Cables –Power cables for local control board to

equipment, local control board to unit control boards and up to

distribution board shall be provided by the Supplier. Control cables,

racks, dressing of cables by nylon /plastic belts, ferrule, glands,

copper lugs etc. for entire system of equipment covered under the


64

scope of supply shall also be provided by the supplier. All cables

shall be FRLS, HRPVC insulated copper conductor stranded type.

Lot Oil, grease, lubricants sufficient for first filling and 25% spare

quantities.

Lot All accessories viz. sole plates, foundation and anchor bolts,

platforms, ladders, guards, hand rail, bolts, nuts, turn buckles etc.

complete including requirement during installation and of

permanent nature.

1 Set Turbine junction box.

1 Set Runner inspection & maintenance platform (if required)

1 Set Necessary instrumentation, control, safety devices etc. along with

the spares and special tools and plants required for erection,

operation & maintenance including the following.

• Runner removal tools complete.

• Hydraulic jacks for pre-stressing of the shaft coupling bolts,

• Hydraulic jacks for pre-stressing of the Turbine cover and

bottom ring.

• Tools and Tackles required for handling of bearings.

• All tools for assembling and dismantling guide bearing, shaft

seal, nozzles, deflectors, nozzle pin, runner, turbine shaft

support collar etc.

1 Set All test kits, instruments, meters etc. for commissioning, routine and

special tests at site.

1 Set Slings for handling the bearing, runner, shaft head cover,

servomotor etc.

3.2 GOVERNOR

1Set Governing system including digital governor, speed signal

generator, over speed trip device, emergency shut down device,

restoring mechanism, Oil pressure Unit etc.


65

3.3. SPHERICAL VALVE

1 No. Spherical valve (to suit for 1000mm dia. Penstock ) with service

and maintenance seals complete with oil hydraulic drive, Oil

pressure Unit, main and stand-by pump-motor unit for servomotor

for opening operation, air valve, counter weight or pressurised

water piping with valves for closing operation, draining system, all

accessories, gauges, meters, indicators etc. complete.

1 Set Erection and maintenance tools for Spherical valve.

3.4 STATION AUXILIARIES

3.4.1 COMPRESSED AIR SYSTEM

Compressed air system is required for Governor OPU, MIV OPU,

Generator Braking and service air and consists of :

2 nos. 3 Stage Reciprocating Compressors

2 nos. Moisture Separators

1 no. High Pressure Air receiver

1 no. Pressure reducer

1 no. Low Pressure Air receiver (for Generator Braking and service air)

1 lot Pipes, valves, instruments & fittings.

3.4.2 COOLING WATER SUPPLY SYSTEM

Cooling water required for unit operation shall be tapped from

penstock before Spherical valve. The exhaust water shall be led

down in to the tail race. Cooling water system shall cater for the

cooling water requirements of entire power plant i.e. turbine and

generator and shall comprise of :

• Water Pressure reducer set

• Stop Valves, safety valves, strainer duplex filters and piping with

control devices, instruments etc., complete.

• The piping shall be complete from penstock tap upto discharge

point.


66

3.4.3 DRAINAGE & DEWATERING SYSTEM

Comprising of adequate no. of submersible type pump-motor units,

complete with control, protection and switchgear panels, level control

devices, piping, valves, check valves, clamps, supports, anchors etc. The

piping shall be complete from pump room up to discharge point.

3.5 SPARES

MANDATORY SPARES FOR MECHANICAL LOT

Item No. Description Quantity

I MACHANICAL LOT

A) TURBINE

1 Needle 1 No.

2 Nozzle 1 No.

3 Bush of needle assembly 2 Sets

4 Deflector 1 Set

5 Bush of Deflector assembly 2 Sets

6 Seals of nozzle assembly 2 Sets

7 Springs (each type) 2 Sets

8 Bearing segments/pads 1 Set

9 Piston rings for servomotor 1 Set

10 Bearings for regulating mechanism 1 Set

11 Shaft gland/ seal assemblies finished with fixing

elements.

1 Set

12 Shaft seal water filter elements (If filters are

required)

1 Set

13 Removable protective bush of shaft 1 No.


67


14 Solenoid coils per solenoid used 1 Set

15 Flow relay of each type used 1 Set

16 Annunciator lamps of each type used 1 Set

17 Mercury thermometer of each type used 1 Set

18 Resistance thermometer of each type used 1 Set

19 Limit switch of each type used 1 Set

20 Necessary recording charts for one year

operation.

Lot

21 Consumables such as all packing, gasket and

jointing material used throughout the turbine,

including those for the servomotors and for the

man doors.

1 Set

22 Ten per cent (10%) of all bolts, screws nuts and

washers used up to and including M30 size.

1 Set

B) FOR GOVERNOR AND OIL PRESSURE

SYSTEM

1 Oil Pump complete with motor 1 Set

2 Hydraulic amplifier 1 Set

3 Pilot and control valve complete 1Set

4 Transducers 1 Set

5 Equipment for checking

turbine speed

1 Set

6 Equipment for limiting the opening of nozzle 1 Set

7 Oil pump for pumping leakage oil 1 Set

8 Printed circuit boards used for speed and limit

setting.

1 Set

9 Safety relief valve 1 Set

10 Setting Potentiometer of each type used. 1 Set

11 Float switches, pressure, flow and temperature

relays of each

1 Set


68


12 Solenoids for each type of solenoid valve used 1 Set

13 Fuses of each type used 1 Set

14 Each kind of filter used 1 Set

15 Com Complete set of all packing, gasket and jointing

material used.

1 Set

16 percent (10%) of all bolts, screws, nuts and

washers up to and including M 30

1 Set

C) FOR INLET VALVES (MIV)

1 Service seal with all fixing 1 Set

2 Maintenance seal with all fixing 1 Set

3 Servomotor piston rings and packing 1 Set

4 Instrument and indicator of each type used. 1 Set

5 Control solenoid of each type used. 2 Set

6 Flow relay and man stat of each type used 1 Set

7 Limit switch of each type used 1 Set

8 Necessary recording charts for one year

operation.

1 Set

D) FOR STATION AUXILIARIES

a) DEWATERING EQUIPMENT

Completely assembled submersible pump-motor

set

1 No.

b) DRAINAGE EQUIPMENT

Completely assembled submersible pump-motor

set

1 No.

c) COOLING WATER EQUIPMENT

Pressure Reducer set 1 No.


69


d) COMPRESSED AIR SYSTEMS

1 Piston Rings 1 Set

2 Unloader valves 1 Set

3 Bolts 1 Set

4 Gasket 1 Set

5 Oil filter elements 1 Set

6 All types of valves 1 Set

e) CONTROL AND SAFETY DEVICES

1 Limit Switches 1 Set

2 Level Switches 1 Set

3 Float Switches 1 Set

4 Pressure Switch 1 Set

5 Flow Relays 1 Set

E WATER LEVEL MEASURING DEVICE

1 Printed circuit card One (1) of

each kind

2 Converter One (1) of

each kind

3 Surge Protector One (1) of

each kind

5 Water level detector One (1) set of

each kind

6 Recorder Chart Fifty (50) rolls

7 Digital indicator One (1) of

each kind


70

ll ELECTRICAL LOT

3.6 GENERATOR AND STATIC EXCITATION EQUIPMENT.

One No. Horizontal shaft generator suitable for direct coupling with the

turbine. Generator shall comprise of:

One No. Ventilation system air-cooled type

One No. Stator assembly complete with frame, core and winding.

One No. Rotor assembly complete with spider rim, brakes, jacks, field

winding etc.

One No. Terminal cubicle for machine housing surge capacitor, potential

transformers, current transformers, lightning arresters, cable boxes,

etc., complete.

One No. Neutral grounding cubicle consisting of grounding transformer,

secondary loading resistor, current transformer, cable boxes, etc.

One No. Shaft with coupling flanges and bolts etc. complete.

One No. Generator bearing (Non-drive end side) with H. S. lubrication (if

required), oil coolers, Resistance temperature detector (R.T.D.’s),

Dial type thermometers (D.T.T.’s) etc. with piping, valves etc.

One No. Forced/self lubrication system for bearings with externally mounted

oil coolers complete with all the oil and water piping with valves,

flow relays.(if required)


71

One Set Air coolers (Air/Water heat exchangers) with valves, connecting

piping, flow meter, thermometers and other fittings for generator

cooling. (if required)

One Set. Sole plates, foundation bolts, dowels and other fittings required for

proper erection, leveling and alignment of stator, bearings, Turbine

housing etc.

One Set. Air guide cum air seal assembly. (if required)

One Set. Brake and jack (if necessary) cylinders complete with all the

necessary internal and external pipe work, valves, electrical remote

switches with contacts and with brake dust collector.

One No. Speed signal sensing device. Signal sensing device shall be

complete with casing suitable to cover over speed device also.

One Set. Brush gear system with slip rings and brushes.

One Set Static excitation system complete with excitation transformer,

thyristor cubicles, field flashing system, battery field flashing

provision, field suppression cubicle with field breaker and discharge

resistor, etc. complete.

One No. Digital voltage regulator.

One No. 11 kV Junction Bus panel with copper bus and necessary

provisions of tapping for UAT etc.

One Set All instruments and devices such as dial type thermometers,

pressure gauges, resistance temperature detectors, thermostats,

flow relays, oil level switches etc. complete shall be provided.


72

One Set. Turbine, generator gauge panel containing temperature gauge both

of turbine and generator

One Set. Temperature scanner

One Lot Local control boards for equipment wherever necessary for control

indication and alarm of the system shall be provided.

One No. 415 volt A.C. Power Distribution Panel required for motors of unit

and auxiliaries.

One Set Rotor lifting device (if required)

One Set Complete erection tools required for unit.

One Lot Testing equipment comprising the following

I) 5kV megger, mains operated. 1No.

II) Lubricating oil filter 1No.

III) 10kV, tan-delta measuring kit 1No.

One Lot: Mulsifire system for generator

One Set: Operation and maintenance tools

3.7 11/11 kV, 1 X630 SQ.MM, COPPER CONDUCTOR UNARMOURED XLPE

INSULATED POWER CABLE AND 12 kV BUS DUCT

11/11 kV, 1X630 sq. mm, copper conductor unarmoured XLPE

insulated power cable for a machine shall comprise of :


73

Lot 11/11 kV, 1X630 sq. mm, copper conductor unarmoured XLPE

cable from LAVT to isolator and from isolator to junction box bus

panel to step-up transformer with one spare core. As shown in

single line diagram.

Lot 11/11 kV, 1X630 sq. mm, copper conductor unarmoured XLPE

cable tap run from 11kV Junction bus panel to unit auxiliary

transformer with one spare core

Lot 12 kV, segregated 3 phases, 3 cores, Aluminum Bus Duct from

Generator terminal to LAVT cubicle.

Lot 12 kV, segregated 3 phase, 3 core, Aluminum Bus Duct tap run to

the cubicle of voltage transformers and disconnecting switches.

Lot 12 kV, segregated 3 phase, 3 core, Aluminum Bus Duct run to the

cubicle of excitation transformer, disconnecting switches and

current transformers.

Lot 12 kV, segregated 3 phase, 3 core, Aluminum Bus Duct tap run to

the cubicle of surge absorber, voltage transformers and current

transformers.

Lot 12 kV, segregated 3 phase, 3 core, Aluminum Bus Duct cable tap

run from generator neutral connection to neutral grounding cubicle.

Lot Support steel structure, hardware, trays, fixing belts etc. for entire

XLPE cable run.

One Set Shorting Links for dry out and short circuit test

One Set All special tools required for erection and maintenance.

3.8 ISOLATOR, EARTHING SWITCH, MAGNETIC VOLTAGE

TRANSFORMER, CURRENT TRANSFORMER

12 kV, 5 kA rating isolator as follows for each unit :

One No. Isolator having own operating mechanism (before Unit Auxiliary

transformer tapping in 11 kV junction bus panel and after LAVT


74

panel) for back charging of step up transformer shown in single

line diagram.

One No. Earthing switch (after isolator and before 11kV junction bus panel)

as per shown in single line diagram.

One Set 3 nos. of Current transformer of two cores in Neutral Grounding

Cubicle as per shown in single line diagram.

One Set 3 nos. of Current transformer of four cores in LAVT cubicle for

Protection and Metering as per shown in single line diagram.

One Set 3 nos. of Current transformer of single core in LAVT cubicle for

spare as per shown in single line diagram.

One Set 3 nos. of Current transformer of two core in LAVT cubicle for

excitation transformer ratio correction factor as per shown in single

line diagram.

One Set 3 nos. Current transformers of three cores in Junction Bus panel for

differential protection of UAT and ratio correction factor of UAT for

transformer and overall differential protection (as per shown in

single line diagram ).

One Set 3 nos. of Current transformer of two cores in Excitation cubicle for

excitation transformer protection (as per shown in single line

diagram).

One Set 3 nos. of Current transformer of two cores in UAT cubicle for UAT

protection and metering (as per shown in single line diagram).


75

One Set Six nos. of Magnetic voltage transformers of two cores for

Protection and Metering in LAVT Cubicle (as per shown in single

line diagram).

One Set Totally enclosed Surge protection capacitors and arrestors for

connection in tap run of Bus Duct.

One set Generator neutral Terminals

One set Neutral grounding cubicle with grounding transformer/ resistor and

voltage transformer.

Lot Fittings, accessories.

One Set Special tools required for erection and maintenance.

3.9 PROTECTIVE AND METERING SYSTEM

3.10.1 One set Static protection system comprising of following

protective relays:

A) Generator, step-up Transformer Unit Protection

1. Generator Differential Protection.

2. Overall Differential Protection.

3. Step-up transformer differential protection.

4. Generator Stator Earth-fault protection.

5. Generator-Rotor Earth-fault protection ( Two steps)

6. Voltage controlled over-current protection.

7. Loss of excitation (Minimum reactance protection)

8. Reverse power protection.

9. Under-impedance protection.

10. Thermal over-load protection.

11. Negative sequence phase current protection.


76

12. Restricted earth-fault protection for star-connected

secondary winding of step-up transformer.

13. Over-frequency protection.

14. Under-frequency protection

15. Generator over-voltage protection.

16. Generator under-voltage protection.

17. Step-up transformer over-current protection.

18. Over-current protection for Unit Auxiliary Transformer.

19 Excitation transformer Over-current protection

20 Unit auxiliary transformer differential protection

21 Generator phase sequence check.

Protection for D.C System

* Under-voltage protection for 220 V D.C.

* Under-voltage protection for 48V D.C.

* Earth-fault protection for 220V D.C.

* Earth-fault protection for 48V D.C.

B) One Set In addition, the following static protective relays shall be

provided

i. Negative phase sequence relay (46)

ii. IDMT Over current relay (51)

iii. Stator earth fault protection (64G)

C) One Set Following mechanical protections shall be provided:

a. Resistance temperature detectors (Pt-100) in stator

core (12 no.) and in the bearings for indication, alarm

and recording. RTD’s are to be provided by Generator

Suppliers.


77

b. Turbine and generator bearing, metal and oil

temperatures – alarm/shutdown.

c. Governor oil pressure low to block starting and very

low for emergency tripping.

d. Over speed for normal and emergency shutdown

depending upon its extent.

e. Our speed relay-Mechanical And Electrical (12)

D) One Set The following protection shall be provided on the

transformer.

(i) 220 kV side of transformer

(a) Digital IDMT over current and earth fault relay with

high set instantaneous element (50/51/64.)

(b) T/F winding temp high alarm/trip control.

(c) T/F oil temperature high alarm/trip control.

(ii) LV side of the transformer

(d) Digital IDMT over current and earth fault relay with

high set instantaneous element (50/51/64.)

(e) T/F winding temp high alarm/trip control.

(f) T/F oil temperature high alarm/trip control.


78

3.10.2 Metering System

Lot Following metering equipments shall be provided on relevant

panels.

1. kW meter

2. kWh meter

3. kVA meter

4. Ampere meter

5. Voltmeter

6. Power factor meter

7. Frequency/speed meter

8. Temperature meters.

3.10 SUPERVISORY CONTROL AND DATA ACQUISITION SYSTEM

One set Microprocessor based control system comprising :

1. Integrated Operation Station (IOS)

2. Integrated Data base station (IDS)

3. Integrated Engineering Station (IES)

4. Printer.

5. Micro Controller (HDC)

6. Power Distribution Equipment (CVCF).

7. Main control board, 220 kV control & interface board and

mosaic board

8. Man machine Interface. (MMI)

9. Computer system with main control board and function

keyboard.


79

3.11SPARES

MANDATORY SPARES FOR ELECTRICAL LOT


3.11.1 FOR GENERATOR

1 Stator upper and lower bar with insulating

material to form 1/3 stator winding

1 Set

2 Field coils. 1 set

3 Generator bearing segment/ pads 1 set

4 Brushes with brush holders 1 set

5 Brake liners 1 set

6 Generator air coolers ½ set

7 Oil coolers for Generator bearing. 1 set

8 Dial type thermometer 1 set

9 Thermostat for air circuit,

bearing etc.

1 set

10 Water flow relays for air coolers, bearings,

etc.

1 set

12 Gaskets for brake cylinders 1 set

13 Gasket/ washers for air water coolers 1set

14 Speed device equipment 1 set

15 Fans with driving electrical motors ½ set

16 Embedded detector for bearings 1 No.

3.11.2 EXCITATION AND DIGITAL VOLTAGE

REGULATOR EQUIPMENT

1 Parts of magnetic contactor

a) Contactor 1 piece of each kind of contactor

b) Operating coils 1 piece of each kind of

contactor

3 Uninterrupted Power supply in DVR 1 set


80


4 Converting measuring and supervision units

for slips stabilization

1 set

5 Rotor angle limiter 1 set

6 Rotor Current limiter 1 set

7 Stator Current limiter 1 set

8 Pulse Comparison units 1 set

9 Digital Voltage Adjuster 1 set

10 Digital potentiometer 1 set

11 Feed back module 1 set

12 Grid control unit 1 set

13 Pulse Amplifier 1 set

14 Pulse Supervision unit 1 set

15 Voltage supervision unit 1 set

16 Over – current relay for excitation

transformer

1 No..

17 Rotor earth fault relay 1 No.

18 Network filter No.

19 Thyristor element and fuse 1 piece of each type.

20 Thyristor bridge 1 No. of each type

21 Field breaker 1 No.

22 De-excitation discharge resistor 1 set

23 Tripping coil 1 set

24 Closing Coil 1 set

25 Field flashing rectifier 1 No.

26 Blocking diodes for field 3 Nos.

27 Ventilation fans 2 Nos.

28 Modules relating to DVR shall be digital

1 Bus support insulators 3 nos.


81


3.11.3 11 kV JUNCTION BUS PANEL

2 Flexible connectors 3 nos of each

3 Rubber bellows 3nos.

3.11.4 SUPERVISORY CONTROL AND DATA ACQUISITION SYSTEM

(POWER SYSTEM CONTROL AND MONITORING SYSTEM)

1 Relay

*Protective Relay

One(1) of each kind.

*Auxiliary Relay Ten(10) of each kind

2 Moulded case circuit breaker One (1) of each kind

3 Meter One (1) of each kind

4 Recording chart recorder Fifty (50) rolls

5 Ink and pen for recording Ten (10) bottles of ink and Ten (10) Pieces of

pen 6 Fault, operation and symbol indicator

assembly.

Five (5) of each kind

7 Lens for symbol Five (5) of each kind

8 Indicating LED & Lamp 100% of installed

quantity

9 Fuse Twenty (20) of each kind

Recording chart and ribbon for logging

printer

Fifty (50) rolls & chart and ten (10) strips of

ribbon

10 Recording chart and ribbon for line

printer

Fifty (50) rolls & chart and ten (10) strips of

ribbon

11 Printer Circuit card One (1) of each kind

12 Control selector and cut – off switch. One (1) of each kind

13 Transducer One (1) of each kind

14 Wrapping label and marketing strip 10% of installed quantity

DVD drive One plus one spare


82


COMPUTER

15 Power supply unit One for each cubicle

16 Printed circuit cards used for C.P.U. Disc,

drive, watch dog etc.

One (1) of each kind

SPECIAL TOOLS

The following special tools shall be provided

17 A/D converter checker for water level

measuring

One (1) set

18 Portable controller set equipment One (1) set

19 Printed circuit card

20 Converter

21 Surge Protector

22 Fuse.

23 Water level detector

24 Recorder Chart

25 Digital indicator

3.11.5 PROTECTIVE GEAR

1 1.Printed Circuit Boards used for Numerical

relay

One (1) Number of each

type PCB.

2 2.Printed Circuit Boards used for static

relay

One (1) Number of each

type PCB.

3 3. Other necessary parts (to be listed by the

bidder)

Recommended by the

bidder

Printed circuit cards used for C.P.U. Disc,

drive, watch dog etc.

3.11.6 SPECIAL TOOLS

The following special tools shall be provided

1 A/D converter checker for water level

measuring

One (1) set

2 Portable controller set equipment One (1) set

83

SECTION IV

TECHNICAL SPECIFICATION OF GENERATOR


84

SECTION IV


INDEX Sr.no. Description Page no. 4.1 Scope 85 4.2 Standards 85 4.3 Type and main characteristics 86 4.4 Particular mechanical design characteristics 86 4.5 Particular electrical design considerations 87 4.6 Performance guarantee 89 4.7 Tolerances 89 4.8 Technical specification of generator 90 4.9 Technical specifications of static excitation system 105 4.10 11/11 kV,1 x 630 sq. mm , copper conductor

unarmoured XLPE insulated power cable and 12 kV bus duct

113

4.11 Current transformers and Potential transformers 114 4.12 Lightning arrestor 114 4.13 Surge capacitor 115 4.14 Isolator and Earthing switch 115 4.15 Generator bearing 115 4.16 415 volts ac distribution board for utilities 117 4.17 Factory tests for generator and related equipment 118 4.18 Material test 120 4.19 Site tests for generator and related equipment 126 4.20 Drawings, designs, studies and manuals to be submitted

after award of contract by the bidder. 129

4.21 Spares 130 Annexure ––IV-1 131 Annexure ––IV-2 135 Data Sheet E1 to 27 136


85

SECTION IV


4.1 SCOPE:

This section of the specification covers the complete engineering, design,

manufacture, testing at factory, delivery to project site, onsite erection, testing,

commissioning, putting into commercial use and giving satisfactory trial

operation for a period of 90 days of one number of three phase horizontal

shaft synchronous generator and related equipment including static excitation

equipment, power & control cables, spares, tools and erection equipment as

mentioned hereafter.

The generator shall be capable of giving a continuous rated output of 10000

kW at 0.9 p.f. (over excited), unity p.f and 0.9 p.f (under excited). The

generator shall be suitable for direct coupling to the turbine specified under

Section –V. Any fittings, accessories or apparatus which may not have been

specifically mentioned in these specifications but which are indispensable for

reliable operation of the plant shall be provided by the supplier at no extra

cost to the Purchaser.

4.2 STANDARDS

The applicable standards are as follows:

1) IEC 34/1991

2) VDE Standards of group 0530

3) IEC 85 (Insulation classes)

4) ANSIB 49-1-1967 Shaft couplings, Integrally Forged

Flange type for Hydro Electric units.

5) V.D.I. 2056 for provisions regarding Radial Vibration

Amplitudes.

6) V.D.I . 2060 for provisions regarding Rotor balancing.

7) “Rathbone curves” for provisions regarding Radial & Axial Vibration

accelerations.


86

8) I.E.C. 287 - Calculation of continuous current rating

(100% load factor).

9) I.E.C. 38 - Standard Voltages

10) I.E.C. 71 - Insulation co-ordination (Part 1,2, &3 )

11) I.E.C. 136 - Dimension of brushes & brush holders for electrical

machinery.

12) Please refer list of standards contained in “Mechanical Lot”. These are

also applicable wherever relevant.

4.3 TYPE AND MAIN CHARACTERISTICS

For the ratings and other parameters of the Hydro generator please refer

‘Technical Data Sheet’ enclosed here with. The bidder shall fill in these Data

Sheets and submit them in his bid. The bidders shall specifically note the

requirements and fulfil it in all respect without fail.

4.4 PARTICULAR MECHANICAL DESIGN CHARACTERISTICS

In addition to the provisions contained in section I of this volume regarding

operational and other design requirements, the equipment specified in this

section shall also comply with the following stipulations:

1) All parts of the generator shall be designed to withstand safely the electrical,

mechanical and other stresses which may be induced during abnormal

conditions such as runaway speed, electrical faults and the machine shall

shutdown and come to standstill position without damage.

The electrical faults which shall be considered must include faulty

synchronising, sudden three phase short circuit, two phase short circuit and

terminal short circuit at normal voltage with simultaneous over-speed for 3

seconds. The design shall be such that stresses induced in any part under

steady state runaway condition and electrical fault conditions shall not exceed

two-thirds of yield point strength of the material used in that part.

2) Static and Dynamic stability of the Mechanical Parts :

Critical speed of the complete shaft line (generator + turbine) must be beyond

120% of maximum runaway speed during most unfavourable conditions.


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The rigidity of the entire shaft line must be such that asymmetries of the stator

air gap will not be increased markedly. Oscillations of rotor and shaft line

must not be initiated by pulsations of the torque or horizontal hydraulic thrust

from the turbine or by sub-harmonic oscillations resulting from the stator

winding or by pulsating torques originated by failures (e.g. sudden short

circuits ) etc.

The stator must be safe against core buckling. Its circular stability and the

centricity of the shaft line must be safely secured.

3) Vibrations & Balancing :

The relative locations of the generator bearing and the turbine bearing shall

be so determined that vibrations shall be minimum and a smooth operation is

ensured on the whole of the operating range i.e. at any load and at any head

within the range specified in section I & Section V of this Volume .

4) Hydraulic Thrust :

The unit and its bearings shall be designed to support the combined weight of

the rotating parts of the generator and turbine including the maximum

horizontal and vertical hydraulic thrust due to the turbine during transient

conditions.

4.5 PARTICULAR ELECTRICAL DESIGN CONSIDERATIONS

1) Generator Rated Voltage (Un) : The rated voltage (Un) of Generator

shall be 11kV. The continuous automatic voltage regulation shall be

ensured within the range 0.9 Un to 1.10 Un (Un ± 10%). Rated

frequency is 50 Hz. The supplier shall guarantee rated continuous

output within the range of frequency from 47.5 Hz. to 51.5 Hz and

voltage range of 0.9 Un to 1.1 Un. Supplier shall furnish information

regarding outputs available below 47.5 Hz. (47 and 46 Hz) and

duration of such output. Rated power factor is 0.90 (over excited) -

1.0-0.90 (under excited). The most unfavourable conditions such as

sudden two phase terminal short circuit at nominal voltage, 50% pole

short-circuits with simultaneous over speed for 3 seconds shall be


88

considered. No damage whatsoever must occur to the generator itself

and the foundations in either case.

2) STATOR WINDING CONNECTION

The stator winding shall be star connected and neutral point to be

grounded through primary of power or voltage transformer and resistor.

3) Winding Insulation Class

The stator and field windings shall be entirely insulated with class F

materials (thermosetting type).

4) Wave form and Telephone Harmonic Factor ( THF)

The wave form of the open-circuit terminal voltage shall not deviate

from a true sine wave by more than 5%. The Telephone Harmonic

Factor shall not exceed 1.5%.

5) Limits of Temperature and Temperature Rises:

The rated output which should be available at its terminals at power

factors cos ∅ 0.9(over excited)...1...0.90(under excited) shall be more

than 11111 kVA. When the generator operates at rated output, rated

power factors, speed and voltage, the stator and field winding

temperature of generator measured by embedded thermostat

temperature detector and resistance method shall not exceed 1250 C

& 1300 C respectively. When the generator operates at maximum

output, rated power factors, speed and voltage, the stator and field

winding temperature of generator measured by embedded thermostat

temperature detection and resistance method of generator shall not

exceed 1350 C and 1400 C respectively.

6) Short Circuit Ratio of the generator shall not be less than 1.00. Direct

synchronous reactance shall not be higher than 1.10 p.u. Direct - axis

transient reactance (unsaturated value) shall not be higher than 0.45

p.u.

7) Dielectric strength: -

a) The stator and rotor windings shall withstand the following

power frequency test voltages for 1 minute: -

2.75 times of rated voltage (11 kV) before coil insertion


89

2.25 times of rated voltage (11 kV) after coil insertion and at the

time of completion of coil assembly.

b) The rotor winding shall withstand 10 times of rated field voltage

for 1 minute.

4.6 PERFORMANCE GUARANTEE:

The output and efficiency guarantees shall be subject to verification and

therefore applications of liquidated damages are stated in clause No 3.25 of

Vol. I. In addition, the supplier shall guarantee that the performance values in

respect of vibrations, power output, bearing temperature and direct axis

synchronous reactance stated in ‘Data sheet’ shall not actually exceed in

operation.

If during site tests, it is observed that any one or all these values are not

within guaranteed values, the supplier shall take corrective steps so that

guarantees are met / achieved.

Absolute Temperature rise

- Stator windings 1250 C 85 K

-Field windings ( by 1300 C 90 K

resistance method)

The above temperature limits shall be reduced by the amounts as specified in

clause 16.2 of IEC 34- 1.

4.7 TOLERANCES

However, for a selected number of key characteristics given below, tolerances

on the unfavourable side has been disallowed in this specification:

i) Guaranteed Voltage Range.

ii) Rated Power Factors.

iii) Moment of inertia.

iv) Stator Winding Temperature rise.


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vi) Field Winding Temperature rise.

vii) Bearings temperature .

viii) Synchronous and transient direct-axis reactances.

ix) Excitation rated Current.

x) Excitation rated Voltage.

xi) Excitation Ceiling Voltage.

xii) Excitation response.

xiii) De-excitation time from rated voltage to 10% of rated voltage.

4.8 TECHNICAL SPECIFICATION OF GENERATOR

1) All material to be used shall be suitable and adequate for the purpose

intended and shall conform to the IEC standards. No patching,

blocking, shimming or any other similar means of overcoming defects,

discrepancies or errors shall be permitted without approval of

Purchaser or/and Consultants.

The generator design shall be such that the movements and

deformations due to temperature variations are compensated and the

loads and resulting forces, which would act on the foundation, are

substantially reduced. It should further be ensured that:

i) No buckling of stator core laminations takes place.

ii) The concentricity and the size of air gap shall remain

unchanged.

The unit shall be designed for unit assembly during erection and for the

removal of the complete assembled generator rotor during major

maintenance programs. This design shall permit the assembly and

dismantling operations to be performed as conveniently and quickly as

possible with the facilities of the powerhouse crane. Proper stator and

rotor lifting device (if required) for connecting to power house crane

shall be provided. If lifting device is not used, the bidder shall give the

reasons for not providing the lifting device. The necessary information

regarding the shape of the hooks shall be taken into consideration.


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Supplier shall declare along with bid his work plan for stator and rotor

building at site on service bay, built up in situ or partial building on

service bay and situ. Periods for such activities shall be distinctly

shown and his proposal for execution of job shall be declared in the

bid. Considerations in the design shall be given to the following

requirement for maintenance program.

- Rotor field poles shall be arranged in such a manner as to permit

easy removal with the rotor in place. Field pole electrical connections

shall be located in a position to facilitate ease in inspection, separation

and reconnection.

The neutral terminals of the phase shall be brought out separately to

abominate current transformers before forming the star point of the

winding . The two ends of field windings shall be connected to two slip

rings mounted on shaft.

2. STATOR GENERAL

The stator shall consist of a frame with air heat exchangers on its outer

periphery, built-in laminated core with radial/axial air ducts and bar

winding in slots. The stator frame shall also support the bushing of the

phase bus bars and generator neutral connection.

STATOR FRAME

The stator frame shall be fabricated from steel plates and shall be of

welded construction. The frame shall be sufficiently strong to

withstand the most severe forces during the abnormal conditions e.g.

sudden short circuit & faulty synchronisation. Air coolers shall be

mounted around the outer periphery of stator frame. The frame shall be

provided with adequate number of horizontal stiffeners.

STATOR CORE

The stator core shall be made of low loss, high grade, non-ageing,

silicon magnetic steel laminations having a favourable bending


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co-efficient. The lamination shall be accurately punched and deburred

so as to obtain very smooth surface at winding slots and keys slots.

Each lamination shall be coated on both sides with class F insulating

layer to eliminate inter lamination and eddy current circulation.

The stator core shall be built up in stacks of equal height as far as

possible, the bottom and top most stacks shall give a special treatment

so as to form solid mass.

While stacking the lamination, intermediate pressure treatment shall be

given several times and the whole core should be pressed at both

ends, by means of clamping rings with fingers pressing over teeth

portion to ensure high tightness and mechanical strength of the core.

The stack of laminations must be firmly anchored to the frame and

pressed together in a firm and uniform way, which does not require

readjustments after installation. In particular, vibration of stator as a

whole is practically eliminated during any operating condition and

stator migration phenomenon is avoided during life expectancy.

The supplier shall describe in his bid the measures and means that will

be provided by him totally to avoid the displacement of stator core

punching.

For cooling of the core and winding in the slots, the core shall be

divided into several packets spacer punching provided with radial/axial

air ducts of appropriate height and breadth shall be used between the

packets.

After completion of core building, a low induction core test with flux

density of 1.0 T shall be conducted to find out if any laminations are

short-circuited. The testing procedure shall be simple and efficient

such that the same can be repeated on the core even at a later date.

In case the design of core is such that neither a heating of the core nor

an induction test of finished core with rated flux are necessary, the

completed core shall be tested by means of non-destructive

magnetizing test for detecting and locating short circuit faults in the

core.


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STATOR WINDING

The suitable stator winding type shall be designed by bidder. The

insulation shall be of Class ‘F’ material (Epoxy mica type). The slot

portion of the coil shall be pressed to closed limits and the complete

treatment shall ensure that the coil is fully thermoset and dimensionally

stable. The overcharge portion of the coils will be insulated with flexible

tapes. The end winding will be painted with suitable anti-tracking

moisture resistant paint. The winding will be tightly wedged in the slots

with non-shrinking epoxy glass laminate wedges. RTDs shall be

permanently fitted in between coil of same slot at the centre of slot

portion to measure the winding temperature. All RTDs in stator of the

generator shall be wired to a terminal box mounted on the outside of

generator frame.

Each phase winding shall be so distributed around this stator as to

minimize unbalanced magnetic pull and the circulating current between

the parallel circuits.

The two ends of each phase shall be brought out to terminals on the

stator frame The main and neutral leads and associated current

transformers in neutral leads shall be protected by suitable non-

magnetic enclosures to prevent accidental contact by personnel.

Final details of the main and neutral lead termination at the unit shall

be subject to approval by purchaser. All bolted main current carrying

terminals shall be silver-plated.

All neutral connections of the stator windings shall be parallel and all

neutral current transformers shall be mounted beyond the generator

housing and before the formation of neutral. The neutral lead shall

terminate at the neutral cubicle, which shall contain the grounding

transformer, resistor and accessories. The neutral grounding

equipment, cubicle, interconnections, and ground connections shall be

supplied.

All generator windings, connections between individual windings or

between a winding and a related generator component as well as all


94

other primary connection and conductor shall be made of copper in

accordance with applicable material standards. All bolted main current

carrying terminals shall be silver-plated.

The insulation of coils shall be continuous and of equal thickness along

the entire coil. Insulation materials used shall be class F designed

conforming to the requirements of IEC standards and manufactured in

accordance with modern technology. Functional evaluation of

insulation system shall be provided according to IEC 34-18-1/1992.

The duro plastic insulation system used shall have excellent dielectric,

thermal and mechanical properties with proven reliability to withstand

high voltages not only under operational conditions but also under

severe fault conditions. The insulation on the stator coils shall be

sufficiently durable so that in case it is necessary to remove coils,

removal and replacement may be effected without damage to the

insulation of any of the other coils. The quality and life of the insulation

shall not be impaired in attaining the above requirements. Class F

insulation of proven design and which has shown no breakdown shall

be used. The details of the installation where such insulation system is

used shall be stated in the bid.

The construction of winding bars and the winding in slots shall be fully

explained with drawings and detailed description.

The class F insulation system used shall be proven. The bidder must

furnish examples where the same system is used and is in trouble free

operation.

Corona shielding applied to the fully insulated bar shall have the

following structure.

The straight part of the bar shall be covered with a conducting varnish

(outer corona protection) in order to avoid potential differences

between the surface of insulation and the core iron. The bend end

portions of bars are covered with a semi-conducting varnish and in

addition a special tape be wound over a certain portion to ensure the

desired potential distribution (Capacitive control of potential

distribution). These measures would avoid creeping discharges along


95

the surface of insulation or even a breakdown.

The bars shall be carefully inserted in slots and properly aligned. It

shall be ensured that the wedges are firmly and permanently seated

and there are no possibilities of damaging the core lamination edges in

the slot. Rewedging should be virtually not necessary. The packing

shall be effective in both the circumferential and radial directions.

When installed, the coil sides shall be tight within the slot so that a 0.5

mm. filler gauge will not enter any gap between the coil and slot sides.

The 0.5-mm. fillers gauge “no-go” standard shall apply to at least 90%

of the stacked core length. The remaining 10% has individual ‘go ‘

length of less than 0.80 mm.

After final wedging, there shall be no measurable radial clearance

between the coil and slot or wedge. Slot wedges shall be of phenolic

or glass-reinforced polyester material, highly resistant to thermal

ageing and designed to minimize any tendency to relax the radial

pressure exerted on the coils.

The stator coil insulation, wedging, packing, brazing and tying shall be

such as to minimize the effect of thermal shock and of additional

differential expansion which may occur as a result of the cyclic loading.

End connections of the stator coils shall be made at the top of winding.

The end portion of the winding shall be rigidly supported to prevent any

movement and distortion even under the most unfavourable short

circuit conditions. No metallic part, which does not correspond to class

F, shall be used for this purpose.

The slot portion of the bars must be manufactured to close tolerances.

No grinding of insulation will be permitted to achieve required

dimensions.

The connections between half coils shall be covered in the ends by

glass fibre insulation caps. Bracing shall make all connections in end

windings. The strands of corresponding upper and lower layers bars

shall be soldered at the connecting end using copper clips to ensure

adequate mechanical strength and conductivity. A fibreglass-insulating

cap shall be placed over each connection and filled with an epoxy


96

compound to secure it to the ground insulation.

The winding overhang portion shall be rigidly supported, lashed

together by impregnated glass cords so as to form a rigid cone, which

can withstand the forces due to a sudden short circuit. The system

must be described in bid. Circulating primary split-phase current under

normal operating conditions shall be less than 2.5% of total rated

phase current.

Each winding bar shall be subjected to tangent delta measuring kV test

in shop and the dielectric losses of each coil shall be measured in the

factory and also after assembly at site.

Resistance elements for temperature recorder shall be mounted at 6

positions in the portions where the stator coils of each phase are

presumed to show the highest temperature.

3) ROTOR GENERAL

The rotor shall consist of a spider, laminated rims with brake ring at the

bottom, salient poles with field coils and damper winding cage as well

as shaft.

ROTOR SPIDER

The rotor spider shall be of fabricated structure. High strength high

yield steel shall be used in the construction of the central hub and the

radial arms. The attachment of laminated rotor rim with the spider arms

shall be designed to withstand the maximum forces induced in the

runaway condition of the unit. The arrangement of arms shall not only

compensate the expansion and contractions during operation of

generator but also those due to welding. Approved tests for material

and welds such as X-ray and ultrasonic tests and/or liquid penetration

tests to ensure the reliability of the whole spider shall be conducted.

ROTOR RIM

The rotor rim shall be of laminated floating type i.e. it should be

attached to the spider by means of wedges driven in between the key


97

supports on spider arms and the slots on the inner periphery of the rim.

The rotor rim shall be made up of circular segmental punching from

sheet steel, stacked overlapped layer by layer around the outer

periphery of the spider. The laminated rims shall be clamped to a

compacted ring of solid segmented end plates by means of high tensile

axial bolts so as to ensure firm mechanical connection between the

adjacent segments of any two layers for transmission of tensile forces.

The shape and geometry of laminations and the pattern of stacking

shall be such that the completed rim corresponds to an ideal

homogenous cylinder as the uniform distribution of mass. The brake

ring shall be provided at the bottom of rim. The brake ring may be

constructed in segments so as to allow any replacement.

ROTOR POLES

The pole body shall be made up of steel laminations made of same

material as is used in construction of rim laminations. The pole

laminations shall be held tight between end plates by means of suitable

number of bolts.

The poles shall be secured to the rim by means of wedges in such a

way as to allow the removal of poles in the horizontal direction without

requiring removal of the rotor out of the stator bore.

FIELD COILS AND DAMPER WINDING

Each pole will carry a field coil fabricated from straight lengths of

copper strip dovetailed and brazed at corner. The insulation between

turns shall be of specially treated asbestos paper. Insulation to ground

(Pole body) shall be a epoxy glass laminates and rectangular insulation

washers shall be placed at the top and bottom of the coil.

The completed coils will be electrically heated & pressed while not to a

pressure greater than the maximum centrifugal force which would be

experienced in service. The field poles shall be provided with adequate

damper windings to insure stability under fault conditions and to meet

I2t value of 40.


98

The insulation system of class ‘F’ shall be used to ensure

compact assembly with excellent electrical and mechanical properties.

The turn insulation should be thoroughly cemented to adjacent turns to

permit removal of field pole coil as a unit. The pole core insulation

must be separate from the coil. Special attention shall be paid to

ensure prevention of end turns of a coil from deforming or slipping due

to centrifugal forces on the inter-connections. End turn insulations

must be reinforced if necessary. The field coils of poles shall be

connected by means of flexible copper plates to form as field winding

whose ends are brought out for connection with slip rings.

The coils shall be tested at medium frequency test voltage or impulse

voltage test on the terminals. During this test, the magnetising current

must be measured and this current shall not differ by more than 10%

between various coils. Low resistance damper winding of fully caged

construction shall be provided to improve stability under fault

conditions and specially to reduce voltage disruption under conditions

of single-phase fault.

4) BRAKES

Brakes shall be provided for bringing the unit to stop when the speed is

reduced to approximately 10% of rated speed. The brakes will be

operated by air pressure The brake shoes shall bear on a brake which

is an annular ring attached to the rotor. The brakes shall be liberally

designed keeping in view the frequent stops of the unit (2/3 times per

day) and with margins to allow for emergency conditions. The

mechanical brake shall be effective for either forward or reverse

rotating direction and shall be automatically released after the

generator stops.

The brakes shall be capable of operating, without appreciable wear

and tear of the brake shoes from 50% rated speed in emergencies.

The brake shoes liners must be able to withstand at least 3 years

operations. The braking system shall be so interlocked that application


99

of brakes will not be possible at speeds exceeding 50% of rated speed.

A brake dust extraction system ( if necessary ) shall be provided by the

supplier. A position switch having two sets of contacts shall be

provided for each brake shoe. One set of open contacts (when brakes

‘OFF’) shall be wired in parallel and will be used for brakes ‘ON’

indication. The set of closed contacts (when brakes ‘OFF’) shall be

wired in series and will be used in the unit start interlock circuit. Wires

from both sets of contacts shall be brought out and terminated in the

generator terminal box. The equipment shall be complete with

necessary control cabinet, piping, valves, fixtures etc.

5) SOLE PLATES AND FOUNDATION BOLTS

The supplier shall provide adequate number of soleplates, anchor bolts

etc., for fixing stator frame to foundation. The whole anchorage shall

be designed and constructed to resist the forces under most abnormal

condition, resulting from sudden short circuit or faulty synchronising.

The supplier shall furnish the detailed drawings & calculations to the

Purchaser for his consent and approval.

6) VENTILATION :

The generator shall be provided with screen protected enclosure. The

air shall be drawn from both the ends. The combined action of the rotor

poles and axial fans shall be sufficient to extract the heat generated in

the generator.

The generator shall be forced air cooled, self-ventilated type. Air

passage in the stator, rotor, fans etc. shall be designed to give a

smooth quite flow of air.

7) HEATERS :

Space heaters of black heat type of adequate rating shall be provided

inside the protection caps on the stator frame for maintaining stator

surrounding air temperature above ambient during prolonged shut

down period. At each end of the generator heating elements of suitable


100

capacity shall be installed to avoid condensation when the unit is under

shutdown. The temperature to be maintained shall be 50 C above the

surrounding temperature. Necessary thermostat be provided for auto

on / off of the heating elements.

8) GENERATOR TERMINAL BOX, ELECTRICAL ITEMS AND WIRING

& PIPINGS.

All electrical items supplied by supplier shall comply with the

appropriate sections of the relevant IEC standards. They shall be

arranged in a manner approved by the Purchaser. The supplier shall

provide and install terminal boxes in locations approved by Purchaser,

and shall provide and install all wiring and conduit from its electrical

components to these terminal boxes. All wiring shall be standard wire,

with oil proof insulation. Further a common marshalling box shall be

provided. Wiring from all individual terminal boxes shall be brought by

the supplier up to this marshalling box. Leads for all auxiliary electrical

circuits such as current transformers, resistance elements, limit

switches; various kinds of relays shall be supplied up to the terminal

blocks installed in the generator housing.

All wiring within the generator housing, including main field leads,

lighting, resistance temperature detectors leads and control and

indicating leads shall be adequately clipped or otherwise supported

and protected. The wiring shall be bundled and tied together, where

possible, to provide a neat arrangement. The wiring passing through

openings in metal members of the generator, or otherwise passing

over or near metal edges, shall be carefully protected against abrasion.

In general, close attention shall be given in order to prevent failures or

shutdowns occurring as a result of generator vibration. The wire

insulation shall be resistant to flow and abrasion under the conditions

to which it may be exposed. Liquid type flexible conduit shall be used

where wiring may be exposed to oil or water leakage.

All piping shall be supplied such as feed / drain oil pipes of the

generator bearing oil tank, oil jacks, piping of oil level relays and oil


101

level gauges, feed / drain water pipes for bearing coolers and air

coolers, connecting pipes between respective coolers, drain pipes of

leakage oil and leakage water at respective positions and other piping

installed in the generator air housing including valves and flanges.

9) TEMPERATURE DETECTORS

The Supplier shall provide six resistance temperature detectors (pt.

100 ohm at 0 degrees C) per parallel circuit per phase, embedded in

the various parts of the stator winding in accordance with relevant IEC

standards.

Twelve resistance temperature detectors (pt. 100 ohm at 0 degrees C)

shall be embedded in a suitable location, six at each end of the stator

core for temperature measurement for the detection of end iron

heating. One at each teeth location in the stator core for temperature

measurement of teeth.

RTD’s and hotspot temperature indicator shall be furnished.

Requirements of temperatures to be measured have been described;

however supplier shall decide number of scanners required. The exact

location of the temperature detectors in the stator winding and core

shall be subject to the approval of purchaser. All temperature

detectors in and around the generator shall be wired to the terminal

box mounted on the outside of the generator air housing. This terminal

box shall be separated from other terminal boxes.

All connections from the temperature detectors to the terminal box

shall consist of twisted leads in shielded cables. The leads from each

stator bearings, water and air temperature detectors shall be brought in

a neat and substantial manner to suitable terminal blocks located in a

terminal box on the generator housing. This box shall be used

exclusively for resistance temperature detectors. The terminal box, to

be provided by supplier shall have provision for connection to external

conduit and wiring. The leads shall be supplied as twisted three wire

leads suitably shielded and otherwise protected to minimize stray “pick-

up”. The insulated leads shall be capable of with-standing an applied


102

potential test of 2000V to ground for 1 min. Separate terminals shall

be provided for terminating the shields of individual Resistance

Temperature Detector (RTD) leads. The resistance temperature

detectors shall be platinum type and have a resistance of 100 ohms at

00C. Resistance ratio between 00C and 1000C shall be 1.3926.

All temperature measuring equipment and its connections supplied by

supplier shall be accurately calibrated against accepted standards.

10) OIL GAUGES AND OIL LEVEL RELAYS

The following oil gauges and oil relays shall be provided.

a) Oil gauges :

i) For generator bearing oil tank : 1No.

ii) For turbine bearing oil tank : 1 No.

b) Oil level relays : 1No.

i) For generator bearing oil tank : 1No.

ii) For turbine bearing oil tank : 1 No.

Oil gauge :

The oil gauge shall be of gauge type or float type and free from oil

leakage. The oil gauges shall be mounted on a convenient position for

inspection. The gauge shall be clearly marked on the surface with

standard oil level, the upper limit and lower limit of oil level.

Oil level relay:-

The relays shall be accurate in operation and mounted on a convenient

position for inspection and shall be provided with alarm contacts for

rising and lowering of oil level and provided with automatic reset

mechanism when the oil level is restored within the normal range.

Sufficient lubrication oil for the generator shall be supplied by the

supplier. The supplier shall recommend the suitable lubricating oil for

the generator.


103

11) FIRE PROTECTION

A dry type deluge fire protection system shall be provided by supplier

complete with deluge valve, control unit and sprinkler rings with

atomising nozzles. The atomising nozzles shall be so placed that the

streams of water will be directed on the top and bottom coil ends and

connections of the stator winding. The exact direction of flow shall be

subject to approval by purchaser.

The fire fighting system shall be of emulsifier water jet system and shall

be designed to inject sufficient quantity of water in the form of jets to

extinguish the fire in minimum possible time. The fire extinguishments

shall be achieved by a combination of cooling and smoothening

effects.

SAFE DISTANCE FROM LIVE EQUIPMENT

The ring headers, smoke / heat detectors etc. shall be provided in the

generator such that the clearance between un-insulated live parts of

generator and any portion of water spray system is not less than the

minimum clearances stipulated.

TESTING OF THE SYSTEM

Suitable provisions for testing the system without discharging water

into the generator shall be made.

WATER DRAINAGE:

Supplier shall prepare a scheme for drainage of the water from

generator housing to dewatering pit from where water will be pumped

out into the tail race channel.

12) LINE TERMINAL AND NEUTRAL GROUNDING CUBICLES

The generator suppliers shall supply 1 no. terminal cubicle for surge

capacitor, magnetic voltage transformers, current transformers,

lightning arresters, cable boxes, etc., The cubicle shall be complete

with necessary tappings for excitation system, etc. The rating of the


104

CTs for DVR shall be decided by the supplier taking into account the

requirements of DVR.

The supplier shall supply one no. neutral grounding cubicle consist of

grounding transformer, secondary loading resistor, current transformer,

cable boxes, etc.

The cubicles shall be sheet suitably compartmentalized with doors and

shall be furnished complete with base mounting arrangement,

foundation bolts, etc. The internal illumination for cubicles shall be

provided with guarded lamps with on/off switches. Copper/Aluminium

conductors of appropriate size shall be used for bus bars and

connections in the cubicles. The bus bar and main connecting

conductors shall be suitably insulated to make them compatible with

generator temperature rise and insulation. The support insulators for

the bus connection will be provided as necessary. GI earth bus of

adequate cross section will be provided in the cubicle.

13) CABLE SCHEDULES AND WIRING DAIGRAMS

The supplier shall prepare cable schedule and wiring diagrams of the

station equipment as a whole. Terminal wiring diagrams for the

equipment and plant not covered by this package will be furnished by

purchaser to the bidder of this tender and he shall prepare

consolidated wiring and cabling schedule for the entire power station.

14) 11kV JUNCTION BUS PANEL

11kV Junction Bus panel shall be provided at suitable location in

power house for tapings of 11 kV XLPE cable. Tap for Unit

Auxiliary Transformer is provided at this panel. Copper Bus with

necessary insulators is provided for tapings. Fault calculation of

bus bar shall be carried out by bidder and accordingly panel is to

be designed. 11kV, 3 phase, single core, 630 sq. mm, XLPE

cable with one spare core from junction Bus panel to step-up

transformer is to be provided by bidder. Other XLPE cables as


105

per Section III of this volume shall also be provided by bidder.

15) Temperature scanners: Temperature scanner with built in

datalogging and printing facility to be mounted on unit control

board and for monitoring temperatures of bearings, stator and

field windings, cold and hot air temperature of generator cooling

air with 3 sets of contacts. Each set consisting of two potential

free normal/open contacts operating at two different levels of

temperatures to be used for external annunciation scheme. The

scanner shall be suitable to operate on the inputs from RTD

(Resistance Temperature Detectors).

4.9 TECHNICAL SPECIFICATIONS OF STATIC EXCITATION SYSTEM

4.9.1 GENERAL

1) TYPE, CHARACTERISTICS AND PERFORMANCE

The generator excitation system shall be of the solid- state controlled

rectifier (static thyristors) type, complete with excitation transformer

and solid-state type of digital voltage regulator (DVR) and rectifier

controls, capable of providing negative exciter voltage and extremely

rapid changes in generator excitation voltages.

The excitation system shall take out the power from terminal voltage of

generator through a power supply transformer and supply it to the field

winding of generator. The field flashing circuits shall be supplied from

an auxiliary transformer / rectifier assembly suitable for connection to a

400-V, 50-Hz., 3- phase supply of a capacity to be specified by

supplier. Provisions shall also be made for field flashing from the

station battery in emergency with manually deployed connections,

preferably transfer links.

The field flashing equipment shall be rated to supply approximately

rated excitation current continuously for test purposes and shall be

capable of adjustment in 10% steps from 10% up to 100% rated


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voltage.

Excitation supply shall hold during break period of change over of

supply from Station Auxiliary Transformer / D.C. supply to Unit

Auxiliary Transformer, acceptable break period shall be indicated by

the Bidder.

The thyristors shall be used for the rectifier of excitation system. The

supplier shall supply forced cooled type 110% duty thyristor cubicle

so that the excitation system shall be capable without exceeding the

temperature limit of the thyristor with one thyristor per phase out of

service. Indicator lights to indicate and locate the thyristor failure shall

be provided. A suitable protection shall be provided to protect the

thyristor from the surge, which might enter from the generator field and

power supply transformer. Connections between the secondary of the

transformers, air circuit breaker, and static excitation equipment shall

be made with cables.

The air circuit breaker shall be draw-out type individually enclosed and

electrically operated. All controls, protection and operations of the

equipment shall be either automatically or electrically operated,

suitable for operation through remote control panels located at the unit

control board. Remote control shall be limited to as few controls as

possible, and shall include only such functions as “stop-start” and a

“raise-lower”. The excitation equipment shall be designed to be

capable of starting and running at reduced capacity and independent of

a separate station service A.C. supply. Components and wiring shall

be suitably designed and shielded to prevent excessive noise. The

design of the excitation system shall be such that the effect on the

balanced and/or residual Telephone Influence Factor (TIF) of the

associated Generator is minimal and shall not cause the TIF to exceed

the limits specified in applicable IEC standards.

The final parameters for performance, capability, system response,

etc., shall be confirmed by supplier and approved by Purchaser.

Voltage regulator shall have dual channels consisting of two identical

electronic control circuits plus a common voltage matching, fixed


107

excitation, output selection and relay circuit. Usually both the main

and stand by channels shall be energised and functional. However,

only output selection circuit to control the converter will switch the

output of main channels. If this channel fails then the controls shall be

automatically switched to standby channel.

The normal mode of operation shall be auto-control. Additionally,

manual control of the excitation shall be available for testing and

setting up purposes or in unlikely event of failure of the auto control of

both channels.

The auto-control circuits shall consists of two interdependent feed back

control loops (Voltage and Current) with limiting circuits for under-

excited MVAR, rotor heating, current and power system stabilisers.

The excitation system shall be capable of switching from 25% of rated

generator voltage and at 60% of voltage it shall be capable of

supplying rated excitation current. The time constant of excitation

system shall be less than 0.10 sec.

2) CAPABILITY

With rated generator voltage, the excitation system shall be capable of

delivering continuously, within rated temperature rise, any value from 0

to 120% of the field current required when the generator is operating at

110% of rated voltage, and rated power factors at 0.90 (over-excited).

With rated generator voltage, the excitation system shall be capable of

providing a ceiling current to the field of not less than 1.5 times rated

field current for at least 30 seconds. De- excitation time between rated

voltage and 10% of voltage shall not be more than 10 sec.

3) SYSTEM RESPONSE

With the generator initially at rated apparent output power, rated

voltage, power factor and speed, the excitation system shall be

capable of changing from rated field voltage to 100% of ceiling voltage

within 25 to 30 ms. for a sustained drop in generator terminal voltage of

10 %. The rated voltage shall be calculated assuming that at rated


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apparent power, field winding is operating at rated field current.

Response in the negative (reverse) direction to suppress terminal

voltage shall be similar. The small signal gain, defined below, shall be

variable from 25 to 300 and should be lockable to prevent tampering.

Excitation response shall be guaranteed with 4s.

4) CEILING VOLTAGE

The exciter ceiling voltage with rated generator voltage and rated field

voltage and current shall not initially be less than 1.5 times the

excitation voltage required for rated field current with the operational

field temperature.

The exciter ceiling voltage with rated supply voltage and 1.5 times

rated field current shall not be less than 2.0 times rated field voltage

with the field windings temperature 1250C.

With supply voltage less than rated value, the ceiling voltage may be

reduced approximately in proportion to the reduction in supply voltage.

With positive field current flowing, the excitation system shall be

capable of providing a negative ceiling voltage of no less than 75% of

the positive ceiling voltage for forcing the field current to zero.

5) OVER VOLTAGES

The excitation system may be subjected to lightning and switching

surges and dynamic over voltages, and shall be able to withstand them

without damage to equipment or loss of life.

The static excitation equipment shall comprise of: -

- Microprocessor based Digital Voltage Regulator cubicles.

- Thyristor cubicles.

- Switchgear cubicle (Field breaker, de-excitation resistor, field

flashing etc.).

- Excitation Transformer connected directly to the thyristor

cubicle.


109

- Power supply to cubicles shall be duplicated and no interruption

shall be allowed during changeover.

4.9.2) DIGITAL VOLTAGE REGULATOR

1) Micro-processor based voltage regulator shall be digital type. It shall

be liberally designed so as to be as reliable as possible and shall

incorporate sufficient redundancy so that failure of any control

equipment will not cause mal-operation of the system.

2) The digital voltage regulator should periodically calculate the control

signal from measured and reference values. Calculation should be

repeated at every short time intervals where by an apparently

continuous regulator output characteristic is produced.

3) Calculation is to be carried out in binary system. The analog measured

values of generator voltage and current as well as field current must be

transformed in an Analog / Digital converter into binary signals. From

the calculated control signals, pulses should be generated for firing the

thyristor.

4) Various control functions like voltage regulation, limitations of field

current, rotor angle, stator current, slip stabilising etc. shall be stored

as programs to be executed in a cyclic pre-programmed manner.

5) Control to maximum converter voltage shall be achieved in less than

10 milliseconds thus ensuring fast reaction to network disturbances.

6) Internal conditions monitoring of devices with light emitting diode (LED)

indication be provided which means short failure detection times.

7) Set values shall be digital, absolutely reproducible and not vulnerable

to changes ensuring long term stability

8) Number of different units shall be small so that spare parts stock could

be kept to a minimum.

9) Low sensitivity to external electro-magnetic influences shall be ensured

which means high noise immunity.

10) Electrical control points shall be bare minimum to reduce potential

trouble sources.


110

11) Comprehensive measuring and setting shall be possible, which should

enable direct setting of characteristics values without the necessity of

calibration instruments.

12) The Digital Voltage Regulator shall perform following functions: -

- Regulation of generator voltage.

- Limitation of field current.

- Limitation of stator current.

- Stabilization of power pulsations.

- Power factor control.

13) A local control, input and display unit shall be provided for

communication with the processing unit during operation. It should be

possible, from this control unit, to call up the stored parameters, measured

values etc. and to change control parameters such as limit values or

characteristics values of the control algorithms.

14) It should be exceptionally reliable with no changes in operating

performances. If even a failure should occur, it should announce itself

so that it can be removed fast.

15) Frequency drop compensation shall be provided to ensure over

excitation compensation of transformer in the event of low frequency.

16) Automatic reactive power compensation or power factor regulation

should be provided. The power factor regulating range shall be

manually adjustable from lagging power factor 90% to leading power

factor 90% rated output and rated voltage.

17) Current regulating equipment

The current regulating equipment shall be provided in order to

approach the operating power factors to unity when the generator

current exceeds 105% of the rated current due to a voltage drop during

generating operation.

18) In case the load is rejected due to any external fault during generating

operation at the rated output, rated voltage and rated power factor, the

voltage rise of the generator shall be less than 20% with speed

regulation of 35% without opening the field circuit breaker.

19) Emergency demagnetising device


111

Emergency demagnetising device shall be provided so as to perform

quick demagnetisation of generator in the event of electrical internal

fault of the generator.

20) Two independent modes of operation are envisaged.

i) Automatic mode with automatic channel in service.

ii) Emergency manual mode with the help of manual channel.

Voltage adjusting device shall preferably, not be potentiometer

but a solid-state device for example, push button controlled

analog registor etc.

In the automatic channel, the control shall be through DVR, DVR

should derive its sensing signal through Voltage Transformers and

Current Transformers in the generator main terminal circuit. This shall

be compared with a highly stabilised auto reference value. Correction

pulse generated shall be fed to the gate of thyristors. Output of DVR

should thus control the firing angle of thyristors thereby adjusting the

excitation current to the required level.

In the manual channel, the voltage variation and excitation current shall

be changed manually, while in auto mode also, the manual channel

shall follow the auto channel so that all resistances of manual channel

are at the correct positions corresponding to those of auto channel so

that, if due to a minor fault the channel changes to manual the unit will

not trip.

DVR shall have two auto channels i.e. one main, one stand-by together

with one manual channel only. Each channel shall be fully independent

with separate pulse control unit, pulse amplifier and power supply

units.

4.9.3 THYRISTOR CUBICLE

1) This cubicle contains full three phase thyristor bridges with its

associated equipment. The design should be modular in such a way

that changing of a thyristor or part of a bridge shall be easily possible.

In case forced ventilation system is adopted, noise level outside the

panel shall be negligible.


112

2) Number of thyristor cubicles provided shall be such that, even with

failure of one Thyristor Bridge, the generator should be able to supply

rated output and with failure of two bridges, the generator should trip.

3) All thyristors shall be fuse protected. Voltage safety factor for thyristor,

defined as the ratio between the maximum operating voltage and the

rated peak cut-off voltage shall be more than 2.5. Excitation response

shall not be less than 4.0 s.

4) Suitable protection shall be provided for thyristor to prevent voltage

spikes from reaching them and damaging them.

5) Over voltage protection to protect the thyristor bridges and the field

circuit shall be provided.

4.9.4 EXCITATION TRANSFORMERS

1) Three phase, dry type, Excitation Transformers shall be of indoor type

cast resin or equivalent dry insulated for direct connection to the bus

ducts and cable connection to the thyristor cubicle. Transformers shall

conform to IEC 726.

2) They shall be totally moisture proof

3) They must be free from partial discharge up to 150% of the rated high

voltage.

4) They have to be resistant against sudden temperature changes. The

insulation must cease fire and must not contain any PVC material.

5) The cores shall be built up of high grade oriented crystal magnetic

steel sheets, insulated on both sides.

6) The cores shall be compressed sufficiently to avoid any undue noise

generation and vibration.

7) All metal parts shall be amply protected against corrosion.

8) Coil casting or impregnating process must be conducted under vacuum

and pressure.

9) High voltage and low voltage windings shall be separated by a high

grade insulating material cylinder.

10) Adequate consideration shall be given to thermal coil dilation.

11) Transformers must be able to withstand a short circuit on their low


113

voltage terminals without suffering any damage. The time for which

the transformer should withstand such short circuit should not be less

than the longest fault clearing time for generator.

12) Cooling system of the transformers shall be as far as possible natural

or shall occupy minimum space available on the floor.

13) Suitable built-in over-heating protection device shall be provided.

14) Transformers shall be impulse voltage tested according to IEC.

15) Short circuit impedance shall be according to choice of design for

excitation system.

16) Total losses at rated load should be at minimum.

4.10 11/11 kV,1 X630 SQ.MM , COPPER CONDUCTOR UNARMOURED

XLPE INSULATED POWER CABLE AND 12 kV BUS DUCT

The supplier shall be responsible for complete job which will involve

design, manufacture, testing at manufacture’s works before dispatch,

supply to project site including loading, transport, insurance , unloading,

laying, fixing, both end termination with necessary lugs, cable glands,

fixing ties/belts, cable trays, supporting structures, testing before

charging etc. complete.

11/11 kV, 1 x 630 sq. mm , copper conductor unarmoured XLPE

insulated power cable for a machine shall comprise of cable from

LAVT cubicle to junction box Bus panel to step-up transformer with

one spare core and cable tap run to the cubicle of unit auxiliary

transformer with one spare core. Cable termination at both ends shall

be done by supplier. Eventhough the total length of cable is mentioned

as 250 mtr. in price schedule, Supplier is required to ensure the actual

length of cable as per site condition.

The supplier shall supply 12 kV, segregated 3 phases, 3 cores,

Aluminium Bus Duct of suitable size for following:

i) Tap run from Generator line Terminal to LAVT cubicle.

ii) Tap run to the cubicle of excitation transformer, disconnecting switches

and current transformers.


114

iii) Tap run to the cubicle of surge absorber, voltage

transformers and current transformers and disconnecting

switches.

iv) Tap run from generator neutral connection to neutral

grounding cubicle.

Supplier shall also supply the necessary Support steel structure,

hardware, trays, fixing belts etc. and one Set of Shorting Links for dry

out and short circuit test.

4.11 CURRENT TRANSFORMERS AND POTENTIAL TRANSFORMERS

The current transformer will be epoxy cast, dry type unit

conforming IS:2705. The current transformer shall be designed to

withstand the thermal and magnetic stresses resulting from the

maximum short circuit current. Detailed design and quantity shall be as

per plant requirements. The current transformers shall be suitable for

metering and protection. The protections specified in section VIII of

this volume shall be provided. Inter posing CTs

The potential transformers will be single phase, epoxy cast, dry

type units. Potential transformer will be protected on primary and

secondary side by current limiting fuses. The PT shall conform to

IS:3156. The potential transformers shall be designed to withstand the

thermal and magnetic stresses resulting from the maximum short circuit

current. Detailed design and quantity shall be as per plant requirements

4.12 LIGHTNING ARRESTOR

The lightning arrestors shall be heavy duty indoor station class non-

linear resistor type suitable for repeated operation to limit voltage surges

on alternating current power circuits and to interrupt power follow

current. The arrestors shall conform to IS:3070 (latest edition) Part-I.

The nominal discharge current of lightning arrestor shall not be less

than 10kA.


115

4.13 SURGE CAPACITOR

The surge capacitors shall conform to the latest edition of IS:2834 The

capacitors shall be connected in parallel with lightning arrestors and

shall be provided with a built-in discharge resistor. The capacitor shall

be suitable for indoor mounting.

4.14 ISOLATOR AND EARTHING SWITCH

One No. Isolator with own operating mechanism before Unit Auxiliary

transformer tapping in 11 kV junction bus panel and after LAVT panel

shall be provided by bidder . Isolator shall have control switch in unit

control board in control room and also included in sequence of unit

starting and stopping. This isolator is provided for back charging of step

up transformer and uninterrupted power supply from UAT. Earthing

switch shall be provided after Isolator and before Junction Bus panel for

discharging step up transformer and UAT in case of maintenance and

shut down. Earthing switch shall be controlled in local position only.

Isolator and earthing switch shall be provided as per shown in single

line diagram. Isolator and earthing switch shall be as per requirement

and conform latest relevant IS.

4.15 GENERATOR BEARING

The Generator bearing at Non drive end side shall be pad / segment type, oil

lubricated either self- lubrication or forced lubrication type.

The bearings shall be provided with a dial type or resistance type

thermometer and a pressure gauge with provision for alarm annunciation/shut

down on excessive bearing temperatures. The generator bearing shall be

provided with H.S. Lubrication (if required). The number and type of bearings

shall be stated in the bid. These bearings shall be guaranteed for a minimum

continuous operation of 100,000 (One Hundred Thousand) hours and the

design and performance shall be well proven and established.

Further the bearing shall be designed to operate satisfactory (i.e. without any


116

damage) under following conditions:

* Continuous operation at any speed between 30% and 110% of rated speed at

no load and maximum load.

* For 15 minutes at maximum runaway speed.

* For 15 minutes, upon sudden rejection of maximum power and in continuation

thereafter till the unit comes to standstill as a result of tripping and interruption

of cooling water supply.

The bearing area and the bearing oil reservoir capacity shall be such that

temperature shall not exceed 70oC under worst conditions of operations.

The bearing shall be located as near to generator as possible consistent with

the distance assumed in shaft system analysis and keeping in view the space

required for accessibility and maintenance. The mechanical design of the

bearing shall take into account the abnormal radial forces during starting,

stopping, trip-outs and running at runaway speed of the unit and also provide

axial movement of the shaft. The method of construction shall be fully

described in the bid. The bearing design shall prevent the leakage of oil down

along the shaft. Piping for filling oil in the bearing and reservoir shall be

separate from the drain piping.

The supplier shall supply and install the following indicating and protection

devices for bearing.

- One dial type thermometer to indicate the hottest part of the bearing.

The thermometer shall have two (2) sets of separately adjustable contact

suitable for operating alarm and tripping circuits at 220 V D.C. The

thermometer indicator shall be mounted in governor panel.

- The resistance temperature detectors R.T.D (Pt 100 Ohms at 0oC). One for

bearing segment and one for oil indication and recording the temperatures at

unit control board.

- One direct reading water flow meter with two electrical contacts (suitable for

operation at 220V D.C. for signalling low cooling water supply / stoppage of

cooling water supply.

- One oil level gauge properly graduated marked in litres and high and low level

adjustable alarm contacts with 220V D.C. contact rating.

All thermometer bulbs and detectors shall be installed in dry walls.


117

4.16 415 VOLTS AC DISTRIBUTION BOARD FOR UTILITIES

The supplier shall be responsible for complete job which will involve

design, manufacture, testing at manufacture’s works before dispatch,

supply to project site including loading, transport, insurance , unloading

, laying, fixing, termination with necessary lugs, cable glands, testing

before charging etc. complete of 415 V AC Distribution board for

machine utilities. This includes all pump-motors, motors and auxiliaries

supply required for machine. The detailed Design of panel and provision

of out going feeders, capacity, nos. etc. shall be as per requirement.

Provision for spare feeders shall be made. Necessary indicating and

metering instruments including indication lamps, any other item / equipment

required to make the system complete (KW meter, Voltmeter, Ampere meter)

shall be provided. The distribution board shall be completely wired. The scope

of power and control cables is also included. This distribution boards shall be

attractive in design, mechanically strong, robust in construction and shall be

totally enclosed in a mild steel cabinet of 3 mm. thickness. It shall have

specified sets of MCBs and shall be vermin and dust proof complete with

double door, lock and key arrangement. The doors shall be properly hinged.

Cable entry shall be through suitable conduit pipe. The interior and exterior

shall be painted with two coats of red oxide primer after 7 tank treatment and

two coats of approved colour paint as per IS: with a minimum thickness of 60

microns. This distribution board shall be suitable to be mounted on concrete

wall/columns or it may be mounted on floor. Suitable fixing arrangement such

as nuts, bolts, washer, anchors shall be provided at suitable places for its

proper fixing.

The isolator / MCBs units shall be of reputed make only and shall be

complete and fully comply with latest edition of IS:2516-1977, IEC 157-1983.

The operating handle shall be properly insulated from the live portion of

MCCBs / MCBs and shall always be easily accessible. The MCCBs/MCBs

used for A.C. supply and D.C. supply shall be designed for a fault level of 10

KA for 1 second. These S.D.B.'s shall be suitable for voltage variations as per

latest relevant I.S.S. Suitable earthing arrangement shall also be provided


118

with sub distribution boards. The above description is a broad outline of the

control, metering and protection system.

4.17 FACTORY TESTS FOR GENERATOR AND RELATED EQUIPMENT

Tests to be conducted in factory on various material, assemblies etc. on

generator at different stages of manufacture are indicated in the enclosed

statements. legends of the nomenclature of tests is as below

LEGEND FOR FACTORY TESTS OF ELECTRICAL LOT

1) Test at shop on random sample of raw material.

2) Test at shop on random sample of raw material and on semi or fully

finished part.

3) Test at shop on 5% of consignment.

4) Check straightness of bolts taking random sample of 10 bolts per

machine.

5) Test at shop in the presence of Purchaser’s representative.

6) Test at shop on each piece.

7) Spot check at shop of brazed parts of semi or fully finished parts.

8) Test at shop on random sample of one per sheet.

9) Test at shop on complete sheet.

10) Test at shop - once per item.

11) Test to be conducted by manufacturer and Test Certificates given to

Purchaser.


119

SUBMISSION OF TEST CERTIFICATES

The Supplier shall submit 6 copies of test certificates to the Purchaser as per

the procedure given below :

i) FOR INSPECTION AND TESTING TO BE DONE IN PRESENCE OF

PURCHASER’S REPRESENTATIVE.

Test certificates shall be submitted for approval.

ii) FOR ALL OTHER INSPECTION AND TESTS

Test certificates showing that the specified tests / inspection has been

carried out successfully by the Supplier shall be submitted for

reference.


120

4.18 MATERIAL TEST

Sr.No

.

Particular of Test 1 2 3 4 5 6 7 8 9 10 11

1) ROTOR RIM SHEETS:

Tensile Test √ √

Chemical analysis √ √

Visual check √ √ √

Dimensional check √ √ √

2) ROTOR RIM BOLTS

Tensile Test √

Chemical analysis √

Visual check √

Dimensional check √ √

3) FIELD WINDING (POLE COIL)

FINISHED

Tensile Test √

Visual check √

Dimensional check √

Test for short circuited turns √

Acceptance test of each piece √

Insulation Simulation Test √

4) POLE FINISHED

Visual check √


High voltage test √

Test for short circuited turns √

Weight check √

Acceptance Test of each piece

(H.V.Test)

√

5) DAMPER BAR

Hardness Test √


121

Sr.No

.


Visual check √


Electric conductivity Test √

Acceptance Test on 5% of

consignment

√

6) DAMPER SEGMENT RAW

Hardness Test √

Visual check √


Acceptance Test on 5% of

consignment

√

7) POLE LAMINATION SHEETS

Tensile Test √

Chemical Analysis √

Visual check √ √

Dimensional check √ √ √

Induction Test √

8) POLE AND PLATE RAW

Tensile Test √

Notched Bar Impact

Test

√


Ultrasonic Test √

Visual Test √

Dimensional Test √

Acceptance Test of each piece √

9) POLE END PLATE

MACHINING

Visual check √


122

Sr.No

.




10) POLE BOLTS

Tensile Test √




11) ROTOR LAMINATION

Tensile Test √

Notched Bar Impact Test √


Ultrasonic Test √ √

Aging characteristic √


12) STATOR LAMINATION SHEETS

Tensile Test √




Induction Test with determination

of specific losses at 1.0 and 1.5 t

√

13) STATOR PUNCHING

Tensile Test √




14) STATOR RIM BOLTS

Tensile Test √



123

Sr.No

.


Visual check √


15) STATOR FRAME

Tensile Test √

Notched Bar Impact Test √


Ultrasonic Test √ √

Aging characteristic √


Trial Assembly √

16) STATOR WINDING BARS

FINISHED

Tensile Test √

Visual Test √


Test for short circuited Turns √

Acceptance Test of each

piece(H.V. Test) with Tangent

delta measurement

√

Insulation simulation Test √

17) WATER/AIRHEAT EXCHANGER

(EACH)

Tensile Test √

Visual Test √


Hydrostatic Test √

18) OIL COOLERS (EACH)


124

Sr.No

.


Tensile Test √

Visual Test √


Hydrostatic Test √

19) GENERATOR SHAFT

Material Analysis √

Tensile Test √

Notch Impact Test √

Visual Inspection √

Magnetic particles Examination √

Ultrasonic Test √


Roughness Test √

Baroscopic Inspection √

Matching with Turbine shaft √

20) BRAKE

Visual Test √ √ √ √

Dimensional check √ √ √ √

Measurement of Stroke

Hydrostatic Test √ √ √ √

21) E.T.D.THERMOMETER THERMAL

SWITCH

Calibration Test √

Check and setting of switches and

relays

√

22) VARIOUS SWITCHES AND

RELAYS

Check and setting of pressure, √


125

Sr.No

.


Level, Flow

Temperature switches and Relays √

23) STATIC EXCITATION EQUIPMENT

A) FOR EACH SET

H.V. Test √

Functional Check of modules by

simulation

√

Control sequence interlock Test √

Load Test and current sharing Test

on thyristor bridge

√

Heat run test on thyristor bridges √

Heat run and Impulse test on

excitation transformer

√


126

4.19 SITE TESTS FOR GENERATOR AND RELATEEQUIPMENT

Site tests to be conducted on various assemblies in presence of

Purchaser are as below but shall not be limited to.

DURING ERECTION

STATOR WINDING :

- D.C. Resistance.

- Insulation Resistance.

- H.V. Test

- Dielectric Test.

ROTOR WINDING :

- D.C. Resistance

- Insulation Resistance.

- H.V. Test

- Rotor Impedance.

- Dielectric Test

- High frequency induced voltage test on poles.

MEASUREMENT OF CENTERING AND LEVELLING

BEARING

- Insulation Resistance

- Check of vibration response

- Check of setting of oil level switches.

SHAFT :

- Check of shaft alignment together with Turbine Shaft.

- Check of vibration response.

- Check of slip ring deflection.

BRAKE AND SYSTEM

- Check of setting of pressure switch, limit switches,


127

relays etc.

- check of pumps.

- Operation pump check in all mode.

STATOR FINISHED

- Magnetic flux test

- Di-electric Test.

- Measurement of stator winding D.C. resistance.

- Measurement of stator winding insulation resistance.

- Measurement of stator winding impedance.

- H.V. Test

- Check of concentricity of core.

- Check of core height.

ROTOR FINISHED

- Measurement of Rotor winding D.C. resistance.

- Measurement of rotor winding impedance.

- Measurement of rotor winding insulation resistance.

- H.V. Test

- Check of concentricity.

DURING PRECOMMISSIONING AND POST COMMISSIONING

AUXILIARIES

Auto/Manual operation of all auxiliary system connected with

Generator .

OTHER GENERATOR TESTS

NO LOAD TESTS :

- Initial run

- Check of smooth run at gradually increased speed from zero to rated

speed


128

- Vibration and noise level measurement

BEARING HEAT RUN

- Running test of bearings

- Recording of bearing metal and oil temperature at rated speed no

load until all bearings reach stable temperature.

OVER SPEED TESTS

- Functional check of vibration & seismic monitor

- Run for 2 minutes at 150% over speed.

EXCITATION SYSTEM

- Commissioning test .

SYNCHRONISING TEST

- Auto / Manual synchronising.

LOAD REJECTION TESTS

- Load rejection at 1/4, 1/2, 3/4 and 1.0 of rated output at rated power

factor.

- Oscillograph measuring of voltage rise at each

rejection.

SHUT DOWN TESTS

- Normal stopping operation of generator

- Quick shut down tests.

- Emergency shut down test.

- Vibration and noise level measurement.

LOAD TESTS

- Check of operation of various controlling and

`regulating.

- Temperature recording of windings and bearings.


129

- Vibration and noise level measurement.

- Measurement of Turbine and generator bearing

bracket deflection.

STATIC EXCITATION SYSTEM

- Measurement of insulation resistance.

- H.V. Test. .

- Functional test of system component.

- Loading characteristic test.

- Measurement of range of voltage regulation.

- Measurement of range of power factor regulation.

- Test of generator current limiter and exciting current limiter.

GENERATOR CHARACTERISTIC AND PERFORMANCE TESTS :

- Open circuit characteristic (without step-up power transformer).

- Three phase sustained short circuit condition characteristic.

- Line to line sustained short circuit condition (without step-up power

transformer)

- Various Reactances

- Measurement of Air gap

- Measurement of Noise level.

- Measurement of Moment of Inertia.

- Determination of balanced and residual component of telephone

harmonic factor (THF)

- Measurement of following losses (according to IEC 34-2A

Calorimetric method)

i) Losses in active iron and additional no load losses in metal

parts.

ii) Losses due to friction and windage

iii) Stator winding copper losses at 750 C

iv) Additional load losses


130

v) Field winding copper losses at 750 C

vi) Excitation system losses (Excitation transformer + thyristors

+ ac/dc link)

vii) Electrical losses in brushes.

- Measurement of vibration and noise level at rated output

- Measurement of all bearing temperatures at rated output.

- Measurement of reactive power

- Determination of generator guaranteed output with reference to

guaranteed temperature rise.

4.20 DRAWINGS, DESIGNS, STUDIES AND MANUALS TO BE

SUBMITTED AFTER AWARD OF CONTRACT BY THE BIDDER.

The list of drawings, designs, studies, data needed and manuals etc.

required to be submitted by the supplier is enclosed with this section

(Please refer Annexure IV - I). Mode of submission of designs and

drawings will be intimated to the successful bidder in due course.

4.21 SPARES

Spares shall be supplied as per the list under Section - III of this

volume.


131

ANNEXURE –IV-1

DRAWINGS, DESIGNS AND MANUALS TO BE FURNISHED AFTER

AWARD OF CONTRACT.

Sr.

No

.

Brief description within months from

the date of award

of contract

Remarks

1 2 3 4

I GENERATOR

1. Arrangement drawings describing

and illustrating the information of:

3 For approval

* General layout drawing

* Combined turbine and

Generator cross section

* General arrangement and

overall dimensions of

generator showing

position and marking of main and

neutral leads, important elevations

etc

Bearing

Assembly

* Air circulation arrangement

* Excitation system

* Description of bearings

and data regarding

construction, adjustment,

accessibility and method.

* Description and section of

stator and rotor insulation


132

2. Installation, assembly drawings of :

1 2 3 4

Generator and turbine shaft

coupling

4 For approval

Rotor 4 For approval

Stator Foundation 4 For approval

Stator windings 4 For approval

Rotor arrangement including poles 4 For approval

Slip ring arrangement 4 For approval

Generator brakes 4 For approval

Assembly of stator and rotor with

lifting arrangement

4 For approval

Speed sensing element

arrangement

4 For approval

Lifting and attachment drawing 4 For approval

3. Drawings illustrating dimensional details with schematics for :

1 2 3 4

Lubrication and cooling system

of bearings

4 For approval

Generator cooling 4 For approval

Schematic diagram of air, oil

and water piping

4 For approval

Schematic diagram of brake 4 For approval

Thermometers, R.T.Ds etc 6 For approval

General scheme giving details

of excitation system, D.V.R.

Thyristors, field breaker, field

discharge resistance, etc.

8 For approval

Arrangement of generator

heaters

8 For approval


133

Arrangement of rotor on

service bay, Rim building

stools and loading on service

bay floor.

4 For approval

Arrangement of oil cooler

withdrawal

8 For reference

4 Layout, plan and cross sections

of floor openings for piping,

cables etc. for units for:

4 For approval

Trenches

Block- out / cut- out etc

Opening in housing

6 Sole plate, stator and bracket

fixing

18 For approval

8 Layout of cooling water piping 4 For approval

9 Layout of oil piping and air piping 4 For approval

10 Drainage arrangement for

mulsifire water jet system

4 For approval

11 Layout of Mulsifire, fire

protection system with

schematics and equipment

details.

10 For approval

12 Cable schedules for all

equipments of entire power

station as a whole and covering

all equipment under

10 For approval

i) Electrical lot.

ii) Mechanical lot

13 Detailed wiring schedules for

interconnection of equipment

stated in (12) above

10 For approval


134

MANUALS.

1 2 3 4

1 Manual for storage, preservation

and handling of the supplied

goods

12 For reference

2 Manual for erection /

dismantling, testing and

commissioning of the supplied

goods

12 For reference

3 Manual giving operating

instructions for all the ‘DO’s and

‘DONT’s’

18 For reference

4 Manual giving detailed

maintenance schedule

18 For reference


135

ANNEXURE IV-2

DEPARTURE FROM SPECIFICATION

(To be filled in by Bidder)

----------------------------------------------------------------------------------------------------

Item. Description of departure. Reference

to clause in the

specification.

----------------------------------------------------------------------------------------------------


136

DATA SHEETS

DATA SHEETS E 1 TO E24 FOR TECHNICAL SPECIFICATIONS OF GENERATOR AND RELATED EQUIPMENT (THE BIDDER MUST FILL IN THIS DATA SHEETS COMPLETELY) Note : The indicated sign and the assigned meaning shall be as follows:

> no negative tolerance allowed < no positive tolerance allowed

(r). required value

(d) desired value (o) offered value (*) guaranteed values inclusive of tolerance.


137

DATA SHEET E1

Bidder's Remarks (if any)

DATA SHEETS E 1 TO E 24

A GENERATOR

GENERAL TECHNICAL DATA

A1. Direction of Rotation

Seen from generator end – Counter Clockwise(d) ------ (o)

A2. Rated Speed

nn = 500 rpm (d) ------ rpm(o)

A3. Maximum momentary over speed under most unfavourable transient

conditions (according to turbine designer and IEC 41/1991 )

(nn max. < 1.5 nn (d)] nn max.------ rpm(o)

A4. Maximum steady state runaway speed at Qmax = 4.00 m³/sec and Hnmax =

410 m and suddenly load removed according to turbine designer and

IEC (1/1991-11 subclause 2.3.1.15)

[nRmax. < 1.70 nn (r)] : nRmax = ……. rpm (o)

A5. Rated voltage and range of voltage regulation. ------ (o)

Un = 11 kV Un = +10%kV (r)

A6. Rated frequency and range of frequency regulation for continuous operation

fn =+3% & -5% (d) : fn = …….-Hz(o)

A7. Telephone harmonic factor on open-circuit and ------ (o)

rated speed and rated voltage:THF < 1.5% (r)

A8. Insulation class of stator and ------ (o)

Field winding : Class F (r)

A9. Degree of protection (according to IEC 34.5/1991) ------ (o)

: IP 44 (r)

A10. Method of cooling of generator

(according to IEC 34-6/ 1969) ------ (o)


138

DATA SHEET E2


B. GENERATION OUTPUT :

B1. Rated continuous apparent power output under entire zone A operation

according to IEC-34-1 amend 2/1989 and temperature rise not higher than

according to insulation class B (according to IEC – 34-1) and rated power

factor.

[SN1 ≥ 11.11MVA (r)] : SN1 = ……. (o)

B2. Rated continuous apparent power output under entire zone B operation

according to IEC-34-1 amend 2/1989 and temperature rise not exceeding 95

K (and sub-clause 16.2 of IEC-34-1 embedded thermostat temperature

detector method for stator windings and 100 K by Resistance method for field

windings respectively with cooling water temperature at 300C and primary

coolant maximum temperature 400C and rated power factor.

SN2 ≥ 11.11 MVA (r) : SN2 = ……. (o)

B3. Maximum permissible continuous apparent power output at Un + 10% fn+3%

,-5% and temperature rise according to IEC-34.1 amend 2/1989 at rated power

factor. Exceeding 95 K (and sub-clause 16.2 of I.E.C. 34.1) by embedded

thermostat temperature detector method for stator windings & 100 K by

resistance method for field windings respectively with cooling water

temperature at 300C and primary coolant maximum temp. 40

0C and rated

power factor.

SN3 > 11.11 MVA (r) : SN3 = ……. (o)

B4. Rated Power factor

: cosØn = 0.9 (overex) ..1.0..0.9(underex.) (r) ----- (o)

B5. Rated current at rated voltage UN and :

SN1 = ------- MVA : IN1= …….. A (o)

SN2=-------MVA :IN2= …….A(o)

Smax=…….MVA :Imax=……. A(o)

B6. Occasional excess of the rated current ------ A (o)

< 1.5 times (r) armature current.

(not less than 30 s)


139

DATA SHEET E 3


B7. Apparent output for operating

Conditions of rated voltage Un+

10% and Hz 47.5 …50…51.5 at

Temperature rise of stator winding

85K and field winding 90 K

(Primary coolant temperature

40-degree C.) : ……………… MVA (o)

Remark:

Time for which generator can be run at rated apparent power output without fans in

operation (if any) and without cooling water flow > 15 minutes without exceeding an

additional temperature rise of 10 K.

Bidders shall indicate permissible continuous apparent power for temperature rise not

higher than insulation class F at Un + 10% Cos Ø = 0.9 over excited) ……. 1.0 …….

0.9 (under excited) for following frequency decreasing range.

F net w = 46 Hz .. adm ……. KVA (o) Duration ……. Hrs (o)

F net w = 47 Hz .. adm ……. KVA (o) Duration ……. Hrs (o)

C. ELECTROMAGNETIC VALUES

C1. Electric loading (armature

Ampere conductors per length)

At rated current. A1 = ……. kA/m (o)

C2 Maximum magnetic flux

Density of the air gap

Surface at Un and no-load :Bδ 1 = ……. T (o)

C3. Average magnetic flux

Density of the stator core

Teeth at Un and no load : Bzl= ……. T (o)

C4. Average magnetic flux

Density of the pole core at

Un and no – load :Bp=……….T(o)


140

DATA SHEET E4


C5. Utilization factor

Sn kVA

C = --------------------- :C=------------------ (o)

ds2. 1 nn m

3 x rpm

C6. Current density of armature A

windings at rated current : S1------------- (o)

mm2

C7. Current density of field windings at

rated excitation current for rated

apparent power. Un and cos Ø = 0.9 A

(over excited) : S2 =................ (o) mm2

C8 . Maximum permissible continuous negative sequence component current

[ 12 / IN > 0.1 p.u (d). ] : 12 / IN =..... p.u. (p)

C9. Maximum permissible value of

(12 / IN) 2 x t for operation under

fault conditions

(12 / IN) 2 x t > 20 (d) :( 12 / IN)2x t =.... p.u. (o)

D. PERMISSIBLE LIMITS OF TEMPERATURE RISE

PERMISSIBLE LIMITS OF TEMPERATURE RISE

AT RATED APPARENT POWER OUTPUT OF SN2 OF DATA SHEET El-2 and Un

cos <Øn = 0.9 ( over excited ) .... 1.0…… 0.9. ( under excited )with MAXIMUM

PRIMARYCOOLANT TEMPERATURE 40° C.

D1 Stator ( by embedded thermostat temperature detectors -

ETD ) [AD a < 95 K (r) according to class B and subclause 16.2 of IEC 34- l] :Aoa < .... K (o)

D2. Field windings [ Auf < 100K (r) ] : Auf < ....... K (o)


141

DATA SHEET E5


D3. Permanently short-circuit insulated

damper bars ( by thermometer )

[Aud<60K(d ) ] :Aod< ..... K(o)

D4. Magnetic core and parts not in

contact with windings (by thermometer)

[AuFe< 60K(d ) ] :AoFe< ..... K (o)

D5. Magnetic core and parts in contact

with windings (by thermometer)

[Ao'Fe < 60 K (d)] : Au'Fe <......K (o)

D6. Slip- rings enclosed (by thermometer)

[Aos r<60K (d ) ] :Aus r< K (o)


142

DATA SHEET E6


E DESIGN AND GEOMETRIC DIMENSIONS

(QUANTITIES ACCORDING TO IEC PUBL.27-4/1985)

E1 Stator design

a) Construction of core segments ………………………… (o)

b) Inner diameter of stator core ds = ………. mm (o)

c) Length of one ventilation duct Iv = …………. mm (o)

d) Number of ventilation duct nv = ……. (o)

e) Iron Length (1Fe = 1-nv.1V) IFe = ……. mm (o)

f) Overall length of the core (Including ventilation duct) 1 = ……. mm (o)

g) Outer diameter of the stator core (excluding heat

exchangers and frame

dso = ………. mm (o)

h) Air gap (maximum / minimum) δmax/min = …../…… mm (o)

i) Equivalent air gap (including slotting) δ = ……./…….mm (o)

j) Number of armature slots Q = ……. mm (o)

k) Armature slot dimensions (depth x width) hs x bs = ..X..mm (o)

l) Copper section per each Armature bar Ss = ……. mm2 (o)

m) Total number of conductors z = ……. (o)

n) Number of parallel paths a = ……. (o)

o) Estimated maximum current circulating between the

parallel circuits

A = ……. Amp (o)

p) Number of conductors in a slot ZQ = ……. (o)

q) Number of slots per pole and phase q = ……. (o)

r) Gap between coil & slot sides g = <0.5 mm (d) g = mm (0)

s) Number of armature windings per phase (turns in

series in a coil)

Nc = ……. (o)

t) Stator slot pitch τS = ……. mm (o)


143

DATA SHEET E7


u) Pole pitch τP = ……. mm (o)

v) Pitch factor (chording factor) Kp = ……….. (o)

w) Winding factor Kw = ……. (o)

x) Carter factor due to slotting of the stator Kc = …….(o)

y) Thickness of material for core laminations. t1 =………….mm (o)

z) Specific losses of materials for laminations at 1.0 T &

50Hz

c = ……. W/Kg (o)

aa) Class of armature windings insulation F (r)

ab) Number of partial stator parts n = ……. (o)

ac) Maximum mass of one stator part for transport G1 = ……. t (o)

ad) Maximum mass of the stator to be lifted during

erection

Ger = ……. t (o)

ae) Total mass of finished stator (Without coolers) G1 tot.= ……. t(o)

af) Is winding fully insulated from line to neutral ?

(yes / no) Yes (r)

ag) Anti corona protection (yes/no) Yes (r)

ah) Stator slot wedge material ……… (o)

ai) Necessary dimensions of Generator Housing

- Diameter of generator Housing Dp = ……… mm (o)

- i) inner Dp = ……… mm (o)

- ii) Outer Hp = ……… mm (o)

- total length of generator Housing

E2 Rotor design

a) Construction of rotor …………………… (o)

- laminated rotor or other construction type …………………… (o)


144

DATA SHEET E8


- material for laminated rotor …………………… (o)

- thickness of material for laminations t2=…………………… mm (o)

- material for shaft …………………… (o)

- material for body …………………… (o)

- material of pole core …………………… (o)

- material of pole shoe …………………… (o)

- material of field windings insulation …………………… (o)

- material of slip ring …………………… (o)

- class of field windings insulation F (r)

b) Outer diameter of rotor dr = ……. mm (o)

c) Height of pole body hp1 = ……. mm (o)

d) Height of pole shoe hp2 ……. mm (o)

e) Width of pole body bp1 = ……. mm (o)

f) Width of pole shoe bp2 ……. mm (o)

g) Maximum stress in rotor Pole body at :-

- rated speed B = ……. Mpa (o)

- max. steady state runaway speed B'' = ……. Mpa (o)

h) Number of field windings Nf = ……… (o)

i) Section of field windings Sf = ……… mm2 (o)

j) Total number of damper bars nb = ……… (o)

k) Diameter for damper bars db = ……… mm (o)

l) Section of dampers ring (if any) Sdr = ……. mm2 (o)

m) Total number of slip ring brushes nbr =- ……. (o)

n) Brush coverage ratio = ……… (o)


145

DATA SHEET E9


o) Can brushes be replaced on load (Yes / No) Yes (r)

p) Maximum mass of rotor part and description to

transport

G2= ……… t (o)

q) Maximum mass be to lifted during erection (complete

rotor)

G2 tot = ……… t (o)

E3 Terminals bushings and connections

- Rated voltage level of terminals bushing Ur = ……. kV (o)

- Rated current of terminals bushings In = ……. A (o)

E4 Mechanical braking design

a) At which speed are mechanical brakes applied for

normal shutdown

nbr = ……. rpm (o)

b) How long to stop of unit tbr = ……… s (o)

c) At which speed are brakes applied for emergency

shutdown

n'br ……… rpm (o)

d) How long to emergency stop of unit t'br ……… s (o)

e) Operating rated air pressure for braking system Pbr ……… MPa (o)

F SYNCHRONOUS MACHINE QUANTITIES

(According to IEC Publ. 34-4/1985)

F1 Rectances

a) Short-circuit ratio (clause 4.5 ) Kc > ……… p.u (o)

b) Direct-axis synchronous reactance (unsaturated)

(clause 4.5 )

Xd = ……… p.u (o)

c) Quadrature-axis synchronous reactance

(unsaturated, tolerance + 5%)

X'q = ……… p.u. (o)


146

DATA SHEET E10


d) Direct-axis transient reactance (clause 4.5 )

- At In X'dIn < ……. p.u. (o)

- at Un X'dUn < ……. p.u. (o)

e) Direct-axis substransient reactance

- At In X'dIn = ……. p.u. (o)

- at Un X'dUn > ……. p.u. (o)

f) Quadrature axis substransient reactance

- At In X'dIn = ……. p.u. (o)

- at Un X'dUn = ……. p.u. (o)

g) Negative sequence reactance

- At In XzIn = ……… p.u. (o)

- at Un XzUn = ……… p.u. (o)

h) Zero sequence reactance

- At In XoIn = ……… p.u. (o)

- at Un XoUn = ……… p.u. (o)

i) Potier reactance Xp = ……… p.u. (o)

F2 Resistances

a) Positive-sequence resistance r1 = ……… p.u (o)

b) Negative sequence resistance r2 = ……… p.u (o)

c) Zero-sequence resistance r0 = ……… p.u (o)

d) Armature windings direct current resistance at 75

degree C

Ra = ……… /Ph (o) ra = ……… p.u. (o)

e) Field windings direct current resistance at 75 degree

C

Rf = ……… (o)

rf = ……… p.u. (o)


147

DATA SHEET E11


F3 Generator moment of inertia, acceleration time and

stored energy constant

a) Generator moment of inertia for rated speed. J > ……. (o)

b) Generator acceleration time constant reported at rated

active power Pn= 10 MW and rated speed

J = ……… s (o)

c) Generator stored energy constant reported rated

apparent power output Sn2 = 11.60 MVA and rated speed

H=…….s(o)

F4 Short-circuit currents at rated speed

a) Sudden short-circuit currents at no-load and rated

voltage :

- initial symmetrical three phase short-circuit current

(rms-value)

I" K3= ……… p.u. (o)

- initial symmetrical line- short- circuit current (rms-value) I" K2= ……… p.u. (o)

- initial symmetrical line neutral- short- circuit current

(rms-value)

I" K1= ……… p.u. (o)

- initial symmetrical three phase short - circuit current

(d.c. -value)

I" Ka = ……… p.u. (o)

b) Sustained short-circuit currents at no-load and rated

voltage :

- at three phase short-circuit (rms value) IK3=……… p.u. (o)

- at line-line phase short-circuit (rms value) IK2 =……… p.u. (o)

- at line neutral phase short-circuit (rms-value) IK1= ……… p.u. (o)

c) Sudden short-circuit at rated apparent power output, Un

and cosØ = 0.9 (over excited)


(rms-value)

I" K3= ……… p.u. (o)


148

DATA SHEET E12


- initial symmetrical line line short-circuit current (rms-

value)

I" K2 =……… p.u. (o)

- initial symmetrical line neutral short-circuit current

(rms-value)

I" K1= ……… p.u. (o)


(d.c.value)

I" Ka= ……… p.u. (o)

d) Sustained short-circuit currents at rayed apparent

power output, Un and cos Ø = 0.9 (over excited

- at three phase short-circuit (rms value) IK3= ……… p.u. (o)

- at line-line phase short-circuit (rms value) I K2= ……… p.u. (o)

- at line neutral phase short-circuit (rms-value) I K1= ……… p.u. (o)

G. EXCITATION SYSTEM

I. DATA FOR RATED SPEED

(According to IEC 34-16-1/1991 and 34-16-2/1991)

1. No-load field current at rated voltage Ifo = ……… A (o)

2. No-load field voltage at rated voltage Ufo = ……… V (o)

3. Rated field current at rated apparent power output,

Un and

- Cos = 0.9 (overexcited) Ifn = ……… A (o)

- Cos = 1.0 I'fn = ……… A (o)

- Cos = 0.9 (underexcited) I"fn = ……… A (o)

4. Rated filed voltage at rated apparent power output

Un and

- Cos = 0.9 (overexcited) Ufn = ……… V (o)


149

DATA SHEET E13


- Cos = 1.0 U'fn = ……… V (o)

- Cos = 0.9 (underexcited) U"fn = ……… V(o)

5. Telephone harmonic factor < 1.5% (d) ………………………… (o)

II. EXCITATION SYSTEM GENERAL

(According to IEC 34-16-1 and 34-16-2)

1. General

a) Preferred system Static excitation system with

thyristors supply of excitation transformer from

generator terminals (d)

b) System offered ………………………… (o)

c) Excitation system nominal response (VE > 4.0 s-1

(r)]

VE > ……… s-1 (r)

d) Rated field voltage and current at rated output

power, rated voltage and rated power factor 0.9

(overexcited)

- Rated field voltage Ufn = ……… V (o)

- Rated field current Ifn = ……… V (o)

e) Maximum field forcing d.c output

- Excitation system ceiling voltage [Up > 2.V fn (r)] Up > ……… V (r)

- Excitation system ceiling voltage [Ip > 1.5. In (r)] IP > ……… A (r)

III Main excitation transformer

(Rectifier transformer)

a) Manufacturer ................. (o)

b) Type [1 three phase excitation dry transformers (d)] ................. (o)

c) Standard specification with which the transformers

comply

................. (o)


150

DATA SHEET E14


d) Rating

i) Continuous maximum output ……… kVA (o)

ii)Rated Voltage ………Kv(o)

* high voltage side ……… kV (o)

* low voltage side ……… kV (o)

e) Type of cooling ................. (o)

f) Cooling medium ................. (o)

g) Connection group ................. (o)

h) Short-circuit impedance at 750 C and 50 Hz ………… % (o)

i) No-load losses per phase ……….. kW (o)

j) Load losses per phase

(I2R + stray losses) at 750 C and 50 Hz

……… kW (o)

k) Magnetizing current at rated voltage and 50 Hz ……… % In (o)

IV) Main excitation rectifier

(Controlled rectifier)

a) Input

i) Maximum continuous A.C.voltage ………… V (o)

ii) Frequency ………… Hz (o)

iii) Number of phases ................. (o)

iv) Power at maximum permissible continuous apparent

power

b) Output

i) maximum continuous direct voltage ………. V (o)

ii) maximum continuous direct current ………. A (o)

iii) maximum direction current during 10 seconds ………. A (o)


151

DATA SHEET E15


c) Configuration

i) Is rectified built in sections which can be individually

removed and replaced with the machine at full load ?

......... (o)

ii) How many such sections per phase are there in the

complete rectifier ?

......... (o)

iii) How many such sections per phase are required to

maintain excitation on the generator max. permissible

continuous apparent power

......... (o)

d) Main diodes

i) Number used in complete rectifier ......... (o)

ii) Make ......... (o)

iii) Type ......... (o)

iv) Maximum permissible continuous direct current ......... A (o)

v) Maximum permissible continuous direct current

during 10 seconds

......... A (o)

vi) Peak inverse voltage ......... V (o)

e) Rectifier main diode fuses

i) Number used in complete rectifier ......... (o)

ii) Make ......... (o)

iii) Type ......... (o)

iv) Current Rating ......... A (o)

v) Rating of fuse failure alarm contacts

* Voltage ......... V (o)

* Current ......... A (o)

f) Cooling medium

i) Rectifiers ……… (o)

ii) D.C. busbars ……… (o)


152

DATA SHEET E16


g) Power consumption of

i) all fan motors on complete rectifier ……… kW (o)

ii) all pump motors on complete rectifier (if any)

V) Automatic Digital Voltage Regulator (DVR)

a) Make ......... (o)

b) Type ......... (o)

c) Adjustment range of generator reference level for

automatic control

......... % (o)

d) Adjustment range of generator voltage for hand

control (at rated speed)

i) Increasing Voltage ......... % (o)

ii) Decreasing Voltage ......... % (o)

e) Provision for remote electrical selection and setting

of automatic and hand control

......... (o)

f) Provision of automatic follow –up of voltage setting by

hand voltage setting

......... (o)

g) Ratings of limit switches on automatic and hand

remote setting devices

i) Voltage ......... V (o)

ii) Current ......... A (o)

h) Provision for under-excitation monitor ......... (o)


153

DATA SHEET E17


i) Method of preventing excitation boosting if voltage

transformer fails

.........

j) Operating frequency range [45 to 55 Hz (d) ......... to ……. Hz (o)

k) Auxillary power required

i) Voltage ......... V (o)

ii) Current ......... A (o)

iii) Supplied from ......... (o)

m) Current transformers for automatic voltage regulator

if Required

i) Burden ......... V A (o)

ii) Accuracy class ……… (o)

iii) Current Ratio ……… A/A (o)

iv) Number per regulator ……… (o)

v) Provided by ……… (o)

NOTE :

i) Tolerance shall be guaranteed along with Bidders remarks, if any.

ii) Location of Excitation transformer. V.T. cubicles, dynamic brake cubicle, field

suppression cubicle etc. shall be proposed by generator supplier and shall be co-

ordinated with other supplier.


154

..................DATA SHEET E18

..................Bidder's Remarks (if any)

H) GENERATOR BEARING

Type of bearing

[adjustable pad/segmental type self lubricated

bearing ( d ) ]

: ………………….(o)

Diameter of generator bearing : d =………mm (o)

Number of pads/segments : N =…………...(o)

Total effective surface of all segments : A =….m2 (o)

Circumferential length of pads/segments : L = ….mm (o)

Axial length of pads/segments : b =….mm (o)

Dynamic viscosity of oil : v =….m/s2 (o)

Maximum temperature for oil film : =…..0C (o)

Maximum temperature for Segment

( < 70 0C ( r )

: =…..0C (o)

Whether H.S. Lubrication is used (yes/no)

Quantity of lubricated oil reservoir : =.. ….m3 (o)

Quantity of cooling water (if required) : =……. 1/s (o)

Total losses in bearing at rated load : = …. ….Kw (o)

Permissible duration of operation of the unit at

rated load without supply of cooling water.

: =…

Vibration limit of generator bearing for complete

range of operation <75µm (r)


155

.................. DATA SHEET E19


I CURRENT TRANSFORMERS

(To be supplied for each core separately in tubular form)

a) CT Number/Location

b) Qty.

c) Application

d) Name of manufacturer

e) Type

f) Winding of connection

g) Rated burden of earth secondary winding per phase

h) Insulation level

i) Insulation class

j) Impulse withstand voltage of primary winding

k) (1.2/50 micro second wave) kV (peak)

l) One minute power frequency dry withstand voltage (kV)

m) Primary winding

n) Secondary winding

o) Characteristic enclosed (Yes/No)

p) Accuracy class

J POTENTIAL TRANSFORMER

(To be supplied for each core separately in tubular form)

(a) Type

(b) Name of manufacturer

(c) Standard to which it conforms

(d) Manufacturer’s type design Volts

(e) Rated primary voltage

(f) Rated secondary voltage

(g) Rated burden

(h) Accuracy class

(i) Temperature rise at 1.1 times rated voltage with rated burden and frequency

(j) One minute power frequency withstand test voltage on primary kV (rms)


156

DATA SHEET E20


K LIGHTNING ARRESTER

a) Make

b) Type

c) Rated voltage

d) Max. system voltage across arrestor

e) Power frequency spark over voltage (kV)

f) Impulse spark over kV (peak)

g) Max. front of wave impulse Spark over kV (P)

h) Rated discharge current

i) Max. discharge voltage in kV crest for discharge Current 8/20 micro sec.

Wave

j) Leakage current at rated voltage insulator (kV)

k) One minute dry withstand voltage of arrestor external insulator (kV)

L SURGE CAPACITOR

l) Make

m) Type

n) Nominal voltage

o) Max. voltage

p) Insulation class

q) Phase

r) Frequency

s) Capacitance

t) impulse withstand voltage (1.2/ 50 micro second wave)

u) Qty.

v) Applicable standard

w) Residual voltage after 5 minute of disconnection


157

DATA SHEET E21


M INSULATORS (in junction bus panel)

a. Make

b. Type

c. Material of insulator

d. Colour

e. Insulation level:

f. Dry (PF)

g. Wet (PF)

h. Impulse

N Neutral Grounding Equipment

(i) Distribution Transformer and secondary Resistor

(a) Type


(c) Voltage ratio

(d) Continuous rating

(e) One minute rating

(f) Secondary load resistance (ohms)

(g) Current rating of resistor

(h) Duty cycle of resistor and cooling medium

(ii) Neutral Isolation Switch

(a) Type


(c) Voltage rating, frequency

(d) Normal current

(e) Short time rating

(f) 1.2/50 Micro Second impulse level

(g) 1 minute power frequency dry withstand voltage


158

DATA SHEET E22


O 11 kV XLPE CABLE

General

i. Name of the manufacturer

Cable Type

i. Type and size of Cables

ii. Standard applicable

iii. Voltage rating

iv. Permissible variation in voltage, frequency

and combined voltage and frequency.

v. Suitable for earthed/ unearthed system

Conductor

i. Material

ii. Nominal cross-sectional area.

iii. Form of conductor-circular/ shaped

iv. No. of strands

v. Nominal dia. of each strand

Conductor Screen

i. Material

ii. Minimum thickness

iii. Whether extruded

Insulation

i. Material (Mention type)

ii. Minimum average thickness

iii. Tolerance on the smallest of the

measured values of thickness of insulation.

iv. Dia of core over insulation.

v. Specific insulation resistance at 27oC

vi. Colour scheme of identification of cores.

vii. Average dielectric strength

viii. Suitability with regard to moisture zone,

acid, oil and alkaline cup-roundings.


159

DATA SHEET E23


Electrical Properties

i. Conductor resistance at 20oC per km.

ii. Maximum permissible conductor temp.

a. Under continuous full load

b. Under transient conditions

iii. Loss tangent at normal frequency

iv. Reactance at 50 C/s per km.

v. Capacitance at 50 C/s per km.

vi. Current rating.

a. In air (continuous)

b. In duct (continuous)

c. Reference ambient temperature for the above

d. Short circuit current rating for 1 sec. duration

vii Impulse withstand voltage

viii Power frequency withstand voltage (50 Hz) for 30 Minutes.

ix Partial discharge

x) Permissible Overload

xi) Electrical stress (AC voltage)

a) On conductor

• Average

• Maximum

b) On Inner Semi conductor layer

• Average

• Maximum

c) On Outer Semi conductor layer

• Average

• Maximum


160

DATA SHEET E24


xii) Electrical stress ( Impulse withstand voltage)

• Average

• Maximum ( On Inner Semi conductor layer

Mechanical Data

i. Overall dia. of the cable

ii. Dia. of the cable under the sheath

iii. Weight of cable per kg.

iv. Drum length

v. Recommended minimum installation radius

Maximum safe pulling force.

P Heaviest package for shipment

(a) Name

(b) Weight

(c) Dimensions (L x B x H)

Q Largest package for shipment

(a) Name

(b) Weight


R. Heaviest assembly to be lifted by power house crane

(a) Name

(b) Weight



161

TABLE NO.1 DATA SHEET E25


GUARANTEED VALUES OF GENERATOR LOSSES AND EFFICIENCY AT RATED VOLTAGE Un and cos -0.90 (overexcited)

No. Losses (According to IEC 34-2) Symbol unit Apparent power at generator terminals

Smax= 105 % MVA

SN = 100% MVA

SN =95% MVA

Losses in active iron and additional no load Losses in metal parts

Pfe kW

1 Constant losses

Losses due to friction and windage (*)

Turbine bearing losses Pu.g.b kW

Generator bearing losses Pl.g.b. kW

Windage and friction losses Pwi+f kW

Brushes losses Pbr kW

2 Excitation parameters

Field voltage Uf V

Field current If A

3 Load losses Stator windings copper losses at 75° C Pcu 1 kW

Additional load losses Padd. kW

Field winding copper losses at 75° C Pcu2 kW

Excitation system losses (excit trasf. + thyristors + ac/dc links)

Pe.s kW

Electrical losses in brushes Pe.br kW

4 : SUMMATION OF LOSSES I p kW 5 CALCULATED GENERATOR EFFICIENCY f i G.c 6 GUARANTEED GENERATOR EFFICIENCY f jG.g


162



GUARANTEED VALUES OF GENERATOR LOSSES AND EFFICIENCY AT RATED VOLTAGE Un and cos -1.00 No. Losses (According to IEC 34-2) Symbol unit Apparent power at generator

terminals

Smax 105 % MVA

SN = 100% MVA

95% SN MVA


Pfe kW

1 Constant losses







Field voltage Uf V

Field current If A





Pe.s kW




163



GUARANTEED VALUES OF GENERATOR LOSSES AND EFFICIENCY AT RATED VOLTAGE Un and cos -0.90 (underexcited)

No. Losses (According to IEC 34-2) Symbol unit Apparent power at generator terminals

Smax 105 % MVA

SN = 100% MVA

95% SN MVA


Pfe kW

1 Constant losses







Field voltage Uf V

Field current If A





Pe.s kW



164

SECTION – V

TECHNICAL SPECIFICATIONS OF TURBINE


165

SECTION – V


INDEX Sr.no. Description Page no.

5.1 Scope 166

5.2 Type and rating 166

5.3 Guarantees vis-à-vis liquidated damages 168

5.4 Liquidated damages for failure to meet performance guarantee

172

5.5 Model test 173

5.6 Field test and acceptance 175

5.7 Detailed construction specifications of components of turbine

175

5.8 Governing system 181

5.9 Penstock drainage system 187

5.10 Water level measuring & transmitting device 187

5.11 Special tools, slings, consumables etc 188

5.12 Spares 189

5.13 Tests 190

5.14 Guaranteed technical particulars 192

5.15 Electrical equipment 193

5.16 Standards 196

Annexure ––V-1 198

Annexure ––V-2 199

Data sheet M1 to M13 200


166

SECTION – V


5.1 SCOPE

5.1.1 This section of the specifications covers the design, manufacture, tests at

works, supply, delivery at site, erection, testing at site and commissioning of

1 (One) No. horizontal Pelton type hydraulic turbine and associated auxiliary

and ancillary equipment, main inlet valve, equipment for auxiliary systems

such as compressed air system, Cooling water system, drainage &

dewatering system, lubrication system, oil, water and air piping with valves

and fittings, instrumentation, controls and safety devices(as required),

necessary LT power, control, measurement & data cables, cable trays, tray

supporting arrangement, Spares for five year operation of the plant, special

tools etc., as described and detailed in the specification and listed in the

schedule of requirements.

The scope includes model testing including preparation of model and

field efficiency tests of prototype in accordance with relevant IEC test code.

The scope of supply shall include all parts, accessories, and spares etc.,

which are essential for construction, operation and maintenance of the

complete prime mover even though these are not individually or specifically

stated or enumerated. The turbine manufacturer shall co-ordinate with the

generator supplier so that the generator to be coupled to the turbine is

matched in respect of speed, runaway speed, moment of inertia, overload

capacities, coupling and other relevant requirements.

5.1.2 The turbine and generator unit shall match in respect of speed, over-

pressure, over-speed and runaway speed, moment of inertia, outputs,

coupling and other requirements.

5.2 TYPE AND RATING:

The turbine shall be of the Horizontal shaft Pelton type. The direction of

rotation shall be counter clock-wise when viewed from generator/drive end.

The turbine shall be capable of giving output higher than rated output to


167

match the overload capability of the generator..

Number of units : 1 No.

Type : Horizontal shaft single stage Pelton type turbine

and suitable for direct coupling with the generator.

The hydraulic data in respect of reservoir and the other data regarding

water conductor system is as follows.

LEVELS

A Minimum Draw Down level (m) 579.11 EL

B Full Reservoir water level (m) 602.00 EL

C Maximum tail water level 190.00 EL (tentative)

D Minimum tail water level 189.00 EL (tentative)

E Design discharge 3.12 m3/sec

G Nozzle level (m) 190.00 EL

H High Flood level of river (m) 187.52 EL

I Total Head loss due to friction 1.91 m

K Rated head (Design) (m) 402 m

The specific speed of the turbine shall be as per the best

modern practice and of proven design and operation.

The tentative layouts of the powerhouse shall be given by the bidder. The

turbine shall be designed to give a rated output of 12222 kW at rated head

with nozzle opening of about 80-85 percent. The turbine shall have adequate


168

capacity commensurate with the 10 % continuous overload capacity of the

generator. The turbine would have output higher than the rated output when

operating at heads higher than the rated head. During monsoon season more

discharge will be available. The capacity of the turbine shall be suitable for

smooth operation to give higher output at rated net head when higher

discharges are available The supplier may offer his nearest standard design.

The maximum output both at maximum and minimum heads shall be stated in

the offer.

In case of failure of governor or D.C.supply a positive device/arrangements

shall be provided to cut off the water supply to turbine bring the machine

immediately to stand still without any damage to generating unit or the

foundation.

The bidder should explain in his bid about the device/arrangement

proposed by him to achieve the above special requirement along with write /

up and the drawing of the same.

5.3 GUARANTEES VIS-À-VIS LIQUIDATED DAMAGES:-

GENERAL:

The supplier shall guarantee that the turbine in its entirety, including all related

equipment, material and structure furnished under this specification will be

free from defects in design, material and workmanship. The Supplier shall

warrant the successful operation of all such equipment.

i) Performance guarantees:

The meaning assigned to various performance guarantees shall be according

to IEC 41(1991), IEC 193(1965), IEC 193A(1972), IEC308(1970), IEC

609(1978), IEC 545(1976), IEC 994(1991), and IEC 995(1991).

ii) Turbine output and efficiency guarantee:

The rated output of the turbine at rated head shall be stated and guaranteed.

The efficiency of the turbine at rated head, maximum head, and minimum

head for 105%, 100%, 95% rated output shall also be guaranteed. These

figures shall be applicable for purpose of liquidated damages, rejection limits

and bid evaluation. In addition, the output of the turbine at full nozzle opening


169

at net head and rated head shall be stated in the bid.

The supplier shall state and guarantee the weighted average efficiency value

and shall furnish the estimated values of efficiency, nozzle opening and

discharge in a tabular form enclosed in data sheets.

iii) Weighted average efficiency

The weighted average efficiency of the prototype turbine shall be determined

from the field test or model test values of efficiency at rated head in

accordance with the following formula for purpose of penalty and rejection

limit and bid evaluation.

Tµav =k1 x Tµ105 +k2 xTµ100+ k3 x Tµ95

Where Tµav Weighted average efficiency of the turbine, Tµ105, Tµ100 and

Tµ95 are efficiencies of turbine at 105%, 100% and 95% of rated output at

rated head respectively. The value of k1, k2 and k3 are to be decided as per

working table and discharge dependability..

The weighted average efficiency chart is given in data sheet. The

bidder shall submit the values.

iv) Rejection limit

The purchaser has the right to reject the turbine if the test value of

either weighted average efficiency or the rated output is less than the

corresponding guaranteed value by 2(two) percent or more after allowing

tolerance in computation of efficiency.

v) Rectification to meet guarantees

The contractor shall be given mutually agreed time to improve/modify

the design of turbine or to carry out rectifications, etc., as may be required so

that the guarantees are met in case the tests prove unsuccessful in meeting

the guarantees. If the second meeting is also unsuccessful, penalty or

rejection of the equipment, as the case may be, shall be applied. However, no

delay in the original delivery schedule shall be allowed if the model test

results do not meet the guarantees and rectifications are made by the

contractor thereafter within a mutually agreed period as stated above.


170

vi) Pitting

The bidder shall guarantee the runner against excessive pitting for 24

months from the date of commissioning or 5000 hours of operation,

whichever is more. If the 24 months of guarantee period expires before

completion of 5000 hours of operation, the guarantee shall apply to the actual

hours of operation proportionately. Excessive pitting shall be defined as the

removal of metal from the runner of a weight of W= 0.15 D² per 1000 hours

of operation, where, D = Discharge diameter of the runner and W = weight in

Kg. Checking of this guarantee shall be as per IEC 609

In case of pitting exceeding the guarantee, the turbine supplier shall, at

his cost, take corrective measures such as modification of design, finish,

replacement, repair, etc., and the turbine after modification, etc. shall be

subject to guarantee as for the original equipment. In determining whether or

not excessive pitting has occurred metal removal by erosion, corrosion or by

the presence of injurious elements in water, etc., shall be excluded.

vii) Maximum momentary overspeed:

The supplier shall guarantee that the maximum momentary over speed under

most unfavourable transient conditions according to IEC 41(1991), sub-clause

2.3.4.14 will not exceed 1.50 times the rated operating speed.

viii) Maximum steady state runaway speed :

The Supplier shall guarantee that the maximum steady state runaway speed

according to IEC 41(1991), sub-clause 2.3.4.15 will not exceed 1.70 times

rated speed.

ix) Maximum/minimum momentary pressure:

The supplier shall guarantee that the maximum and the minimum momentary

pressure under most unfavourable transient conditions according to IEC

41(1991), sub-clause 2.3.5.7 shall not exceed guaranteed values of data

sheets.


171

x) Vibration amplitude:

The amplitude (zero to peak) of vibration according to Rathbone chart shall

be less than 75 µm (microns). Should for any reason the above limit exceed,

the supplier shall take at his own cost, all steps to remedy the situation and to

reduce the vibration to the above-stated limits.

xi) Noise level:

When units are in operation at most unfavourable conditions in any mode,

noise level measured in the turbine housing shall not exceed 90 dB(A).

Further, the maximum noise level, on the turbine and generator floor levels at

a point outside barrel shall not exceed 90 dB(A).

xii) Resonance:

The supplier shall guarantee that turbine is capable of operating continuously

and smoothly without hunting in the entire operating range. The supplier shall

confirm that the turbine design is such that the power pulsation at generator

terminal is within ±1.5% at full load and ± 5% at partial load of actual rated

output.

5.4 Liquidated damages for failure to meet performance guarantee:

The Supplier shall submit model test previously conducted for to ascertain

guaranteed performance values, the model tests results would form basis for

acceptance. The guarantees at the discretion of Purchaser shall be subject to

verification by field tests. If the field tests are conducted for final acceptance

and for arriving of liquidated damages non-conformity with guaranteed values,

field tests will prevail. The testing protocol shall be as per IEC and the

method of testing shall be Thermo-dynamic method and performance

particulars would be established. The cost of performance of such tests shall

be to the supplier’s account. Charges for conducting field tests by thermo-

dynamic method shall be indicated distinctly and separately in the price

schedules of bid .The supplier shall account for the layout of water conductor

system so that no arguments/disputes shall be raised. If the results obtained

during these tests differ from those guaranteed by the supplier he shall pay

the liquidated damages as per the provisions stipulated in Annexure III-2 of


172

Volume I. The Supplier shall have to establish the data guaranteed by him in

respect of energy generated.

If the goods under the contract fail to meet the performance

guarantees, the supplier shall agree to pay to purchaser as liquidated

damages as per the provisions stipulated Annexure III-2 of Volume I of

Commercial terms and conditions of contract . The liquidated damages for

output and efficiency shall be computed separately and the total amount of

penalty shall be the sum of these two. No tolerance shall be permissible over

the test figures of rated output. In case of efficiency, tolerance will be allowed

as per appropriate IEC test code. The ceiling on the total amount of penalty

on account of shortfall in the weighted average efficiency and output shall be

10% of the total unit price of turbine and governing system

5.5 MODEL TEST

Model test shall be carried out and the rates for model test as per relevant

standards shall be quoted separately. The performance of the model tests

shall be as per IEC standards 193 and 193A in all respects. The model shall

be truly homologous and shall include the hydraulic parts from outlet of

spherical valve including the connection pipes, nozzle and runner. Hydraulic

performance tests shall be made at various nozzle openings percentage to

determine machine characteristics including regimes of safe operations,

zones of cavitation and vibration, etc. The phenomenon of cavitations and

vibration shall be specially investigated. These tests shall include

determination of capacity, cavitation limits, hydraulic thrust, runaway speed,

etc., and such other details as covered in IEC 193 and 193A. Prototype

efficiencies shall be derived from model tests as contained in IEC 193 for

Pelton turbines. Model tests shall simulate all possible normal operating

conditions of the prototype for entire range of forebay / reservoir and tailrace

levels.

The bidder shall clearly mention the time within which the model tests

including manufacture of a new model, if required, will be completed. The

delivery schedule given by the bidder shall be reckoned from the date of

approval of model tests or model test report or from the time of permission to

proceed with the prototype manufacture. The contract price shall include


173

charges of model test and all expenses including to & fro air/first class

Railway travel and accommodation of three (3) representatives of Purchaser

for witnessing the test.

MEASUREMENTS:

Measurement of efficiency, power output and corresponding discharge for

each of the nozzle opening position corresponding to 100%, 95%, 90%,

80%, 50%, 35%, 20% of the nozzle opening.

* Further, all these tests shall be conducted for operation at maximum net head,

the rated net head and the minimum net head.

* Measurement of turbine runaway characteristics under most unfavourable

conditions.

* Determination of the turbine cavitations characteristics i.e. efficiency Vs

cavitations co-efficient relationship.

* Determination of the zone of stable operation in turbine mode between 35%

and 100% of nozzle opening position at minimum net head, rated net head

and maximum net head and the influence of air admission at part load

operation.

* Power pulsations at the shaft.

* Determination of axial hydraulic thrust and axial displacement of the shaft for

various nozzle openings and different heads.

* Measurement of nozzle torque under abnormal transient conditions.

* Determination of the magnitude and frequency of radial forces on the turbine

bearing during starting, stopping and running at runaway conditions.

* No load operation.

MODEL ACCEPTANCE

Within two months after the receipt of the final model test report, the

purchaser shall communicate his approval of the model to the supplier.

Should the model fail to meet the guarantees and other requirements, the

purchaser shall direct the supplier to modify the model until it complies with

the requirements. The supplier shall make good the deficiencies and conduct

(repeat) the model testing programme. All expenses involved for the

modification and subsequent model tests shall be borne by the supplier.


174

No delay, however shall be allowed in the original delivery schedule

due to any reasons on account of model testing process. The rejection shall

be applicable if the second attempt is also unsuccessful in meeting the

guarantees.

5.6 FIELD TEST AND ACCEPTANCE

Only the tests regarding output, vibration, noise, temperature-rise, stable

operation, losses, over speed and over pressure, shall be conducted to verify

the guaranteed performances. The guarantees at the discretion of the

Purchaser shall be subject to verification of the prototype by field tests.

Charges for field test shall be shown separately. If the field tests are decided

to be done for final acceptance, for arriving at the liquidated damages for non-

conformity with guaranteed values, field tests will prevail. Provisions for

discharge measurements required to be adopted for field test shall be

included in the cost of bid.

No bonus will be given to supplier in case of better results however Purchaser

reserve the rights to reject the equipment in case of failure to meet the

guaranteed values in variation is more than 3 %.

5.7 DETAILED CONSTRUCTION SPECIFICATIONS OF COMPONENTS OF

TURBINE

The turbine shall be constructed as to allow all the removable parts to

be dismantled conveniently. The design shall also permit removal of rotating

parts without disturbing the deflector-nozzle assembles. The design shall also

permit horizontal movement of runner shaft by an amount sufficient for

adjustment of bearings and for clearing the joint at the coupling between the

turbine and the generator.

i) Runner

The runner shall be of 13/4 chromium-nickel stainless steel. The

composition of the material and the source of runner casting shall be stated in

the bid. The runner shall be cast integrally of stainless steel. The runner will

have adequate number of buckets which shall be polished and ground

smooth and shall be free from roughness, cracks, high spots, etc. The


175

finished machine and ground runner shall be dynamically balanced in the

works before dispatch. Mounting of runner on extended generator shaft (if

offered by any bidder) shall be allowed.

The runner buckets shall be evenly and symmetrically spaced. The surface

of the runner in contact with water shall be ground to a smooth finish so as to

achieve surface without any humps or hollows. The runner band, the crown

and shaft coupling surfaces shall be accurately machined and ground. If

required these records shall be made available to purchaser on request.

Runner and turbine shaft shall be connected by coupling. To facilitate

replacement of runner in future and interchange ability, connecting parts shall

be accurately finished and use of template and keys shall be provided.

Connecting bolts shall be suitably covered to minimise resistance when

rotating in water. The runner shall be designed to withstand safely the

dynamic stresses at maximum runaway speed. The supplier shall provide

complete arrangement of runner removal .

ii) Shaft and Coupling

Mounting of runner on extended generator shaft (if offered by any

bidder) shall be allowed. The turbine shaft shall be forged carbon steel or

alloy steel conforming to IS or other equivalent international standards.

Wherever the flanges are integral with the shaft, the same should conform to

American standard ANSI-49.1, 1967. The turbine shaft shall be connected to

the runner on one side and to the generator shaft on the other side. It shall be

of ample size to transmit torque at rated speed without excessive vibration or

any distortion. It shall be provided with integrally forged coupling flanges for

connecting to the generator shaft and to the runner. It shall be of ample size

to operate at any speed up to the maximum runaway speed without

detrimental vibration or distortion and to transmit the maximum output. The

maximum stress induced under such abnormal condition shall not exceed

67% of the yield point stress. Besides, the shaft shall be designed to

withstand safely the shocks and abnormal stress induced under conditions of

line to line short circuit, faulty synchronising and turbine trip-outs without

harmful vibrations or distortions.


176

The shaft system shall be designed so that the first critical speed shall be at

least 1.25 times the maximum steady state runaway speed, which may occur

under most unfavourable transient conditions of turbine. The shaft shall be

accurately machined all over and polished smooth in the portions where

turbine bearing is fitted such that surface finish is within 0.4 microns. The

amount of shaft run out shall be checked by rotating the finished turbine shaft

in a lathe or lining device in factory. The turbine - generator shaft coupling

shall be designed in accordance with ANSI B 49.1 The turbine supplier shall

be responsible for the final reaming of the coupling bolt holes, aligning of the

turbine and generator shaft and conducting the combined run-out to NEMA

Standard No. MG-5.1-3.04 (R 1979). The field alignment procedure for shaft

and bearings shall be approved by the Purchaser prior to the start of

assembly. Under the conditions of rotational test, the run outs at the turbine

bearing shall not exceed 0.10 microns per meter length of shaft between the

generator bearing and the turbine bearing. Hydraulic jack for pre-stressing of

shaft couplings bolts, head cover & bottom ring shall be provided.

iii) Bearings

The turbine bearings shall be pad / segment type, oil lubricated either self-

lubrication or forced lubrication type.

The turbine shall be provided with adequate number of bearings. The

bearings shall be provided with a dial type or resistance type thermometer

and a pressure gauge with provision for alarm annunciation/shut down on

excessive bearing temperatures. The turbine bearing shall be provided with

H.S. Lubrication (if required). The number and type of bearings shall be

stated in the bid. These bearings shall be guaranteed for a minimum

continuous operation of 100,000 (One Hundred Thousand) hours and the

design and performance shall be well proven and established.

Further the bearing shall be designed to operate satisfactory (i.e. without any

damage) under following conditions:

* Continuous operation at any speed between 30% and 110% of rated speed at

no load and maximum load.

* For 15 minutes at maximum runaway speed.


177

* For 15 minutes, upon sudden rejection of maximum power and in

continuation thereafter till the unit comes to standstill as a result of tripping

and interruption of cooling water supply.

The bearing area and the bearing oil reservoir capacity shall be such that

temperature shall not exceed 70oC under worst conditions of operations.

The bearing shall be located as near to runner as possible consistent with the

distance assumed in shaft system analysis and keeping in view the space

required for accessibility and maintenance. The mechanical design of the

bearing shall take into account the abnormal radial forces during starting,

stopping, trip-outs and running at runaway speed of the unit and also provide

axial movement of the shaft. The method of construction shall be fully

described in the bid. The bearing design shall prevent the leakage of oil down

along the shaft. Piping for filling oil in the bearing and reservoir shall be

separate from the drain piping.

The supplier shall supply and install the following indicating and protection

devices for bearing.

- One dial type thermometer to indicate the hottest part of the bearing.

The thermometer shall have two (2) sets of separately adjustable contact

suitable for operating alarm and tripping circuits at 220 V D.C. The

thermometer indicator shall be mounted in governor panel.

- The resistance temperature detectors R.T.D (Pt 100 Ohms at 0oC). One for

bearing segment and one for oil indication and recording the temperatures at

unit control board.

- One direct reading water flow meter with two electrical contacts (suitable for

operation at 220V D.C. for signalling low cooling water supply / stoppage of

cooling water supply.

- One oil level gauge properly graduated marked in litres and high and low level

adjustable alarm contacts with 220V D.C. contact rating.

All thermometer bulbs and detectors shall be installed in dry walls.

iv) Shaft Gland

The shaft gland shall be of the stuffing box/carbon ring type with self-

lubricated packing and lantern ring. Any other suitable type of shaft gland will

also be considered. The gland shall effectively prevent leakage of water along


178

the shaft under all operating conditions and at standstill and prevent entry of

air. A stainless steel sleeve shall be provided on the shaft where it passes

through the gland. Arrangement for providing clean water supply to the gland,

if required, shall be made by the contractor.

v) Turbine housing

The turbine housing shall be cast fabricated in low alloy Mn. Steel in two parts

– upper and lower. The wall thickness shall be sufficient to ensure adequate

rigidity. Adequately sized air admittance piping enabling the turbine to draw

air from atmosphere shall be provided. Turbine housing shall be equipped

with the necessary lugs to facilitate easy handling by a hoist / crane.

Necessary foundation shall be provided for securing the housing on turbine

floor. Turbine housing and generator stator shall be supported on a common

foundation frame. The bearings of turbine and generator shall be aligned in

manufacturing shop. Brief description along with tolerances in location and

plan, provisions for concrete placement and grouting, details of connections

(e.g. turbine pit drain, test connections etc), erection support and handling

devices etc. Type of material for its fabrication quoting relevant ISS.

Brief description, design pressure, dismantling joint, material for fabrication

quoting relevant Indian Standard, protective quoting, tolerance in plan &

elevation, details of connection and erection support and handling devices

shall be given

vi) Branch pipes (including intake and nozzle pipe)

General description of branch pipe, type of material for fabrication quoting

relevant Indian Standard, no. of jets, design pressure, test pressure,

protective quoting, erection supports and handling devices shall be given

.Besides, details of turbine inlet connections and other connection (eg. Brake

jet, cooling water etc.) with tolerances, access for inspection, description of all

indications, test connections shall also be given.

vii) Turbine cover

Type of material for fabrication, its location on turbine housing or on pit floor.

The cover should be strong but dismountable as it is meant for service access


179

to the runner. Special loading conditions, if any protective coating shall be

given.

viii) Nozzle and deflector assembly

Nozzles shall be of the straight-flow type with internal hydraulic servomotors.

Adequate adjusting rings shall be provided for each nozzle to ensure correct

alignment of the nozzles. The needles shall have self-closing tendency due to

penstock pressure and spring action. Needle servomotors shall be double

acting hydraulic jacks with spring assistance. The needle tips and seat ring

will be made of erosion resistant stainless steel. Jet deflectors shall be

provided on each nozzle and shall be regulated by governor. The nozzle body

will be adequately reinforced to support the jet deflector. The deflector and

the supports will be designed to prevent any harmful vibrations during

operation, including complete load rejection and to ensure that no deflector

can contact the runner in the event of operating mechanism breakdown. The

deflectors will be of rigid design integrally cast or forged in 13 Cr 4 Ni, erosion

and cavitations resistant stainless steel. Each deflector will turn on a shaft of

stainless steel, supported in two self lubricating type bearings. All

components of the deflector will be inside the turbine housing and shall be of

corrosion resistant materials. Each deflector shall be provided with an

external position indicator. The deflector servomotors will be double-acting,

hydraulically operated on opening, but closed by spring action. The

servomotors will have sufficient capacity to operate the deflectors under all

conditions of operation and to move them through full opening or closing

stroke in the minimum time specified. The servomotors will be equipped with

a mechanical position feedback mechanism, for connecting to the governor

restoring mechanism.

ix) Brake jet assembly

Turbine will be fitted with one nozzle intended to emit a brake jet, to be

automatically operated during shutdown of the turbine. The brake nozzle will

be fed from a pipe tapped from penstock upstream of the turbine inlet valve

with a manual shutoff valve for maintenance. The operation of brake jet shall


180

be controlled through a solenoid operated control valve with over riding

manual operation facility.

x) Speed Signal Generator (SSG)

A toothed wheel type speed signal generator shall feed speed signal to the

governor electronic circuits for speed regulation and operation of speed

relays. The toothed wheel shall be mounted on the shaft and two magnetic

pick-ups shall be mounted near the toothed wheel. One of the two pickups will

work as redundant. The output signal of the magnetic pick-up shall be fed to

the governor electronic cubicle.

xi) Over Speed Device

A centrifugal type over speed protection device with provisions for electrical/

mechanical tripping shall be mounted on the turbine shaft (outside the turbine

housing). The tripping points shall be adjustable independently for speed

higher than the maximum speed; the turbine can develop with loss of full load.

The mechanical tripping device shall directly actuate the governor actuator

shut-down valve through a hydraulic connection. The electrical tripping

contact shall be wired to the turbine terminal cubicle. The rotating parts of the

over speed protection shall be protected by a guard.

5.8 GOVERNING SYSTEM

Turbine shall be provided with electronic PID governor to control the turbine

during starting, stopping and operation at any load. The governor shall be of

proven design capable of controlling speed / output under all operating

conditions. The governing system shall comprise oil pressure system,

governor actuator (Mechanical), governor electronic regulator, speed signal

generator, oil pipe lines and deflector position restoring mechanism. The

electronic regulating functions of governor i.e., speed / nozzle setting,

deflector limit setting, start, stop, main circuit breaker position, shutdown etc.

shall be operate the unit in manual mode in case governor electronic

regulator is non-operative. Local control unit have the indicators for deflector

position, speed of the unit and power generated by the unit.


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5.8.1 The governor system should have following qualities:

i) Fast acting

ii) Stable (No hunting).

iii) Reliable

iv) High sensitivity.

v) Easy control.

The governing system shall be designed to perform the following

functions.

1) Unit start-up.

2) Idling and synchronisation

3) Normal stopping and emergency shut-down with necessary

monitoring and safety functions, and

In addition the governing system must allow the operation of the unit either in

‘frequency control’ (i.e. speed governing) function or in ‘output control’

function. In ‘frequency control’ function, the frequency (and therefore the

operating speed) shall be maintained at set point, when the unit is in isolated

operation or in idling mode. In output control function, the power output of the

unit shall be maintained at set point.

Configuration

The governing system comprising of oil pressure system, the hydro

mechanical cabinet (HMC) i.e. actuator and the electronics shall divide

functionally so as to achieve, “Local” i.e. ‘Manual Control’ or remote control of

the unit.

The manual control shall be directly from the HMC i.e. actuator cabinet. The

remote control shall be from station control room by means of operator

console and programmable logic controller.

Speed and pressure regulations:

The maximum momentary speed rise caused by sudden rejection of the rated

output under the normal head shall not exceed 1.50 times of the normal

speed, when coupled with the generator.

The maximum momentary pressure caused by sudden rejection of any load

at any operating head shall not exceed 700m.


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Performance

The speed governor shall be of such structure that assures stable and reliable

operation, high sensitivity and easy control operation. At any load it shall

regulate the turbine to a uniform speed free from hunting or racing. The

speed governor shall be so arranged that the speed adjusting and load

limiting operations can be carried out by both the remote control by the

operating handles provided to the control board in the control room and the

local operation by the operating handles provided to the speed governor

cabinet or regulator board.

Pressure oil for operation of the speed governor shall be supplied from the oil

pressure supply system described hereafter in this section.

All hand controls shall be clearly and concisely marked as to purpose. The

speed governor shall have the following facilities and performance.

1) Speed adjusting range 85 - 105%

2) Adjusting range of permanent droop 0 - 6%

3) Adjusting range of incremental

momentary speed droop 0 - 50%

4) Adjusting range of time constant

of damping 0 - 15 sec

5) Governor dead band 0. 02%

6) Nozzle setting operation

The speed governor shall be capable of nozzle setting operation by the load

limiting device and will be capable of easily changing over from automatic

operation to nozzle setting operation or vice versa.

7) Nozzle opening regulating device

This device shall be capable of the following control.

a) Starting control.

b) Control of maximum output. The water level detector for the

upper reservoirs and tailrace required for the above shall be supplied

by contractor.

8) Protective device:

The protective device shall be capable of fully closing the nozzle in case that

a trouble occurs in the speed governor and shall stop the turbine quickly.


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5.8.2 Both the speed control governor and power output governor shall actuate the

same servo-positioner through the opening set point.

5.8.3 The electronic PID controller’s behaviour shall be enhanced by special means

such as disturbance super position and secondary variable super position.

Speed sensing :

The speed sensing for governor operation shall be taken from toothed disc

method or via transducers using residual remainance.

5.8.4 MANUAL CONTROL

Manual control of setting of turbine power directly via the actuators by-passing

the governor control loop shall be provided. In that case, the safety of unit

shall rest with over speed protection.

5.8.5 FOLLOW - UP CONTROLS

To achieve bump-free transition from one operational mode to another

following follow-up controls shall be provided:

i) The power output governor command signal shall follow the actual

power output signal in the speed control mode.

ii) The speed command signal shall follow the actual frequency-signal in

the power output control mode or during the start up phase (speed

command signal pre-adjustment).

iii) The manual control set point shall follow the actual actuator position in

the various control modes.

iv) In case of remote control, respective local control shall follow the

respective command signals.

v) It shall be possible to adjust the pre-opening of varying heads to

minimise start up times.

a) GOVERNOR REGULATOR

The speed sensing shall be achieved through speed signal generator and line

PT. The governor shall control, with stability, the turbine at any speed

between 85 and 105% of rated speed when operating isolated from the

system and while connected to the system at any load between zero and the

load corresponding to maximum opening of the nozzles with both nozzles


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operating. Partial Shutdown/Controlled Action Shutdown device shall be used

for automatically shutting down the turbine to the speed-no-load position by

the operation of certain protective devices. It should be possible to operate

deflector position manually at the local control unit.

b) GOVERNOR ACTUATOR

Governor actuator shall have the following provisions :

• Adequate capacity to operate the deflector servomotor and the needles

through complete opening or closing strokes in desired time under all

operating conditions.

• Hand control device for stroking of deflectors followed by needles so as to

operate the machines manually even if electronic regulator is non-functional.

• Relationship between deflector position and needle stroke may be achieved

through mechanical linkage utilizing a cam. Necessary data for relationship

between deflector opening and needle stroke shall be given by turbine

designer to the governor manufacturer. It should be possible to control the

needles for off-cam position.

• Emergency shut down device, which can be operated manually at the

actuator.

• Auto - clean double element filter to ensure that clean oil is supplied to

control valves. The change over to standby filter and cleaning of clogged filter

must be possible while unit is under operation.

• Means of independent adjustment of the opening and closing times of the

deflectors and needles. The time for deflector closing under full load throw off

shall be adjustable to limit the speed rise and pressure rise within guaranteed

values.

c) SERVOMOTORS

Turbine shall be provided with two (2) Nos. oil pressure operated hydraulic

servomotors. The capacity of the servomotors shall be sufficient to supply the

maximum force necessary to operate and hold the nozzles at any desired

position at the minimum oil pressure.

Further, the servomotors shall be rigidly supported and shall be capable of

moving the nozzles from a completely closed position to a fully open position


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in one stroke and vice versa. Cushioning shall be provided in the last ten

percent (10%) of the stroke in each direction. The servomotor cylinders shall

be provided with flanges for connecting oil piping. Connection for pressure

gauges shall be provided at each end of each cylinder. An air vent and a

drain cock shall be provided on each servomotor for draining purpose. The

inner surface of the cylinder shall be bored accurately to a uniform diameter.

The surface finish shall be such that roughness shall be within 1.6 micron.

The piston fitting shall be such as to allow the piston to travel, freely and

smoothly but to reduce oil leakage past the piston to an absolute minimum.

Chevron type packing shall be used for this purpose. Each piston shall be

fitted with not less than three piston rings, suitably shaped to give close

contact and uniform pressure on the cylinder walls.

The servomotor piston rod shall be provided with lubricated bearings.

Lubrication shall be arranged to ensure that lubricant is admitted to high

pressure areas regardless of vane position. This piston rod shall be arranged

for adjustment of stroke. The connecting rod shall be of forged steel and of

uniform cross section. A specially designed and a strong joint using

accurately ground pin of hardened steel shall be provided between piston rod

and connecting rod. The joint shall be provided with greaseless bearings of

self-lubricating type.

Provision shall be made for adequate field alignment of the servomotors using

levelling or dutchmen (shim) plates supplied by manufacturer. The

servomotor flange shall be dowelled in the field to its mounting flange.

A manual locking device of a simple construction to permit locking in the fully

open and closed positions and capable of withstanding safely the full

operating force of the servomotors shall be provided at the servomotors. The

device shall be such that it can be easily engaged and disengaged by one

man. Besides, limit switches (with electrical contacts suitable for operating on

220 V D.C. system ) shall be provided, to indicate the fully open and fully

closed positions of the nozzles and for using in the control circuit as interlocks

for starting the unit. All contacts shall be wired up to terminal box .

By-pass connections, equipped with orifices and/or adjustable needle valves,

with a secure means of locking the adjustment, shall be provided on the


186

servomotors to retard connections shall be fitted with check valves to prevent

sluggish movement during opening the nozzles from the fully closed position.

A suitable pointer and graduated scale shall be provided to indicate the stroke

of the servomotor (i.e. % opening from the closed position) in steps of 5 %.

The scales shall be calibrated in the field and marked “closed” at one end of

the scale and “opened” at the other end. The servomotor stroke must be

capable of manual adjustment. Means for positively locking the adjustment

must be provided.

Servomotor cylinders and all the oil piping and valves in the system shall be

shop tested to a pressure equal to 150% of the design pressure of the oil

system.

5.9 PENSTOCK DRAINAGE SYSTEM

Necessary piping with fittings and steel Nozzle valves shall be supplied

for draining the penstock into tail race channel.

5.10 WATER LEVEL MEASURING & TRANSMITTING DEVICE

Scope of Supply

Water level measuring & transmitting device for intake and tail race channel

shall comprise of the following :

• Level transducer with transmitting device for intake with complete mounting

arrangement,

• Level transducer with transmitting device for tail race with complete

mounting arrangement,

• Water level signals receiving and processing device with mounting

arrangement,

• Interconnecting cables between sensors, transmitters and control unit.

General Design and Constructional Requirements :

i) For monitoring water level upstream of intake Nozzles, one set of suitable

electronic level sensor ( strain gauge or capacitance type ) and transmitter

unit shall be provided for transmitting the water level signal to controlling unit

mounted in control & metering panels in control room. One set of identical

level sensor and transmitter unit shall be provided for water level in tail race.


187

The signals from both the units shall be analogue signals in the form of 4 to

20 mA. These signals shall be processed in centralized control unit.

Necessary power supply to sensors and transmitting units shall be provided

from control unit.

ii) Output signals for Surge Tank level, tail race level and their difference shall

be provided from the control unit for further utilization in Governor electronic

cubicle and SCADA. Digital indictors shall be provided in the control unit for

indicating fore-bay level, tail race level and their difference i.e. gross head.

The device should be of reliable make.

iii) The level sensors shall be mounted inside a pipe in such a way that

oscillations in water level are damped out and pipe do not get clogged by

floating materials or silt etc. complete with mounting accessories.

iv) Level sensors should be hermitically sealed and it should be possible to

take out and calibrate them easily.

5.11 SPECIAL TOOLS, SLINGS, CONSUMABLES ETC.

* Tools and tackles required for handling bearings shall be provided.

* All tools required for assembling and dismantling bearing, seals,

rings, nozzles, links, shaft support collars etc shall be provided.

* Test equipments of all kinds, which are necessary for erection, testing

& commissioning at site shall be provided.

* All kinds of slings, tools, pressure test equipments, spanners, O & M

tools etc. shall be provided.

* metering for penstock water pressure

* Mechanical over speed device shall be provided by generator supplier.

Turbine supplier shall co-ordinate with respect to his requirements.

* Turbine junction boxes suitable for mounting on barrel wall outside.


188

* Control and power cables: Power cables for local control panels to

equipment, local control panels to unit control boards and up to

distribution centres provided by the purchaser shall be provided by the

supplier, control cables racks, cleating, ferrule, glands etc for entire

system of equipment covered under the scope of supply of the supplier

shall also be provided by the supplier.

* Oil, grease, lubricants sufficient for first filling and 25% spare

quantities.

* All accessories viz. sole plates, foundation & anchor bolts, platforms,

ladders, guards, handrail, bolts, nuts, turn buckles etc complete

including requirement for installation.

* Tools & Tackles for the turbine.

* Shaft seal with cooling water system complete including pressure

reducers, strainers, filters and plant to provide clean water.

* Turbine bearing of design with pads, oil coolers, Resistance

temperature detector (RTD’s) Dial type thermometers (DTT’s) etc. with

piping, valves etc.

* Thermometers, thermal relays, oil level gauges and relays, water

pressure gauges and relays etc. Gauges, temperature indicators etc. to

be mounted on unit control board covered under Electrical Lot.

Supplier of Mechanical and Electrical lot shall co-ordinate to include all

interfaces suitable of local/remote and auto operations of the system.

* Oil leakage system if needed (requirement shall be justified at bidding

stage) complete with tank, motor-pump sets, pipes, valves, level

switches, gauges etc.

All special tools, slings, lifting devices, jacks, turn buckles, foundation

plates/bolts, testing devices etc., required for erection and commissioning


189

of the equipments shall be listed and supplied. First filling of oil and grease

(if applicable) with 20% extra quantity shall be included in the offer and

supplied along with equipment. Welding electrodes as required for site

welding and paint for finishing coat shall be supplied by the contractor.

5.12 SPARES

Spares shall be supplied as per the list under Section - III of this volume.

.

5.13 TESTS

5.13.1 SHOP ASSEMBLY AND TESTS ( AT MANUFACTURING WORKS)

The Bidder shall submit the quality assurance plan indicating the tests

to be performed and witnessed by Purchaser and acceptance criteria for the

same. The Contractor shall get the quality assurance plan approved from

Purchaser as per Contract Conditions. For inspection and tests to be

witnessed by Purchaser, requirements elaborated in Conditions of Contract

shall be followed.

i) The following assembly and testing requirements in Contractor’s

works shall essentially be included in quality assurance plan :

• Deflector and Needle Servomotors – hydraulic testing, stroke checking,

minimum oil pressure required for movement and oil leakage past piston and

piston rod.

• Turbine Runner – Dimensional checks, bucket profile checking, casting

soundness tests, static and dynamic balancing.

• Deflector and Needle Assemblies: Free movement, minimum pressure

required for movement, and stroke relationship

• Complete assembly of turbine in the shop for matching

• Oil Pressure System – Performance testing of pumps, U/T of weld joints and

hydrostatic testing of pressure vessels.

• Governor – Assembly and complete performance testing as per relevant

IEC code

• Turbine Inlet Valve : Assembly, hydraulic testing and Operational tests


190

ii) Material Tests - Material tests for important components such as runner,

turbine shaft, deflector, needles, nozzles, deflector bushes, turbine housing,

bearing sleeve/shell and other important components shall be carried out as

per agreed quality assurance plan. Purchaser’s Engineer shall review the test

certificates during inspection.

iii) Tests on Bought out Components: All motors, pumps and compressors

etc. shall be tested as per relevant Indian Standards.

513.2 PRE-COMMISSIONING FIELD TESTS

a) Following measurements/tests in addition to tests recommended by

Contractor shall be included in quality plan for pre-commissioning tests :

• Characteristic - Servomotor stroke Vs Deflector Opening

• Characteristic – Deflector opening Vs Needle stroke

• Deflector and Needle opening and closing times and servomotor cushioning

time.

• Insulation Resistance Tests on all electrical motors as per relevant Indian

Standards

b) Operational tests on oil pressure system to verify :

• Setting of pressure relays for automatic control of pump

• Setting of pressure relay for emergency low pressure

• Test to verify pumps capacity

• Tests to verify number of close/open operations with oil pump not operating

c) The governor shall be assembled, adjusted and tested in the field for

optimum performance. Specifically, the following tests/checks will be

performed :

• Verify logic control scheme from local including start/stop, load control,

emergency shutdown, controlled action shutdown, locking and other feature

• Verify stability and response of governor during 10% to 20% step change in

load (acceptance and rejection or a combination of these).

• Verify setting range of permanent droop, on/off-line temporary speed droop,

derivative time constants, frequency dead band, speed setting limits, Nozzle

setting limits, no load Nozzle limit, speed relays etc.

5.13.3 COMMISSIONING TESTS


191

• Following commissioning tests shall invariably be included in tests

recommended by Supplier before putting the machine on 72 hours continuous

trial run prior to handing over of equipment to Purchaser:

• Logic control scheme from local/remote including start/stop, speed control,

load control, level control, emergency shutdown, controlled action shutdown

and other features,

• Automatic starting, stopping, synchronizing, loading and emergency shut down

by simulating emergency conditions,

• Checking the setting of over speed trip device by actually over speeding the

machine,

• Checking speed rise and pressure rise at 100% sudden load rejection of

generating unit. The Supplier shall carryout the commissioning test in

accordance with the agreed procedures.

• 72 hours continuous operation test: The turbines shall be tested for 72 hours

continuous operation to ensure trouble free from problems of leakage,

overheating, failures, damages, etc.

5.13.4 FIELD ACCEPTANCE TESTS

The turbines shall be tested at site for establishing fulfilment of guarantees in

respect of turbine output and efficiencies including weighted average efficiency.

The tests shall be carried out as per IEC 41 for Field Acceptance Tests of

hydraulic turbines. The arrangements for these tests will be made, including the

testing devices, by the Supplier.

5.13.5 Inspection for Pitting

It is to be ensured that operating records during guarantee period are properly

maintained. It is also to be verified that machines are operated within specified

range of output head and discharge.

After specified period of running of machine joint inspection is to be carried for

pitting and establishing that pitting is within limits and provisions of pitting

guarantee are met.


192

5.14 GUARANTEED TECHNICAL PARTICULARS

The bidder shall furnish all the data, information and other particulars called for

in the sheets at the end of section under data sheets.

5.15 ELECTRICAL EQUIPMENT

CABLES AND INTERFACES.

Cables from each auxiliary system equipments to its control panel (both of which are

included in supplier’s scope) shall be supplied and erected; cables for

interconnection between computers, computer based control panel shall also be

supplied and installed.

Turbine supplier shall co-ordinate with supplier of electrical lot in respect of

interfaces and cables needed for the system. All interfaces cables, racks, formula

glands, clamping and dressing arrangements for the equipment covered under

scope is included in the scope of supply. Supplier of mechanical lot shall confirm

that all these items are covered in scope of electrical lot or he shall provide the same

without extra cost.

FLOW METER CABLES.

All flow meter cables required between the transducers and electronic converters

shall be supplied.

INSTALLATION.

The flow meters, electronic converters and instruments shall be installed in an

approved manner so that operation is satisfactory and the accuracy requirements

are obtained.

CONTROL AND MONITORING DEVICES.

The instruments and devices shown for mounting other than local, shall be decided

in consultation with the suppliers of the respective board/panel mentioned in the

above said annexure. The control and monitoring devices shall include but not

limited to following:

1. Automatic operation control devices

a) Solenoid valves.

i) For opening and closing of the

inlet valve

ii) For starting and stopping of unit

iii) For the brake of the generator


193

The solenoids shall be so arranged that they do not remain continuously

energised in whichever case the unit is running or in standstill.

b) All necessary limit switches 1 set.

c) All necessary auxiliary relays 1 set.

d) All necessary relay valves 1 set.

e) All necessary piping and valves 1 set.

2. Turbine control Panel.

The turbine control panel shall be of cubicle type of steel plates and shall be

arranged in line with the speed governor cabinet. On the front of the turbine

control board, a name plate shall be mounted.

The turbine control board shall be capable of manual operation of the turbine and

auxiliaries such as flowing of cooling water opening and closing of the inlet valve

of the turbine, starting, stopping, and operation of the brake, etc. Manual

operation shall be of such type as to actuate the solenoid by operation of the

switches on the turbine control board individually. The control board shall house

the solenoid valves etc., shall be provided with the measuring instruments,

operation indicators, on the front surface and shall keep sufficient space so that

inspection and adjustment can be carried out easily. The turbine control board

shall comprise the following.

a) Control switch change-over switch 1 No.

(local-remote)

b) Manual operation switches for :

i) Solenoid valves for opening and

closing of the Spherical valve. 1 No.

ii) Solenoid valve for starting and

stopping of turbine. 1 No.

iii) Solenoid valve for the brake of the

generator 1 No

iv) Other solenoid valves housed in

turbine unit control board 1 set

v) Limit switches 1 set.

vi) Auxiliary relay. 1 set.


194

vii) Piping and valves. 1 set.

viii) Indicating lamps. 1 set.

c) Oil pressure relays :

i) For starting condition of turbine.

(operates when oil pressure for nozzles

operation is same as or higher than the

specified value.) 1 No.

ii) For alarm at oil pressure drop 1 No.

iii) For quick stop at operating oil

pressure drop 1 No.

iv) For start and stop of the stand by

oil pump 1 No.

v) For oil level control 1 No.

vi) For Actuator pressure. 1 No.

vii) Water pressure relay 1 No.

. d) Instruments :

i) Water pressure gauge for steel

lined shaft 1 No.

ii) Water pressure gauge for Nozzle 1 No.

iii) Pressure gauge for oil pressure

tank. 1 No.

iv) Dial thermometer for turbine

bearing 1 No.

v) Dial thermometer for

bearing of generator 1 No.

vi) Dial thermometer for lower guide

bearing of generator. 1 No.

vii) Dial thermometer for inlet and

outlet of each air cooler of

generator. 1 No.

viii) Sequence indicators. 1 set.


195

PUMP JUNCTION BOX AND ELECTRICAL ITEMS.

Supplier shall supply all the necessary switches, contactors, magnetic starters and

relays with the turbine and generator governor electrical auxiliaries according to this

sub section and the electrical lot of these specifications.

All electrical items supplied by supplier shall comply with the appropriate section of

IEC- Standards. Supplier shall provide and install terminal boxes in locations to be

approved by purchaser, and shall provide and install all wiring and conduit from his

electrical components to these terminal boxes. All electrical wiring and conduit

within the turbine housing, including wiring for pressure and flow switches,

temperature relays and thermometer, alarms shall be supplied by the supplier, and

shall terminate at terminal blocks in the turbine terminal box located in the turbine

housing and supplied by supplier. All wiring shall be stranded wire, insulated with

1000 V oil proof insulation. For turbine a common junction box shall be provided. All

controls, indications, alarms shall be brought by the supplier up to this junction box.

Supplier shall supply schematic diagrams, wiring diagrams of connections, outlined

drawings and catalogue numbers for all electrical components.

All circuits of schematic , wiring diagram and equipment shall be properly identified

and subject to approval by purchaser.

Supplier shall provide data on all electrical motors being supplied.

Alarm contacts shall be electrically separate and rated for a minimum interrupting

capacity of 0.5A, non - inactive and be suitable for voltages up to 250 V D.C.

5.16 STANDARDS.

Turbine and governing system shall be designed, manufactured and commissioned

to the latest I.E.C standard accepted standard practices. A few of the standards are

listed below but not limited to.

IEC-41/1991 Field acceptance tests.

IEC- 545 Commissioning procedure.

IEC-607 Thermodynamic method measuring.

IEC-609 Cavitations pitting evaluation.

IEC-193/1965,193-A/1972

and 995/1991 Scale model testing.

IEC-994/1991 Guide for field measurement.


196

ASME Tank and hydraulic cylinders.

IEC- 308 Governor testing.

ASME VIII,

ASME V

ASTMA 435

ASTMA 609, Welding materials

ASTMA 709 .

ASTMA A 388 and

IEC 404

ASME Boiler and pressure vessel code section VIII, Dim 2 Low cycle fatigue.

IEC- 34.9 Noise limits for electrical machines.

ISO- 1996 Noise measuring.

VDI-2056 Vibration limit.

ANNEXURE –V-1


AWARD OF CONTRACT.


197

Sr.

No

.

Brief description within months

from the date

of award of

contract

Remarks

1 2 3 4

1. Overall arrangement drawings,

schematic drawings describing and

illustrating the information of:

i Turbine runner 3 For approval

ii Nozzle assembly , Deflector assembly,

needle assembly, needle control

device, Servomotors

3 For approval

iii Brake jet assembly 3 For approval

iv Inlet valve 3 For approval

v Governor 4 For approval

vi Emergency closing device, return

motion gear,

4 For approval

vii Speed signal generator, over speed trip

device

4 For approval

viii Turbine Housing 4 For approval

ix Turbine shaft & coupling 4 For approval

x Shaft Gland 4 For approval

xi Penstock specials & branch pipes 4 For approval

xii Turbine Bearing 4 For approval

xiii Compressed Air System 4 For approval

xiv Drainage and dewatering system 4 For approval

xv Cooling water system 4 For approval

xvi Penstock drainage system 4 For approval

xvii Schematic drawings of oil pressure

system of MIV & Governor

4 For approval

2 Foundation drawing for turbine

housing, bearings, and other

mechanical equipments used for unit

5 For approval


198

3 Quality assurance plan 3 For approval

4 Quality assurance plan for tests at

supplier’s / vendor’s works indicating

customer hold points and acceptance

criteria.

3 For approval

5 Catalogues of pumps, valves and other

purchased items

6 For reference

6 Schedule of indicating and recording

instruments and safety devices

4 For approval

7 Tentative list of vendors for major

purchase items and instruments.

6 For reference

MANUALS.

1 2 3 4

1 Manual for storage, preservation

and handling of the supplied

goods

12 For reference

2 Manual for erection /

dismantling, testing and

commissioning of the supplied

goods

12 For reference

3 Manual giving operating

instructions for all the ‘DO’s and

‘DONT’s’

18 For reference

4 Manual giving detailed

maintenance schedule

18 For reference

ANNEXURE V-2




199

----------------------------------------------------------------------------------------------------


to clause in the

specification.

----------------------------------------------------------------------------------------------------

DATA SHEETS

DATA SHEETS M1 TO M13 FOR TECHNICAL SPECIFICATIONS OF


200

PELTON – TURBINE AND RELATED EQUIPMENT (THE BIDDER MUST FILL IN THIS DATA SHEETS COMPLETELY) Note : The indicated sign and the assigned meaning shall be as follows:

> no negative tolerance allowed < no positive tolerance allowed

(r). required value

(d) desired value (o) offered value (*) guaranteed values inclusive of tolerance.

Bidder’s Remark (if any) Water Levels for reference of bidders/suppliers (I) Reservoir

i) Full Reservoir Water Level - 602.00EL


201

ii) Minimum Draw Down Level - 579.11 EL

(II) Tail Race Channel

i) Maximum Water Level - 190.00 EL(Tentative)

ii) Minimum Water Level - 189.00 EL(Tentative) (III) Nozzle Level - 190.00EL (IV) Gross Heads

i) Maximum Gross Head - 412.00 m (602.00 -190.00)

ii) Minimum Gross Head- 389.11m

(579.11 -190.00) (V) Design Head

i) Gross Rated Head = Min. Head + 2/3 (Max.head – Min.head)

= 389.11 + 2/3 (412 – 389.11) = 389.11 + 15.26 = 404. 37

Say = 404.00 mtr

ii) Net rated Head = Design Head – head losses

= 404 -1.91 = 402.09

Say = 402.00 mtr.

iii) Max. rated head - 410.00 mtr.

iv) Min. rated Head- 387.00 mtr.

DATA SHEET –M1 Bidder’s Remark (if any) A) TURBINE SPEED, MECHANICAL OUTPUTS AND EFFICIENCIES:


202

1 - Rated turbine speed --------------(o)

nn = 500 rpm (d) 2 Direction of rotation

(seen from generator end) --------- (o) Counter Clockwise(d)

3. Guaranteed Output

(a) Guaranteed rated output at rated head. --------- (o)

(b) Guaranteed max. output at max. head. --------- (o)

(c) Guaranteed max. output at min. head. --------- (o)

4. Efficiency

Guaranteed efficiency at rated head for the

following outputs:

(a) 105% --------- (o)

(b) 100% --------- (o)

(c) 95% --------- (o)

5 Weighted Average Efficiency

(clause 5.3.1 of this vol.)

Tµav =k1 x Tµ105 +k2 xTµ100+ k3 x Tµ95

Where K1=0.30, K2=0.60 & k3=0.10 --------- (o)

DATA SHEET –M2 Bidder’s Remark (if any)


203

Load

Net head

‘m’

Max.

Head ‘m’

Rated

Head ‘m’

Minimum

Head ‘m’

Average

Efficiency

105% Output kW

Efficiency %

Nozzle Opening %

Discharge m3/sec

100% Output kW

Efficiency %

Nozzle Opening %

Discharge m3/sec

95% Output kW

Efficiency %

Nozzle Opening %

Discharge m3/sec

6 Speed

(a) Specific speed in M.K.W. units.

(b) (*) Maximum momentary over speed

under most unfavorable transient conditions : nm max =…rpm( o) [ nm max < 1.50 nn (d) ] (c) (*) Maximum steady state runaway Speed at Qmax and Hg max 412 m and suddenly load removed : nR max =…rpm (o) [nR max < 1.70 nn ( r )


7. Time of nozzle closing for regulation ------- secs.


204

in item (c) above

8. (a) Momentary drop in speed in increasing ------% of rated speed.

load from zero to full load

(b) Time of nozzle opening for regulation at (a) above ----- secs.

B. Factor of safety

(a) Guaranteed minimum factor of safety under worst

conditions based on yield point of the material.

(b) Name and location of the part having the

factor of safety in (a) above.

C. Maximum water hammer pressure --------- m

D. MOMENT OF INERTIA (J= mr2

)

Moment of inertia of generator rotating parts (according to generator designer ): : JG >…. tm

2 (o)

- Moment of inertia of turbine rotaing parts : JT >….tm

2 (o)

DATA SHEET –M4 Bidder’s Remark (if any) E) CLOSING AND OPENING LAWS


205

OF THE NOZZLE - Closing law: 100 % to 0 % : Tc =…. s ( o ) - Opening law

- 0 % to 100 % : To =…. s ( o ) - Emergency closure : Te =…..s ( o ) F) AXIAL TURBINE HYDRAULIC THRUST ON RUNNER.

- Maximum hydr. thrust on runner : F max =……kN ( o )

- Nominal hydr. thrust on runner : F n =……kN ( o ) - Minimum hydr. thrust on runner : F min =……kN ( o )

G) MASS OF ROTATION PARTS. - Mass of rotation part of generator ( according to generator designer ) : G g.r =……t ( o ) Mass of rotation part of turbine : G t.r =……t ( o ) DATA SHEET –M5 Bidder’s Remark (if any) H 1) TURBINE BEARINGS

- Type of bearing : ………………….(o)


206

[adjustable pad/segmental type self

lubricated bearing ( d ) ]

- Diameter of turbine bearing : d =………mm (o)

- Number of pads/segments : N =…………...(o)

- Circumferential length of pads/segments : L = ….mm (o)

- Axial length of pads/segments : b =….mm (o)

- Maximum temperature for oil film : =…..0C (o)

- Maximum temperature for Segment

( < 70 0C ( r )

: =…..0C (o)

Whether H.S. Lubrication is used (yes/no)

- Quantity of lubricated oil reservoir : =.. ….m3 (o)

- Quantity of cooling water (if required) : =……. 1/s (o)

- Total losses in bearing at rated load : = …. ….Kw (o)

- Permissible duration of operation of the

unit at rated load without supply of cooling

water.

: =…

Vibration limit of turbine bearing for

complete range of operation <75µm (r)

I GEOMETRICAL DESIGN DATA OF TURBINE RUNNER.

- runner diameter : Dia =…mm (o)

- Runner height : h2 =…mm (o)

- Number of runner buckets : z2 =………(o)

- Finished mass of runner : G2 =………t(o)

- Average surface roughness of runner

buckets

:

: Note:-Please attach runner drawing with

designed zones for roughness.


207

DATA SHEET –M6 Bidder’s Remark (if any) - Runner seal clearance in new condition

- runner crown seal ( clearance between

the runner crown and the turbine cover)

: c =….mm (o)

- Material of runner (stainless steel ) : …………(o)

- Method of attachment to shaft : …………... (o)

- Finished mass of one bucket : Go1 = .. …kg (o)

- Average surface roughness of buckets : Rou.o =…..m (o)

- Material of Buckets (stainless steel) : ……………..(o)

J SERVOMOTORS

- Number of servomotors : ns ……………. (o)

- Design oil Pressure ; Pd =…………Mpa(o)

- Operating oil pressure : Pomax =……..Mpa(o)

: Pomin =……..Mpa(o)

- Rated operating oil pressure, Tripping oil

pressure

; Pn =……....Mpa (o) :

Ptr =……....Mpa (o)

- Minimum required oil pressure : PR =……....Mpa(o)

Volume per servomotor

- - closing cylinder : Vc =……….m3

(o)

- opening cylinder : Vo =……….m3

(o)

- Inside diameter servomotor Ds =………mm

(o)

- Servomotor Force : F =………kNm (o)

- Stroke of servomotors : Y =………mm (o)

- Performance under major disturbances

- minimum servomotor closing time :Tf =………….s(o)

- Minimum servomotor opening time :Tg =………..s(o)

- cushioning time of servomotor : Th =………..s (o)

- Mass of one servomotor : Gs =………..s (o)


208

DATA SHEET –M7 Bidder’s Remark (if any) - Material of servomotors

-body : ………………. (o)

-piston : ……………… (o)

- Roughness of inner surface of cylinder <

1.6 micrometer

: ……………… (o)

K TURBINE SHAFT AND SHAFT GLAND

- Total length of turbine shaft : LT =………mm(o)

- Shaft diameter at turbine bearing : Ds =………mm(o)

- Hollow diameter : DH =………mm(o)

- Diameter of coupling flange , ; DC=……….mm(o)

- Type of coupling

- Mass of turbine shaft : Gs =………….t (o)

- Type of shaft : ………………. (o)

Quantity of cooling water for shaft gland

: =………………1/s (o)

Guaranteed life of shaft gland operating

hours > 20,000

: =……………..HRs (o)

L STARTING TIMES

- Standstill to synchornising including start

up of all auxiliaries and valves [< 300 s

(d)]

: <…………….s (o)

- Standstill to rated speed : <…………….s (o)

- No load to full load : <…………….s (o)

- Total time from stand still to full load : <…………….s (o)


209

DATA SHEET –M8

Bidder’s Remark (if any) M GOVERNING SYSTEM ( Hydraulic

turbine control system ) (according to IEC- 308/1970)

- Control of rotation speed : ………………. (o)

- Setting range of speed range : n =………….% (o)

- Setting range of permanent speed drop

[bp =0 to 10% (d) ]

: bp =…………% (o)

- Setting range of maximum stroke speed

drop

: bs =…………% (o)

- Setting range of temporary speed drop : bt =…………% (o)

- Proportional gain

[Kp = 0.6 to 10 (d) ]

: Kp =………….. (o)

- Derivative gain : Kv =………… (o)

- Speed dead band : ix =………… (o)

- Power output [ix /2< 2.10-2

(d) ] : ix/2 =………… (o)

- Admissible steady-state power output

pulsation (in relation to actual generator

output power [∆p < + 1.5% (d) ]

: ∆p < +………..% (o)

- Penstock reflection time : Tr =………… s (o)

N GOVERNOR PRESSURE OIL SYSTEM

FOR TURBINE

- Oil tank volume : v =………….m3 (o)

- Number of governor oil pumps : n =…………… (o)

- Governor oil pump discharge : Qoil =………1/s (o)

- Rated power of governor oil pump motor : Pn =……… kW (o)


210


- Rated speed of governor oil pump motor : nn =……….rpm (o)

- Number of pressure vessels per each

turbine

: nt =………….m3 (o)

- Total volume of pressure vessels : v t =………….m3 (o)

- Oil volume of pressure vessels : Voil =………….m3.

(o)

- Air volume of pressure vessels : Vair =………….m3 . (o)

- Maximum pressure in pressure vessel : Pmax =…… …Mpa (o)

- Rated pressure in pressure vessel : Pn =………….Mpa (o)

- Minimum pressure in pressure vessel : Pmin =………..Mpa (o)

- Maximum oil leakage of pressure oil

supply system

: Qoil =………1/s (o)

- Cooling water discharge for oil pressure

vessel

: Qw =……… 1/s (o)

- Rated power of motor to cooling oil pump : Pn =………….kW (o)

- Rated speed of motor to cooling oil pump : nn =………….rpm (o)



211

PITTING (according to IEC 193/1965, 193/1972 and 609/1978)

The Bidder shall complement the bid by charts with η = f (σ) showing distinctly σ0 σ S and σ 1 defined in IEC publication 193A/1972 for the following net heads :

387 m 402 m 410 m

Such charts shall be given for 11000kW,10000 kW and 90000 kW output of the

turbines

Plant sigma (σ p) for these operations shall be fixed at min. 1.05 σ 0 or min. 1.2

σ s (whichever is greater) and guaranteed as such.

The Bidder shall guarantee the runner, and other hydraulic passages for

cavitationless operation for 24 months from the date the plant is put to commercial

use of 5000 hours of actual operation, whichever is earlier, considering IEC

Publication 609/1978, sub-clause 8.1 " Reference duration of operation – 5000 h

(for machines operating with low load factor such as peak load turbines, storage

pumps, pump-turbines during pumping operations)". Excluded from this guarantee

is the removal of metal by erosion or damaging by the presence of injurious

foreign elements in the water.

Measurement must be done after 5000 hours but before 6000 operating hours.

Evaluation will be done on the basis of IEC 609/1978

* Cavitation guarantee duration of

operation [minimum 24 months or

5000 hours generator operation

mode (d)]

= ……… (o)

* Reference duration of operation in

peak load mode [between 5000 and

6000 hours (d)]

tR = ……. h (o)

- Expected annual duration of

generator operation for 387 to 410

m

NOTE : The partial load operations shall be considered for as below

- 95% output during 300 to 400 h/year

- Optimum output during 1400 to

1500 h/year

- Max. output during 700 to 800

h/year

Material removal after tr = 5000

hours


212


* Absolute maximum depth of any

pitted area measured from the

original surface

S < ……… cm (o)

* Total area damaged by pitting A < ……… cm2 (o)

* Total volume of material removed by

pitting

V < ……… cm3 (o)

* Total weight of material pitting

[G < 0.15 D2 (r) ]

* D-outlet diameter in m G < ……… Kg (o)

The formula given is the required degree of pitting. The Supplier will be allowed

to repair the runner for excessive pitting. Definition regarding area and depth shall

be considered as per IEC – 609.

P MODEL DATA

Model data to be supplied by the

Bidder

- Model scale factor m = DM = ……… (o)

D

P

- Gravitational constant at the place of

model laboratory

gM = ……… m/s2

- Acceleration due to gravity of the

prototype

gP = ……… 9.783 m/s2

- Runner outlet reference diameter

[Dm > 300 mm (d)]

Dm = ……… mm

- Water temperature during model

test

tw = ……… 0C

- Kinematic viscosity of water at

model test

VM = ……… m2/s

- Kinematic viscosity of water at

prototype (for tw = 300C – according

to IEC 995/991/08/table B3)

VP = 0.8 x 10-6

m2/s

- Atmospheric Pressure Pa = ……… m.w.c. (o)

ha = ……… m.w.c. (o)

- Vapour Pressure Pva = ……… m.w.c. (o)

hva = ……… m.w.c. (o)

- Test net head Hm = ……… m (o)


213


- Prototype net head

(387-402-410 m)

Hp = ……… m (o)

- Test rotational speed nM = ……… rpm (o)

- Cavitation coefficient σ M = …………….. (o)

- Reference Reynolda number at

optimum point

Reuref= ……. 7 x 106 (r)

- Model Reynolds number at

10880 kW R output

ReMA= …….. x 106 (r)

= ……… x 106

- Prototype Reynolds number Rep= ……. 7 x 106 (o)

- Hydraulic efficiency of the model at

optimum point

ηhMA = ……… (o)

- Relative scaleable losses at point

Reuref

δrefM = ……… (o)

- Increase of hydraulic efficiency at

kW output point

∆hMA = ……… (o)

- Hydraulic efficiency of the prototype

at kW output

ηnhp ̂= ……… (o)

- Total uncertainties for model [f < + 0.25% (d)] Real roughness of wetted surface

Fn + ………% (o)

Q FIELD TEST

(According to IEC 41/1991) Pressure-time

Method

(Gibson method)

1. Method proposed by Bidder ……………......

2. Detailed description and taps location for proposed method

……………......

3. Time necessary for execution of the field test (incl. installation of instrumentation)

days ………………..

4. Final tests reports after beginning of the field test Tolerance of measurement

days ………………..

………………………… (o)


214


R VIBRATIONS AND NOISE LEVELS OF TURBINE

* Vibration limit of turbine for complete operating range (max. bearing vibration) [double amplitude < 200 m (r)]

S1/max < ……… / m

- maximum shaft displacement S2/max < ……… / m

- Noise level of turbine for complete operating range in turbine housing 1 m. away from shaft [< 90 dB (S) (d)

< ……. d B (A) (o)

- Vibration limit turbine bearing according to VD 12056 / 1964 for machine set up G – Fig.6 S < 40 µm (simple amplitude)

NOTE :

Tolerance shall be guaranteed along with Bidder's remark, if any Figures shown

(*) shall be guaranteed and are inclusive of tolerances.

S. Heaviest Package of Shipment

(a) Name

(b) Weight

(c) Dimensions (L x W x H)

T. Largest Package for Shipment

(a) Name

(b) Weight


U Heaviest assembly to be lifted by power house crane

(a) Name

(b) Weight


215

SECTION VI

TECHNICAL SPECIFICATION OF SPHERICAL VALVE


SECTION VI


INDEX


6.1 Scope and operational requirements 217

6.2 Design requirements 217

6.3 Design specifications and performance 218

6.4 Construction 220

6.5 Oil pressure system for spherical valves 222

6.6 Accessories 225

6.7 Tools and erection requirement 225

6.8 Hydraulic pressure test at site 225

6.9 Drawings, designs, manuals to be submitted after

award of contract

226

6.10 Inspection and tests 226

6.11 Miscellaneous 229

6.12 Spares 229

Annexure VI-1 230

Annexure VI-2 232

Data Sheet 233


SECTION VI


6.1 SCOPE AND OPERATIONAL REQUIREMENTS.

This section of the specifications covers the complete engineering, design,

manufacture, testing at factory before dispatch, supply, delivery to project

sites, supervision of on site erection, testing, commissioning putting into

commercial use and giving satisfactory trial operation for a period of 90 days

of one number of turbine inlet spherical valve complete alongwith its

associated control equipment, accessories, piping etc. and also supply and

delivery at site of spares, tools and erection equipment as mentioned

hereafter. Any fitting, accessories of apparatus which may not have been

specifically mentioned in these specifications but which are required for

reliable operation of the plant shall be provided by the supplier at no extra

cost to the purchaser. For operational requirements relevant provisions from

Section I of this volume shall be applicable.

6.2 DESIGN REQUIREMENTS

For design requirements relevant provisions from section I shall be

applicable.

BASIC DESIGN DATA

1) Number of spherical valves : One (1)

ii) purpose. : Turbine guard valve.

iii) Nominal diameter of inlet valve :1000 mm Diameter

(Should be same as that of Penstock diameter i.e.1000 mm)

iv) Design head. : 700mwc (6.85MPa)

v) Test pressure. : 1050m.w.c. (10.27MPa)

vi) Rated discharge. : 3.12 m3 /sec.

vii) Breakdown discharge, : 6.24 m3 /sec.

viii) Operation. :

Opening : by oil pressure

Closing : closing by counter weights /

water pressure


ix) Closing time of spherical valve :

-at still water : <40 sec.

-at rated discharge : <40 sec

-under breakdown discharge : <30 sec

x) Opening time : <90 sec

xi) Spherical valve shall have its own pressure oil system with oil

accumulator.

xii) The spherical valve and its control system shall be suitable for

frequent opening and closing. The minimum opening and closing

operations per day shall be four.

xiii) The head loss in spherical valve for rated discharge of 3.12 m3 /sec

shall be guaranteed.

6.3 DESIGN SPECIFICATIONS AND PERFORMANCE

The spherical valve shall be free from vibration or other abnormality

under steady- state operating conditions and under any possible

transient conditions and shall have sufficient strength and rigidity

against maximum transient water pressure.

.

6.3.1 REQUIRED SERVICE CONDITIONS

It shall always be possible to close the spherical valve safely, without

vibrations or pressure surges, particularly,

1) In normal service conditions with turbine nozzles closed. i.e. without

significant water flow .

2) In case of emergency with turbine nozzles fully open i.e., with rated

discharge and with full pressure on one side of the closing element near the

end of closure.

3) In case of an accidental rupture of the pipe between the spherical valve

and the turbine inlet (i.e. with the breakdown discharge and the whole

pressure on one side already at the beginning of closure.)

6.3.2 GUARANTEES

Guarantees for spherical valves must be given by the Bidders for:

1) Low level of vibration and noise during closing .

2) Strong construction and adequate design of housing.


3) Proved design of rotative parts.

4) High level of water sealing.

5) Minimum losses in the opened position.

6.3.3 CONTROL

Control of spherical valve shall be hydraulically by means of its own oil

pressure unit.

Following modes of control shall be provided.

- Manual local from the respective control cabinet near spherical

valve location.

- Manual remote from the unit control board located in power

Station control room.

- As a part of automatic control sequence of turbine generating

unit, the control shall be so arranged that the motion of

spherical valve can be reversed at any time during the opening

and closing cycle stroke. The spherical valve shall have automatic interlock

devices.

6.3.4 DISCHARGE SHUTDOWN PERFORMANCE

Inlet valve shall be capable of shutting down rated discharge of turbine at

all heads safely and reliably under unbalanced conditions. Also spherical

valve shall be capable of closing during emergency conditions, safely and

completely against full unbalanced flow occurring as a result of breakdown

nozzle/Deflector assembly. Opening under balanced conditions or otherwise

shall be decided in consultation with turbine manufacturer so as to achieve

stipulated time for synchronizing of unit from stand still.

6.3.5 AMOUNT OF WATER LEAKAGE.

Amount of water leakage past downstream side seal shall be less than 0.5

litre per minute at the maximum static pressure of 700 m.w.c. Amount of water

leakage past from upstream side seal at above mentioned water pressure

shall not be more than 0.8 litre per minute.


6.4 CONSTRUCTION.

The spherical valve shall be provided with two seals One ‘service

Seal’ on downstream side and the other ‘maintenance seal’ on the

upstream side.

6.4.1 VALVE BODY

Valve body shall be made of carbon steel casting or welded steel

plates. It shall be suitably divided in maximum two pieces which shall be

connected by a flange at site. Valve body shall be of sufficiently stiff structure

to withstand the maximum water pressure during transient conditions of

turbine and to cause no detrimental deformation. Valve rotor shall be provided

with trunnions of forged steel at both ends. Valve trunnions shall have

sufficient diameter and shall not cause excessive deflation. Trunnion bearing

shall be greaseless self lubricating with bronze backing and with Teflon fabric

liner. Trunnion bearing seals shall be on both ends of each bearing and shall

be made of self lubricating PTFE compound with integrated rubber. Bearing

shall be capable of safely supporting the weight of the valve rotor and force

caused by water pressure and shall be capable of operating valve smoothly.

6.4.2 SERVICE SEAL AND MAINTENANCE SEAL.

The sealing system one for normal service on downstream side of the

spherical valve and the other on the upstream side for maintenance of the

service seal shall be provided.

The design and construction of the seals shall be such that a service life of

about 50,000 hours is guaranteed i.e. the expected mean time between failure

(MTBF) shall be about 50,000 hours. Further the sealing arrangement shall be

such that when worn out, the service seals could be replaced without having

to dismantle the valve proper or without having/ requiring dewatering of

pressure shaft. The complete method and sequence of replacing the service

seals shall be furnished in the bid with explanatory write- ups, sketches and

drawings. The design and construction of the maintenance seals shall be

similar to that of service seal.


6.4.3. VALVE ROTOR

Valve rotor shall be made in spherical shape by carbon steel casting

or welded steel plates. The rotor shall have sufficient strength against all

operating conditions so that it will not cause any detrimental deformation.

Besides, the rotor shall not cause any abnormal vibration during full opened

position or during opening and closing operations or fluttering during transport

conditions.

Arrangement for removal of air trapped in the dome of valve shall

be made. No air shall accumulate inside valve body.

6.4.4 AIR VALVES

Suitable capacity air admission valve shall be provided on down

stream side of valve to protect Inlet piping and shall also act as air exhaust

valve. However leakage of water shall not occur during operating conditions.

Suitable air valve shall also be provided on the upstream of spherical valve to

protect pressure shaft.

6.4.5 PENSTOCK SPECIAL

A connecting pipe shall be provided between the inlet valve and the

Penstock. The connecting pipe shall be made of same material as Penstock

(ASTM 517 Gr. for equivalent). The inlet valve and connecting pipe shall be

connected by rigid flanges and connecting bolts and nuts and packing shall be

supplied.

6.4.6 PENSTOCK DRAINAGE SYSTEM

Necessary piping with fittings shall be supplied for draining the penstock into

tail race channel. (as per specified in section v cl. no. 5.9 of this volume.)

6.4.7. OPERATING MECHANISM

Valve operating mechanism shall comprise of servomotor, operating

rods, levers, interlocks and limit switches, counter weight (if closing operation

by weight), pressurized water piping necessary for closing . Opening of the

valve shall be achieved by oil pressure. Closing of the valve shall be achieved

by counter weight / pressurised water of penstock. Necessary provisions for

closing by water pressure shall be made as per requirement. The pipe dia.


and its discharge shall be as per requirement. The Servomotors shall be of

balancing type and heavy supporting plates with anchor bars, fastening etc.

shall be provided to mount the same on foundation block.

Main parts of the operating mechanism such as servomotor, operating rods,

levers, and connecting part with the valve trunnions shall have strength and

capacity sufficient for safely and reliably shutting down and opening full flow

discharge under all operating conditions of turbine without causing any

excessive vibration and other abnormality. Dimensioning of piston shall be so

as to transmit all operational forces without deflections. All pivots shall be

preferably of self lubricated type. Operating mechanism shall be provided with

a locking device capable of manually locking both the main valve and by pass

valve when they are closed. Parts which come in contact with water supply

shall be made of stainless steel. Limit switches, for open /close, transmitters,

contacts etc.for local / remote operation and indication of valves shall be

provided.

ACCESSORIES

Following accessories shall be supplied.

� Position switch.

� Valve opening / closing indicator.

� Pressure gauge for inlet to spherical valve with relay.

6.5 OIL PRESSURE SYSTEM FOR SPHERICAL VALVES

Spherical valve shall be provided with one independent oil pressure unit to

supply oil under pressure to servomotors.

6.5.1 PURPOSE

Oil pressure unit system shall be used for opening of the spherical

Valve. Operation control devices for the valve system shall be independent of

the governing system of turbine.

6.5.2. SYSTEM

A complete oil pressure unit shall be provided for spherical Valve. Each

system shall compromise of following:

One sump tank located adjacent to each spherical valve and

dimensioned for 120% of the combined oil volume in the servomotors in fully


open positions, oil piping valves and pumps. The tank shall be provided with a

filling opening (with strainer and cover) breather, breather opening, sight oil

gauge with cocks and drain with cock and one manhole for inspection. Dial

type oil level gauge and oil level relays for oil level low / high warnings.

Two screw type silent running and self priming oil pumping unit

One each for normal and stand by, each with suction strainer and capable of

continuous operation. The pumps shall be vertical rotary type coupled directly

with their drip proof alternating current electric induction motors. Both

pumping units shall be identical and equipped with complete control system

permitting the selection of either unit acting as stand-by and starting

automatically when other pumping unit fails.

Each pressure oil pump shall be a vertical shaft rotary pump. The oil flow

rate per pump at the maximum delivery pressure will be sufficient for

operating the spherical valve from the fully closed state to the fully opened

state without supply of pressure oil from the pressure tank. The normal

operating oil pressure shall be suitable to meet the stipulated operational

requirements.

Each of the normal and stand by pumps shall be provided with the

Following accessories.

1 set Safety valve.

1 set Non-return valve.

2 set Strainer.

One small pressure oil accumulator in parallel arrangement

between the oil pumps and servomotor and located near the valve.

This accumulator shall act as buffer and pressure oil holding means to

prevent the oil pump from frequent starting. One hand operated double

acting oil pump mounted in the sump tank shall be provided.

Control valves for spherical valve drives and seal applications shall be as

follows:-

� All valves : such as safety valves, non-return valves etc.

� All oil piping and isolating valve within the oil pump tank and

between the oil pumping set and servomotors.

� Control cabinet containing following instruments and switches:

� Two pressure gauges with contacts for indication of upstream and

downstream water pressure of valve with recording facilities.


� One pressure gauge for indication of oil pressure with contacts.

� Selector switches for local / remote and auto / manual control of

pumps.

� Control switches for pumps.

� One pump selector switch for main and stand –by.

� Three push selector switch for opening, stop and closing of spherical

valve.

� One selector switch for local / remote and auto / manual control of

spherical valve.

� One switch with ‘ON’ and ‘OFF’ position for testing of

oil pumping units.

� One electric heating element.

� All necessary relays, fuses, signal lamps, terminal blocks

and other equipment for a complete and safe local and remote control

of the spherical valve.

The cabinet shall be of self standing sheet metal type, moisture,

vapour and dust proof, with locable front door. All wiring shall be in the most

efficient manner from point to point. There shall no jointing or teeing of wires

between terminals. All control cabling between individual devices,

instruments, switches etc. upto local control cabinet of spherical valve shall

be provided.

Control of pumps shall also be possible from the unit control

board in addition to local control and shall operate in conjunction

with turbine controls. Operation of the pressure oil pump shall be controlled by

pressure switches when the normal oil pump fails, the stand by pump shall

start automatically. Change over between the normal operation and stand-by

pump will be carried out through the change over switch provided on the

control cabinet. Provisions in the control scheme for shutting off the unit

be provided in case of valve closure.

Besides, starting and stopping shall be carried out not only automatically and

remotely but also manually from control cabinet .All position indicators

annunciations and control shall be suitable for local and remote operations.

First filling plus 25% extra quantity for each unit of pressure system oil,

required for each Sp. valve and its pressure oil system shall be supplied by


the supplier. Supplier shall suggest the oil equivalent available in India for

future maintenance and operation of the plant.

6.6 ACCESSORIES

Following shall be supplied but shall not be limited to

- All necessary sole plates, foundation bolts, anchors etc. for Sp. valve

and servomotor.

- All platforms, ladders, stairs, handrails, plate coverings, hooks, pulley

blocks etc. necessary for obtaining easy and safe access to parts and

item which are fitted with equipment.

- The name plate for each equipment showing manufacturers name,

serial number, year of manufacture, type, rating, capacity etc. for valve

assembly and servomotor shall be provided.

- All necessary washers, bolts, nuts etc. of high quality steel.

- All necessary turn buckles and pipe jacks needed for erection,

operation and maintenance.

6.7 TOOLS AND ERECTION REQUIRMENT

One (1) complete set of ordinary and special spanners, wrenches, special

tools, slings, shackles, ropes etc. for the proper erection and maintenance of

the valve shall be supplied.

One complete set of smaller and standard tools and equipment shall be

furnished with a sheet metal lockable toolbox, fitted internally so that the tools

may be stored in a proper manner.

6.8 HYDRAULIC PRESSURE TEST AT SITE

If the transport limitations permit, the spherical valve shall be dispatched in

one piece duly assembled in workshop. In case, it is not possible to transport

assemble valve to project site, it shall be pressure tested at site at 1050

m.w.c. (10.27 MPa) for 60 minutes after its erection. To carry out the pressure

testing at site, the supplier shall provide one set of bulkheads for spherical

valve together with all necessary pickings and jointly material and test

equipment.


6.9 DRAWINGS, DESIGNS, MANUALS TO BE SUBMITTED AFTER AWARD

OF CONTRACT.

These shall be supplied as per the list given in the Annexure VI - 1 to this

section. Mode of submission of designs and drawings will be intimated to the

successful bidder in due course.

6.10 INSPECTION AND TESTS

Inspection and tests at factory shall be carried out by the supplier in respect of

the spherical valve as per the list given below: -

LEGEND

1. Material analysis.

2. Tensile test.

3. Notch impact test.

4. Bending test.

5. Visual inspection.

6. Magnetic particle examination.

7. Liquid penetrant examination.

8. Ultrasonic test.

9. Radiographic test..

10. Pressure Test

11. Leakage test .

12. Dimensional check.

13. Erection check.

14. Welding procedure approved by purchaser.

15. Corrosion protection.

(Suffix - A) Test at workshop in the presence of purchaser and / or

Consultants:



The supplier shall submit six (6) copies of test certificates to the purchaser as

per the procedure given below:

i) FOR INSPECTION & TESTING SPECIFIED TO BE DONE IN

PRESENCE OF PURCHASER’S REPRESENTATIVE.

Test certificate shall be submitted for approval.

ii) FOR ALL OTHER INSPECTION AND TESTING:

Test certificate showing that the specified test / inspection has been

carried out successfully by the supplier for reference.

Following assembles will be inspected for tests under the item

Sr

No.

Particulars of

Assembly

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

a) BIPARTITION

flanges

√

√

√

√

√

b) CONNECTING

flanges.

√

√

√

√

√

c) BEARING

HUBS

√

√

√

√

√

d) Cylinder Shell

√

√

√

√

√

√

√

√

√

e) Valve body

√

√8A

f) ROTOR

Trunnions.

√

√

√

√

√

√

g) ROTOR plates.

√

√

√

√

7A 8A√

h) ROTOR √

√8A

√

√

√

i) Assembled

valve

√

10A

√

11A

√

13A


j) Operating

mechanism

• Cylinder

flanges

• Cylinder shell

• Cylinder

covers

• Welded

cylinder

• Piston rod

• Piston

rod heads

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

7A

√8A

√

√9A

√

k) • Assembled

operating

mechanism.

• Operating

mechanical

lever hub.

• Welded Lever

• Auxiliary

valve.

• Air valve.

√

√

√

√

√

√

10A

√

√

11A

√

√

√

√

13A

l) • Upstream

pipe

• Connecting

flange.

• Cylinder

Shell.

• Welded pipe.

√

√

√

√

√

√

√

√

√

√

√

√

√8A

√12A

√

m) • Downstream

pipe.

• Flange rings.

• Cylinder shell

• Welded pipe.

√

√

√

√

√

√

√

√

√

√

√

√

√8A

√10A

√12A

√

√


Relevant commissioning tests of mechanical lot are listed under section-V of

turbine and shall be followed but not be limited .

6.11 MISCELLANEOUS

Relevant provisions wherever applicable needed for indicating, recording-

instruments, control switches, safety devices, gauges, flow meters etc. for

normal operations and field tests shall be made by valve supplier in

consultation with turbine supplier and facilities needed by supplier of control

and protection system.

6.12 SPARES

Spares shall be supplied as per the list under Section III of this volume.


ANNEXURE VI-1

List of drawings, designs and manuals to be submitted by the supplier after the award of

contract.

Sr.

no

Brief Description Within months

from the date of

award of

contract

Remark

1. 2. 3. 4.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

DRAWINGS

i) Arrangement of spherical valve.

ii) Installation of spherical valve.

Valve servometer

Tools, tackles & erection devices of spherical

valve.

Arrangement of spherical valve piping.

Outlet pipe with dismantling joint.

Control gear diagram for spherical valve.

Arrangement of air valve.

Foundation of valve and servomotor and

loading on foundation under worst operating

and earthquake condition.

Arrangement of opening mechanism.

Sealing arrangement.

Pressure oil system with piping.

Compressed air system with piping in co-

ordination with scope of pump-turbine

manufacturer/auxiliaries supplier.

Layout with section of trenches, blackouts etc.

for piping & cables.

Interconnection and wiring diagrams and

cable schedule.

Arrangement of sp. Valve piping for closing

the valve

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

For Approval

For Approval

For reference

For reference

For Approval

For Approval

For Approval

For Approval

For Approval

For Approval

For Approval

For Approval

For Approval

For Approval

For Approval


DATA

1. Opening and closing characteristics.

2. Max. Efforts and Max. Toque on foundation &

Steel shaft.

3. Considerations made in data about loading on

foundations of inlet valve and servomotors.

4. Adequacy of oil pressure shaft unit for spherical

valve.

3

3

3

3

For Approval

For Approval

For Approval

For Approval

MANUALS

1. Manual for storage, preservation and handling of

the supplied goods.

2. Manual for erection /dismantling, testing &

Commissioning of the supplied goods.

3. Maintenance manuals.

4. Tolerance for assembly.

5. List of consumables, oils and spares.

12

12

18

12

12

For reference

For reference

For reference

For reference

For reference


ANNEXURE VI-2



----------------------------------------------------------------------------------------------------


to clause in the

specification.

----------------------------------------------------------------------------------------------------


DATA SHEETS

DATA SHEETS S1 to S2 FOR TECHNICAL SPECIFICATIONS OF MAIN

SPHERICAL VALVE AND RELATED EQUIPMENT

DATA SHEETS SHALL BE FULFILLED OBLIGATORILY BY BIDDER

Note: In all data sheets, the following signs have the indicated meanings :

≥ No negative tolerance allowed.

≤ No positive tolerance allowed.

(r ) required value.

(d) desired value

(o) offered value.

(*) guaranteed values.


DATA SHEET 1

DATA SHEETS

(To be filled by Bidder (obligatory) Bidder’s Remark (if any)

MAIN INLET SPHERIAL VALVES

Preferable opening and closing mode

operation

-Opening

-Closing

- Nominal diameter of spherical valve same

diameter as distributor pipe (nn= 500rpm)

: D s = 1000mm(d)

- Number of servomotors

- Diameter of servomotors

- Design head [HD = 6.85

MPa (=700 mwc) (d)]

- Test pressure of SP.valve (1050 mwc)

- Maximum gross head of Sp. valve in

Normal operation. [Hg max. = 602-

190= 412 mwc

- Maximum discharge of Sp. valve in

Normal operation.[Qmax ≥ 4.00m3 /s (d) ]

- Maximum discharge of Sp. valve in

Breakdown discharge

[Q’ max ≥8.00 m3/s (d) ]

- Total loss of head in Sp. valve at

[Qmax ≤ 4.00 m3/s) ]

- Maximum allowable leakage through closed

Valve. [ Qo ≤ 2 l / s (d) ]

- Sp. valve opening time at still water

[ to = 60-120s (adjustable) (d)]

- Sp. valve closing time at still water

[tc ≤ 90 s (d) ]

- at discharge Qmax 4 m3/s [t’c ≤ 30 (d) ]-

: with oil

: with

: D s v

: n s

: D s

: H D

: PT

Hg max

FP

Q max .

Q’ max

∆ H FP

Q o

to

to

t’c

t’c

pressure

counter weight /

water pressure head

=…………. mm

= ...............

= ...............mm

= ............... MPa

=................ m.w.c

= ............... MPa

= ............. m.w.c.

≥ ................ m3 /s

≥ .............. ...m3/s

=.............m. w .c.

≤ ...................l / s.

≤.......................s

≤.......................s

≤......................s≤.....

.................s

(0)


at discharge Q’max 8 m3/s [t”c ≤ 20 s (d)]

- Maximum valve shaft torque during

- Opening

- Closing

- Operating oil pressure

- Total mass of Sp. table

- Maximum transportation mass of Sp.

Valve

- Dimension of largest transportation single

Piece

- Total mass of completed Sp. valve

- Material of Sp. valve

* Valve body

* Valve table

- Shaft bearing housing

- Bearing [self-lubricated Teflon type (d) ]

- Counterweight

- Servomotor

Mo

Mc

P

G ft

G Tr

LxWx H

G FP

..............

............

..............

..............

.............

..............

DATA SHEET 2

Bidder’s Remark (if

any)

≤......................s

=.................. kN.m

= .............. ...kN.m

= ..................MPa

= .............. .........t

= ........................t

= ...x....x...x mm

= .......................t

............................

............................

............................

............................

............................

.............................

- (*) Total loss of head in Sp. valve

- Leakage past closed valve

i) Upstream side

ii) Downstream side

- Vibrations transmitted to foundation

i) Valve opening

ii) Valve in operation

iii) Valve closing

- Noise level near 2 m. from valve during

operation of unit

H L3

=...................mm

......................l / s

......................l / s

...........Micrometer

……..Micrometer

……..Micrometer

.................dB ( A)

(o)

236

SECTION VII

TECHNICAL SPECIFICATIONS OF STATION AUXILIARIES.


SECTION VII


INDEX


7.1 Scope and operational requirements 238

7.2 Schedule of requirements 238

7.2.1 Compressed air system 238

7.2.2 Drainage and dewatering system 242

7.2.3 Cooling water system 244

7.3 Auxiliaries control board 247

7.4 Standards 249

7.5 Drawings and data to be submitted with bid 250

7.6 Drawings, designs and manuals to be furnished after

award of contract

250

7.7 Spares 250

Annexure VII - I 251

Annexure VII- 2 254

Data sheets A1 to A6 255


SECTION VII


7.1 SCOPE AND OPERATIONAL REQUIREMENTS.

This section of the specifications covers the complete engineering, design,

manufacture, testing at factory before despatch, supply, delivery at site,

supervision of onsite erection, testing, commissioning, putting into commercial

use and giving satisfactory trial operation for a period of 90 days of the station

auxiliary system complete with associated piping, fittings, motor control board

and also supply and delivery at site of spares as mentioned hereafter. Any

fittings, accessories of apparatus which may not have been specifically

mentioned in these specifications but which are indispensable for reliable

operation of the plant shall be provided by supplier at no extra cost to the

purchaser.

The capacities and ratings mentioned for various auxiliaries in the scheme

shall be designed by the supplier and these shall be subject to approval by the

purchaser.

Relevant provisions of sections No. I of this volume shall be applicable.

7.2 SCHEDULE OF REQUIREMENTS.

7.2.1 COMPRESSED AIR SYSTEM.

A centralized high pressure compressed air system for the unit shall be

provided for charging the governor oil pressure unit, Main Inlet Valve O.P.U.,

Generator breaks and service system. The system shall comprise two numbers

high pressure compressors of suitable capacity, one of them being a standby,

a common air receiver and necessary pipes, fittings, valves, pressure switches,

etc. One low pressure air receiver shall be provided for generator brakes and

common service. Compressed air from high pressure air receiver shall be

tapped and fed to low pressure air receiver through one pressure reducer. The

capacity of the system shall be sufficient to cater to the generating unit. The


compressed air system shall be of the automatic start-stop design operating

under pressure switches control sensing the pressure in the receiver. Nitrogen

filled cylinders as an alternative system for pressurizing the oil pressure unit

shall not be accepted. Bidder shall have to give detailed design of the system.

Equipment shall be as per relevant IS

7.2.1.1 Scope of Supply

Compressed air system is required for

Governor OPU, MIV OPU, Generator Braking and service air and consists of :

• 3 Stage Reciprocating Compressors, - 2 nos

• Moisture Separators - 2 nos

• High Pressure Air receiver -- 1 no

• Low Pressure Air receiver -- (for Generator Brakes) - 1 no.

• Pipes, valves, instruments & fittings. - 1 lot

7.2.1.2 General Design and Constructional Requirements :

i). Two reciprocating multistage compressors driven by electric motors shall be

provided to feed compressed air in the air receiver.. One of the compressors

shall work as main and other as standby. Their operation shall be made

automatic with the help of pressure switches. Compressed air after passing

through air dryers shall be fed to one high pressure air receiver. One low

pressure air receiver shall be provided for generator brakes. Compressed air

from high pressure air receiver shall be tapped and fed to low pressure air

receiver through one pressure reducer.

ii) Pressure rating of each compressor shall match maximum pressure

requirement of oil pressure unit of Governor, MIV OPU and generator brakes.

The supplier shall check air requirement of the system and provide higher

capacity, if required considering the compressor duty cycle in view. Design

calculation regarding compressor capacity and strength calculation of air

receivers shall be submitted for approval of the Purchaser.

iii) The compressors will be driven by 3 phase, 415 VAC completely enclosed,

fan cooled, squirrel cage induction motors with class F insulation through belt


drive. Compressor and motor shall be mounted on a common base plate which

shall be installed on floor with the help of foundation bolts.

iv) Indian Standard IS 2825 shall be followed for design, manufacture and

testing the air receivers.

v) The motor starter panel housing contactors, switch fuse units and meters etc

shall be mounted on the wall near the compressors and wired complete with

leads labelled. The connections to each motor shall be arranged so that either

compressor may be removed for repair or replacement without interfering with

the continuous operation of the other.

vi) System design shall be subject to approval of the Purchaser.

LUBRICANTS.

Sufficient quantity required for first fill of lubricant, grease, oil etc. plus 25%

extra shall be supplied and included in bid cost.

CABLES.

Power supply cables and all control cabling from motor control board to

compressors, receivers etc. shall be included in Bidder’s scope. Compressor

starting shall be regulated from the pressure switches provided on air

receivers. The motor control board shall be located near compressor. Cables

from each auxiliary system equipment to its control panel (both of which are

included in supplier’s scope) shall be supplied. Cables for interconnection

between computer and computer based control panel shall also be supplied.

7.2.1.3 Shop Tests

The shop tests on compressed air system shall include :

i) Dielectric and insulation tests on all electric motors,

ii) Routine operational tests including starting current, output torque Vs current

characteristics, noise, vibrations on electric motors as per Indian Standard or

International standard,

iii) Operational tests and tests for verification of Performance Characteristics of

compressors as per Indian Standard/ International standard. Compressors will

be tested with their respective motors.

iv) Hydrostatic pressure tests on air receivers at 1.5 times the rated pressure.

v) Hydrostatic and leakage tests on all valves at 1.5 times the rated pressure.


vi) Operational tests on pressure reducer.

7.2.1.4 Field Tests

Following testes will be carried out at site after installation :

i) Dielectrics and insulation tests on all electric motors,

ii) Operational tests on compressors for minimum 8 hrs continuous operation to

establish trouble free operation without abnormal vibrations and noise,

iii) Operational tests on control panels and instruments.

7.2.1.5 Special tools, slings, consumables etc.

All special tools, slings, lifting devices, jacks, turn buckles, foundation

plates/bolts, testing devices etc., required for erection and commissioning of

the equipment shall be listed and supplied. First filling of oil and grease (if

applicable) with 20% extra quantity shall be included in the offer and supplied

along with equipment. Welding electrodes as required for site welding and

paint for finishing coat shall be supplied by the contractor.

7.2.2 DRAINAGE AND DEWATERING SYSTEM:

One set of Dewatering and Drainage Equipment comprising three submersible

pump motor sets for dewatering and drainage system with pump control

cubicles duly wired with switchgear, instrumentation, control, automatic level

control, float switches, associated valves, necessary piping and fitting and staff

gauges in tail race sump. The arrangement of drainage and dewatering system

shall be proposed by the bidder. The scopes of supply include all pipes, valves

etc. required for the complete dewatering & drainage system. Bidder shall have

to give detailed design of the system. Design of Dewatering and Drainage

Equipment shall be as per relevant IS.(i.e. IS:1742.IS:1172,IS:4721)


Dewatering of pressure shaft will be achieved by pressure shaft drain valve.

Entire system is for free flow tailrace discharge and drainage is also arrange for

gravity flow to tail race channels by gutter/pipe. Equipment comprising three

submersible pump motor sets are to be provided for dewatering and drainage


system. Dewatering system shall consist of two submersible pump, (one main

& one stand by), one set of level controllers, pipe lines and valves. Level

controllers shall be provided in the dewatering sump to start/stop the pumps

automatically & to give alarm at a preset level. The pump shall discharge into

tail race above the maximum tail water level. The drainage system shall consist

of one submersible turbine pumps, one set of level controllers, pipe lines and

valves. Automatic control of the pumps shall be arranged through level

sensors. Provision for manual operation shall be made on the control panel.

Control of the pumps shall be built in Unit Control Panels and their starter

panels will be located near the pumps. These three pumps will be used as per

leakages and dewatering requirement in power house.

7.2.2.3 Pump – Motor Sets

The impellors of pumps shall be manufactured from stainless steel and the

casing of impellor from steel casting. The pump casing and impellors shall be

provided with removable type of stainless steel liners. The electric motors shall

be squirrel cage induction motors with hollow shaft and ratchet arrangement to

prevent reverse rotation. The enclosure of the motors

shall be drip proof type.

LUBRICANTS.



CABLES.

Power supply cables and all control cablings from motor control centre to

motors, load controllers etc. shall be included in Bidder’s scope. Cables from

each auxiliary system equipment to its control panel (both of which are



7.2.2.4 Valves, Pipes and Fittings

All Nozzle valves and non-return valves shall have housing in steel casting and

valve seat in stainless steel. Piping shall be complete with sufficient number of

bends, elbows, tees, clamps, flanges and fasteners.


7.2.2.5 Shop Tests

The shop tests on drainage / dewatering system shall include:


ii) Routine operational tests including starting current, torque/speed

characteristics, output torque Vs current characteristics, noise, vibrations on

electric motors as per Indian Standard or International standard,

iii) Operational tests and tests for verification of Performance Characteristics

offered of pumps as per Indian Standard/ International standard. Pumps will be

tested with atleast one actual motor tested and supplied for each type of pump

motor set

iv) Hydrostatic and leakage tests on all valves at 1.5 times the rated pressure.

v) Operational tests on level controllers

7.2.2.6 Field Tests

Following testes will be carried out at site after installation:


ii) Operational tests on Pump Motor sets for determination of pump capacity,

power drawn at full discharge, vibrations and noise,

iii) Operational tests on Pump Motor sets for minimum 8 hrs continuous

operation to establish trouble free operation,

iv) Operational tests on control panels and instruments.

7.2.3 COOLING WATER SYSTEM

The cooling water for generator air coolers (if applicable), generator and

turbine bearing coolers, turbine shaft seal if applicable and for other equipment

in the powerhouse is required. Cooling water shall be provided by tapping the

penstock. As the pressure at the tapping is high, suitable pressure reducer

shall be provided. The system shall be complete with required number of

duplex strainers, pressure reducer valves, safety valves, stop valves, fine mesh

filters, flow meters, flow indicators, flow relays, pressure gauges, etc. Bidder

shall have to give detailed design of cooling water system. Equipment shall be

as per relevant IS



Tapping arrangement from intake

Water pressure reducer set with PRV, stop valve, safety valve etc. -sets

Motorised self cleaning strainer (duplex) - sets

Servo operated hydro valve with solenoids - sets

Necessary flow meters, flow indicators, flow relays,

pressure gauges, pipes, supports etc. – lot

7.2.3.2 General Design & Constructional Requirements

i) Cooling water will be tapped from penstock through embedded pipes and

connected to a common header through isolating valves. Water pressure

reducer set with PRV, stop valve, safety valve etc. shall be used to supply

adequate cooling water to generator air coolers and bearings of the unit.

Cooling water after passing through strainers will be fed to a common header

and distributed to unit.

Motorized self cleaning strainer with discharge capacity 1 ½ times the

requirement shall be provided to various cooling circuits. The strainers shall be

cleared off accumulated silt automatically through a motorised rotating arm

mechanism. Cleaning operation will be operable through pressure differential

switch and timers. Servo operated hydro valve controlled by 48 VDC solenoids

or motor operated valve shall be provided on feeding line of unit to control

cooling water supply during starting/shut down of unit.

Valves, Pipes and Fittings: All Nozzle valves and non-return valves shall have

housing in steel casting and valve seat in stainless steel. Piping shall be

complete with sufficient number of bends, elbows, tees, clamps, flanges and

fasteners. The duplex strainer (2 in nos.) shall be fitted with pressure switches

to give alarm in case the pressure differential across it exceeds a pre-set value.

Pressure gauges shall also be provided to indicate water pressure at its inlet

and outlet. This cooling water supply scheme is of flexible type such that any

combination of duplex strainer can be used for the unit in operation while the

other is in shutdown.


LUBRICANTS.



CABLES.

All power and control cables with clamps, trays, ferrules etc. (both of which are



7.2.3.3 Shop Tests

The shop tests on cooling water system shall include :

i. Operational tests and tests for verification of Performance

Characteristics offered of valves as per Indian Standard/ International

standard.

ii. Hydrostatic and leakage tests on other valves at 2 times the rated

pressure.

iii) Operational tests of self cleaning strainers

7.2.3.4 Field Tests

Following testes will be carried out at site after installation :

i. Pressure reducer set shall be pressure tested at site at 1050 m.w.c.

(10.27 MPa) for 60 minutes after its erection.

ii. Operational tests on self cleaning strainers.

7.3 AUXILIARIES CONTROL BOARD.

This board shall comprise of following:

1) CONTROL SWITCHES FOR

(a) COOLING WATER PUMPS

Strainer A/ B

(b) DEWATERING PUMPS:

Pump Selector Switch Pmp1/ Pump2

Pump Auto/ Manual switch Auto/ Manual.


Pump A Start/ Stop

Pump B Start/ Stop

(c) COMPRESSED AIR SYSTEM

Compressor Selector Switch Pmp1/ Pump2

Compressor Auto/ Manual switch Auto/ Manual.

Local/Remote switch Local/Remote

Compressor A Start/ Stop

Compressor B Start/ Stop

(2) INDICATOR LED LAMPS

(a) COOLING WATER PUMPS

Strainer A ON/OFF/Trip.

Strainer B ON/OFF/Trip.

(b) DRAINAGE & DEWATERING PUMPS:

Pump A ON/OFF/Trip.

Pump B ON/OFF/Trip.

(d) COMPRESSED AIR SYSTEMS FOR

Compressor A ON/OFF/Trip.

Compressor B ON/OFF/Trip.

7.4 STANDARDS

Equipment shall be in accordance with the latest IEC standards or equivalent

internationally accepted standards. Some of the standards are listed below but

shall not be limited to: -

IEC 298 - Cased equipment

IEC 264 - Common clauses, IEC 502 - M.V. Cables

IEC 227 - PVC Conductor and Cable.

IEC 287 - Calculations and Dimensions.


IEC 269 - Fuses.

IEC 364 - Installation

IEC 439 - Operating Mechanism, IEC 51-1 to 51-5

Measuring Devices.

IEC 145 & 521 - Counters, IEC 255 (1 to 22) - Relays

IEC 72 - Motors

IEC 404 - Magnetic Materials

IEC 349 & ISO 1996 - Noise

VDI 2056 - Vibrations

Swedish Standard 515 - Corrosion Protection

ASTMA 435 - Steel Plate Testing

ASME V - Welding Materials

ASTMA 609 & 709 - Cast Part testing

ASTMA 388 - Forged part testing


The supplier shall submit 6 copies of test certificates to the Purchaser as per

the procedure given below:

i) FOR INSPECTION AND TESTING SPECIFIED TO BE DONE IN

PRESENCE OF PURCHASER’S REPRESENTATIVE.

Test certificates shall be submitted for approval.

ii) FOR ALL OTHER INSPECTION AND TESTING

Test certificates showing that the specified tests/inspection has been

carried out successfully by the Supplier, shall be submitted for

reference.

7.5 DRAWINGS AND DATA TO BE SUBMITTED WITH BID

Bidder shall submit in his bid information and general drawings describing and

illustrating the equipment he proposes to offer, in such a manner as to make

possible a complete understanding of the equipment on which bid is based.

The information shall include all essential dimensions, types of materials to be

used in major parts with the chemical and physical properties of materials and

the schematics, layout drawings, control schemes and data for the:


1. All “Data Sheets” enclosed with this section must be completely filled in

by the Bidder. The Bidder shall specifically note this requirement and

fulfil it in all respect without fail.

2. Cooling water system

3. Drainage and dewatering system

4. Compressed air system

7.6 DRAWINGS, DESIGNS AND MANUALS TO BE FURNISHED AFTER

AWARD OF CONTRACT

These shall be submitted as per the list given in Annexure VII-I to this

section. Mode of submission of drawings and designs will be intimated to the

successful Bidder in due course.

7.7 SPARES

Spares shall be supplied as per list under Section III of this Volume.


ANNEXURE VII - I

List of drawings, designs and manuals to be submitted by the Supplier after the award

of contract.

Sr. Brief Description Within months from the Remarks

No. date of award of contract

DRAWINGS

1. Layout and dimensional

Drawings showing equipment for, 4 For approval

* Cooling water station

* Drainage and dewatering Pump station

* Compressor station

* Trenches, blackouts etc. for

pipe line and cables

* Support details of pipelines

2. Pipe layout of cooling water

system 4 For approval

3. Schematic of cooling water

system. 4 For approval

4. Control panel for

cooling water system 4 For approval

5. Arrangement diagram of

compressed air system 4 For approval


6. Pipe layout of compressed

air system 4 For approval

7. Schematic of compressed

air system 4 For approval

8. Motor Control centre panel for

compressed air system 4 For approval

9. Arrangement of drainage and

dewatering system. 4 For approval

10. Pipe layout of drainage and

dewatering system 4 For approval

11. Schematic of drainage and


12. Motor Control centre panel for

drainage and dewatering system 4 For approval

13 Interconnection and wiring

diagram and cable schedules

of equipment 6 For approval

14. Foundation / support

arrangement of, 4 For approval

* Cooling water system

* Drainage/dewatering pumps

* Compressor air equipment,


air receivers

* All water piping, valves

pump columns

* Switchgear panels of cooling

water, drainage/dewatering

and compressed air system.

DATA

1. Adequacy of cooling

water system 2 For approval

2. Adequacy of dewatering and

drainage pit size and volume 2 For approval

3. Adequacy of pump capacity for

cooling water, drainage and


4. Adequacy of compressed air

systems including capacities

of compressors and air receivers. 2 For approval


MANUALS

1. Manual for storage, preservation

and handling of the supplied goods. 8 For reference

2. Manual for erection, dismantling,

testing and commissioning of the

supplied goods. 8 For reference

3. Maintenance manuals 12 For reference

4. List of consumables, oils, grease,

spares etc. 10 For reference


ANNEXURE VIII- 2


(To be filled by Bidder)

Item Description of departure Reference to Clause in specification


DATA SHEETS

DATA SHEETS A1 TO A5 FOR TECHNICAL SPECIFICATIONS OF

1. COMPRESSED AIR SYSTEM

2 COOLING WATER SYSTEM

3. DRAINAGE AND DEWATERING SYSTEM

AND RELATED EQUIPMENT

*DATA SHEETS SHALL BE FULFILLED OBLIGATORILY BY BIDDER

Note: In all data sheets, the following signs have the indicated meaning:

≥ No negative tolerance allowed

≤ No positive tolerance allowed

(r) Required value

(d) Desired value

(o) Offered value


DATA SHEET A1

Bidder’s Remark (if any)

DATA SHEETS

COMPRESSED AIR SYSTEM FOR GOVERNOR, M.I.V., GENERATOR BRAKES

AND GENERAL REQUIREMENT

-Total number of compressors

-Discharge of one compressor at working

rated pressure

-Rated working pressure of compressor

-Rated power of compressor motor

-Rated speed of compressor motor

-Total number of air tanks

-Volume of one H.P. air tank for Governor and

MIV

-Air leakage during operation

-Volume of one air tank for generator brakes

and general requirement

n’ c =................(o)

Q’c =.... N m3/s (o)

=.........kg/s (o)

p’ = ... MPa (o)

P’η =.........kW (o)

n’n =..........rpm (o)

n’t =................ (o)

Vair=............ m3 (o)

∆ Q=... ...kg/s (o)

Vair=............ m3 (o)


DATA SHEET A2


DRAINAGE AND DEWATERING SYSTEM

TECHNICAL DATA SHEET FOR SUBMERSIBLE / VERTICAL MOTOR - PUMP

UNITS

------------------------------------------------------------------------------------------------

D&D PUMPS UNIT ASSIGNED OFFERED

VALUE VALUE

-----------------------------------------------------------------------------------------------

Quantity ............

Type of operation

Manufacture ......... ............

Type

Rated speed rpm 1480 .............

Discharge m3/sec ... .............

Heads Hn m 10m .............

Corresponding .............

Discharges Qn (atHn) m3/sec .............

Efficiency

(Nominal point % >70 .............


DATA SHEET A3


Input power nominal kW .............

Maximal kW .............

Motor voltage V 400 + /-10 % .............

Net work frequency Hz 50 .............

Motor power kW .............

(With star/delta starting)

Materials - body Cast iron .............

- Impeller Cast iron or

Phosphor Bronze ............

- Shaft steel ............

Length of guide system m ...........

Length of electrical cable

Up to connection box m ...........

Diameter of discharge

Nozzle mm - ...........

Weight of Pump + motor kg - ...........


DATA SHEET A4


COOLING WATER SYSTEM

TECHNICAL DATA SHEET

COOLING WATER SYSTEM UNIT ASSIGNED OFFERED

VALUE VALUE

1) WATER PRESSURE REDVCER VALVE

i) Type

ii) Manufacture

iii) Design

Pilot / Piston operated (d)

iv) Material

• body

• seals & disc

• core, core plug nut

• core spring

• core tube

v) Installation configuration

Two stage serial reduction (d)

vi) Inlet pipe diameter

vii)Outlet pipe diameter

viii) Operating pressure differential


DATA SHEET A5


ix) Maximum outlet pressure

x) Maximum flow rate

xi) Actuation method

solenoid(d)

xii) Valve opening type

normally closed(d)

2) SAFETY VALVE

i. Type

ii. Manufacturer

iii. Minimum operating pressure

iv. No. of safety valves used

v. Material

3) STRAINERS

i. Type

ii. Manufacturer


iii. Designed flow rate

DATA SHEET A6


iv. Material

v. Motor capacity

vi. No. of strainers used

261

SECTION VIII

TECHNICAL SPECIFICATION OF PROTECTION AND METERING


SECTION VIII

PROTECTION AND METERING DETAILS

INDEX


8.1 Protection and Metering Scheme 263

8.2 CTs / VTs 263

8.3 Special Features of Proposed Protection System 263

8.4 Generator And Transformer Protection 264

8.5 Protection for D.C System 266

8.6 Metering System 266

8.7 Spares 266

Annexure VIII - I 267

Annexure VIII- 2 268

DATA SHEETS P1 to P3 269


SECTION VIII

PROTECTION AND METERING

8.1 Protection and Metering Scheme

The following protection shall be provided by using integrated numerical generator

protection relay for generator, generator transformer and auxiliaries. Back up

electromagnetic relays with instrument transformers may be provided as mentioned

cl.8.4.2 of this volume. All the protective relays will be housed in the control room of

the Power Plant. The tentative locations of CTs and PTs housed in GT and NG cubicle

for the protection and metering shown in single line diagram. Alternative arrangements

may be proposed by the bidder.

The final drawings for the protection & metering shall be submitted by the

contractor and will be subject to the approval by the Purchaser.

8.2 CTs / VTs

All current and voltage transformers required for protection system of the unit shall

have adequate VA burdens, knee point voltage, saturation factor and characteristics

suitable for the application, and shall be subject to approval of the purchaser.

8.3 Special Features of Proposed Protection System

i. The protection system shall be built on latest technology and the bidder has to

guarantee for supply of spares for at least 10 years. Moreover, the bidder

should have full range of manufacture of the system offered.

ii. Wide setting ranges with fine setting steps for each protection shall be

available.

iii. The protective relays shall preferably be housed in draw out type of cases with

tropical finish.


iv. Common tripping relays (each for similar functions) will be provided with lock-

out facilities. All these relays shall have potential free contacts for trip and

alarm purposes and externally hand reset type of flag indicators

8.4 Generator And Transformer Protection

8.4.1 An integrated numerical protection relay incorporating the following functions

shall be provided for generator and Transformer protection

a) Generator, step-up Transformer Protection

1. Generator Differential Protection.

2. Overall Differential Protection.

3. Step-up transformer differential protection.

4. Generator Stator Earth-fault protection.

5. Generator-Rotor Earth-fault protection.

6. Voltage controlled over-current protection.

7. Loss of excitation (Minimum reactance protection)

8. Reverse power protection.

9. Under-impedance protection.

10. Thermal over-load protection.

11. Negative sequence phase current protection.

12. Restricted earth-fault protection for star-connected secondary

winding of step-up transformer.

13. Over-frequency protection.

14. Under-frequency protection

15. Generator over-voltage protection.

16. Generator under-voltage protection.

17. Step-up transformer over-current protection.

18. Over-current protection for Unit Auxiliary Transformer.

19 Excitation transformer Over-current protection

20 Unit auxiliary transformer differential protection

21 Generator phase sequence check.

.


8.4.2 In addition, the following static (analog) protective relays shall be

provided

i. Negative phase sequence relay (46)

ii. IDMT Over current relay (51)

iii. Stator earth fault protection (64G)

The bidder may propose additional protection as an option.

8.4.3 Following protection provided on the generator transformers shall also be

integrated with the main protection described above:

i. Oil temperature indicator with alarm and trip control.

ii. Buchholz relay with alarm and trip control.

iii. Winding temperature indicator with alarm and trip control

iv. Oil gauge with low-level alarm.

8.4.4 Following mechanical protections shall be provided:

a. Resistance temperature detectors (Pt-100) in stator core and in the

bearings for indication, alarm and recording.

b. Turbine and generator bearing, metal and oil temperatures –

alarm/shutdown.

c. Governor oil pressure low to block starting and very low for emergency

tripping.

d. Over speed for normal and emergency shutdown depending upon its

extent.

e. Our speed relay-Mechanical And Electrical (12)


8.5 Protection for D.C System

i. Under-voltage protection for 220 V D.C.

ii. Under-voltage protection for 48V D.C.

iii. Earth-fault protection for 220V D.C.

iv. Earth-fault protection for 48V D.C.

8.6 Metering System

Power generated shall be metered at generator terminal through metering CT

and PT. The power transferred to 220 kV feeder shall also be metered though

CTs and PT. Following metering equipments shall be provided on relevant

panels.

1. kW meter

2. kWh meter

3. kVA meter

4. Ampere meter

5. Voltmeter

6. Power factor meter

7. Frequency/speed meter

8. Temperature meters.

8.7 SPARES



ANNEXURE VIII - I


AWARD OF CONTRACT.

Sr.

No

.


from the date

of award of

contract

Remarks

1 2 3 4

1. Circuit diagram/block diagram of all

protections listed in clause 8.4

6 For approval

2 Circuit diagram metering. 6 For reference

MANUALS.

1 2 3 4

1 Manual for storage, preservation and

handling of the supplied goods

12 For reference

2 Manual for erection / dismantling,

testing, setting and commissioning of

the supplied goods

12 For reference

3 Manual giving operating instructions

for all the ‘DO’s and ‘DONT’s’

18 For reference

4 Manual giving detailed maintenance

schedule

18 For reference

5 Manual for back up, loading software,

data supplied system.


ANNEXURE VIII- 2





DATA SHEETS

DATA SHEET P1


DATA SHEETS P1 TO P3 FOR TECHNICAL SPECIFICATIONS OF PROTECTION

SYSTEM AND METERING

*DATA SHEETS SHALL BE FULFILLED OBLIGATORILY BY BIDDER

D.

PROTECTION SYSTEM

1 Make

2 Type of numerical relays their functions

a. For Generators

b. For transformers

3 Built in testing facility

4 Methodology to provide redundancy

5 Type of back-up protection in case of failure of

numerical relays

a. For generators

b. For transformers

6 Parameter/command documentation

7 Maximum operating time

8 Sensitivity in %age of rated current

9 ANALOGUE INPUT VARIABLES

a. Rated frequency

b. Rated current

c. Thermal rating of current circuits

i. Continuous

ii. For 10 seconds

iii. For 1 second

iv. Dynamic


DATA SHEET P2


10 Rated Voltage

11 Thermal rating of voltage circuits (continuous)

12 Burden per phase

a. At rated current

b. At rated voltage

13 CURRENT TRANSFORMER REQUIREMENTS

a. Generator Protection

i. VA burden

ii. Saturation factor

iii. Minimum knee point voltage

iv. Maximum excitation current

b. Transformer Protection

i. VA burden


iii. Minimum knee point voltage

iv. Maximum excitation current

c. Feeder Protection

i. VA burden


iii. Accuracy class

C. ENERGY METERING SYSTEM

1 Make

2 Type

3 CT/PT connection direct or through transducers

5 Accuracy of meters

6 Accuracy of transducers, if any


DATA SHEET P3


7 Parameters measured

8 Maximum current rating for 1 second

9 Service voltage range and tolerance

10 Service frequency range and tolerance

11 Service temperature range

12 Power consumption

a. Current circuit

b. Voltage circuit

13 Service life

14 Protection against electromagnetic/radio interference

272

SECTION IX

SUPERVISORY CONTROL AND DATA ACQUISITION SYSTEM


273

SECTION IX


INDEX

Sr. no. Description Page no.

9.1 General requirement:- 274

9.2 Computer based SCADA system 274

9.3 Physical and Environmental Requirements 278

9.4 User and plant interfaces 279

9.5 Control parameters 282

9.6 SCADA controllers 283

9.7 Unit control board (UCB) 291

9.8 Factory testing 295

9.9 Site testing 295

9.10 Spares 296

Annexure VII - I 297

Annexure VII- 2 298


274

SECTION IX


9.1 GENERAL REQUIREMENT:-

1 Comprehensive system for automation of the power station complex

as a whole shall be provided by the supplier.

2. The plant to be controlled shall consist of the following :-

i) One no. Turbine-Generator set including all connected

auxiliaries.

ii) Station service auxiliaries

iii) 220 kV switchyard equipments.

3. The system shall use the most upto date & proven technology based

on microprocessors reliable transducers which require no, or little,

maintenance and/or calibration during services, and the

communication link of optical fibre.

4. The system shall be arranged to provide (2) two levels of controls: -

i) “Remote plant Control” in automation mode from Unit Control board

(UCB) or from LCD console and manual mode from UCB.

ii) “Local Unit control,” in manual mode from respective control cubicles

(generator excitation cubicle, auxiliary equipment control board and

generator voltage metal clad switchgear cubicle/etc.)

5. Normally, the plant control in remote automatic mode shall be used.

When the communication link is not available, or when the equipment

in central control room is being inspected and/or is under repairs, the

control and monitoring functions of the unit can be performed in Unit

Control in “Manual Mode,”.

9.2 COMPUTER BASED SCADA SYSTEM:-

9.2.1 Control scheme:

The unit control scheme shall include following sequence:

• Starting and stopping of essential auxiliaries like governor oil


275

pumps, cooling water, H.S. Lubricating pump and braking system

manually.

• After manual/auto start of auxiliaries, automatic starting of the

unit from stand still to speed no load condition.

• Synchronizing (Manual / Automatic)

• kVA / kVAR setting (Manual / Automatic)

• Control action shut down of the unit.

• Emergency shut down of the unit.

• Catastrophic shut down of the unit.

• Operation (Starting and stopping) of the unit from Unit Control

Board from control room.

While preparing the control scheme and providing controls, indications

the bidder shall keep in view that the excitation equipment and the governor

cubicle are proposed to be located in the control room. For Control panels

arrangement bidder shall keep in view the power house layout. In addition to

the protection signals, control action shut down and emergency shut down

shall be initiated by normal stop command and emergency stop command

respectively from control board. The indicating meters shall be 144 x 144 mm.

size Annunciator of static type shall be provided. The scheme shall include

auxiliary relays, timers, flags, relays, flicker relays, etc. complete.

9.2.2 System:

Computer based SCADA system shall be used. Computer based SCADA

system comprising of microprocessor based control technology physically

distributed through out the power house. The separate microprocessor units

are linked together by a number of digital communication paths to form a

completely integrated control system.

Microprocessor based control system comprising:

1. Integrated Operation Station (IOS)

2. Integrated Data base station (IDS)

3. Integrated Engineering Station (IES)

4. Printer.

5. Micro Controller (HDC)


276

6. Power Distribution Equipment (CVCF).

7. Main control board

8. Man machine Interface.

9. Computer system with main control board and function keyboard

9.2.3 Specifying response time

The bidder shall define response time speed of control system clearly. He

shall define following times:

• Time duration required to update a graphical display from the instant a field

contact changes state

• Time duration from the instant a control is activated at the operator station

until the command is implemented at the field device; and

• Over all time duration to process and log an alarm once it is received at the

computer. The specification shall define the acceptable time durations

for each of the above events in both normal leading and high activity

loading scenario. The computer system response times should be

verified at the factory acceptance test to confirm the system will

operate as required by specifications.

9.2.4 Software Requirements

The operating system:

The software shall run in a priority interrupt driven, multitasking operating

system. The system should provide each task with dedicated random access

memory to allow pre-emptive scheduling of tasks without loss of information.

Programming language

The controlling programs shall be written in a high level compiled language

whenever possible for ease in maintenance, with the exception of time critical

tasks which shall be written in assembly language. The code shall be

re-entrant and employ mutual exclusion techniques to prevent deadlock of

resources.

Standardization

The software shall reside in non-volatile EPROM memory, which shall not

require reloading for routine power interruptions to the controller.


277

Configurability

Configuring of the control software shall be accomplished via a menu driven

user-friendly program that will be run on an PC or compatible computer.

The configuring shall be able to be accomplished at an area remote from the

controller and shall not prevent operation of the controller during configuring

except during the transfer of the configuring information to the controller.

Functions

The software shall allow the operator to examine and modify those

parameters of the control software that will specify the operating conditions

and restrictions of a particular plant. These features shall include but are not

limited to:

- Timings

- Decision paths

- Set points

- Equation coefficients

- Enabling functions

- Plant description information

The software shall also allow for specifying particular contact inputs, analog

inputs and analog outputs. The software shall allow user designation and

titling of contact inputs. Analog scale factors shall be set via the configuring

program.

Communications

The configuring information shall be communicable with the controller via

standard RS-232C communications protocol. The communication shall have

the ability to be via voice grade telephone communication as well as a direct

connection with the controller.

Security

The configuring software shall provide a means of preventing unauthorized

access to the configuring information. Further it shall provide a means of

differentiating three or more security levels of configuring information to

create three or more depths of configuring accessibility.

Man-Machine Interface (MMI)

The operator’s station of the station controller (SCADA system) shall


278

have an elaborate and friendly man-machine interface. A 19” or larger

monitor shall be provided for the display. Provision shall be made for

connecting a second colour monitor in parallel. The screen displays

shall be suitably designed to provide information in most appropriate

forms such as text, tables, curves, bar charts, dynamic mimic diagrams,

graphic symbols, all in colour. An event printer shall be connected to PC

of the SCADA system. Events shall be printed out spontaneously as

they arrive. Provision shall be made to connect and use another printer

simultaneously. Touch control screen, voice and other advanced modes

of MMI are desired and shall be preferred. The entire customization of

software for MMI and report generation shall be carried out. A windows

based operating system shall be preferred.

9.3 Physical and Environmental Requirements

(i) Physical Requirements

The equipment shall be constructed on a modular basis, using plug-in

connection. The controller shall be suitable for mounting in a standard

19-inch rack with a minimum depth of 24 inches. Input/output

termination cabinets shall be internally labelled, to permit ready

identification of the incoming and outgoing wiring. The equipment shall

be of self protecting against surges that may be generated on power

supply bus by contact operation, circuit resonance, etc. External

connections shall utilize modular screw terminal blocks which shall be

shall be suitably mounted and readily accessible. Each terminal device

shall suitably identify all conductors. All wiring shall be clearly marked

and so designated on the drawing to permit identification for

maintenance. Wire not colour coded shall be identified by a wire number

marker on each end. All cables and jacketing material shall be oil,

moisture, and heat resistance thermosetting compounds under

operating conditions. Controller AC power connection shall be a

standard NEMA PI5-5 plug configuration.


279

(ii) Environmental Requirements

The controller and video display shall be capable of withstanding the

environmental conditions of the site of plant during air condition failure.

9.4 USER AND PLANT INTERFACES

9.4.1 User interfaces

The look and feel of a personal computer shall be desirable to reduce

special training. In order to make the system acceptable to the

operations personnel, care must be taken in the selection of the

hardware and software used.

9.4.2 Input devices

Input devices are not mutually exclusive and may be combined to

incorporate desired features.

9.4.3 Output devices

As with input devices, various output devices may be combined to

incorporate desired features. Some typical devices are as follows:

a) Printers..

b) CRT screens.

c) Mimic boards.

9.4.4 Plant Interfaces

Types

Plant interfaces include analog transducer signals, dry contacts (i.e.,

contacts without sensing voltages) and digital data. This clause covers

several generic types, however, installations may have special

application requirements to meet unique concerns.

Digital, contact, and pulse inputs

Digital or contact inputs shall meet minimum criteria for operations at the

voltages and current loads anticipated. The current required to drive the

input circuitry shall be adequate to ensure false indication changes do

not occur due to noise. The current shall be as low as possible to

conserve power and reduce heat generation. Wetting voltages (e.g.,


280

those voltages required to sense the status of dry contacts) may be

provided by the control system or the field device.

Contact bounce in the input signal can cause erroneous data in the

system. Digital inputs shall have filters to detect only sustained input

signals. These filters may be in the hardware or the software. Filters

must be selected in accordance with time tag accuracy. Simple low-

pass filters can introduce undesirable delays. Voltage levels for logic

detection shall be sufficient to prevent erroneous readings. Digital inputs

may also serve the functions of pulse accumulators or counters. This

function is normally in software or firmware at the I/O. Accuracy,

counting, and pulse accumulation rates shall be sufficient for the

intended use. Digital input status indicators, shall be provided.

Digital and contact outputs

Digital or Contact outputs provide data and control contacts for external

circuits. These contacts must have sufficient current and voltage rating

for the external load. These ratings must often be considered in total for

a given card or group of I/O as well as for individual circuits. Wetting

voltage is typically provided by the external circuit. The ability of the

solid-state devices in the output circuitry of the I/O to absorb the

required current (without thermal instability of the devices) is a function

of temperature (heat generation). Where higher current ratings are

required, interposing relays are typically installed. The current ratings

are then those of the interposing relays. Digital outputs may be latched,

momentary, or maintained. These functions may be implemented in

software or in the output relay. Digital output status indicators shall be

provided, similar to those on input I/Os. The failure state of digital

outputs shall be defined and specified.

Analog inputs

Analog inputs shall be low-level (e.g., 0-1 mA dc, 4-20 mA dc, 1-5 V dc,

etc.) current or voltage, resistance, or thermocouple signals.

Resistance or millivolt (thermocouple) inputs may be scaled to

engineering units by the I/O processor, or a separate RTD or


281

thermocouple to current or voltage converter located with the I/O. The

I/O is often capable of providing the loop power supply for analog inputs.

Voltage, tolerance, stability, and loading shall be considered. Scaling

accuracy, resolution, dead band, and thermal stability shall all be

specified to meet the needs of the applications. Thermocouple and RTD

replications shall meet the standard accuracy for these devices. Open

thermocouple detection is desirable. Common and differential mode

rejection ratios shall also be specified. When multiplexing technology is

used, the multiplexing hardware shall be solid-state and not

electromechanical. Multiplexing schemes must be fast enough to ensure

that the most recent values are available when required for all control

loops.

Analog outputs

Analog outputs are typically low-level voltage or current. Accuracy,

resolution, dead band, and thermal stability shall all be specified.

Analog-to-digital/digital-to-analog conversion

The accuracy of any analog input or output depends on the conversion

between the computer's digital data system and the analog information.

The conversion is typically performed by multi-bit A/D converters.

Conversion accuracy and resolution are a function of the number of A/D

converter bits and I/O amplifier design. Further, the accuracy is affected

by temperature-induced drift. Thus, A/D resolution, input accuracy, and

temperature stability shall all be specified.

9.4.5 Field devices and field bus standards

Another major source of interface signals are those originating from

intelligent electronic devices (IED) and intelligent field devices (e.g., a

field device capable of measuring more than one parameter and

transmitting the measured parameters over one pair of wires

9.4.6 Input/output protection

All inputs and outputs shall be specified to withstand the Surge

Withstand Capability (SWC) test, -as described in IEEE C37.90.1-1989,


282

without any false operations. The SWC test has proven to be a reliable

means to identify noise problems similar to those found in a

Hydroelectric powerhouse.

9.4.7 Grounding

Each equipment rack in which automation system components are

located shall be separately connected to the powerhouse ground mat by

a large gauge wire. Shielded cables shall be used for analog signals

between the transducers and the automation system. Each shield shall

be tied to the signal common potential at the transducer end of the

cable. If there is termination or junction boxes between the transducers

and automation system, each shield circuit shall be maintained as a

separate continuous circuit through such junction or termination boxes.

9.4.8 Static Control

Equipment shall be immune to static problems in the normal operating

configuration. Anti-static carpet and proper grounding for all devices that

an operator may contact shall be provided.

9..5 Control Parameters:

SCADA system shall be complete with primary sensors, cables

analysers/transmitters, monitors, system hardware/ software and peripherals

etc. to monitor/control the following parameters.

• Generator stator and rotor winding temperatures

• Generator and turbine bearing temperature

• Lubrication oil temperatures

• Status of generator cooling system

• Governor control monitoring of turbine speed

• Generator terminal voltage current KW, KVAR, KVA, KWH,

Hz, PF, field voltage and field current.

• Annunciation for violation of permissible limits of above parameter

• Turbine bearing temperature detector

• Generator bearing temperature detector

• Turbine bearings oil level indicator


283

• Generator bearing oil level indicator

• Generator winding temperature detector

• Turbine speed / Generator speed

• Governor oil pumps, oil pressure indicator and low pressure

indicator

• Cooling water valves, section and discharge pressure switch/ gauge.

• Inlet pressure gauge at inlet of turbine

SCADA shall provide monitoring of parameters listed above. The list may

have additional parameters as per requirement and shall be finalised during

design stage.

9.6 SCADA controllers:

SCADA shall have following controlles:

• Unit controller

• Common plant controller/ supervisory control

• Remote supervisory control

9.6.1 Unit Controller:

It shall be microprocessor based and is required to perform all functions as

below. It is required to have capability to implement closed loop PID function

for governing and to perform all monitoring, control, protection and recording

functions that a power plant required independently.

(a) It shall monitor and control items

• Turbine Nozzle opening/closing

• Turbine/ Generator RPM

• Generator power out put

• Generator excitation

(b) Automatic unit control modes shall include following:

• Unit automatic start sequence

• Unit automatic shutdown sequence

• Unit automatic synchronizing

• Unit Nozzle opening/closing set point control

• Unit load set point control

• Unit flow control

(c) The unit shall include digital governor with proportional, integral and

derivative gains. The governor be with in a position loop controlled by speed


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loop and capable of 0-10% droop. A manual position control shall be

provided. Following governing functions shall be provided.

• Speed evaluator

• Speed control

• Speed set point adjustment

• Nozzle opening/closing limiter

• Start up and shutdown control of turbine

• Position controller for Nozzle opening/closing with power amplifier for control

of servo valve.

(d) Unit Auto synchronisation

The controller shall be capable of synchronizing the generator to the 220 kV

bus by reading the slip frequency (generator-bus) and adjusting the governor

speed set point until the correct slip frequency is obtained while sending

voltage raise/lower pulses to the voltage regulator to match generator voltage

to bus voltage. When the slip frequency is obtained and the generator and

bus voltage are equal, the controller shall send a close breaker command to

220kV Circuit Breaker when the generator voltage and the bus are in phase.

An additional external synchro check relay shall also be provided to supervise

the controller close breaker command and the manual close breaker

command. The controller shall follow synchronization limits in terms of

breaker closing angle and voltage matching condition specified by generator

manufacturer.

(e) Shutdown sequence

The shutdown sequence provided by controller shall be such that the turbine

generator set from any moving state to a complete standstill with all

auxiliaries correctly shutdown. The unit controller shall automatically shut

down if the control system detects turbine mechanical system faults;

generator electrical faults or specific shut down conditions are generated with

in system. Following three types of shutdown to be performed on the

turbine/generator set shall be provided by the controller.

(i) Normal shutdown

A normal shutdown shall be initiated by a shutdown command that has been

issued by an operator either from the panel mosaic or the supervisory system

locally or remotely. This sequence shall allow the plant to be shutdown in a


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standard orderly manner. After the plant has completely shutdown it shall

return to a state in which it can be restarted again on the issuing of a start up

command.

(ii) Emergency shutdown

An emergency shutdown shall be initiated if a failure occurs in a critical item

of plant, which is likely to cause unsafe operation of plant such as an

electrical trip. The plant shall quickly and safely shutdown with lockout to

avoid damage to plant or injury to personnel. The plant shall be blocked from

restarting again until the fault is rectified and acknowledged by the operator

from either the UCB or the supervisory system.

(iii) Rapid shutdown

A rapid shutdown is initiated if a safety trip occurs on the plant. The plant is

rapidly shutdown taking care not to cause unfavourable effects such as

pulsations, backwater surges and suction waves. The plant is blocked from

restart

(iv) Unit start-up sequencing

The controller shall allow the unit to be started manually (if all permissive are

met) and bring generating unit speed to synchronous speed. Alternately if

automatic start up mode is selected either locally or remotely then unit shall

automatically start provided all the start up permissive are met. The unit

controller shall allow parameters of the start-up sequence to be configured to

match the turbine generator.

(v) Lockout

The controller shall include a generator lockout function. Whenever the

lockout function is on it shall inhibit the generator from starting. Any alarm

shall be configurable as a lockout alarm. The lockout shall be reset with a

command entered on the keyboard. When the lockout is on, it shall be

displayed on the screen annunciator.

(vi) Auto restart

The controller shall be capable of automatically restarting the turbine after

certain shutdowns if so enabled and if the lockout is not set. The time to wait

for a restart and the enabling of the restart function shall be configurable.


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(vii) Automatic power control modes

The unit controller when the unit is not under plant control mode shall be

capable of several forms of automatic power control. The operator shall be

able to select automatic power control modes at any time and enter a new set

point at any time. .The available power control modes shall meet the

requirements of system.

• Nozzle opening/closing position shall be automatically controlled to match

the nozzles to a position set point.

• Nozzle opening position shall be controlled to match the kW output of the

generator to a kW set point. Regardless of the kW set point, the generator

output shall be limited by a maximum kVA limit specified during configuration.

• Nozzle opening position shall be controlled to match a flow set point that is

calculated by the controller from a flow versus gate Nozzle opening position

curve for the operating head which is entered during the configuration

process.

(viii) Override control

• The controller shall provide at least two override controls that when enabled

will take over turbine control from the Automatic Power Control mode when

certain set point limits are reached. When these interim conditions return to

normal, the controller shall automatically revert to the primary automatic

power control mode.

• The controller shall modulate the turbine output so that the measured

generator stator temperature (hottest of the three phases) does not exceed

the Temperature Control set point.

(ix) Reactive power control

The controller shall have four reactive control modes, one manual and three

automatic. The generator capability curve shall be entered into the controller

during configuring. All automatic reactive power control modes shall be limited

by the generator capability curves. If an operator enters a set point, that will

take the generator outside its capability curves, the reactive power control

program shall control reactive power to get as close to the set point as

possible, but remain within the generator's capability.


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• Manual:

The controller shall provide operator capability, using "raise/lower"

keys on the VDT keyboard and the "raise/lower" switch on the manual control

panel to control voltage and reactive power.

• Automatic VAR control:

The controller shall automatically control the generator output to that VAR set

point set by operator. The generators voltage limit and capability curve shall

not be exceeded regardless of the VAR set point.

• Automatic PF Control:

The operator shall enter power factor set point from the keyboard and the

controller shall automatically control the generator output to that power factor

(leading or lagging) set point set by operator. The generator voltage limit and

capability curve shall not be exceeded regardless of the power factor set

point.

• Automatic voltage control:

The controller shall automatically control the generator output to match that

voltage set point set by operator. The generator's voltage limit and capability

curve shall not be exceeded regardless of the voltage set point.

• Alarm Annunciation

There shall be two types of alarms used by the controller. One type shall be

the external alarms from contacts fed into the digital inputs of the controller

and the second, the internal alarms generated by the controller. All alarms,

whether internal or external, shall be capable of being configured to cause

different sequences. Unit controller shall be capable of providing audible and

visual alarms in the event of faults occurring in the power plants. The instant

the fault occurs the relevant fault indicator is activated. All faults have to be

acknowledged by the operators and can only be reset when the fault has

been resolved. On the occurrence of faults audible warning shall be activated

to attract the attention of the plant operators.

(x) Unit Protection

The protection system shall be based on the use of discrete

Microprocessor based relays with the following features:

• Continuous self monitoring

• Online display of actual values


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• Shall be capable to communicate with supervisory system through unit

controller The bidder may also quote for multifunctional numerical relay.

9.6.2 Supervisory Controller

It shall monitor and control the status of power plant, provide automatic

unmanned operation, log data, display the process through a mimics,

supervise water levels of reservoir, start up and shutdown of units, control

manually control auxiliary and alarm monitoring. All such control shall subject

to passward-bases security system. Depending on the station requirements,

the operator shall be able to enter set points for power output, voltage and

power factor. It shall also have online documentation and expert diagnostics,

efficiency management and plant management.

(i) Operating Regimes:

The plant shall be controlled either manually or automatically under different

operating regimes. Following operating regimes may be provided.

a) Plant efficiency control mode:

In this mode of operation, the automatic control system shall maximize the

plant's energy production for a given headwater level. To achieve this, the

system shall automatically select with the most efficient unit loading point to

dispatch all available water for a particular gross operating head. The

operator shall be able to specify the order in which unit is to be started and

stopped by the control system.

b) Reactive power control mode:

In this mode of operation, the control system shall automatically adjust the

excitation field current to maintain the output power factor or VARs within a

defined range (i.e., leading or lagging). The operator shall be capable of

entering a set range that the power factor or VARS must fall within for each

unit. The control system shall maintain the unit's output power factor or VARs

within this set range unless limited by the generator capability curve or the

exciter output current capability. The system shall verify that the VAR set

point is an identical percentage of rated output for all units when used in

conjunction with automatic load sharing control.


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ii) Operator Interface Requirements:

The controller shall use a video display terminal or PC as the main operator

console. It shall have powerful graphical user interface to the operators. The

operator shall be able to completely operate the plant by typing

commands/function key on the keyboard or by push button on control panel.

All information required to operate the plant shall be shown on the screen. A

printer shall be used to print out plant information. Symbols and colours

specified in the international standard IEC 204 shall be used for display.

iii) Screen display:

The screen display shall include all metering, indication and annunciator

information normally displayed on a typical power plant control panel. This

shall include all metered data such as three phase generator volts and amps,

generator watts, VARS, power factor, speed and frequency. This display shall

also show generator stator and bearing temperatures, breaker status, line

volts, line frequency, and kilowatt-hours. The time and date shall also be

displayed with time to the minute. Screen data shall be updated promptly

whenever actual data changes. Alarm and status information shall be

updated within one second of actual changes. Analog data shall be updated

within two seconds of a change. Calculated value such as temperature, watts,

VARS, and power factor shall be updated within five seconds of an actual

change. All DC analog readings on the screen display shall have configurable

scale factors. All except speed shall have configurable labelling on the

screen.

The AC scaling shall be configurable by specifying WYE or DELTA and

maximum AC voltage and current.

Data shown on the display shall have the following minimum accuracies.

AC Voltage 1% of full scale

AC Current .1% of full scale

Frequency ± .005 HZ

DC Inputs .25% of full scale

KW,KVAR, PF .25% of full scale

Temperatures + .5 degrees C


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iv) Annunciator display:

A portion of the screen shall be dedicated for an annunciator. Alarms shall be

displayed in order of occurrence with the oldest alarm at the top of the

screen. The sequence of alarms shall be distinguishable if alarms are more

than 1/60 th of a second apart. The display shall include space for a least 23

alarms. When 20 an alarm clears, the alarm below it shall move up to fill in

the blank space keeping the sequence. No alarms shall be lost. Any alarms

that do not fit on the screen shall be save until these is room. Alarms shall

flash until the acknowledge key on the keyboard is presses. If the alarm is still

on after it is acknowledged, it shall stop flashing but remain on the screen. If

the alarm has cleared, it shall disappear from the screen when the

acknowledge key is pressed.

The annunciator shall display both alarms that are internally generated by the

controller and alarms that are sensed external to the controller. The controller

shall be capable of generating a contact closure (option) on selected alarms

for use with a horn or telephone dialler.

v) Control status display:

The display shall include an indication of the status of the turbine i.e., starting,

stopped, synchronizing, etc...

vi) Automatic control status display:

The display shall show the current automatic control mode, its set point,

turbine nozzle opening limit, and any overriding control modes.

vii) DT Keyboard:

The keyboard shall be a standard keyboard with upper and lower cases, ten

key numeric pad and at least ten function keys. The function keys shall be

assigned important functions. The operator shall be able to start and stop the

turbine from the keyboard using simple commands. The operator shall be

able to enter set points via keyboard, select any one of automatic power

control modes and select any one of reactive power control modes.


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viii) External Interface

Supervisory Controller shall have a number of protocol modules which shall

provide connectivity to other devices including remote terminal units and

programmable logic controllers.

ix) Event Recording and Data Logging

(a) Data logging

Their shall be a provision for a data logging printer at the plant to provide data

logging at adjustable intervals, trouble logs and operator comments entered

manually at the keyboard. The data logging interval for each printers shall be

adjustable by the operator in increments of one minute.

(b) Alarm and status logging

All alarms annunciated on the screen shall be recorded on the data log, time-

tagged to 1/60 of a second resolution. Plant status or operational changes

shall also be recorder on the data log, time-tagged to 1/60 of a second

resolution. The operator shall be able to enter comments on the log manually

through the keyboard.

(c) kWH logging

Plant watthours shall be accumulated and recorded on the data log at both

daily and monthly intervals. The integrated power generation controller shall

have the capability to accumulate these data by one of two methods:

internally, by a calculation method based on direct monitoring of generator CT

and PT inputs, or externally, by receiving and totalizing counts from pulse

initiator output from an external watthour meter.

9.7 UNIT CONTROL BOARD (UCB)

Unit Control Board shall be installed in Control Room.

Controls, Indications, Alarms etc. required on UCB are given below :

1. All control switches required for manual operation shall be mounted on

this board.

The following controls will be provided: � Switches � Emergency push button (mechanical).


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� Generator anti-condensation heater ON & OFF switch. � Panel heater ON and OFF switch. � Alarm acknowledges push button. � Healthy trip circuit test push button. � Reset push button. � Servomotor opening/ closing switches � Breaker ON/OFF push buttons. � Voltage raise/lower spring return switch. � Any other control as deemed fit.

2. Following control switches for Auto operation of plant shall be provided on UCB

a) Unit Start/Stop

b) Auto Manual

c) Emergency Stop

3. Three annunciation windows shall be provided.

a) Operation indication window

b) 30 window annunciator for Electrical fault

c) 30 window annunciator for Mechanical fault

4. Digital clock for indication of time

5. Digital type temp. scanner (0-150oc) with selector switch for temperature

indication of selective equipments of power plant such as stator, rotor,

bearing etc. shall be provided.

6. Following meters shall be provided.

- Nozzle opening Limiter Position Indicator (0-100%)

- Nozzle opening Position Indicator (0-100%)

- Runner Limiter Position Indicator (0-100%)

- Runner Position Indicator (0-100%)

- Generator Voltage Meter with Selector Switch

(0-20 kV)

- Generator Current Meter with Selector Switch

(0-1kA)

- Generator MW meter (MW-0-20 MW)

- Generator MVAR Meter

- Generator Power Factor Meter (0.9 over excited ....1.0

...0.9 underexcited).


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- Frequency Meter 45-55 Hz

- Field Voltage Meter 0-500 V

- Field Current Meter 0-200A

- Turbine Speed Indicator 0 to 500 rpm

- Speed/Load Setting Indicator.

- Running Hour Meter (Hours)

Indication Lamps The following indications will be provided on the control panel:

• Phase indication lamps on incoming and outgoing panels

• Unit circuit breaker on

• Unit circuit breaker off

• Auto trip-electrical fault

• Auto trip-mechanical fault

• Governor low oil pressure

• Healthy trip circuit

• DC supply fail

• Generator anti-condensation heater ON

• Any other indication as required

7. Dual channel AUTO/MANUAL Synchronizer shall be provided. Auto

synchroniser shall consist of following modules :-

PHASE DETECTION MODULE :

This module shall detect the phase difference between generator and grid

voltage. Output of the module shall be a pulse train whose width shall vary

as the phase difference.

FREQUENCY DIFFERENCE MEASUREMENT MODULE :

This shall measure the frequency difference between the generator and grid

voltage in the frequency difference of 0.01Hz to 1.00 Hz.

POLARITY MODULE :

This module shall compare the frequency difference obtained with the set

value. (The set value is the one which is set on the front plate of the module)

The module shall then generate control signals for frequency matching.

VOLTAGE DIFFERENCE MEASUREMENT MODULE :

This shall measure the voltage difference between the generator voltage and

grid voltage and generate control signals for voltage matching.


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VOLTAGE COMMAND MODULE:

This shall issue final command to AVR for raising or lowering the generator

voltage depending upon the measured condition. Interposing relays shall be

provided for this purpose.

FREQUENCY COMMAND MODULE :

This shall issue the final command to the E.H.G for lowering or raising the

generator frequency depending on the measured condition. Interposing relays

shall be provided for this purpose.

BREAKER COMMAND MODULE :

After the voltage and frequency are matched this module shall issue the

closing command to the breaker. It shall also take into account the breaker

closing time which can be set on the front plate of the module.

AUTOMATIC POWER OFF MODULE :

After synchronisation, the feed back is received in this module which shall

switch off the auto synchroniser.

POWER SUPPLY MODULE:

This module shall accept the input voltage of 230V A.C. and generate

necessary voltage required for functioning of auto synchroniser.

Synchronising Bracket

The synchronizing bracket will be mounted on left hand side of the panel and shall be of swinging type and will have following provisions:

Quantity Description

• 1 Synchroscope

• 1 Double voltmeter

• 1 Double frequency meter

• 1 Synchronising check relay (25) with guard relay

• 1 Synchronising selector switch

• 1 set Auxiliary relays

• 1 Synchronising lamp


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9.8 FACTORY TESTING

9.8.1 Equipment Tests

Each individual equipment shall be routine tested as per IEC/IS at the work’s of supplier in presence of Owner.

9.8.2 System Tests

The contractor shall organize and execute a complete factory test of the system. The system shall be erected in his workshop in the engineered configuration and shall be tested for the following:

i. Operation requirements ii. Operating characteristics iii. Response times iv. Software functions v. Deficiencies

Various process signals shall be simulated for carrying out above system tests. The Supplier shall submit routine test reports of each equipment and the total system.

9.9 SITE TESTING

The contractor shall carryout tests at site as per relevant IEC/IS standards as follows in the presence of and to the entire satisfaction of the owner:

i. Calibration checks (on sample basis) on all factory calibrated

meters and transducers. ii. Acceptance tests on all other devices fitted on the control panels

and earlier tested in factory.

iii. IR tests on panels. iv. Continuing and IR tests on external cablings.

v. Calibration checks/acceptance tests on all devices and equipment

connected to the control panels. vi. Functional checks on each equipment/object controlled from unit

controllers with control circuits de-energised.

vii. Functional checks on controllers with power circuits de-energised.


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viii. Verification of all manual control functions from unit control panels.

ix. Verification of all control sequences from unit controllers with power and control circuits energised.

x. Watch up each generating unit and perform all start/stop

sequences on it.

9.10 SPARES



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ANNEXURE VIII - I

List of drawings, designs and manuals to be submitted by the Supplier after the

award of contract.


AWARD OF CONTRACT.

Sr.

No

.


from the date

of award of

contract

Remarks

1 2 3 4

1. Circuit diagram/block diagram of all

SCADA system

6 For approval

2 Circuit diagram of various controls 6 For approval

3 Circuit diagram of Unit control Board For approval

MANUALS.

1 2 3 4

1 Manual for storage, preservation and

handling of the supplied goods

12 For reference

2 Manual for erection / dismantling,

testing, setting and commissioning of

the supplied goods

12 For reference

3 Manual giving operating instructions

for all the ‘DO’s and ‘DONT’s’

18 For reference

4 Manual giving detailed maintenance

schedule

18 For reference

5 Manual for back up, loading software,

data supplied system.


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ANNEXURE VIII- 2




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