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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
INTENT OF THE SPECIFICATIONS
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
Signature of Bidder Signature of Purchaser 3
SECTION- I
INTENT OF THE SPECIFICATIONS
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 :
Signature of Bidder Signature of Purchaser 4
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.
Signature of Bidder Signature of Purchaser 5
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
Signature of Bidder Signature of Purchaser 6
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
Signature of Bidder Signature of Purchaser 7
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
Signature of Bidder Signature of Purchaser 8
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.
Signature of Bidder Signature of Purchaser 9
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
Signature of Bidder Signature of Purchaser 10
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
Signature of Bidder Signature of Purchaser 11
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.
Signature of Bidder Signature of Purchaser 12
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.
Signature of Bidder Signature of Purchaser 13
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
Signature of Bidder Signature of Purchaser 14
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
Signature of Bidder Signature of Purchaser 15
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
Signature of Bidder Signature of Purchaser 16
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,
Signature of Bidder Signature of Purchaser 17
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.
Signature of Bidder Signature of Purchaser 18
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
Sr.no. Description Page no.
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
Signature of Bidder Signature of Purchaser
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
Signature of Bidder Signature of Purchaser
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,
Signature of Bidder Signature of Purchaser
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.
Signature of Bidder Signature of Purchaser
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
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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
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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
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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
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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
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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
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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
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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
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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
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– 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.
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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.
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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.
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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.
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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.
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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.
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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
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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
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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
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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
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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.
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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.
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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.
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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.
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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
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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)
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- 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.
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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)
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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)
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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
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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)
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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
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SECTION III
SCHEDULE OF REQUIREMENTS
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SECTION III
SCHEDULE OF REQUIREMENTS INDEX
Sr.no. Description Page no.
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
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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
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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
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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.
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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.
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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.
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Item No. Description Quantity
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
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Item No. Description Quantity
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.
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Item No. Description Quantity
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
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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)
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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.
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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 :
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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
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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).
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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.
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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.
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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.
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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.
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3.11SPARES
MANDATORY SPARES FOR ELECTRICAL LOT
Item No. Description Quantity
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
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Item No. Description Quantity
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.
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Item No. Description Quantity
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
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Item No. Description Quantity
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
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SECTION IV
TECHNICAL SPECIFICATION OF GENERATOR
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
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SECTION IV
TECHNICAL SPECIFICATION OF GENERATOR
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.
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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
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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
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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
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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
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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
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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
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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.
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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
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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
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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
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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
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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.
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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
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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
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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
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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.
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- 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.
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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
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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.
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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
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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.
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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.
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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
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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.
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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
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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.
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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.
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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 √
Dimensional check √
High voltage test √
Test for short circuited turns √
Weight check √
Acceptance Test of each piece
(H.V.Test)
√
5) DAMPER BAR
Hardness Test √
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Sr.No
.
Particular of Test 1 2 3 4 5 6 7 8 9 10 11
Visual check √
Dimensional check √
Electric conductivity Test √
Acceptance Test on 5% of
consignment
√
6) DAMPER SEGMENT RAW
Hardness Test √
Visual check √
Dimensional 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
√
Chemical Analysis √
Ultrasonic Test √
Visual Test √
Dimensional Test √
Acceptance Test of each piece √
9) POLE END PLATE
MACHINING
Visual check √
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Sr.No
.
Particular of Test 1 2 3 4 5 6 7 8 9 10 11
Dimensional check √
Acceptance Test of each piece √
10) POLE BOLTS
Tensile Test √
Chemical analysis √
Visual check √ √
Dimensional check √
11) ROTOR LAMINATION
Tensile Test √
Notched Bar Impact Test √
Chemical Analysis √
Ultrasonic Test √ √
Aging characteristic √
Acceptance Test of each piece √
12) STATOR LAMINATION SHEETS
Tensile Test √
Chemical analysis √
Visual check √ √
Dimensional check √ √
Induction Test with determination
of specific losses at 1.0 and 1.5 t
√
13) STATOR PUNCHING
Tensile Test √
Chemical analysis √
Visual check √ √
Dimensional check √ √
14) STATOR RIM BOLTS
Tensile Test √
Chemical analysis √
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Sr.No
.
Particular of Test 1 2 3 4 5 6 7 8 9 10 11
Visual check √
Dimensional check √ √
15) STATOR FRAME
Tensile Test √
Notched Bar Impact Test √
Chemical Analysis √
Ultrasonic Test √ √
Aging characteristic √
Acceptance Test of each piece √
Trial Assembly √
16) STATOR WINDING BARS
FINISHED
Tensile Test √
Visual Test √
Dimensional check √
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 √
Dimensional check √
Hydrostatic Test √
18) OIL COOLERS (EACH)
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Sr.No
.
Particular of Test 1 2 3 4 5 6 7 8 9 10 11
Tensile Test √
Visual Test √
Dimensional check √
Hydrostatic Test √
19) GENERATOR SHAFT
Material Analysis √
Tensile Test √
Notch Impact Test √
Visual Inspection √
Magnetic particles Examination √
Ultrasonic Test √
Dimensional check √
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, √
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Sr.No
.
Particular of Test 1 2 3 4 5 6 7 8 9 10 11
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
√
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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,
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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
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- 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.
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- 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
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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.
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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
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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
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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
Signature of Bidder Signature of Purchaser
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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
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ANNEXURE IV-2
DEPARTURE FROM SPECIFICATION
(To be filled in by Bidder)
----------------------------------------------------------------------------------------------------
Item. Description of departure. Reference
to clause in the
specification.
----------------------------------------------------------------------------------------------------
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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.
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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)
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DATA SHEET E2
Bidder's Remarks (if any)
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)
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DATA SHEET E 3
Bidder's Remarks (if any)
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)
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DATA SHEET E4
Bidder's Remarks (if any)
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)
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DATA SHEET E5
Bidder's Remarks (if any)
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)
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DATA SHEET E6
Bidder's Remarks (if any)
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)
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DATA SHEET E7
Bidder's Remarks (if any)
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)
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DATA SHEET E8
Bidder's Remarks (if any)
- 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)
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DATA SHEET E9
Bidder's Remarks (if any)
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)
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DATA SHEET E10
Bidder's Remarks (if any)
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)
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DATA SHEET E11
Bidder's Remarks (if any)
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)
- initial symmetrical three phase short-circuit current
(rms-value)
I" K3= ……… p.u. (o)
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DATA SHEET E12
Bidder's Remarks (if any)
- 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)
- initial symmetrical three phase short-circuit current
(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)
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DATA SHEET E13
Bidder's Remarks (if any)
- 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)
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DATA SHEET E14
Bidder's Remarks (if any)
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)
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DATA SHEET E15
Bidder's Remarks (if any)
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)
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DATA SHEET E16
Bidder's Remarks (if any)
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)
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DATA SHEET E17
Bidder's Remarks (if any)
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.
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..................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)
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.................. DATA SHEET E19
Bidder's Remarks (if any)
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)
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DATA SHEET E20
Bidder's Remarks (if any)
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
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DATA SHEET E21
Bidder's Remarks (if any)
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
(b) Name of manufacturer
(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
(b) Name of manufacturer
(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
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DATA SHEET E22
Bidder's Remarks (if any)
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.
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DATA SHEET E23
Bidder's Remarks (if any)
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
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DATA SHEET E24
Bidder's Remarks (if any)
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
(c) Dimensions (L x B x H)
R. Heaviest assembly to be lifted by power house crane
(a) Name
(b) Weight
(c) Dimensions (L x B x H)
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TABLE NO.1 DATA SHEET E25
Bidder's Remarks (if any)
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
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TABLE NO.2 DATA SHEET E26
Bidder's Remarks (if any)
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
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
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TABLE NO.3 DATA SHEET E27
Bidder's Remarks (if any)
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
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
164
SECTION – V
TECHNICAL SPECIFICATIONS OF TURBINE
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SECTION – V
TECHNICAL SPECIFICATIONS OF TURBINE
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
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SECTION – V
TECHNICAL SPECIFICATIONS OF TURBINE
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
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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
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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
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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.
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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.
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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
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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
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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.
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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
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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.
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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.
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* 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
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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
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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
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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
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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.
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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.
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* 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
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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
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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
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• 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.
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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
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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.
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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.
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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.
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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
DRAWINGS, DESIGNS AND MANUALS TO BE FURNISHED AFTER
AWARD OF CONTRACT.
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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
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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
DEPARTURE FROM SPECIFICATION
(To be filled in by Bidder)
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----------------------------------------------------------------------------------------------------
Item. Description of departure. Reference
to clause in the
specification.
----------------------------------------------------------------------------------------------------
DATA SHEETS
DATA SHEETS M1 TO M13 FOR TECHNICAL SPECIFICATIONS OF
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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
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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:
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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)
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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 )
DATA SHEET –M3 Bidder’s Remark (if any)
7. Time of nozzle closing for regulation ------- secs.
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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
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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)
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[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.
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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)
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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)
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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)
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DATA SHEET –M9 Bidder’s Remark (if any)
- 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)
DATA SHEET –M10 Bidder’s Remark (if any)
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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
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DATA SHEET –M11 Bidder’s Remark (if any)
* 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)
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DATA SHEET –M12 Bidder’s Remark (if any)
- 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)
Signature of Bidder Signature of Purchaser
214
DATA SHEET –M13 Bidder’s Remark (if any)
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
(c) Dimensions (L x W x H)
U Heaviest assembly to be lifted by power house crane
(a) Name
(b) Weight
(c) Dimensions (L x W x H)
215
SECTION VI
TECHNICAL SPECIFICATION OF SPHERICAL VALVE
Signature of Bidder Signature of Purchaser 216
SECTION VI
TECHNICAL SPECIFICATION OF SPHERICAL VALVE
INDEX
Sr.no. Description Page no.
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
Signature of Bidder Signature of Purchaser 217
SECTION VI
TECHNICAL SPECIFICATION OF SPHERICAL VALVE
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
Signature of Bidder Signature of Purchaser 218
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.
Signature of Bidder Signature of Purchaser 219
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.
Signature of Bidder Signature of Purchaser 220
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.
Signature of Bidder Signature of Purchaser 221
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.
Signature of Bidder Signature of Purchaser 222
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
Signature of Bidder Signature of Purchaser 223
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.
Signature of Bidder Signature of Purchaser 224
� 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
Signature of Bidder Signature of Purchaser 225
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.
Signature of Bidder Signature of Purchaser 226
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:
Signature of Bidder Signature of Purchaser 227
SUBMISSION OF TEST CERTIFICATES
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
Signature of Bidder Signature of Purchaser 228
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
√
√
Signature of Bidder Signature of Purchaser 229
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.
Signature of Bidder Signature of Purchaser 230
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
Signature of Bidder Signature of Purchaser 231
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
Signature of Bidder Signature of Purchaser 232
ANNEXURE VI-2
DEPARTURE FROM SPECIFICATION
(To be filled in by Bidder)
----------------------------------------------------------------------------------------------------
Item. Description of departure. Reference
to clause in the
specification.
----------------------------------------------------------------------------------------------------
Signature of Bidder Signature of Purchaser 233
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.
Signature of Bidder Signature of Purchaser 234
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)
Signature of Bidder Signature of Purchaser 235
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.
Signature of Bidder Signature of Purchaser 237
SECTION VII
TECHNICAL SPECIFICATIONS OF STATION AUXILIARIES.
INDEX
Sr.no. Description Page no.
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
Signature of Bidder Signature of Purchaser 238
SECTION VII
TECHNICAL SPECIFICATIONS OF STATION AUXILIARIES.
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
Signature of Bidder Signature of Purchaser 239
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
Signature of Bidder Signature of Purchaser 240
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.
Signature of Bidder Signature of Purchaser 241
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)
7.2.2.1 Scope of Supply
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
Signature of Bidder Signature of Purchaser 242
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.
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 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
included in supplier’s scope) shall be supplied. Cables for interconnection
between computer and computer based control panel shall also be supplied.
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.
Signature of Bidder Signature of Purchaser 243
7.2.2.5 Shop Tests
The shop tests on drainage / dewatering system shall include:
i) Dielectrics and insulation tests on all electric motors,
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:
i) Dielectrics and insulation tests on all electric motors,
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
Signature of Bidder Signature of Purchaser 244
7.2.3.1 Scope of Supply
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.
Signature of Bidder Signature of Purchaser 245
LUBRICANTS.
Sufficient quantity required for first fill of lubricant, grease, oil etc. plus 25%
extra shall be supplied and included in bid cost.
CABLES.
All power and control cables with clamps, trays, ferrules etc. (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.
7.2.3.3 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.
Signature of Bidder Signature of Purchaser 246
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.
Signature of Bidder Signature of Purchaser 247
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
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 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:
Signature of Bidder Signature of Purchaser 248
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.
Signature of Bidder Signature of Purchaser 249
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
Signature of Bidder Signature of Purchaser 250
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
dewatering system 4 For approval
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,
Signature of Bidder Signature of Purchaser 251
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
dewatering system 2 For approval
4. Adequacy of compressed air
systems including capacities
of compressors and air receivers. 2 For approval
Signature of Bidder Signature of Purchaser 252
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
Signature of Bidder Signature of Purchaser 253
ANNEXURE VIII- 2
DEPARTURE FROM SPECIFICATION
(To be filled by Bidder)
Item Description of departure Reference to Clause in specification
Signature of Bidder Signature of Purchaser 254
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
Signature of Bidder Signature of Purchaser 255
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)
Signature of Bidder Signature of Purchaser 256
DATA SHEET A2
Bidder’s Remark (if any)
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 .............
Signature of Bidder Signature of Purchaser 257
DATA SHEET A3
Bidder’s Remark (if any)
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 - ...........
Signature of Bidder Signature of Purchaser 258
DATA SHEET A4
Bidder’s Remark (if any)
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
Signature of Bidder Signature of Purchaser 259
DATA SHEET A5
Bidder’s Remark (if any)
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
Signature of Bidder Signature of Purchaser 260
iii. Designed flow rate
DATA SHEET A6
Bidder’s Remark (if any)
iv. Material
v. Motor capacity
vi. No. of strainers used
261
SECTION VIII
TECHNICAL SPECIFICATION OF PROTECTION AND METERING
Signature of Bidder Signature of Purchaser 262
SECTION VIII
PROTECTION AND METERING DETAILS
INDEX
Sr.no. Description Page no.
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
Signature of Bidder Signature of Purchaser 263
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.
Signature of Bidder Signature of Purchaser 264
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.
.
Signature of Bidder Signature of Purchaser 265
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)
Signature of Bidder Signature of Purchaser 266
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
Spares shall be supplied as per the list under Section - III of this volume.
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ANNEXURE VIII - I
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
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.
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ANNEXURE VIII- 2
DEPARTURE FROM SPECIFICATION
(To be filled by Bidder)
Item Description of departure Reference to Clause in specification
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DATA SHEETS
DATA SHEET P1
Bidder’s Remark (if any)
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
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DATA SHEET P2
Bidder’s Remark (if any)
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
ii. Saturation factor
iii. Minimum knee point voltage
iv. Maximum excitation current
c. Feeder Protection
i. VA burden
ii. Saturation factor
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
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DATA SHEET P3
Bidder’s Remark (if any)
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
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SECTION IX
SUPERVISORY CONTROL AND DATA ACQUISITION SYSTEM
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
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SECTION IX
SUPERVISORY CONTROL AND DATA ACQUISITION SYSTEM
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
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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)
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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.
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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
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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.
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(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.,
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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
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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,
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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
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• 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
Spares shall be supplied as per the list under Section - III of this volume.
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ANNEXURE VIII - I
List of drawings, designs and manuals to be submitted by the Supplier after the
award of contract.
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
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
DEPARTURE FROM SPECIFICATION
(To be filled by Bidder)
Item Description of departure Reference to Clause in specification