BREATHERMinimum 3 (Three) nos. dehydrating filter Silica Gel Breathers each of100% breathing capacity are required and the same shall be provided. Sizeof breather and its pipe connection is to be indicated. However, each breatherof minimum capacity of 8 Kg having its pipe connection of minimum size ofMPPTCL/TECH/PROC/01/JULY 13 Page 55 of 125one inch dia shall be preferable. Suitable arrangement for parallel mountingof breathers shall be made for connecting Silica Gel Breathers to the mainconservator. The passage of air should be through dual filter & Silica Gel.Silica Gel shall be isolated from atmosphere by an oil seal. Adequate supportsare required to be provided for pipe connection to avoid any swing in air.The capacity of silicagel breather shall be adequate to ensure supply ofdry air only for the volumetric expansion/contraction of oil keeping in view thetotal quantity of oil in the unit. The container of the breather shall be madeof metal with glass enclosure along its periphery to ensure that thetransparency (to verify the colour of dehydrating agent) is maintained duringoperation directly under sunlight (ultra violet rays) for long life. The quantityof the dehydrating agent shall be sufficient keeping in view the climaticcondition specified and that the breather will be maintained generally twotimes in a year. This applies to all the breathers provided with thetransformer.20.12 SURGE CAPACITORS: The Bidder has to provide with each 400 KV315 MVA transformer , three (3) nos 40 KVrms , 0.125 mocro farad SurgeCapacitors with mounting structure & terminal connectors for connection to72.5 KV tertiary bushings. The complete technical particulars of capacitor unitshas been specified in Annexure I. The constructional features of the surgecapacitors shall be as under :a) The dielectric fluid within the capacitor unit shall be environmentally safeand biodegradable. PCB type fluid shall not be used. The capacitorelements shall be vacuum dried inside the case prior to impregnationwith dielectric fluid. After impregnation, the capacitor unit shall be sealedimmediately upon removal of impregnating reservoir.b) The capacitor shall include bushings, discharge resistor, capacitorelements connected in series and/or parallel, internal connections etc. Alljoint of casing shall be tested for leaks.c) Each capacitor unit shall be provided with lifting eyes or similar provisionfor lifting or placing the unit into its position.d) Each capacitor unit shall be provided with discharge device whichreduces the residual voltage from the crest value of rated voltage to lessthan 50 Volt within one minutes after the capacitor is disconnected fromthe source of supply.e) Surge capacitor shall be mounted on a support structure to be suppliedby the Supplier.f) The surge capacitor shall have adequate strength to withstand withoutdamage or loss of life the mechanical load both in operation andtransportation, handling and erection. The loads shall includeelectromagnetic forces including those during fault external or internal tothe capacitors, wind loading forces due to expansion and contraction dueto ambient temperature, load variation and seismic efforts.MPPTCL/TECH/PROC/01/JULY 13 Page 56 of 125g) The capacitor units shall be interchangeable in order to reduce sparerequirements and simplify maintenance procedures.h) The bushings of the capacitor shall be of porcelain or oil communicatingtype. The bushings and other insulators shall have creepage of 25 mmper KV of phase to earth voltage. Bushing terminals shall be providedwith terminal connectors for interconnection with adjacent equipment orbus bars.

21.0 FITTINGS & ACCESSORIES FOR THE POWER TRANSFORMERS21.1 The Bidders should submit a specific confirmation that thetransformers will be supplied complete with all fittings and accessoriesexactly in line with various requirements indicated in Annexure II in thistechnical specification. The basic offered cost must take into considerationcost of all fittings and accessories as under and indicated elsewhere in thisspecification.21.2 The equipments and accessories furnished with thetransformer shall be suitably mounted on the transformer for ease ofoperation, inspection and maintenance and the mounting details shall besubject to the approval of the purchaser. All valves shall be provided eitherwith blind companion flanges or with pipe plugs for protection.21.3 Indication, alarm and relay equipment shall have contacts suitablefor operation with 220V DC supply. Any other accessories or appliancesrecommended by the manufacturer for the satisfactory operation of thetransformer shall also have 220V DC as input.a) OLTC and its controls shall be as per clause 14.b) All cabinets & panels shall be conforming to stipulationsunder Clause-16 .c) All 420KV, 245KV, 72.5KV phase bushings and 72.5 KV neutralbushings shall be of OIP condenser type and as per Clause 11.13 .21.4. Equalizing pipes for maintaining equal pressure between main tankand OLTC and at various other locations as per design shall be provided.These equalizing pipes shall be routed such as not to create any obstruction.21.5 Accessories which are necessary for satisfactory operation ofTransformer shall be deemed to have been included in the accepted pricewithout any extra cost to the Purchaser.21.6 It may be noted that all the name plates/rating plates/diagramplates on transformer shall be engraved type/anodized type and shall be fixedusing rivets/spot welding method. The method of printing of letters on theR&D plate shall be such that inscriptions shall not fade by ultra violet rays andother adverse weather conditions under which the same is subject to duringservice life of transformers.MPPTCL/TECH/PROC/01/JULY 13 Page 57 of 125(a) Rating & Diagram Plate: In the R&D plate following additionalinformation over & above as specified in the IS/CBIP specification shallbe provided.- Weight of the copper for windings- Weight of the core laminations for core- Weight of insulation- Weight of steel- Untanking weight (Core & Coil)- Weight of Transformer Tank along with Fittings &Accessories- Percentage Impedance at all taps- HV winding resistance of all phases at all taps- LV winding resistance of all phases- Weight of the oil for first filling in Kg/Liters- Total quantity of oil (including wastage) and 10% extraquantity in Kg/Liters- If required two separate R& D plates may be used.(b) Valve Schedule Plate: In the valve schedule plate, at least two viewsshould be inscribed so that location of all the valves provided on thetransformer could be indicated/visualised. In the table of valveschedule plate, details of valves viz. type, material, size & positionduring transportation and after commissioning shall be clearly

indicated. The size of the letters shall be such that the same be visibleclearly to a person standing away at a distance of one meter from therespective vertical face of the transformer.(c) Instruction Plate For Oil Filling in the Conservator with Air Cell:An instruction plate shall be provided for oil filling in the conservatorhaving air cell type breathing arrangement. In addition to theinstructions for oil filling on this plate, a diagram indicating mountingdetails of MOLG, oil level gauges, air cell inside the conservator with apictorial view of conservator including make, type & size of air cell shallalso be inscribed. The location of plate should be such that same isvisible to operating personal from a distance as mentioned in (b)above.22.0 CENTRE OF GRAVITY : The centre of gravity of the assembledtransformer shall be low and as near to the vertical centre line as possible.The transformer shall be stable with or without oil. If the centre of gravity iseccentric relative to track gauge either with or without oil, its location shallbe shown on the outline drawing.23.0 PACKING23.1 The packing may be in accordance with the Bidder's standardpractice but Bidder should give full particulars of packing for the approval ofMPPTCL/TECH/PROC/01/JULY 13 Page 58 of 125the purchaser. Special arrangements should be made to facilitate handlingand to protect the projecting connections for damage in transit.23.2 The transformer shall be transported filled with inert gas preferablyNitrogen gas. The Bidder shall ensure that adequate pressure of gas ismaintained inside the tank throughout during transportation by sendingescorts and required apparatus and equipment with the transformers.23.3 All parts shall be adequately marked to facilitate field erection.Boxes and crates shall be marked with the contract number and shall havea packing list enclosed showing the parts contained therein. however theverification of accessories shall be done in presence of suppliersrepresentative.24.0 TESTS24.1 The manufacturer shall carryout routine test ,additional routinetests and type tests on the transformers as per the relevant IndianStandard IS-2026 with latest amendments , IEC 60076, CBIP Publication No295, IEEE or any equivalent International Standard .The details of tests arespecified hereunder. It should be specifically noted by the Bidder that testingof each & every transformer included in this Bid specification shall be carriedout at the manufacturer’s works in fully assembled condition complete with allfittings & accessories.24.2 ROUTINE TESTS AND ADDITIONAL ROUTINE TESTS: All routinetests and additional routine Tests detailed under clauses 24.2.1 & 24.2.2herein under will be carried out on each transformer on "free of cost" basis, inaccordance with IS:2026 part-I.24.2.1 ROUTINE TESTSa) Measurement of winding resistance as per cl.16.2 of IS 2026Part I. The winding resistance shall be measured on all tapsand of all the three phases and values be recorded inrespective test certificates.b) Measurement of voltage ratio at all taps and checking ofvoltage vector relationship as per cl.16.3 of IS 2026 Part I.c) Measurement of Impedance voltage/ short circuit impedance(at all taps) & load loss (at principal tap & extreme taps) asper cl.16.4 of IS 2026 Part I, IEC 60076.d) Measurement of no load loss at 90%, 100%, 110% of ratedvoltage & no load current as per cl.16.5 of IS 2026 Part I.

e) Measurement of insulation resistance as per cl. 16.6 of IS2026 Part I.f) Dielectric tests shall be carried out as per IS 2026 (part I, II &III) & IEC60076 as underMPPTCL/TECH/PROC/01/JULY 13 Page 59 of 125i. 400 KV winding- Lightning impulse on all the line terminals (routine test)- Induced over-voltage with partial discharge indication Onall the line terminals (routine test)- Separate source AC on neutral terminal (routine test)- Switching Impulse testThe test voltage between line and neutral shall be broughtupto 420 KV and held for 5 seconds. It shall then bereduced to 364 KV. This shall be held for 30 minutes whereafter the voltage shall be reduced to zero. During the 30minutes period at 364 KV between the line and neutral,observation of partial discharge shall be carried out at lineas well as neutral terminals of the winding under test.Further, following conditions shall be specifically verifiedNote : There shall be no breakdown during short applicationof higher voltage i.e 420 KV and the continuous level ofpartial discharge during the long application of lower testvoltage shall not exceed 500 pico-Coulomb in any of themeasuring channels.ii. The 220 KV winding- Lightning impulse on all the line terminals (routine test)- Induced over voltage test with partial dischargeindication (routine) .This test gets simultaneously donewhen 400 KV winding is tested, therefore, no separatetest needs be done.iii. The 33 KV winding- Separate source AC on all the line terminals (routine test)- Lightning impulse on all the line terminals (type test)Note : No separate induced over-voltage test need to bedone. The winding gets tested as a consequence of theinduced over voltage test with partial discharge indicationon 400 KV winding.g) All tests on OLTC as per cl.16.9 of IS 2026 Part I, IEC 60214.h) Measurement of Tan-Delta, Capacitance & IR values ofHV,IV,LV & Neutral bushings before & after tests ontransformer.i) Low voltage AC, magnetic balance and magnetizing currentthree phase & single phase at normal tap for field reference.The test shall be carried out only after ensuring proper demagnetizationof the core so as to achieve proper results.MPPTCL/TECH/PROC/01/JULY 13 Page 60 of 125Note : DGA test of oil of main tank of transformer before (initial) &after completion of all testing shall be done and test resultsshall be submitted to the purchaser .24.2.2 ADDITIONAL ROUTINE TESTS(A) Insulation Resistance : Insulation Resistancemeasurement shall be done for 15 Secs. , 60 secs. and 600secs. Duration. Polarization Index (PI) shall be clearlyrecorded on test report for 600 sec /60 sec values and D.A.R.for 60 sec/15 sec values.PI value : PI value (i.e. ratio of IR Values for 600 sec /IR Values for 60 sec) for winding should be greater than

2.0. This requirement is to be confirmed specifically bythe Bidders in their offer.(B) Magnetic Circuit Test :After assembly, core shall be testedfor 1 minute at 2 KV AC between all bolts, side plates &structural steel work. Immediately prior to the despatch of thetransformer from works of manufacturer, the magneticcircuit shall be tested for one minute at 2 KV AC between theCore & Earth and leakage current shall also be recorded.(C) Oil Leakage Test on Tank : All Transformer tank with itsactive part as assembled for type test (i.e. including pipe workand cooling equipment and excluding PRV and conservatorwhen air cell is provided) shall be subjected to apressure corresponding to twice the normal head of oil or tonormal pressure plus 35 kN/ m.sq.(5psi) whichever is lowermeasured at the base of the tank and will be maintainedfor 12 hours during which time no leakage shall occur. Beforeconducting the pressure test, the following are to be takencare of :(i) Pressure relief valve are to be removed and the openingblanked .(ii) Transformer and tap changer conservators are to bedisconnected.(iii) Diverter switch compartment of tap changer to beconnected with transformer tank for equalising thepressure on both sides.(iv) Oil should be completely filled and all trapped airreleased.(D) Capacitance & Tan-delta Test on winding : Themeasurement of capacitance and tan delta to determinecapacitance between winding & earth shall be carried outbefore and after series of dielectric tests by Ampere turnmethod. For temperature correction factors IEEE C.57.90 shallbe referred.MPPTCL/TECH/PROC/01/JULY 13 Page 61 of 125The measured Tan delta values of winding shall notexceed 0.45% at 200C (degree Centigrade) temperature.In case Tan delta of transformers during testing atworks of manufacturer is measured above maximumceiling of 0.45% at 200C (degree Centigrade)temperature, then MPPTCL reserves right not to acceptsuch of the transformer. This requirement is to beconfirmed specifically by the Bidders in their offer.(E) Test Results of calibration & measurement reports of WTI CT &ratio test for bushing CT.(F) Checking & recording of following:a. IR valuesi. Between Core and End frameii. Between Core and Tankiii. Between End frame and main Tank.The measured IR values should be more than 1000 MOhms. This requirement is to be confirmedspecifically by the Bidders in their offer.b. Measurement and recording of currents withapplication of 400 volts, 3phase, AC supply on HVside with IV side shorted, as underi. Between Core and Tank.ii. Between Core and End frame

iii. Between End frame and Tankiv. Between neutral and short circuited links with neutralgrounded and ungrounded conditions.NOTE: The details of arrangements provided outsidethe main tank for connecting core, end frame and maintank body shall be indicated on a diagram , to be attachedwith the test reports.(H) Test results of CT provided in one phase of tertiarywinding before delta formation.(I) Magnetising current measured with LT supply.No Particulars With Single phasesupplyWith Three phasesupplyVolts. Amps. Volts. Amps.a On HVsideb On IV sidec On LV sideMPPTCL/TECH/PROC/01/JULY 13 Page 62 of 125(J) Magnetic balance test on HV , IV and LV side(K) Pressure Relief Device Test :All pressure relief devicesprovided in each transformer shall be subject to test for itssuccessful operation. It shall operate before reaching the testpressure specified in clause 24.3 (C) of this specification. Thedevice shall seal off after the excess pressure has beenrelieved.(L) Frequency Response Analysis (SFRA) Test onTransformer : The SFRA test shall be conducted by themanufacturer at manufacturers works using his own SFRA testset and also SFRA test shall be conducted by the manufacturerat site using same SFRA test set at the time of erection &commissioning of unit.(M) Measurement of Dew point prior to despatch of the unit,filled with N2 gas: Dew point is the temperature at whichwater vapours present in the gas filled in the transformerbegins to condense. The transportation of transformer from thefactory of manufacturer’s works upto the purchaser’s site isdone with dry Nitrogen gas filled condition, due to weightlimitation. Positive gas pressure say 0.25 kg/cm2 is normallymaintained during transportation as well as during storage. Incase positive pressure is not maintained then due tohygroscopic properties of insulation used in transformerpossibility of absorption of moisture in insulation can not beoverruled. Therefore to check the dryness of insulation,measurement of dew point at factory prior to despatch and atsite prior to oil filling is necessary and to be carried out. Itmay be noted that dew point shall be measured at factory priorto despatch. Temperature, pressure and dew point at the timeof gas filling (reading taken after stabilisation) shall be takenand painted on the transformer tank. The minimumpermissible value of dew point shall be (–)25oC at normaltemperature and pressure.(N) Functional tests on auxiliary equipments i.e. Air cell,OTI,WTI , valves , Filters etc as per CBIP publication no295.(O) Supplier’s test certificate in respect of on line

monitoring device (OLMD) , NIFPS, Surge capacitor asper IS , IEC, CBIP publication no 295,.24.3 TYPE TESTS : Following Type Tests shall be conducted on onetransformer of each manufacturer (if there are more than one manufacturer)as per IS:2026 Part I, IEC , CBIP publication no 295.MPPTCL/TECH/PROC/01/JULY 13 Page 63 of 125(A) Temperature Rise TestThis test as per cl. 16.8 of IS:2026(Part- II) shall be conductedat the lowest voltage tap having maximum current with 10%overload conditions. The supplier before carrying out suchtests, shall submit detailed calculations showing thealternatives possible, on various taps and for different ratings(ONAN/ONAF/OFAF), of the transformer and shall recommendthe combination that results in highest temperature rise, forthe test. Since 315 MVA transformer is a auto transformer thetemperature rise test shall be conducted for the condition ofsimultaneous loading of all three windings for their respectiveOFAF rating i.e. 400KV and 220KV winding corresponding tocurrent of 315 MVA, and 33 KV winding for 105 MVA. Loading ontwo windings for 315 MVA transformer for the measured losseswill not be accepted. Gas chromatographic analysis of oilshall be conducted before and after heat run test and thevalues shall be recorded in the test report. The samplingshall be in accordance with IEC-60567. For the evaluationof the gas analysis in temperature rise test, a method will beproposed which is based on the rate of increase of particulargases and the permissible limits of minimum detectable valueof gases and the maximum limit will be mutually discussedand agreed upon between the Purchaser and Supplier. Thisshall be treated as reference during maintenance of transformerin future.The calibration of OTI and WTI shall be done by TransformerManufacturer and these calibrated OTI, WTI shall be used duringtesting of transformer. The Sr.No. of WTI,OTI shall be recordedduring testing of transformer and these indicators only shallbe supplied with the transformer. During test themanufacturer selects suitable tap from CT based on gradientbetween the readings of WTI & OTI. This tap position is to beclearly recorded on test report so that selection of correct tapcould be done at site to avoid discrepancy in temperaturegradient recorded during factory test and the value recorded atsite.(B) Impulse Test on line terminals as per IS 2026 part III, on onetransformer of Bid(C) Tank tests : Following Vacuum and Pressure tests shall becarried out on one transformer tank.(a) Vacuum Test (Fabrication stage)One transformer tank of each design shall be subjected tothe vacuum of 760 mm of Hg. The tanks designed for fullvacuum (760 mm of mercury at sea level or the barometricreading at the location of test) shall be tested at a maximuminternal pressure of 3.33 kN/m.sq. (25 mm of Hg) for oneMPPTCL/TECH/PROC/01/JULY 13 Page 64 of 125hour i.e. 760-25=735 mm of Hg at sea level and (Barometricreading -25mm Hg) at other location. The permanentdeflection of flat plates after vacuum has been released shallnot exceed the values specified below:

Horizontal Length of flat plate (inmm)Permanent Deflection (inmm)Up to and including 750 5751 to 1250 6.51251 to 1750 81751 to 2000 92001 to 2250 112251 to 2500 12.52501 to 3000 16Above 3000 19(b) Pressure Test (Fabrication stage)One transformer tank of each design , its radiator, conservatorvessel ,and other fittings together or separately shall besubjected to a pressure corresponding to twice the normalhead of oil or to normal pressure plus 35 kN/m2, whichever islower, measured at the base of the tank and will bemaintained for 1 hour during which time no leakage shall occur.The permanent deflection of the flat plate after the excesspressure has been released shall not exceed the figures specifiedabove for vacuum test as per clause 24.3(C)(a).24.4 SPECIAL TESTS : Following special tests other than type and routinetests shall also be carried out as per IS:2026 Part-I on onetransformer of each manufacturer (if there are more than onemanufacturer) .a) Measurement of zero seq. impedance as per CL.16.10 ofIS:2026 Part-I.b) Measurement of acoustic noise level as per CL.16.12 ofIS:2026 Part-I, NEMA TR1 & IEC 60076-10. Detailed calculations& conditions outlined in the IEEE standard C 57.12.12.90 shallbe followed.c) Measurement of power taken by fans & pumps as percl.16.14 of IS:2026Part-I.d) Measurement of harmonic level of no load current and totalharmonic distortion of voltage & current as per CL.16.13 ofIS:2026 Part-I. Details of rms voltage applied & print out ofHarmonic Analyser shall be enclosed with report.MPPTCL/TECH/PROC/01/JULY 13 Page 65 of 125e) One Cooler Control Cabinet and OLTC cabinet of each type oftransformer shall be tested for IP:55 protection inaccordance with IS:2147.f) Test to prove over fluxing capability of transformer.24.5 To summarize the requirement of tests for 400KV 315 MVApower transformers covered in this Bid specification, are as under :ClauseNo.Nature of testsNumber oftransformers tobe testedTest charges1 2 3 424.2.1&24.2.2.Routine tests &

additional routinetestsOn each unit While offering for the Bid, costof all these tests for specifiedno. of units as per column ‘3’should be included in the totalBid price. Thus no additionalcharges shall be payable forany of the tests andtherefore, offered Bid priceshould account for all thecosts to be incurred for thispurpose24.3 Type test:(A)Temperaturerise testOn one unitincluded in Bid(B)Impulse test On One Unit ofBid(C)Vacuum andpressure testOn One unit ofBid24.4 Special tests On One unit ofBid24.7 Tests at site On each unitincluded in BidNote : It is to be noted that after complete final testing of the unit ,it should be kept charge at rated voltage for adequate time to ensureproper demagnetization of core i.e. demagnetization of core shall beensured prior to dispatch of the unit.24.6 Oil to be used by manufacturers at factory for the purpose oftesting at their works shall be of similar or better quality havingparameters matching with the parameters specified in thespecification. Specific approval of oil test results of oil proposed to beused for testing of transformer in factory shall be obtained by themanufacturer from the purchaser before first filling in the unit.MPPTCL shall not accept any other oil for testing purposes havinglower parameters than those specified in the Bid. Bidders shouldspecifically confirm this requirement in their offer.25.0 TESTS AT SITE :On delivery /receipt, after erection at site, thetransformer shall be subject to the following tests, in presence ofsupplier's engineer.(i) Immediately upon receipt of transformer at site and beforeunloading of transformer from trailer, core earthing , endMPPTCL/TECH/PROC/01/JULY 13 Page 66 of 125frame earthing & tank earthing shall be checked . Only aftersatisfactory verification that there is no multiple coreearthing in transformer, unloading of transformer shall beundertaken.ii) Insulation resistance test and polarisation index.iii) Ratio and polarity test.iv) DGA of oil and Dielectric, Tan-Delta, resistivity & moisturecontent test of oil .v) OLTC operational test at each tap for lower and raise operationof tap changer.

vi) Magnetic balance test and measurement of magnetizingcurrent.vii) Vector group test.viii) Percentage Impedance test at all taps.ix) Short circuit current measurement at low voltage and at alltaps.x) Measurement of winding resistance at all taps.xi) Tangent Delta, capacitance and insulations resistance tests ofbushings.xii) Leakage current between core & tank, core & end frame , endframe & tank and between short circuited links & neutral ingrounded and un grounded conditions.xiii) Dew point measurement & recording of pressure of Nitrogengas.xiv) SFRA testxv) After receipt of transformer at site physical inspection shall bedone for checking any physical damage to transformer tank &accessories. Further data of Impact recorder shall be analysed for anychanges before unloading of transformer.26.0 CHECKS & TESTS : Following checks & tests shall be carried out byManufacturer at different stages of manufacture & supply of transformer andthese reports shall be sent to the purchaser for records :(i) Assembled Transformer:a) Check completed transformer against approved out linedrawing, provision for all fittings, finish level etc.b) Jacking test on the assembled Transformer.c) Measurement and recording of temperature and drying time duringvacuum treatment.d) Check for completeness of drying by measuring IR values & TanDelta.e) Certification of all test results.MPPTCL/TECH/PROC/01/JULY 13 Page 67 of 125(ii) Preshipment Checks at Manufacturer's Works:a) Check for interchangeability of components of similar Transformers formounting dimensions.b) Check for proper packing and preservation of accessories likeradiators, bushings, explosion vent, dehydrating breather, rollers,buchholz relay, control cubicle, connecting pipes, conservator etc.c) Check for proper provision of bracings to arrest the movement of coreand winding assembly inside the tank.d) Gas tightness test to conform tightness.e) Derivation of leakage rate and ensure adequate reserve gascapacity.(iii) Commissioning Checks at site :a) Check the colour of silicagel breather.b) Check the oil level in the breather housing, conservator tank, coolingsystem, condenser housing etc.c) Check the bushings for conformity of connection to the line etc.d) Check for correct operation of all protection and alarms.i) Buchholz relayii) Excessive winding temperatureiii) Excessive oil temperatureiv) Low oil flowv) Low oil level indicatione) Check for adequate protection on electric circuit supplying theaccessories.f) Insulation resistance measurement for:

i) Control wiringii) Main windingg) Check for cleanliness of the Transformer and the surroundings.27.0 TEST REPORTS : After all tests have been completed sevencertified copies of each test report shall be furnished. Each report shallsupply the following information :-i) Complete identification data including serial number of thetransformer.ii) Method of application, where applied, duration andinterpretation of results for each test. Complete diagram oftest circuits and details of test equipments including auxiliarytransformer, Instrument transformer shall be furnished.iii) Where ever applicable parameters to be corrected to 75º Ctemperature.MPPTCL/TECH/PROC/01/JULY 13 Page 68 of 125iv) Test certificates of all the accessories and stageinspections.28.0 TOOLS : The transformer shall be supplied with a full outfit of tools,spanners, special tools for assembling and dismantling transformers with arack for holding them as per Annexure X. All spanners shall be double ended& case hardened. The quantity of each item of tools shall be indicated by theBidder in Bid.29.0 DRAWINGS & INSTRUCTION MANUALS29.1 SPECIFIC REQUIREMENT FOR GENERAL ARRANGEMENTDRAWING:For our 400KV switch yard, the bay width adopted is 27 metres. Followingpoints shall be kept in view while finalizing General Arrangement drawing ofthe transformer.i. Along transverse direction (i.e. the parallel to the Bushing line) spread ofthe transformer from one extreme end to the other extreme end shall belimited to 27 meters. This spread shall be distributed symmetrically withrespect to the centre line of the transformer ( i.e. 13.5 meters on eithersides) This is an essential requirement to avoid encroachment of thetransformer body in the adjoining bay.ii. Along the longitudinal direction the 400KV lightning arrestor are locatedat a distance of 11.0 meters from centre line of the transformers. Whiledeciding arrangement of location of the accessories, this requirementneeds to be kept in view from consideration of clearances.29.2 The drawings for each items of transformer and its accessories areto be submitted to MPPTCL at the time of obtaining approval ofmanufacturer.29.3 As soon as possible after the award of the contract themanufacturer shall supply Instruction Manual. This Instruction Manualshall be hard bound manual shall contain set of all approved drawings,instruction books, manufacturer’s catalogue of all bought items & fittings,operation & maintenance manuals , spare part bulletin.(a) Two copies of each drawing mentioned above and InstructionManual shall be sent along with the transformer & its accessories tosite. Further a CD containing soft copy of all drawings in AutoCAD ,instructions manuals and other relevant details in acrobat or MS wordshall be sent with transformer to site . This CD shall contain AutoCADsoftware and acrobat reader software also.(b) Ten (10) sets of hard bound folders containing copies ofapproved drawings, instruction manuals shall be sent to order placingMPPTCL/TECH/PROC/01/JULY 13 Page 69 of 125authority within a fortnight of approval of drawings. Further, Six (6)CDs containing soft copy of all drawings in AutoCAD , instructions

manuals and other relevant details in Acrobat or MS word shall besent to order placing authority. These CDs shall contain AutoCADsoftware and acrobat reader software also.30.0 The offered price shall include cost of drawing / manuals asdetailed out in Annexure VI.31.0 DESIGN CALCULATIONS & DESIGN DATA TO BE ENCLOSEDWITH BID : All the important data of the transformer i.e. Net weight of barecopper in each winding , Weight of core without clamping fixtures , Weight ofcore and windings, Cross section of the core, Flux density calculations ,Calculations for short circuit current and its duration , Current density duringshort circuit , Calculations showing withstand capability of windings forthermal & mechanical stresses during short circuit conditions , MechanicalDesign of transformer tank etc should be invariably submitted by the Bidder .After placement of detailed contract the final design calculations shall besubmitted for our verification and records .Submission of design calculations and data with technical bid is anecessary requirement and those Bids will be rejected whereinthese data & calculations is not found . It may be noted by the Biddersthat no correspondence with the bidder in this regard shall be madeafter opening of technical & commercial offer. All responsibility forSubmission of design calculations and data with the Bid is thereforeof the Bidder & non furnishing of same may run the risk of rejection /non responsiveness of the Bid.31.1 DESIGN CALCULATIONS & DRAWINGS31.1.1 Short Circuit Withstand Capabilities : The calculations to provedynamic and thermal short circuit withstand capability of transformer shallbe submitted by the Bidder for the fault level indicated as under400KV - 63 KA for 3 secs.220KV - 40 KA for 3 secs.33KV - 31.5KA for 3 secs.Results of calculations shall be submitted with the Bid . The design ofwinding assembly , which is to be furnished in the drawing as per Sr.No. (e) of Annexure VI should be commensurating with these calculations.The details of clamping ring shall be indicated in the drawing .It may be noted by the Bidders that calculations for short circuitwithstand capability for two winding transformer is not acceptable under anycircumstances and these calculations shall be submitted for 3 winding autotransformer. The computer output for calculations of short circuit forces withminimum of 7 iterations with limiting values shall be submitted during DesignReview as per Cigre Guidelines.MPPTCL/TECH/PROC/01/JULY 13 Page 70 of 12531.1.2 Design of Tank : Complete mechanical design of transformer tankincluding details of stiffeners shall be submitted . The tank shall be designedto withstand the following without permanent distortion.(i) Mechanical shocks during transportation.(ii) Vacuum filling of oil at 10 milli torr in transformer with all fittings.(iii) Continuous internal pressure of 35 kN/m2 over normal hydrostaticpressure of oil.(iv) Short circuit forces &(v) Under seismic condition /events both horizontal/vertical .The calculations for tank stiffeners shall be submitted with the bid to proveno. & size of stiffeners are adequate to withstand full vacuum & pressure .Drawing of tank shall be submitted indicating stiffners .31.1.3 Design of Static End Rings (SER) and Magnetic Shunts : Detailsof Static End Rings (SER) and magnetic shunts , if provided , shall besubmitted with the Bid with calculations . A drawing indicating locations , size,material of SER and magnetic shunts shall be submitted with the Bid .

31.1.4 Overfluxing Capability: A curve to prove suitability of transformerto withstand various Overfluxing conditions for the duration indicated in clause4.4.1 to 4.4.3 without core saturation shall be furnished with the Bid .31.1.5 Cooling Calculations : Calculations of tank surface for heatdissipation, details of radiators , fans for ONAN , ONAF & OFAF cooling shall beprovided with the Bid.31.2 DESIGN DATA : On the basis of offered flux density and currentdensity, the Bidder shall furnish following design calculations & data.Calculations regarding wt. of core & copper and also calculations for losseswill be brought out to justify the offered transformer losses. :31.2.1 Core Data: Details of core material i.e Name of Manufacturer,Manufacturer’s type designation for core , thickness of core, curve for Loss VsFlux density, No of steps of Core & No of limbs, gross core area , stackingfactor , Net core area ,height & width of core window, center to centerdistance of limb, voltage per turn, wt. of core material, working flux density ,core loss in watts per kg marked on graph for grade of core material &selected flux density, building factor and calculated no load loss in watts,guaranteed no load loss.Design data for core shall be submitted with the Bid. A drawing indicatingdetails of core i.e. limbed construction, step width & thickness , core belting,top & bottom yoke plate etc shall be submitted with the Bid .MPPTCL/TECH/PROC/01/JULY 13 Page 71 of 12531.2.2 Winding Data: wt. of copper for windings ie. for HV(series),IV(common) ,tap, LV(tertiary), cross sectional area , current density, type ofcoil, ID/OD/mean dia of coils, size of winding conductor including parallels,no. of turns per phase, no of spacers, length of mean turn, weight of copperwithout paper covering, resistance per phase of winding at 75 deg C, I2R lossat 75 deg C & normal tap, eddy current & stray loss at 75 deg C , total copperloss at 75 deg C , guaranteed transformer losses at 75 deg C.Complete details of Insulation components i.e. Top & Bottom clamping rings,washers , Pressboard blocks & cylinders, Pressboard spacers & Phase barriers,Pressboard segments etc shall be submitted indicating qty , thickness in mm,width & height , wt. Design data for winding as per clause 31.2.2 shall besubmitted with the Bid.Dimensioned drawings indicating details of winding , ducts, insulation , takeoff arrangement, clamping ring , pressure points etc shall be submitted withthe Bid .31.3 QUANTITY OF OIL : Complete calculations of oil quantity to be utilizedin transformer for first filling shall be submitted with the Bid. The calculationsshall indicate(i) Volume of tank including turrets, conservator main & OLTC ,volumeof headers & Radiators, oil quantity in OLTC & thermosyphon filter.(ii) Oil displacement by Active parts i.e. core - coil assembly,31.4 CAPACITY OF CONSERVATOR & SIZE OF AIR CELL : Whilefurnishing details of conservator & air cell type sealing arrangement, theBidder shall submit details & calculations for adequacy of size and capacity ofPronal make air cell for the rating of the power transformer and also for thequantity of oil required with the Bid. Catalogue of Pronal should be enclosedwith the Bid clearly marking type designation of selected size of Air cell. Adrawing indicating complete details of conservator with Air cell shall besubmitted .31.5 CAPACITY OF PRESSURE RELIEF DEVICE : Our specification callsfor supply of pressure relief device for all power transformers. Biddersmust submit calculation with the Bid to prove that the capacity/rating ofpressure relief device and locations of the same for the transformer willadequately meet our requirement. Constructional and design details ofpressure relief device must be furnished and it should be proved by

calculation that the size and setting of pressure relief device isadequate considering the rating of the transformer and quantity of oil in thetransformer.A drawing indicating complete details of PRDs & their locations on tank shallbe submitted .MPPTCL/TECH/PROC/01/JULY 13 Page 72 of 12531.6 LIMITS OF TEMPERATURE RISE & HOT SPOT WINDINGTEMPERATURE : The limits of temperature rise for windings, oil and hotspot have been specified. Temperature rise calculations at rated full load,110% load and 125% load considering 100% cooler banks, 50% cooler banksand without coolers shall be furnished as indicated below :(a) 100 % Loading : (i) 20 minutes duration - 100 % cooler bank- 50 % cooler bank- without cooler bank(ii) 10 minutes duration - 100 % cooler bank- 50 % cooler bank- without cooler bank(b) 110 % Loading : (i) 20 minutes duration - 100 % cooler bank- 50 % cooler bank- without cooler bank(ii) 10 minutes duration - 100 % cooler bank- 50 % cooler bank- without cooler bank(c) 125 % Loading : (i) 20 minutes duration - 100 % cooler bank- 50 % cooler bank- without cooler bank(ii) 10 minutes duration - 100 % cooler bank- 50 % cooler bank- without cooler bankThe calculations shall indicate temperature gradient (for all windings i.e.HV,IV,LV,tap), load losses at lowest tap for all windings , Eddy current & straylosses, thermal Constant Value & calculations with parameters affecting thevalues for above conditions for top oil temperature & winding hot spottemperature .The Calculations for Hot Spot winding Temperature and Calculations forTemperature Rise shall be submitted with the Bid.31.7 CAPACITY OF FILTER & BREATHER :31.7.1 NUMBER OF THERMOSYPHON FILTER AND CAPACITY OF EACHTHERMOSYPHON FILTER : The Bidder shall submit details & calculationsfor adequacy of size and capacity of thermosyphon filter for the oilquantity in the power transformer . While furnishing details of thermosyphonfilter arrangements, the Bidder must confirm clearly the number ofthermosyphon filter, its size and capacity is adequate for the rating of powertransformer. The Bidder shall submit details & calculation to prove foradequacy of size and capacity of thermosyphon filter with the Bid..31.7.2 CAPACITY OF SILICA GEL BREATHER : The Bidder shall submitdetails & calculations for adequacy of size and capacity of silica gel breatherfor the oil quantity in the power transformer with the Bid .MPPTCL/TECH/PROC/01/JULY 13 Page 73 of 12531.8 RATING OF ON LOAD TAP CHANGER (OLTC) : It has been ourexperience that due to inadequate rating of OLTC elements, the failure ofOLTC components or pitting of contacts have been observed before theclaimed period for maintenance. To verify the adequacy and suitability of theOLTC components, it is necessary to furnish the calculations for selectingthe proper rating of transition resistance as well as the normal currentrating of OLTC. The calculations shall include the temperature rise of the

OLTC diverter switch and also the short circuit current considered forcalculation of temperature rise.Calculations shall be submitted to prove that the current rating of OLTC isadequate for the rating of the transformer winding taking in to account theover loading capability as per IS 6600 . The basis for selection of transitionresistance and its current carrying capacity shall also be submitted. In thisregard the circulating current in tap winding during tap change operationthrough transition resistance shall be taken in to consideration. Adequacy ofinsulation provided in the OLTC between various parts needs to be establishedwith specific reference to the voltage between two taps. Confirmation shall begiven that the OLTC is suitable for bidirectional flow of current. The throughcurrent capacity shall be adequate to handle on continuous basis the windingcurrent including over loading as per IS 6600. The through current rating andthe rating of transition resistance shall take in to account the short timecurrent rating of the winding. Capability to handle short circuit current to beestablished by calculations and also by test reports. The above Calculationsfor OLTC shall be submitted with the Bid31.9 Capacity of Nitrogen Cylinder, pressure in Nitrogen Cylinder to be usedduring transportation of transformer shall be submitted with the Bid.31.10 Size & capacity of Oil sump/ pit for Nitrogen Injection Fire ProtectionSystem shall be submitted with the Bid.31.11 DESIGN REVIEW : The “Design Review” of the 315 MVA, 400KV transformer shall be carried out in accordance with the“Guidelines for consulting Design Reviews for transformers 100 MVA& above” of Cigre working group 12.22 (SC12 WG 12.22). The Biddershall carry out optimization of Dielectric design of insulation includingelectromagnetic design, overload & short circuit withstand capabilities. Duringdesign , transformer modeling shall be done & finite element software (FEM)may be used.31.12 Please note that submission of above calculations withtechnical bid is a must and in absence of the above, the Bid willbe treated as non responsive and rejected. It is assured that these datawill be kept strictly confidential by MPPTCL.32.0 QUALITY ASSURANCE PROGRAMME : The Bidders must establishthat a proper quality assurance program is being followed by them formanufacture of power transformers. In order to ensure this, suitable QAPshould form a part of the technical bid, which will be submittedMPPTCL/TECH/PROC/01/JULY 13 Page 74 of 125against this Bid specification. The quality Assurance Program must havea structure as detailed in the following paragraphs.32.1 Customers Specifications And Contract Review : The qualityassurance and failure prevention starts with careful study and scrutiny ofour technical specifications and requirements. The supplier shall carefullystudy all the technical parameters and other particulars & the supplier shallcategorically give his confirmation that these requirements shall be metin a satisfactory manner.32.2 Design Control : The supplier shall furnish the checksexercised in design calculations particularly in respect of short circuitforces and method of clamping end coil to show the healthiness of thedesign. The salient features of design together with the certificates ofdesign engineers will have to be made available to the Purchaser.32.3 Engineering Documents :The supplier shall give completeinformation regarding copper conductor, insulating paper, core materials,tap changer, gaskets etc. bringing out the detailed description andspecification of these items with explanation as to how our requirements arebeing met in this respect.32.4 Procurement Document Control & Purchased Material &

Services :The supplier shall indicate the various sources of the items namelycopper conductor, insulating paper, core material, tap changer and otheritems such as gaskets etc. are being procured. The type of checks,quantum of checks and acceptance norms shall be intimated and randomtest and check results should be made available for inspection wheneverso desired. The vendor list for various bought out items shall be submittedwith the Bid and the same shall be subject to purchaser’s approval. However,no change in vendor list shall be acceptable after placement of order and listof vendors shall be freezed at the time of placement of order. Furnishingof following certificates is essential ;i) Certificate and proof in the form of bill of lading forpurchase of core material either directly from abroadmanufacturers or their accredited selling agent.ii) Certificate and proof in the form of bill of lading for purchaseof EC grade copper from National & International reputedmanufacturers or from their accredited selling agents.It will however be obligatory on the part of Bidder to allow thirdparty inspection of all important material e.g. copper, core material,Insulating cylinder etc . Bidder shall furnish certificate that thetransformer shall be manufactured with the input material approved by thePurchaser and in case during independent third party inspection any of theabove material is found different than from approved list of vendors, in thatcase Purchaser reserves the right to summarily reject completeMPPTCL/TECH/PROC/01/JULY 13 Page 75 of 125transformer and the manufacturer has to replace complete unit made outfrom all input material from the vendors approved by the Purchaser.32.5 Programme Chart : Based on above QAP and offered deliveryschedule a tentative program chart indicating period for variousmanufacturing/testing activities shall be submitted along with QAP . Theprogram chart should specify periods for various activities i.e. design,ordering of new materials, assembly, testing etc.It should be noted by the Bidders that submission of QAP with the Bidis an essential requirement and such of the Bids wherein QAP is notfound shall be rejected by the Purchaser.33.0 INSPECTION AND TESTING33.1 Inspection33.1.1 The Purchaser shall have access at all times to the works and allother places of manufacture where the transformers are being manufacturedand the Bidder shall provide all facilities for unrestricted inspection of theBidder’s works, raw materials, manufacture of all the accessories and forconducting necessary tests as detailed herein.33.1.2 The successful Bidder shall keep the Purchaser informed in advanceof the time of starting and of the progress of manufacture ofequipment at its various stages of manufacturing, so that arrangementscould be made for inspection.33.1.3 No material shall be dispatched from its point of manufactureunless the material has been satisfactorily inspected and tested.33.1.4 The acceptance of any quantity of Transformer & its accessoriesshall in no way relieve the successful Bidder of his responsibility formeeting all the requirement of this specification and shall not preventsubsequent rejection if such equipments are later found to be defective.Acceptance of condition regarding stage inspection at various stages whichwill be intimated to successful Bidders shall be the essence of the contract tobe placed against this Bid.33.2. Inspection Programme : The Bidder shall chalk out a detailedinspection and testing program for manufacturing activities for the various

components. An indicative program of inspection as envisaged by thePurchaser is given in Annexure-VIII. The Purchaser reserves the right to getcarried out any tests by a third party. All Cost of inspection/tests shall beborne by the Bidder.33.3 Stage Inspections33.3.1 The supplier shall indicate the inspections and checks carried outat various stages of the manufacture of the transformers. A completeMPPTCL/TECH/PROC/01/JULY 13 Page 76 of 125record of stage inspection would be kept by the supplier and this recordshould be made available for inspection by the representative of thePurchaser. The supplier should indicate the manufacturing program andthe Purchaser will have a right to depute its inspecting officers duringthe manufacture. Some of the inspecting stages are tank during fabrication,coil winding , core building, assembly of coil on core, the condition of the coiland core after the treatment in vacuum chamber, assembly within thetransformer tank together with application of tap changer.33.3.2 It may be noted that stage inspection for first unit or all the units, at our discretion , shall be done by us at the following stages.(a) Fabrication stage of tank: After fabrication, tank shall be inspectedfor measurement of its dimensions, thickness of sheets used and leakage testby applying requisite pressure/vaccum.(b) Building up of Core : After the core is built but before itsclamping, our representative will inspect the core to take completeweight of the core and also to measure approximate core loss. Ifnecessary, a small strip of core shall also be taken for testing at CPRI,Banglore or at any other testing lab of repute.I Preparation of Winding : Once the coils are prepared but beforethe same are fitted on to the core, stage inspection shall be done to takevarious measurements and also for weighment of total weight of coil of eachvoltage class. Measurement of resistance shall be taken and for this purpose,a small piece of conductor for each type of winding shall be made availableby the manufacture.(d) Core Coil Assembly before & After VPD or Drying outThe Bidder has to submit with the Bid complete details of Dryingout process of transformer adopted in its works. The detailsshould include cycle, description , termination rate , processdiagram , size of oven , measurement method of moistureextracted etc . Failure of the Bidder to comply with thisrequirement shall result in rejection of the Bid.(e) Final Assembly of Transformer after boxing in of active materialApart from the above, the Purchaser also reserves the right to carry out stageinspections at other stages also, for which advance intimation shall begiven and all necessary cooperation shall be rendered by the manufacturer.33.4 Final Inspection and Testing33.4.1 At the time of final inspection, the supplier shall identify eachand every item/accessories/fittings of the particular transformer undertesting. Unless all the items are identified, the manufacture will not beMPPTCL/TECH/PROC/01/JULY 13 Page 77 of 125treated as complete. Serial number of bushings, serial number of tap changerand other accessories shall be entered into the test report to ensure that thesame are supplied with the transformer. Various tests stipulated in ISshall be performed in the presence of purchaser’s engineers or when theinspection waiver has been given, in such a case, the testing shall bedone at the manufacturer’s works as per IS stipulations and same shouldbe confirmed by documentary evidence by way of Test Certificate whichshall be got approved by the purchaser.33.4.2 The WTI & OTI shall be calibrated during testing of transformer

and Serial Nos. of these instruments shall be recorded in test reports.The WTI & OTI used during testing shall be dispatched with the transformerso that installation of same OTI & WTI on transformer is done which areutilized during testing of transformer at suppliers works. The Bushingsand Radiators on Transformer (if heat run test is conducted ) during testingof transformer at manufacturers works are required to be supplied with thesame transformer to avoid any mismatch / misalignment etc. duringassembly of transformer. This should be noted for strict compliance andconfirmed specifically.33.4.3 Whenever inspection call for a particular transformer is given, theletter of inspection call will accompany the following:a. List of various fittings and accessories which are ready at theworks and will be offered for inspection. The Inspecting Officerwill carry the list and check the items declared to have beenoffered for inspection .b. It is expected that before a transformer is finally offered forinspection, internal testing of the transformer for variousimportant parameters like winding resistance, transformerlosses, IR values etc are already done. Routine test report forsuch tests shall also accompany the letter of inspection callso that the Inspecting Officer at the time of inspection mayverify the parameters brought out in the preliminary report.Details of all tests should be clearly brought out.c. In case for any reasons inspection is not completed orequipment is not found to be complete with all accessories asper confirmation given with the letter of inspection call, thePurchaser will reserve the right to recover the complete costof deputation of inspecting team to the works of themanufacturer.34.0 STORAGE, HANDLING & SHIPPINGWhen the transformer is declared ready, the manufacturer hasto identify each and every item associated with this unit and a `CompletePacking List shall be prepared in advance. The equipments shall be storedand handled properly in shipping depot, while the same is under processMPPTCL/TECH/PROC/01/JULY 13 Page 78 of 125of dispatch. The manufacturer should ensure dispatch of all the related itemsand accessories with a particular unit of transformer along with tank.Tap changer, bushing, radiators and other accessories of thetransformer should not be withheld for use subsequently on units for testingpurposes. If there are any items procured from sub-contractors which are tobe directly installed like instrumentation, panels, control gear etc. test andinspection report for the same shall be kept separately and made available topurchaser’s inspecting officers.It may be noted that NO CHANGE in any accessory orassociated equipments after passing all the test successfully shall beallowed and if this is subsequently detected it shall be binding on the Bidderto replace with the same item with which the initial test were conducted athis part failing which the entire test shall become null and void. ThePurchaser at his discretion may consider for rejection of the units thussupplied. The entire cost, for replacement of such rejected units thussupplied and for repeating acceptance test, shall be borne by the Bidder.35.0 COMPLETENESS OF EQUIPMENT AND BOUGHT OUT ITEMSThe Bidders must furnish the following information along withtechnical bid.35.1 A list of all the accessories which will be supplied with thetransformer should be furnished. This should be as per Annexure II & III.While furnishing the list of accessories , items which will be manufactured by

the Bidder and balance items, which will be procured from sub-suppliersshould be clearly identified and stipulated in the bid.35.2 It is obligatory on the part of Bidder to ensure that supply of allaccessories as per Annexure-II are made alongwith Main Tank or prior todelivery of Main Tank so that erection and commissioning work ofTransformer can be completed properly and uninterruptedly .The date ofsupply of last accessory will be treated as date of delivery of transformerand penalty shall be imposed upto a maximum of 10 % for delay in supplyand supply bills will be processed accordingly.35.3 The responsibility for obtaining timely supplies of bought outitems will rest on the Bidder and only on this basis, delivery period will beoffered in the Bid.35.4 It may be noted that in case of damages/shortages due toimproper packing or any other negligence ,replenishment shall be arrangedwithin 45 days of being noticed by the purchaser. If this is not done, date ofdelivery of such accessory will be treated as date of delivery of mainequipment and full penalty shall be recoverable from the Bidder on totalcost of the equipment. This should be confirmed.MPPTCL/TECH/PROC/01/JULY 13 Page 79 of 12535.5 For bought out items, responsibility for guarantee and obtainingimmediate replacement in case any defects are noticed and in case defectivesupply of any item is reported will rest on the Bidder.35.6 In case for attending to defect in any accessory or inspection/replacement of the accessory, which may be bought out item for theBidder; services of engineer of original manufacturer is required, the same willbe organized on immediate basis by the Bidder at his cost.35.7 The bidders are required to furnish in their bid, the following detailsof packages for supply of complete quantity of materials/one completeequipment:i. Total number of packagesii. Dimensional details of each package.iii. Weight of each package.iv. Nature of content (i.e. fragile or non-fragile)In addition, the bidder from outside India offering CIP prices shallalso indicate the port of entry in India.36.0 For all power transformer included in the Bid specification ,provisions and stipulations as per CBIP Manual on Transformers in regard tothe following except as modified in this document should be strictly adopteda) Design and authorization.b) Galvanising.c) Labels.d) Nuts & bolts.e) Cleaning & Painting.f) Prevention of acidity.g) Continuous maximum rating & over loads.h) Duty under faults conditions for stabilizing windings.i) Flux density and magnetizing current.j) Vibration & noise.k) Suppressions of harmonics.l) Magnetic circuit and mechanical construction of cores.m) Constructional arrangements for winding.n) Earthing arrangements.o) Cooling plant for the transformers.p) Temperature indicating device and alarm.q) Gas actuated relays.r) Marshalling box/control cubicle, panel drives & MechanismBox

s) Control connection and instrument wiring.t) Drying out, transport and erection.u) Valves and air release plugs.MPPTCL/TECH/PROC/01/JULY 13 Page 80 of 12537.0 REQUIREMENT FOR TRANSPORTATION OF TRANSFORMERSThe Bidders shall include charges for fitting atleast one “Electronic impactrecorder “ (on returnable basis) during transportation of Transformers tomeasure the magnitude and duration of the impact in all three directions. Theacceptance criteria and limits of impact in all three directions which can bewithstood by the equipment during transportation and handling shall besubmitted by the supplier during detailed engineering. The recording shallcommence in the factory before despatch and must continue till the unit isinstalled on its foundation. The data of electronic impact recorder(s) shall bedown-loaded at site and a soft copy of it shall be handed over to Engineerincharge.Further, within three weeks the supplier shall communicate theinterpretation of the data. In the unlikely event of impact recorder output notavailable at site, the equipment shall be thoroughly internally inspected by themanufacturer’s representative before erection at site to ensure healthiness ofthe equipment.Further the supplier shall mount “Vehicle tracking system” (GPRS/ GPS/ GSMbased) to track the exact position of the vehicle on which the Autotransformeris being loaded for transportation and during detailed engineering takeapproval for the equipment installed.38.0 Please ensure the bid document containing number of pageshave been properly page numbered and each page is signed by theBidder. All bid documents including Annexures should be indexedproperly and Index of the document should be enclosed/placed atthe beginning of the bid document.MPPTCL/TECH/PROC/01/JULY 13 Page 81 of 125ANNEXURE –IPRINCIPAL PARAMETERS FOR 315 MVA, 400/220/33 KVPOWER TRANSFORMERThe transformer shall conform to the following specific parameters describedhereunder:-No. DESCRIPTION PARAMETERS1 Type of powertransformer/installationAuto 3 phase Suitable for out doorinstallation2 Type of Mounting Mounted on rails Center to centerdistance 1676 mm+ Rail width,longitudinal and transverse both3 Suitable for system frequency 50 Hz4 Rated voltage ratio: HV/IV/LV 400/220/33 KV5 No. of phases Three6 No. of windings Auto transformer with tertiary7 Type of cooling ONAN/ONAF/OFAF8 MVA Rating corresponding to HV IV LVa) ONAN Cooling (60%) 189 189 63b) ONAF Cooling (80%) 252 252 84c) OFAF Cooling (100%) 315 315 1059 Method of connection HV - StarIV - StarLV - Delta10 Connection Symbol (Vector group) YnaOd1111 System earthing Solidly/effectively earthed12 Percentage Impedances, Voltage on

normal tap and MVA basecorresponding to HV/IV rating withapplicable tolerances:Principle / Highest / Lowesttapa. HV-IV 12.5%+10%tol./ 10.3%+ IStol./ 15%+ IS tol.b. IV-LV 30%+15%tol./ 28.9%+ IStol./ 26.8%+ IS tol.c. HV-LV 45%+15%tol13 Anticipated continuous loadinga) HV and IV Not to exceed 110% of its ratedCapacity.b) Tertiary Suitable for no load operation aswell as for loading to its ratedcapacity with capacitive orinductive loading or combinationof both (Subject to a maximum ofMPPTCL/TECH/PROC/01/JULY 13 Page 82 of 125No. DESCRIPTION PARAMETERS33% of the rated capacity of HVwinding14 Tap Changing gear :-i. Type ONLOADii. Provided on Provided on series windingimmediately before IV tappingpoint for variation of 220KVvoltageiii) Tap range -10% to +10%iv) Tap step 1.25%v) Voltage and current rating 245 KV and 1200 Amps.15 Over voltage operating capabilityandDuration110% continuous125% rated voltage for 60seconds.140% rated voltage for 5 seconds16 Minimum Air core reactance of HVWindings20%17 Flux densitya) Working Flux density in any partof core and yoke at rated MVA,frequency and normal voltage1.65 Teslab) Maximum flux density in anypart of core and yoke at 110%voltage &(-) 4% frequencyvariation shall not exceed1.90 Tesla18 Insulation levels :For windings HV /IV /LV:a) 1.2/50 micro second wave shapelightning impulse voltagewithstand (KVp)1300/950/250b) Power frequency voltage

withstand (KV rms)PD at 1.5 Um /√3 /395/95c) Switching surge voltagewithstand (KVp)1050/ - / -19 Type of winding insulationa) HV/IV winding Gradedb) LV winding Full20 System short circuit level andduration for which thetransformer shall be able towithstand thermal and dynamicstresses (kA rms/sec)63 KA for 3sec. for 400KV40 KA for 3sec. for 220 KV31 5 KA for 3sec. for 33 KV21 Noise level when energized at ratedvoltage and frequency but withoutload.As per NEMA standards(Copy of standard to befurnished with Bid)22 Permissible temperature rise OverMPPTCL/TECH/PROC/01/JULY 13 Page 83 of 125No. DESCRIPTION PARAMETERSambient temp of 500C.i) Of top oil measured bythermometer40 deg.Cii) Of winding measured byresistance45 deg.C23 Minimum clearance in air (mm) Ph-Ph Ph-Grounda. HV (400) 4000 3500b. IV (220) 2700 2400c. LV ( 33) 700 66024 Terminals : (Bushings)a. HV winding line end 420 KV OIP condenserb. IV winding line end 245 KV OIP condenserc. HV/IV winding Neutral end 72.5 KV OIP condenserd. LV winding 72.5 KV OIP condenser25 a. Radio Interference voltagelevel at 1 MHz. & 266 kV rmsphase to ground voltage for HVwinding1000 micro voltb. Maximum visual coronaexitinction voltage (KVrms)320c. Partial discharge level at 364KV 500 pico columb (maximum)26 Cooling Equipments :a) Number of banks Two 50% cooler banksb) Number of pumps Adequate number of pumps andoneset of standby pump in each bank.c) Number of Fans Adequate number of Fans withstandby Fans for each bank.

27 Bushings : HV / IV / LV & NEUTRALa. Voltage Rating (KV rms 420 / 245 / 72.5b. Current Rating (Amps) 1250/1250/3150c. Lightning impulse voltagewithstand(KVp1425/1050/325d. Switching surge voltage(KVrms)1050/ - / -/e. Creepage distance (mm) 10500/6125/1813f. One min. power freq. Voltage(KVrms)630/460/14028 a) Bushing Current Transformerfor purchaser’s useHV IVi) Type Single ph. ring type turretmountedQuantity 3 nos 3nosii) Current Ratio HV & IV(A/A) 500-1000/1-1 500-1000/1-1iii) Knee point voltage (V) 1000 V 1000 VMPPTCL/TECH/PROC/01/JULY 13 Page 84 of 125No. DESCRIPTION PARAMETERSiv) Accuracy class PS PSv) Secondary resistance(Ohms) 2.5 2.5vi) No. of cores 2 2b) Neutral side C.T. forPurchaser’s use (forrestricted E/F protection)i) Type Single phase outdoor mountedii) Quantity One no. for three phase bankiii) Voltage class 52 KViv) No. of cores Twov) Current Ratio (A/A) 500-1000/1-1vi) Knee point voltage (KVp) 1000Vvii) Secondary resistance (Ohms) 2.5viii) Type of mounting Frame mountedix) Turns ratioIdentical to the turns ratioprovided on HV & LV sidex) Location for mounting In neutral lead before connectionto s/s. earth the detailedarrangement shall be worked outby the supplier as per actuallayout.29 c) 33 KV class CT for Tertiarywinding.i. Typeii. Current Ratio (A/A)iii. Quantityiv. Accuracy classv. Secondary ResistanceSingle phase ring type turretmounted1200/1-1One NumberCore1- 5P10,Core2 – class I

As per requirement or < one ohm30 Surge capacitors :i) Rated voltage 40KVrmsii) Applicable standards IS 11548 / IS 9348iii) Rated frequency 50 Hziv) Rated capacitance 0.125 micro farad.v) Tolerance on capacitance value -5% to +15% of rated valuevi) One minute power frequencywithstand voltage95 KVrmsvii) Lightning impulse withstandvoltage250 KVpviii)Temperature rise over designedambient temperatureNot more than 10 deg.Cix) Temperature coefficient 0.035%/deg.Cx) Bushing/support insulator forsurge capacitorPorcelain housingMPPTCL/TECH/PROC/01/JULY 13 Page 85 of 125No. DESCRIPTION PARAMETERSa) Applicable standard IS 5621b) Rated voltage 40 KVc) Creepage distance (mm) 1820 minimumd) Power frequency withstandvoltage95 KVrmse) Lightning impulse withstandvoltage250 KVpMPPTCL/TECH/PROC/01/JULY 13 Page 86 of 125ANNEXURE - IILIST OF FITTINGS AND ACCESSORIES TO BE PROVIDEDWITH EACH POWER TRANSFORMERS.1. Each transformer shall be provided with the following accessories.i One no. Dial type Thermometers for oil : A dial typeindicating thermometer with repeater of robust patternmounted inside FCC at a convenient height to read thetemperature in the hottest part of the oil and fitted with alarmand trip contacts. ROTI shall also be mounted on RTCCpanel.ii Winding temperature Indicator : Two nos. WTI for HV(on extreme phases), one no.WTI for IV ( on middlephase) & one no.WTI for LV ( tertiary) winding : Theseshall be indicating type, with repeater responsible to thecombination of top oil temperature and winding current,calibrated to follow the hottest spot temperature of thetransformer winding. The winding temperature indicator shalloperate a remote alarm before the hottest spot temperatureapproaches a dangerous value and it shall automaticallyactuate the cooling fan Motors and Oil pumps.iii Repeater Winding temperature Indicator (RWTI) : Theseshall be as per cl. 11.10 of section I. A precisionpotentiometer mounted inside the case shall function as atransmitter to operate a repeater for RWTI. For two windings( i.e. HV and IV) the transmitter shall be directly connected to

the repeater. For the third winding (i.e. LV) the transmittershall be connected to a Resistance Transducer, which willsupply DC for operating repeater.iv One magnetic type oil level gauge with low level alarmcontacts and dial showing minimum, maximum and normal oillevels.v One plain oil level gauge of over lapped type on either sideof the conservator shall also be provided.vi Valves (As Per Annexure V) In the Annexure-V of valveschedule, 4 nos. valves are required to be provided in eachThermosyphon filter. Out of 4 nos., 2 nos. shall be providedfor the purpose of disconnecting the oil flow between themain tank & Thermosyphon filter and 2 nos. are to beprovided for the purpose of filtration of charge of theThermosyphon without disconnecting the Thermosyphon frombody . Valves required for NIFPS shall be included.vii Minimum 3 nos. pressure relief valves . The quantity ofthese valves should commensurate with the quantity of oil inthe transformer and also location of valves should beMPPTCL/TECH/PROC/01/JULY 13 Page 87 of 125properly designed to adequately release the excessivepressure.viii A set of air release valves on the top and on the radiatorsand also at appropriate places.ix One thermometer pocket for mercury in glass typethermometer.x Buchholz relay : One double float gas detector relay withalarm and tripping contacts to detect accumulation of gas andsudden changes of oil pressure, complete with shutoff valvesand flanges couplings to permit easy removal without loweringoil level in the main tank, a blend valve for gas venting, andtest valve. Make of buchholz relay shall be as per ourdiscretion.xi Heat exchangers or radiators complete with shut of valvesand with facility for oil draining arrangement.xii a. Two oil conservator, with required accessories, onefor main tank and other for OLTC. three nos Silica gelBreathers with main Conservator & one no. for OLTCConservator.b. Air cell type breathing arrangement with oilpreserving equipment complete in all respects of PRONOLmake only.xiii Eye bolts and lugs on all parts for easy handling.xiv Two grounding earthing terminals at diagonally oppositecorner of tank.xv One rating and diagram plate.xvi A set of minimum 4/8/12 nos.(as per requirement) flanged bidirectionalwheels for rail mounting (for 1676 mm rail gauge.)xvii Set of fans, Pumps required for ONAF & OFAF cooling of thetransformer with following informationa. Number of Radiator Banks.b. Required no. of cooling fans (Industrial duty ofadequate voltage & rpm) & pumps be provided in eachbank to ensure 100% ONAF & OFAF rating of thetransformer. As per our specification, for each bank 20 %cooling fan & pump is to be included which will be dulywired-up.

xviii Suitable jacking lugs and haulage holes.xix Inspection window & main holes with bolted cover as perAnnexure-IVxx Adequate no of Thermosyphon filter assembly (minimum 4nos) with suitable supports, valves and pumps for forced butslow circulation of Transformer oil .MPPTCL/TECH/PROC/01/JULY 13 Page 88 of 125xxi Lifting arrangement for the complete transformer, core coilassembly and also tank.xxii One detachable bolted type MS ladder each on main tank andconservator tank.xxiii For the purpose of taking earthing connection from theneutral bushing, adequate number of brackets with smallsupport insulators shall be provided on the body of the tankso that earthing could be arranged by Purchaser near theearthing pit of transformer itself.xxiv A separate weather proof FCC (Fan/Cooler control) cubiclecontaining dial type thermometer and winding temperatureindicator and terminals of dial type thermometer, windingtemperature indicator, buchholz relay, MOG, control of fansetc.Please note provision of separate Fan Control Cubicle(FCC) is a must. FCC shall be suitably dimensioned toaccommodate the following :-a The wiring from RTCC shall be brought to marshalling boxand for terminating the same adequate numbers ofsuitably rated terminal connectors shell be provided.b Necessary cable glands shall be included in the scope ofsupply. The cable gland and the hole on gland plate forcable entry shall be provided.c Arrangement for terminating the connecting leads ofOTI, WTI, buchholz, magnetic oil level gauge etc. shall bemade in the marshalling box. It should be possible toread OTI and WTI readings without opening the boxthrough suitable glass window. All trip alarm andrepeater signals will be transferred to control room forwhich arrangement will have to be made.d Starters for cooling fans & Pumps shall be housed inmarshalling box and necessary switches for local operationof fans and pumps shall be provided.e Local remote control switch for OLTC shall be provided.f Space heater with switch, cubicle illumination lamp,fuses, links overload protection arrangement for motorsand other accessories shall be included in the scope ofsupply.xxv One set of indoor RTCC (Remote tap changer control) cubiclecomplete with provision for remote operation of OLTC, asindependent or master/follower scheme, with oil andwinding temperature repeater, tap position indicator withannunciation for fan group ON/OFF and cooler supply failindication and Tap changer in progress including OTI repeater& WTI remote indicator operated by remote sensors.MPPTCL/TECH/PROC/01/JULY 13 Page 89 of 125xxvi One set of erection manual/relevant drawing/leaflets should besecured permanently inside the RTCC cubicle as a guide line forsite erection and commissioning.xxvii Three separate connection i.e. connection from core,

connection from end frame and connection from tank shallbe brought out on to a terminal box with cover. Arrangementfor inter connecting these terminals in the terminal box shall alsobe provided. This arrangement shall facilitate verification ofcore, end frame and tank insulation.xxix Minimum 3 nos silica gel breathers .xxviii Mounting of radiators on the 33KV side of 72.5 KVbushing should be avoided. In no case, the radiatorsshould be projected above the main tank height.xxix All transformers shall be supplied with a full outfit of tools,spanners, special tools as per annexure IX for assembly andall spanners shall be double ended and of very good qualityof " Gedore " or "Taparia " or equivalent make.2. The equipments and accessories furnished with the transformershall be suitably mounted on the transformer for ease of operation, inspectionand maintenance and the mounting details shall be subject to the approvalof the purchaser. All valves shall be provided either with blind companionflanges or with pipe plugs for protection.3. Indication, alarm and relay equipment shall have contacts suitable foroperation with 220V DC supply. Any other accessories or appliancesrecommended by the manufacturer for the satisfactory operation of thetransformer shall also have 220V DC as input.4. a. OLTC and its controls shall be as per clause 14 Section-Iof specification.b. All cabinets & panels shall be conforming tostipulations under Clause-16 of Section -I of specifications.c. All 220KV, 132KV, 33KV and neutral bushings shall be of OIPcondenser type and as per Clause 11.13 of Section I ofspecification.5. NIFPS : Nitrogen injection type fire prevention & extinguishing systemwith flow sensitive conservator isolation valve shall be provided for all thetransformers as per clause no. 20.9.6. OLMD : On Line Monitoring Device shall be provided for all thetransformers as per clause no. 20.10.7. Surge Capacitor with structure : 3 nos Surge Capacitor with structureshall be provided for all the transformers as per cl. no. 20.12.MPPTCL/TECH/PROC/01/JULY 13 Page 90 of 1258. Provision for Measurement of Degree of Polymerisation ofInsulation of Winding of Transformer :- To assess the life of paperinsulation of winding , a provision is to be made inside the transformer . Forthis purpose, a container of insulating material of good electrical, mechanical& chemical properties having free circulation of oil through it shall be providedat suitable location where maximum oil temperature is expected. In thecontainer, atleast 10-12 spools of paper having size not more than one cm beplaced . The container shall be closed and there should not be any possibilityof spools coming out from the container due to natural circulation as wellturbulence of oil during fault etc.Location of the container shall be selected such that spools may beremoved from the container as and when required by the purchaser duringservice of transformer for the purpose of testing of insulating material for“Degree of Polymerisation” (DP test).9. Accessories, which are not included in the aboveAnnexures but details of which are given in Bid specification andwhich are necessary for satisfactory operation of Transformer shallbe deemed to have been included in the accepted price without anyextra cost to the Purchaser.MPPTCL/TECH/PROC/01/JULY 13 Page 91 of 125

ANNEXURE -IIILIST OF TRANSFORMER ACCESSORIES AND THEIR TESTCERTIFICATESTO BE SUBMITTED BY MANUFACTURERS/APPROVED VENDORSS.No.Accessory Ref. Std. Test-certificates required1 CondenserBushingIS2099,IEC60137 1. Appearance, constructionand dimensional check2. Test for leakage ofinternal filling at apressure of 1.0 kg/cm2 for12hours.3. Insulation resistance IS2099 measurement with2000V Insulation Tester.4. Dry/wet power frequencyvoltage withstand test.5. Dry/wet power frequencyvoltage withstand test fortest tap insulation6. Partial dischargemeasurement up to 1.5UN/_/3 KV.7. Measurement of tangentdelta and capacitance.2. Air Cell of Pronolfrance makeIEC 1. Dimensional check,inflation/Deflation at 10inflation/Deflation at 10KPa2. Pressure test at 10 KPa for24 Hr.3. OLTC IS 2026 part I,IEC 602141. Oil tightness test for the8468 diverter switch oilchamber at an oil pressureof 0.5 kg/cm2 at 100 degreecentigrade for 1 hour.2. Mechanical operation test.3. Operation sequencemeasurement4. Insulation resistancemeasurement using2000V Insulation Tester5. Power frequency voltagewithstand test on diverterMPPTCL/TECH/PROC/01/JULY 13 Page 92 of 125S.No.Accessory Ref. Std. Test-certificates requiredswitch to earth and betweeneven and odd contacts.6. Power frequency voltage

withstand test on tapselector-between stationarycontacts, between max. andmin. taps, between phasesand supporting frames,between phases.7. Operation & dielectric test ofcomplete OLTC4. Winding & OilTemp Indicator1. Calibration test2. Dielectric test at 1.5 kV forone minute.3. Accuracy test for indicationand switch setting scales.4. Test for adjustability ofswitch setting5. Test for switch rating6. Measurement oftemperature rise withrespect to the heater coilcurrent.5. Pressure ReliefvalveIS13947 1. Functional test withCompressed air to checkbursting pressure, indicatingflag operation and switchoperation.2. Dielectric test at 2 KV forone minute.3. Switch contact testing at5A, 240 Volt AC.4. Leakage test at 75%operating pressure for 1Hr.6. Cooling Fan andmotor assemblyIS 2312 1. Appearance, constructionand dimensional check.2. Insulation resistancemeasurement3. Dielectric test at 1.5 KVbetween winding and bodyfor one minute4. Operation check.5. Power consumption, RPM,Current.MPPTCL/TECH/PROC/01/JULY 13 Page 93 of 125S.No.Accessory Ref. Std. Test-certificates required7. Buchholz Relay IS:3637 1. Leak test with transformeroil at a pressure of 3kg/cm2 for 30 minutes atambient temperature forrelay casing.2. Insulation resistance

measurement with 500VInsulation Tester.3. Dielectric test at 2 kV for 1minute4. Elements test at 1.75kg/cm2 for 15 minutes usingtransformer oil at ambienttemperature.5. Loss of oil and surge test.6. Gas volume test7. Mechanical strength test8. Velocity calibration test9. Appearance construction anddimensional check.8. Oil Level gaugeincluding MOGIS 1. Appearance, constructionand dimensional check2. Dielectric test at 2 KV for 1minute3. Switch contact test at 5A240V AC4. Switch operation for lowlevel alarm5. Test for oil levels9. Pressed SteelRadiatorsIS 513 1. Appearance, construction &dimensional check.2. Air pressure test at 2kg/cm2 under water for 15minutes10. OLTC Controlcubical/CoolerControl cubicle1. Appearance, construction &dimensional check.2. Electric operation3. Insulation resistancemeasurement using 500 Vmeggar at ambienttemperature4. Dielectric test at 2kV for 1minuteMPPTCL/TECH/PROC/01/JULY 13 Page 94 of 125S.No.Accessory Ref. Std. Test-certificates required11. Bushing CurrentTransformersIS: 2705 1. Appearance, construction &dimensional check. PolarityCheck, Measurement ofinsulation resistance.2. H V power frequency test.3. Determination of ratio errorand phase angle of

measuring and protectionBCTs4. Interturn insulation test5. Exciting currentcharacteristic test,Secondary windingresistance measurement12. TerminalconnectorIS 5561 1. Dimensional check as perdrawing & visual inspection2. Tensile test, resistance test3. Galvanisation test as per IS2633 on galvanized parts .13 Silica GelBreather1.Pressure tests2. Visual & dimension tests3. Operation test4. silica gel test5. Oil compatibility test14 NIFPS TAC/NEPA norms 1. Lamp test2. Out of Service3. Transformer ConservatorInsulator Valve (TCIV)open4. Transformer ConservatorInsulator Valve (TCIV)closed5. Fire Detector trip6. Buchholz Relay trip7. Differential Relay trip8. PRV trip9. RPRR trip10.Transformer trip11.D.C. fail etc..MPPTCL/TECH/PROC/01/JULY 13 Page 95 of 125ANNEXURE-IVSCHEDULE OF INSPECTION COVER/ACCESS WINDOWSS.No. ParticularsSize(Length xWidth)(mm x mm)Qty.(Nos.)1 Inspection cover (man hole) 450x900 12Inspection cover/ Access Windowfor OLTC (with lifting handle ontank wall)450x900 33Inspection cover/ Access Windowfor HV Bushing500x500 34

Inspection cover/ Access Windowfor IV Bushing500x500 35Inspection cover/ Access Windowfor LV (Tertiary) Bushing500x500 36Inspection cover/ Access Windowfor Common Neutral Bushing500x500 17Inspection cover on HV & IV sidehaving 200 mm dia.200 mm dia. 28Inspection cover on Tank cover– 2nos for HV & 1 no for IV .300x600 39Inspection cover on Tank cover– 1no for neutral– 1no for tertiary– 1no for core-endframe-tankearthing arrangement300x400 310Inspection cover on Conservator500mm dia 1MPPTCL/TECH/PROC/01/JULY 13 Page 96 of 125ANNEXURE-VSCHEDULE OF VALVESItem Description of Valves Size Qty Type(Design)1 Oil inlet / outlet valve for Radiatorheader250NB 2+2 Gate valve2 Top /Bottom Oil filter valve 50NB 2+4 Gate valve3 Top / Bottom oil sampling valve 25NB 1+1 Globe valve4 Drain plug bottom tank 50NB 25 Drain valve (Tank) 100NB 1 Butterfly valve6 Drain valve (Tank) 100NB 1 Gate valve7 Valve for outlet from & inlet totank250NB As perdesignButterfly valve8 Valve for pipe assembly and bankI&II50NB* As perdesignGate valve9 Isolating valve for I&II 250NB As perdesign10 Quick Oil discharge valve 125NB 1 Gate valve11 N2 Injection valve 25NB 6 Gate valve12 Valve for oil inlet & outlet for

OLMD25 NB* 2 Gate valve13 Radiator Isolating valve 100NB As perdesignButterfly valve14 Drain plug on radiators ½ ” Bsp15 Air release plug on radiators ½ ” Bsp16 Drain cum filter valve on header 50NB 4 Globe valve17 Drain plug on header ½ ” Bsp 4* --18 Air release plug on header ½ ” Bsp 4*19 Drain plug on inlet/outlet pipe ½ ” Bsp 2*+2*20 Air release valve on tank cover 15NB 2 Gate valve21 Pressure release valve (Main tank) 150NB 3 Gate valve22 Thermosyphon drain valve 25NB 4 Globe valve23 Thermosyphon filter valve 50NB 8 Gate valve24 Drain plug on Thermosyphon filter ½ ” Bsp 425 Air release plug on Thermosyphonfilter½ ” Bsp 426 Thermosyphon pump isolatingvalve100NB 4 Gate valve27 Thermosyphon pump bypass valve 100NB As per req. Gate valve28 Thermosyphon isolating valve 100NB 8 Butterfly valve29 Oil surge relay isolating valve 25NB 3 Globe valve30 OLTC equalizing valve 25NB 3 Gate valve31 OLTC suction valve 25NB 3 Globe valve32 OLTC Conservator drain valve 25NB 1 Globe valve33 Buccholz relay isolating valve 80NB 2 Gate valve34 Pre Stressed Non return valve 80NB 1 Gate valve35 Gas Sampling valve ¼” Bsp 2 Gate valve36 Main conservator Drain valve 50NB 1 Gate valve37 Main conservator Air release valve 25NB 1 Gate valveMPPTCL/TECH/PROC/01/JULY 13 Page 97 of 12538 Main Breather isolating valve 25NB 1 Gate valve39 Valve for Vacuum breaking duringoil filling25NB 1 Gate valveNOTE: 1. All valves shall have position indicators to indicate the status i.e.valves are in open or shut position.2. All valves shall be made of gun metal (GM); cast iron valves are notacceptable.3. All plugs shall be made of cast iron (CI)/GMNB- Normal Bore – mm.* Size & Qty. indicated is subject to change as per designMPPTCL/TECH/PROC/01/JULY 13 Page 98 of 125ANNEXURE –VI(A)DRAWINGS AND DATA TO BE FURNISHED BY THE BIDDER.The following drawings and data for each items are to be submittedwith the Bid(a) Outline dimensional drawings of transformer and its accessoriesincluding conservator complete with Bill of material and details ofall parts, their quantity, rating & name of Vendors indicatingclearances of transformer body from live terminals i.e. HV,IV,LV.(b) Drawing of transformer tank with location of inspection windows,thickness of side/bottom/top of tank, details of stiffener.(c) Drawing indicating limbed core construction with complete details of

no., width and wt. of core laminations with size of steps; thickness ofcore laminations ; dimension of window; size of limbs; Gross and netcore ; wt. of complete core.(d) Drawing indicating core belting arrangement with details of belting,belting material etc.(e) Large scale dimensioned drawings for HV,IV & LV windings of thetransformer; size and no. of parallel of HV,IV, LV and of, coolingducts, coil clamping arrangement, no./size & location of pressurescrews, clamping ring; top yoke arrangement etc. The details shouldcommensurate with the short circuit calculations submitted by you foreach rating of transformer(f) Detailed drawing of transformer tank with complete core and windingindicating clearances inside transformer tank as also passage andspace for free movement of at least two persons for inspection ofactive parts etc .(g) Schematic diagram showing the flow of oil in the cooling system aswell as each limb and winding. Longitudinal and cross-sectional viewsshowing the duct sizes, cooling pipes etc. for thetransformers/radiators drawn to scale .(h) Drawings giving the weights for foundations.(i) Combined Rating and diagram plate including tap changing, whichshould also include details of guaranteed and measured no load andload losses as also winding resistances and percentage impedances atall taps.(j) Schematic control and wiring diagram for all auxiliary equipmentand control cubicle.MPPTCL/TECH/PROC/01/JULY 13 Page 99 of 125(k) Drawing showing constructional details, dimensions, mechanical& technical particulars of bushings. Arrangement of terminals anddetails of connection of bushing shall also be indicated in drawing withtheir technical particulars.(l) Transportation drawing of transformer.(m) Details of fittings and cable box.(n) Drawing showing arrangement and details of tap changing gearincluding selector switch, diverter switch and drive mechanism.(o) Valve Schedule plate.(p) Oil filling instruction plate for conservator fitted with Air cell breatherarrangement including equalizing arrangement if any required atthe time of taking full Vacuum at site.(q) Drawing and instruction for fitting of Air Cell.(r) Drawing of conservator indicating internal details of air cell MOG, oillevel gauge and silica gel breather pipe fitting arrangement.(s) Drawings of all HV, IV & LV bushings with complete details meeting TSrequirement.(t) Drawings of HV,IV,LV & neutral terminal connectors indicating platethickness, no. of nut bolts with size and other details.(u) Drawing of detachable bolted type MS ladder with its complete detailsand fitting arrangement on transformer/ conservator tank.(v) Drawing for HV/IV neutral earthing arrangement indicating voltagerating of insulators and its fitting arrangements, size of copper strips,terminal connectors etc.(w) Detailed drawing indicating two views of all valves provided in thetransformer tank.(x) Drawing of Thermosyphon filter with fixing arrangement withtransformer tank.(y) Detailed internal drawing of transformer indicating transportationlocking arrangement provided to avoid shifting of core assembly.

(z) Drawing showing weights of transformers, cooling fan structures, FCCstructures with distance from central line of transformer for casting ofcivil foundation for transformer and associated equipments.(aa) Drawing of Earthing terminal box showing earthing arrangement forcore, end frame, tank giving details of voltage class and current ratingof terminal bushings.MPPTCL/TECH/PROC/01/JULY 13 Page 100 of 125(ab) Drawing indicating insulation thickness details and other arrangementprovided between core assembly and bottom yoke and base of bottomof tank.(ac) Drawing indicating details of ‘O’ ring gasketting arrangement providedin transformer tank covers.(ad) Detailed Drawing of jacks.(ae) Drawing of stiffeners provided on top, each faces/sides of tank withtheir number and size.(af) Drawing indicating number, location, size of shields/ magnetic shuntsand its material provided inside the tank as per clause 11.1 (g).(ag) Drawing indicating internal details of transformer giving completedetails of clearances from live parts.(ah) Drawing of internal LV winding termination arrangement indicatingminimum clearance between core and LV take off lead.(ai) Drawing of Neutral Current Transformer with details of its mountingarrangement.(aj) Drawing for Lead termination to bottom of HV & LV bushings.(ak) Drawing of On Line Monitoring Device with details of mountingarrangement.(al) Drawing of Neutral Current Transformer with details of its mountingarrangement.(am) Drawing for Lead termination to bottom of HV & LV bushings.(an) Internal drawing & design of Core & Winding indicating all attachmentwith identification numbers, description including take-off arrangementof lead connection for Core & End frame and related Bill of Material(ao) Locking arrangement drawing for tank top cover, core & winding withcomplete dimension & details.(ap) Plan view of the bottom of Bell Tank for complete details of core coilresting arrangement, indicating clearly dimensional details, material ofinsulation, clamping arrangement with details of nuts/ bolts, clearancefrom all sides provided at bottom.(aq) Drawing indicating complete details, dimension & mountingarrangement of OLTC inside the tank with respect to End frame.(ar) Drawing indicating complete details, dimensions & fixing arrangementof static end rings if used.MPPTCL/TECH/PROC/01/JULY 13 Page 101 of 125(as) Other relevant drawings.As soon as possible after the award of the contract the manufacturer shallsupply four (4) copies of the drawings as listed out above, which willdescribe the equipment in details for approval and shall subsequentlyprovide ten complete sets of final drawings, one of which shall be autopositivesuitable for taking blue prints. Ten sets of instruction books,operation and maintenance manuals and spare part bulletin, shall besupplied. In addition to above two sets of manuals and drawings with testcertificates for each unit to be despatched as per despatch instructions.MPPTCL/TECH/PROC/01/JULY 13 Page 102 of 125ANNEXURE – VI(B)LIST OF DRAWINGS TO BE FURNISHED ALONGWITH BID ANDDETAILS TO BE LISTED IN SCHEDULE-IVS.No. Particulars

1 OGA drawing of transformer2 List of fittings & accessories for OGA3 Drawing for HV,IV,LV , OIP Condenser bushings4 Makes of various accessories and source of raw material5 Universal type bimetallic terminal connector for HV,IV,LV, Neutral6 Conservator with air cell breathing arrangement7 Thermosyphon filter assembly with pump & without pump8 Internal clearances detailed drawing9 Dimensional details for transportation of transformer.10 Radiator arrangement11 Core earthing arrangement box12 Yoke binding details13 Neutral earthing arrangement14 Foundation details15 List of tools & tackles16 Bottom locking & insulating arrangement17 Core insulation details18 MS Ladder19 Sealing arrangement between top & bottom shell.20 OLTC Conservator with breather arrangement21 Drawings for various types of valves.22 Core shunt fixing arrangement23 Rating & diagram plate24 Valve schedule plate25 Oil filling instruction plate for conservator with air cell.26 Roller assembly with anit-earthquake arrangement27 Coil clamping arrangement28 Oil flow diagram29 Winding details arrangement with dimension30 Core details with design data31 Over fluxing curve32 Drawing for tank stiffener & magnetic shunt inside transformer withcalculation.33 NIFPS with complete catalogue, manuals & drawings.34 Schematic drawings for OLTC, FCC & RTCC .35 Cooler control cubicle cum marshalling box with schematic36 RTCC panel drawing37 Drawing for static end ring38 Complete dimensioned details of bottom tankMPPTCL/TECH/PROC/01/JULY 13 Page 103 of 125ANNEXURE VIIDESIGN CALCULATIONS & DESIGN DATA REQUIRED TO BE ENCLOSEDWITH THE BID FOR POWER TRANSFORMERIt should be specifically noted by the Bidders that submission offollowing Design Calculations & Design Data with the offer isnecessary and bids wherein these calculations are not found enclosedshall run risk of rejection.(1) SHORT CIRCUIT WITHSTAND CAPABILITIES : The calculations toprove dynamic and thermal short circuit withstand capability of transformeras per clause 31.1.1 shall be submitted for the fault level indicated asunder:400KV - 63 KA for 3 secs.220KV - 40 KA for 3 secs.33KV - 31.5KA for 3 secs.Results of calculations shall be submitted with the Bid . The design of windingassembly , which is to be furnished in the drawing as per Sr. No. (e) ofAnnexure VII should be commensurating with these calculations. The details

of clamping ring shall be indicated in the drawing .It may be noted by the Bidders that calculations for short circuit withstandcapability for two winding transformer is not acceptable under anycircumstances and these calculations shall be submitted for 3 winding autotransformer. The computer output for calculations of short circuit forces withminimum of 7 iterations with limiting values shall be submitted during DesignReview as per Cigre Guidelines.(2) DESIGN DATA OF CORE & WINDING : On the basis of offered fluxdensity and current density, the Bidders shall furnish furnish followingdesign calculations & data. Calculations regarding wt. of core & copper andalso calculations for losses will be brought out to justify the offeredtransformer losses. :(A) Core Data: Details of core material i.e Name of Manufacturer,Manufacturer’s type designation for core , thickness of core, curve forLoss Vs Flux density, No of steps of Core & No of limbs, gross core area, stacking factor , Net core area ,height & width of core window, centerto center distance of limb, voltage per turn, wt. of core material,working flux density , core loss in watts per kg marked on graph forgrade of core material & selected flux density, building factor andcalculated no load loss in watts, guaranteed no load loss. Design data forcore as per clause 31.2.1 shall be submitted with the Bid. A drawingindicating details of core i.e. limbed construction, step width & thickness, core belting, top & bottom yoke plate etc shall be submitted with theBid .MPPTCL/TECH/PROC/01/JULY 13 Page 104 of 125(B) Winding Data: wt. of copper for windings ie. for HV(series), IV(common),tap, LV(tertiary), cross sectional area , current density, type of coil,ID/OD/mean dia of coils, size of winding conductor including parallels,no. of turns per phase, no of spacers, length of mean turn, weight ofcopper without paper covering, resistance per phase of winding at 75 degC, I2R loss at 75 deg C & normal tap, eddy current & stray loss at 75 degC , total copper loss at 75 deg C , guaranteed transformer losses at 75deg C.Complete details of Insulation components i.e. Top & Bottom clampingrings, washers , Pressboard blocks & cylinders, Pressboard spacers &Phase barriers, Pressboard segments etc shall be submitted indicatingqty , thickness in mm, width & height , wt. Design data for winding asper clause 31.2.2 shall be submitted with the Bid.Dimensioned drawings indicating details of winding , ducts, insulation ,take off arrangement, clamping ring , pressure points etc shall besubmitted with the Bid .(3) DESIGN OF TANK : Complete mechanical design of transformer tankincluding details of stiffeners as per clause 31.1.2 shall be submitted . Thetank shall be designed to withstand the following without permanentdistortion.(i) Mechanical shocks during transportation.(ii) Vacuum filling of oil at 10 milli torr in transformer with all fittings.(iii) Continuous internal pressure of 35 kN/m2 over normal hydrostaticpressure of oil.(iv) Short circuit forces &(v) Under seismic condition /events both horizontal/vertical .The calculations for tank stiffeners shall be submitted with the Bid to proveno. & size of stiffeners are adequate to withstand full vacuum & pressure .Drawing of tank shall be submitted indicating stiffners .(4) DESIGN OF STATIC END RINGS (SER) AND MAGNETIC SHUNTS :Details of Static End Rings (SER) and magnetic shunts , if provided , withcalculations as per clause 31.1.3 shall be submitted with the Bid. A drawing

indicating locations , size ,material of SER and magnetic shunts shall besubmitted with the Bid .(5) QUANTITY OF OIL : Complete calculations of oil quantity to be utilizedin transformer for first filling shall be submitted with the Bid. The calculationsshall indicate(i) Volume of tank including turrets, conservator main & OLTC ,volumeof headers & Radiators, oil quantity in OLTC & thermosyphon filter.(ii) Oil displacement by Active parts i.e. core - coil assembly,MPPTCL/TECH/PROC/01/JULY 13 Page 105 of 125(6) CAPACITY OF CONSERVATOR & SIZE OF AIR CELL : While furnishingdetails of conservator & air cell type sealing arrangement, the Bidder shallsubmit details & calculations for adequacy of size and capacity of Pronalmake air cell for the rating of the power transformer and also for thequantity of oil required with the Bid. Catalogue of Pronal should be enclosedwith the Bid clearly marking type designation of selected size of Air cell. Adrawing indicating complete details of conservator with Air cell shall besubmitted .(7) CAPACITY OF PRESSURE RELIEF DEVICE : Bidders must submitcalculation with the Bid to prove that the capacity/rating of pressure reliefdevice and locations of the same for the transformer will adequately meet ourrequirement. Constructional and design details of pressure relief device mustbe furnished and it should be proved by calculation that the size andsetting of pressure relief device is adequate considering the rating of thetransformer and quantity of oil in the transformer. A drawing indicatingcomplete details of PRDs & their locations on tank shall be submitted .(8) CALCULATIONS FOR TEMPERATURE RISE & HOT SPOT WINDINGTEMPERATURE : The limits of temperature rise for windings, oil and hot spothave been specified in Volume II . Temperature rise calculations at rated fullload, 110% load and 125% load considering 100% cooler banks, 50% coolerbanks and without coolers shall be furnished as indicated below :(a) 100 % Loading : (i) 20 minutes duration - 100 % cooler bank- 50 % cooler bank- without cooler bank(ii) 10 minutes duration - 100 % cooler bank- 50 % cooler bank- without cooler bank(b) 110 % Loading : (i) 20 minutes duration - 100 % cooler bank- 50 % cooler bank- without cooler bank(ii) 10 minutes duration - 100 % cooler bank- 50 % cooler bank- without cooler bank(c)125 % Loading : (i) 20 minutes duration - 100 % cooler bank- 50 % cooler bank- without cooler bank(ii) 10 minutes duration - 100 % cooler bank- 50 % cooler bank- without cooler bankThe calculations shall indicate temperature gradient (for all windings i.e.HV,IV,LV,tap), load losses at lowest tap for all windings , Eddy current & straylosses, thermal Constant Value & calculations with parameters affecting thevalues for above conditions for top oil temperature & winding hot spottemperature .The Calculations for Hot Spot winding Temperature andCalculations for Temperature Rise shall be submitted with the Bid.MPPTCL/TECH/PROC/01/JULY 13 Page 106 of 125(9) COOLING CALCULATIONS : Calculations of tank surface for heatdissipation, details of radiators , fans for ONAN & ONAF cooling shall be

provided with the Bid.(10) OVERFLUXING CAPABILITY: A curve to prove suitability oftransformer to withstand various Overfluxing conditions for the durationindicated in clause 4.4.1 to 4.4.3 without core saturation shall be furnishedwith the Bid .(11) CAPACITY OF FILTER & BREATHER :(A) Number and Capacity of each Thermosyphon Filter : The Biddershall submit details & calculations for adequacy of size and capacity ofthermosyphon filter for the oil quantity in the power transformer .While furnishing details of thermosyphon filter arrangements, theBidder must confirm clearly the number of thermosyphon filter, its sizeand capacity is adequate for the rating of power transformer. TheBidder shall submit details & calculation to prove for adequacy of sizeand capacity of thermosyphon filter with the Bid.(B) Capacity of Silica Gel Breather : The Bidder shall submit details &calculations for adequacy of size and capacity of silica gel breatherfor the oil quantity in the power transformer with the Bid .(12) RATING OF ON LOAD TAP CHANGER (OLTC) : To verify theadequacy and suitability of the OLTC components, it is necessary to furnishthe calculations for selecting the proper rating of transition resistance aswell as the normal current rating of OLTC. The calculations shall include thetemperature rise of the OLTC diverter switch and also the short circuitcurrent considered for calculation of temperature rise.Calculations shall be submitted to prove that the current rating of OLTC isadequate for the rating of the transformer winding taking in to account theover loading capability as per IS 6600 . The basis for selection of transitionresistance and its current carrying capacity shall also be submitted. In thisregard the circulating current in tap winding during tap change operationthrough transition resistance shall be taken in to consideration. Adequacy ofinsulation provided in the OLTC between various parts needs to be establishedwith specific reference to the voltage between two taps. Confirmation shall begiven that the OLTC is suitable for bidirectional flow of current. The throughcurrent capacity shall be adequate to handle on continuous basis the windingcurrent including over loading as per IS 6600. The through current rating andthe rating of transition resistance shall take in to account the short timecurrent rating of the winding. Capability to handle short circuit current to beestablished by calculations and also by test reports.The above Calculations for OLTC shall be submitted with the BidMPPTCL/TECH/PROC/01/JULY 13 Page 107 of 125(13) Capacity of Nitrogen Cylinder, pressure in Nitrogen Cylinder to be usedduring transportation shall be submitted with the Bid.(14) Size & capacity of Oil sump/ pit for Nitrogen Injection Fire ProtectionSystem shall be submitted with the Bid.(15) DESIGN REVIEW : The “Design Review” of the 315 MVA, 400 KVtransformer shall be carried out in accordance with the “Guidelinesfor consulting Design Reviews for transformers 100 MVA & above” ofCigre working group 12.22 (SC12 WG 12.22). The Bidder shall carry outoptimization of Dielectric design of insulation including electromagneticdesign, overload & short circuit withstand capabilities. During design ,transformer modeling shall be done & finite element software (FEM) may beused.Note : Bidders may please note that submission of abovecalculations & design data as mentioned in clause 31 and in thisAnnexure with technical bid is an essential requirement of the Bid.MPPTCL/TECH/PROC/01/JULY 13 Page 108 of 125ANNEXURE VIIIDETAILS OF INSPECTION PROGRAMME

1 . INSPECTION PROGRAMME :1.1 Manufacturer shall chalk out a detailed inspection and testingprogramme for various manufacturing activities for the differentcomponents, fittings & accessories. The MPPTCL also reserves the right tocarryout any tests by a third party at its sole discretion. All Costs ofinspection/ tests shall be borne by Manufacturer.2.2 STAGE INSPECTIONS :2.2.1 Manufacturer shall indicate the inspections and checks carried out atvarious stages of the manufacture of the transformer. A complete record ofstage inspection shall be kept by Manufacturer and this record shall be madeavailable for inspection by the representative of the MPPTCL. Manufacturershall indicate the manufacturing programme and the MPPTCL will have a rightto depute its inspecting officers during the manufacture. The inspecting stagesshall be Fabrication of Tank & Conservator, core building, coil winding ,assembly of coil on core, the condition of the coil and core after thetreatment in vacuum chamber, assembly within the transformer tanktogether with application of tap changer etc .2.2.2 It may be noted that stage inspections for all the units shall be doneby us at the following stages as per the different formats enclosed :(i) STAGE I : Stage Inspection of Transformer Tank and Conservatorafter fabrication. After fabrication, tank & conservator shall be inspected formeasurement of its dimensions, thickness of sheets used and leakage test byapplying requisite pressure.In this stage following shall be measured ,recorded & checked in Format I(A,B,C) .(A) Format I (A) : Inspection of Tank & Conservatora) Certification of chemical composition and mechanical propertiesof plates.b) Welder's and weld procedure qualification.c) Testing of electrodes for quality of base materials as per ASME.d) Dimensional check and visual Inspection of weld .e) Crack detection, of major strength weld seams by dyepenetration test.f) Measurement of film thickness of inside and outside of X'mer tankand conservatori) Oil insoluble varnishii) Zinc chromate paintiii) Light grey paintMPPTCL/TECH/PROC/01/JULY 13 Page 109 of 125g) Check correct dimensions between wheels, rotation of wheelsthrough 90 deg.h) Check for physical properties of materials for lifting lugs, jackingpads, etc. All load bearing welds including lifting lug and jackingparts shall be subjected to DP test.i) Leakage test of conservator and tank.j) Pressure and vacuum test of tank.k) Surface cleaning by sand or shot blasting.l) Certification of all test results.(B) Format I (B) : Inspection of Valves as per Schedule of Valves(C) Format I (C) : Inspection of Tank for Inspection Windows.(ii) STAGE II : Stage Inspection of Transformer Core during CoreBuilding : After the core is built but before its clamping,MPPTCL representative shall inspect the core to take complete weightof the core and also to measure approximate core loss. Ifnecessary, a small strip of core shall also be taken for testing at CPRI,Bangalore at our discretion or at any other testing lab. of repute formeasurement of specific loss .

During this stage, following documents shall be verified by ourinspector as a proof towards use of prime core material material formanufacturer of transformer ordered by us .i) Invoice of the supplierii) Mills test certificateiii) Packing listiv) Bill of ladingv) Bill of entry certificate by custom's.The core material shall be directly procured either from themanufacturer or through their accredited reputed marketingorganisation but not through any agent. A copy of all above documentsshall be sent with joint inspection report for MPPTCL records.In this stage, following shall be measured, recorded & checked in Format II(A,B,C) .(A) Format II (A) : Report in respect of Raw material viz core,copper, insulating material ,tank steel etc.: Details of various rawmaterial shall be recorded viz. Name of Supplier/Sub supplier, TestCertificate, QAP Report , Invoices, Bill of Lading ,bill of entry etc.(B) Format II (B) : Report in respect of Accessories: Details ofaccessories Viz Buchholz relay, Pressure Relief device, Axles andwheels, Winding and oil temperature indicators , Cooling fan andradiator, Condenser Bushing & Bushing Current Transformer, OLTC,Oil level gauge ,OLTC Cubicle and fan control cubicle, RTCC , Valves,MPPTCL/TECH/PROC/01/JULY 13 Page 110 of 125Clamps, Air Cell Breather, Pronol Bag etc. shall be recorded i.e. Make,Rating, Factory Test Certificate, QAP Report , Invoices etc.(C) Format II (C) : Inspection of Core .a) Checking of in house or vendor core cutting facilities. Sampletesting of core steel for checking specific total loss, ductility andbend properties, resistivity, ageing , magnetisation characteristicsand thickness.b) Check on the quality of surface insulation & surface finish;Measurement of thickness and hardness of varnish on stampings;Solvent resistance test to check that varnish does not react in hotoil; Check over quality of varnish on stamping, to ensure uniformshining colour, no hot spots, no over burnt varnish layer and nobubbles on varnished surface.c) Check on the amount of burrs i.e. cutting & edge; Bow Check onstampings.d) During core building dimension, leaning or waviness of core,tightening torque, dia of resiglass tap to be checked.e) Check for the over laping stampings. Corners of the sheets are tobe apart.f) Visual and dimensional check during assembly stage.g) Check for interlaminar insulation between core sections afterpressing.h) Visual and dimensional check for straightness and roundness ofcore.i) High voltage test on fully built core 2 kV for one minutebetween core & yoke bolts, core & core clamps, core clamps & yokebolts, core loss measurement weighment of core.j) Certification of all test results.(iii) STAGE III : Stage Inspection of Winding after their preparation: Once the coils are prepared but before the same are fitted on tothe core, stage inspection shall be done to take various measurementsand also for weighment of total weight of coil of each voltage class.Measurement of winding resistance shall be also done. A small piece of

conductor for each type of winding shall be made available by themanufacturer to our representative.During this stage, following documents shall be verified by MPPTCLinspector as a proof towards use of prime copper and insulating materialfor manufacturer of transformer ordered by us :i) Invoice of the supplierii) Mills test certificateiii) Packing listiv) Bill of ladingv) Bill of entry certificate by custom's.MPPTCL/TECH/PROC/01/JULY 13 Page 111 of 125The winding and insulating material shall be directly procured eitherfrom the manufacturer or through their accredited reputed marketingorganisation but not through any agent. A copy of all above documentsshall be sent with joint inspection report for our records.In this stage, following shall be measured, recorded & checked in FormatIII.(A) Winding:a) Sample check on winding conductor for mechanicalproperties and electrical conductivity.b) Visual dimensional checks on conductor for scratches,dent marks etc.c) Sample check on insulating paper for PH value, electricstrength.d) Check for the reaction of hot oil on insulating paper.e) Check for the bonding of the insulating paper on conductor.f) Check and ensure that physical condition of all materials takenforwinding is satisfactory and free of dust.g) Check for absence of short circuit between parallel strands.h) Check for brazed joints wherever applicable.i) Measurement of voltage to be carried out when core/yoke iscompletely restacked and all connections ready.j) Conductor-enamel test for checking of cracks, leakage and pinholes.k) Conductor-flexibility test.l) Heat shrink test for enamelled wire.m) Measurement of no. of turns, cross sectional area of eachwinding , winding resistance and weighment of windings.n) Certification of all test results.(B) Insulating Material:a) Sample check for physical & chemical properties of material.b) Check for dielectric strength.c) Visual and dimensional checks.d) Check for the reaction of hot oil on insulating materials.e) Dimensional stability test at high temperature for insulatingmaterial.f) Tracking resistance test on insulating material.g) Certification of all test results.(iv) STAGE IV : Stage Inspection of Core – Coil Assembly beforeVapour Phase Drying/Dryout : In this stage , following shall bemeasured, recorded & checked in Format IV.MPPTCL/TECH/PROC/01/JULY 13 Page 112 of 125a) Check Clamping Ring with approved drawing. Check Core Belting,Check condition of insulation on the conductor & between thewindings.b) Check insulation distance between high voltage & low voltage

connections with respect to earth and other parts.c) Insulation test of core earthing .d) Check for proper cleanliness and absence of dust etc.e) Certification of all test results.(v) STAGE V : Stage Inspection of Core – Coil Assembly after VapourPhase Drying/Dryout : In this stage , following shall be measured,recorded & checked in Format V.a) Measurement and recording of temperature and drying time duringvacuum treatment.b) Check for completeness of drying by measuring IR values & TanDelta.c) Measure minimum clearance from all sides/bottom/top.c) Certification of all test results.(vi) STAGE VI : Inspection of Final Assembly of Transformer afterboxing in of active material : Complete details of all bought accessories ,their test certificates shall be appended. Minutes of meeting shall recordoverall workmanship and other pertinent details.a) Check completed transformer against approved out linedrawing, provision for all fittings, finish level etc.b) Jacking test on all the assembled Transformers.Pre-shipment Checks at Manufacturer's Works:a) Check for interchangeability of components of similarTransformers for mounting dimensions.b) Check for proper packing and preservation of accessories likeradiators, bushings, explosion vent, dehydrating breather, rollers,buchholz relay, control cubicle, connecting pipes, conservator etc.c) Check for proper provision of bracings to arrest the movementof core and winding assembly inside the tank.d) Gas tightness test to conform tightness.e) Derivation of leakage rate and ensure adequate reserve gascapacity.Installation & pre-commissioning test of Nitrogen Injection FireProtection System : After installation the system pre-commissioningtests shall be carried out jointly before the system is put in service.2.2.3 Details of Procurement : Manufacturer shall provide us completedetails of procurement of raw materials i.e. core, insulation and copper .Manufacturer shall also record a certificate .MPPTCL/TECH/PROC/01/JULY 13 Page 113 of 1252.2.4 The MPPTCL also reserves the right to carry out stageinspections at other stages also, for which advance intimation shallbe given and all necessary cooperation shall be rendered by themanufacturer.MPPTCL/TECH/PROC/01/JULY 13 Page 114 of 125ANNEXURE IXLIST OF HAND TOOLS FOR SUPPLYALONG WITH TRANSFORMER(A) One tool box consisting of the following 41 Hand tools ofGEDORE make or equivalent with better quality shall besupplied1. Spanners of different sizesa) Open Jaw Double Ended - 8 Nos.b) Cranked ring double ended - 3 Nos.c) Tubular Box Double Ended - 1 No.2. Tommy Bar - 1 No.(For Tabular Box Spanner)3. Adjustable Wrenches - 2 Nos.4. Pipe Wrench - 1 No.

5. Screw Drivers Of Different Sizes - 5 Nos.6. Flat Nose, Round Nose, Side Cutting - 3 Nos.Pliers7. Gasket Punches - 10 Nos.8. Files With Handles - 2 Nos.9. Hammers With Handles - 2 Nos.10. Knife With Handles - 1 No.11. Adjustable Hacksaw - 1 No.12. Cold Chisel - 1No.Total 41 Nos.MPPTCL/TECH/PROC/01/JULY 13 Page 115 of 125ANNEXURE – XDESCRIPTION OF EQUIPMENT FOR SCHEDULE OF RATES & PRICESFor this Bid which includes 400KV 315MVA transformers, description of mainequipments and other items should be brought out exactly as per detailsfurnished herein and accordingly schedule of price should be enclosed withthe Bid.ItemNos.Description Quantity(No)1. Supply of 315MVA 400/220/33KV, Three phase ONAN/ ONAFcooled auto transformer fitted with Pronol air-cell, NitrogenInjection Fire Protection System (NIFPS) as described in cl20.9, on line monitoring device (OLMD) as described incl.20.10 , Surge capacitor with structure as described in cl20.12 and all accessories/ fittings as described underannexure II , duly passed all routine additional routine andacceptance tests as per IS-2026 with one set of tools asper annexure IX complete with first filling of oil includingwastage & 10% extra of that quantity & meeting alltechnical requirement as per Volume II Part-I &annexure I. The offered cost includes cost of all tests as perclause 24.5 of volume II Part-I and conforming to allrequirements as described in bid document. Thetransformers shall be supplied fitted with Impact Recorder(on returnable basis) during transportation of Transformersand Vehicle tracking system (GPRS/ GPS/ GSM based) totrack the exact position of the vehicle during transportationof Transformers as per clause no. 37.0.As perpriceschedule2 Against Item no.‘1’ above, composite total cost of powertransformer alongwith various accessories, equipments, tool,oil etc as well as cost of testing as described in details above,will be furnished by the bidder. However, bidders arerequested to indicate the following unit price of itemsincluded in composite cost mentioned under Item no. ‘1’above for the purpose of computation price variation afteraward of contact:-(a) On Line Monitoring Device(b) Surge capacitor with structures(c) Complete System of Nitrogen Injection Drain and StirMethod type fire prevention and extinguishing system(NIFPS) including required Nitrogen cylinders dully filled, all

piping works, Civil works with material etc.MPPTCL/TECH/PROC/01/JULY 13 Page 116 of 125(d) Charges for fitting Impact Recorder (on returnable basis)during transportation of Transformers and Vehicle trackingsystem (GPRS/ GPS/ GSM based) to track the exact positionof the vehicle during transportation of Transformers as perclause no. 37.0SIGNATUREWITH SEAL OF BIDDERMPPTCL/TECH/PROC/01/JULY 13 Page 117 of 125ANNEXURE –XILIST OF VENDORS FOR MAJOR ITEMS OF TRANSFORMERThe vendors of various major items from whom procurement was made byvarious suppliers of transformers and quality of which was found acceptableare listed below. However, Major items/inputs in transformers have toconform to highest quality standards and these items/inputs procured fromany vendors meeting the required specification would be acceptable.No. Name of Item Supplier1. CRGO M/s Nippon steel corporation, JapanM/s JFE Steel corp., Japan ( Erstwhile M/sKawasaki Corp. Japan)M/s AK Steel,USAM/s Armco, USA,M/s Posco,KoreaM/s Covefi, FranceM/s Salzgittar, GermanyM/s Usinor, FranceM/s Transfer, FranceM/s Mitsubishi, Japan.M/s AST Terni, ItalyM/s EBG India Pvt Limited, (Indian Agent) for M/sGELSE NKIRCHEN, GermanyM/s British Steel Corporation , UKM/s Thyseen Krupp Group of Companies2.(a)Winding copper &conductorM/s Invex Filli Isolati Speciali s.p.a. ItalyM/s Sam Dong KoreaM/s Asta, AustriaM/s Smit Draad, HollandM/s Incab Industries, JamshedpurM/s Sterlite Industries, MumbaiM/s Hindalco IndustriesM/s Bhandary Powerlines Private Limited (BPPL),Manipal.M/s BCPL Conductors Private Limited, Manideep,Bhopal.M/s Bhandary Powerlines Private Limited(BPPL),Vadodara.M/s Shakti Insulated Wires,MumbaiM/s KSH International Pvt Limited, TalojaM/s Delta-Trans Conductor, MumbaiM/s Vijay Electricals, HyderabadMPPTCL/TECH/PROC/01/JULY 13 Page 118 of 125No. Name of Item Supplier

M/s RIMA Transfomers & Conductors Pvt. Limited,Bangalore.M/s Lacroix and Kress (GMBH) germanyM/s Pirellicavi ItalyM/s Shree Cable & ConductorsM/s Chandra Metals,allahabad(b) CTC Conductor M/s Sam Dong KoreaM/s Invex Filli Isolati Speciali s.p.a. ItalyM/s Loc Roix AND KRESS – GermanyM/s Chandra Portico ltd silvassaM/s KSH International Pvt Ltd, Chakan3. Precompressedpress Board & pressBoard componentsM/s H. Weidmann, SwitzerlandM/s Fige Holms Brruk, SwedanM/s Senapathy Whiteley, BangloreM/s Raman Board, Mysore4. Insulating Material M/s Dupont, USAM/s Senapathy Whiteley, BangloreM/s H. Weidmann, SwitzerlandM/s MunksioM/s Amotfors, SwedenM/s Krammerer5. Air Cell M/s PRONAL, FranceM/s PRONAL, Asia manufacturing SDN BHDMalaysia6. Gaskets M/s Talbros, FaridabadM/s Cortica, ChennaiM/s Packing & Jointing, ChennaiM/s Indian Rubber Products, HaridwarM/s Bombay Oil Seal Mfg. MumbaiM/s MGM Rubber KolkataM/s Bharat Corrub Industries, Vadodara.M/s Indian Cork Industries,BahadarpurM/s Nucork, Gurgaon7. OIP CondensorbushingM/s BHELM/s CGLM/s TELKM/s ASEA-MICAFILM/s Passonivilla8. Terminal Connector M/s Best & Crompton, ChennaiMPPTCL/TECH/PROC/01/JULY 13 Page 119 of 125No. Name of Item SupplierM/s PeeVee Engg., BangaloreM/s Milind Engg., MumbaiM/s Nootan, BarodaM/s Utsav, BarodaM/s Vinayak and Co., MumbaiM/s Megha Engg. Enterprises, ChennaiM/s Klemmen Engg. Corporation , Chennai9. OTI/WTI withrepeaterM/s Accurate Control,UKM/s AKM, Swedan

M/s Perfect Control, Chennai, IndiaM/s Preci Measure, BangloreM/s Radix Electrosystems Pvt. Ltd/ Radix PyrotechIndia10. Magnetic oil gauge M/s Sukrut Udyog, PuneM/s Yogya, Jhansi11. Buchholz Relay &Oil surge relaysM/s Fukuda Instrument, JapanM/s Atvus,CalcuttaM/s English Electric, ChennaiM/s Prayog; M/s BHELM/s Instrument and Control, Vadodara12. Pressure ReliefDeviceM/s Qualtrol, USAM/s GE, USA;M/s Sukrut Udyog, PuneM/s ATVUS Industries, Kolkatta13. Fan & Motor M/s Marathon Electric Motors (India) Ltd, Kolkata(Erstwhile M/s Areva, (Alstom), Kolkata)M/s CGL, MumbaiM/s Khaitan,Calcutta.M/s EPC, Calcutta14. Un-impregnatedDensified laminatedwoodM/s Permali Wallace BhopalM/s Kit ply AssamM/s Mysore Polymers BangloreM/s Narmada Forest Ind. Pvt. Ltd. Bhopal.M/s Western India Plywood , Kerala15. Valves M/s LeaderM/s Bombay Metal & AlloysM/s AudcoM/s PetsonM/s ManixonMPPTCL/TECH/PROC/01/JULY 13 Page 120 of 125No. Name of Item SupplierM/s CreseantM/s Precision Engg. Kottayam,M/s Eapen Joseph, KottayamM/s Apex Piping Systems, JalandharM/s Liberty Engg., MumbaiM/s Niton Valves, MumbaiM/s Eapen Joseph & co., CoimbatoreM/s GG Valves ,Udaipur16. MCB Ms SiemansM/s MDSM/s S&SM/s Havell's17. Fuse M/s Siemens/ S&S / Areva / Havell's18. Tank Steel M/s SAILM/s Essar19. OLTC Complete M/s BHELM/s TELKM/s Easun, Madras

20. Terminal Blocks M/S ELMEXM/S Technoplast,M/S Tosha21. Silica gel Breather M/S Yogya Enterprises, Jhansi.M/S Anusen Industries, Pune.M/s Instruments & Controls , Vadodara, India22. Transformer oil M/s Apar Limited, MumbaiM/s Savita Chemicals Ltd, New Mumbai23. Radiator M/s CTR Manufacturing Industries, PuneM/s Thermal Transformer Product, BangaloreM/s Exotherm, Bangalore.M/s P.E. Engg. Hyderanad.M/s Hitech Switchgear, Mumbai24. On Line MonitoringDeviceM/s Kelman, UK25 NIFPS M/s CTR , Pune26. Oil flow indicator M/s Sukrut Udyog, PuneMPPTCL/TECH/PROC/01/JULY 13 Page 121 of 125APPENDIX ICalculation for Hot Spot winding temperature for EHV transformersOverloading capability of the transformer and also the loadingcapability of transformer with and without cooling fans (coolers) for ashort period of 10/20 minutes with out exceeding temperature rise ofwinding beyond specified limits have been indicated in the technicalspecification. In this regard following calculation based on maximumambient air temperature as 50 degree centigrade and maximumyearly average weighted air temperature as 32 degree centigradeusing the under mentioned formulae or any other authentic formulaeshall be furnished.-t/ τ 2yθc = θa + Δ θ b0 + (Δ θ b- Δ θbo) ( 1- e ) + (Δ θ c τ - Δ θb τ) k2 x⎨ ( 1+dk )⎬Δ θb = Δ θ br --------------⎨ ( 1+d) ⎬xWhereθa = Weighted ambient temperature (cooling medium)θc = Winding hot-spot temperature at K load = θa + Δ θcθcr = Winding hot-spot temperature at rated loadΔ θc = Winding hot-spot temperature rise at K loadΔ θcr = Winding hot-spot temperature rise at rated loadθbo = Original oil temperatureθb = Top oil temperature at K load = θa + Δ θbθbr = Top oil temperature at rated loadΔ θb = Top oil temperature rise at load KΔ θbr = Top oil temperature rise at rated powert = Time duration in hours of any load powerτ = Oil air thermal time constant of transformer at ratedload, in hoursMPPTCL/TECH/PROC/01/JULY 13 Page 122 of 125K = Ratio of any load/rated load = S /SrK1 = Ratio of initial load/rated load = S1 /SrK1 = Ratio of permissible load/rated load = S2 /SrK2 = Ratio of permissible load/rated loadx = Exponent for oil risey = Exponent for winding rise

d = Ratio of load loss at rated load/no load loss.a = Subscript representing ambient (cooling medium)b = Subscript representing top oilc = Subscript representing hot-spot of windingr = Subscript representing rated value.SIGNATUREWITH SEAL OFBIDDERMPPTCL/TECH/PROC/01/JULY 13 Page 123 of 125APPENDIX IITECHNICAL PARTICULARS TO BE FILLED-IN BY BIDDERS. No. Particulars Values1 Maximum flux density (Tesla)2 Maximum current density (Amp/sq.cm)3 Magnetising current (mA)4 Short time current rating (Amp.)5 Lossesa. No load Losses (KW)b. Load Losses including stray losses(KW)c. Auxiliary losses (KW)6 Impedance voltage (Percentage)7 Weight of copper (Kg)8 Weight of core (Kg)9 Weight of core + winding (Kg)10 Quantity of oila. For first filling including wastage(KL/Kg)b. 10% extra of ‘a’ (KL/Kg)11 Total weight of Transformer. (Kg)12 Transport weight of main tanka. with oil (Kg)b. without oil (Kg)13 Rating and make of Surge CapacitorSIGNATUREWITH SEAL OF BIDDERMPPTCL/TECH/PROC/01/JULY 13 Page 124 of 125List of Abbreviation used in technical specification1. OLTC - On load tap changer2. OIP - Oil impregnated paper3. DL type - Draw lead type4. COPS - Conservator oil preservation system5. RTCC - Remote tap changer cubicle6. Cl - Clause7. IEEMA - Indian Electrical & Electronics ManufacturingAssociation8. KV - Kilo voltage9. KW - Kilo Watt10. IV - Intermediate voltage11. LV - Low voltage12. VPD - Vapour phase drying13. ONAN - Oil natural air natural14. ONAF - Oil natural air forced15. OFAF - Oil forced air forced16. CBIP - Central Board of Irrigation and Power

17. OTI - Oil temperature indicator18. WTI - Winding temperature indicator19. KA - Kilo Ampere20. TC - Terminal connector or test certificates asapplicable21. V - Voltage22. f - Frequency23. VN - Normal voltage24. FN - Normal frequency25. CT - Current Transformer26. PT - Potential Transformer27. Xmer - Transformer.28. PRD - Pressure Relief Device29. PRV - Pressure Relief valve30. MOLG - Magnetic Oil Level Gauge31. OSR - Oil Surge Relay37. Isc - RMS value of symmetrical short ckt current,KA38. V - rated voltage of system ,KV39. Zt - short ckt impedance of transformer ,Ohms40. Zs - short ckt impedance of system ,Ohms41. θ1 - final temperature in degree centigrade42. θ0 - Initial temperature in degree centigrade43. J - short ckt current density ,amp/mm sq.44. t - duration of short ckt in secs45. Iph - rated phase current in amps46. Zpu - per unit impedanceMPPTCL/TECH/PROC/01/JULY 13 Page 125 of 12547. Rdc - DC resistance of the per phase of winding at 75degree centigrade48. Hw - height of winding in cm49. N - no of turns per phase of winding50. Dmi - mean diameter of inside winding ,cm51. Bi - thickness of inside winding conductor ,cm52. E - modulus of elasticity of conductor, cm53. Sn - rated KVA54. Pu - per unit impedance55. Fa - axial imbalance force, Kg56. Ai - (no of spacers x length x width ) for innerwinding57. Ao - (no of spacers x length x width ) for outerwinding58. m - no of conductors in the radial direction= no ofturns x no of parallel conductor59. bo - thickness of outer winding conductor, cm60. Dmo - mean diameter of outer winding, cm61. Ao - supported area of outer radial spacers62. F - total axial force in MT63. D - mean diameter of clamping ring ,cm64. b - width of clamping ring ,cm65. t - thickness of clamping ring ,cm66. n - no of jacking or clamping points67. mA - milli ampere

68. kg - kilogram69. kl - kilolitre70. temp. - temperature71. max. - maximum72. min. - minimum73. vol. - volume

MADHYA PRADESH POWER TRANSMISSION CO. LTD.SHAKTI BHAWAN RAMPUR: JABALPURVOLUME –IIPART-2Technical Book Serial No.MPPTCL/TECH/PROC/02/July13TECHNICAL SPECIFICATION FOR SUPPLYOF EHV EQUIPMENTS AND MATERIAL FORSUB-STATIONS AND FEEDER BAYSO/o CHIEF ENGINEER (PROCUREMENT)MPPTCL, JABALPURVolume-II contains eight booklets as under:-Section Description Technical BookSerial No.Part-1 TECHNICAL SPECIFICATION FORSUPPLY OF 400KV/220KV, 315MVAPOWER TRANSFORMERSMPPTCL/TECH/PROC/01/JULY13Part-2 TECHNICAL SPECIFICATION FORSUPPLY OF 400KV/132KV, 100MVAPOWER TRANSFORMERSMPPTCL/TECH/PROC/02/JULY13Part-3 TECHNICAL SPECIFICATION FORSUPPLY OF 400KV, 125MVAR REACTORMPPTCL/TECH/PROC/03/JULY13Part-4 TECHNICAL SPECIFICATION FORSUPPLY OF 220KV/132KV, 160MVAPOWER TRANSFORMERSMPPTCL/TECH/PROC/04/JULY13Part-5 TECHNICAL SPECIFICATION FORSUPPLY OF 220KV/33KV, 50MVAPOWER TRANSFORMERSMPPTCL/TECH/PROC/05/JULY13Part-6 TECHNICAL SPECIFICATION FOR

SUPPLY OF 132KV/33KV, 63MVAPOWER TRANSFORMERSMPPTCL/TECH/PROC/06/JULY13Part-7 TECHNICAL SPECIFICATION FORSUPPLY OF 132KV/33KV, 40MVAPOWER TRANSFORMERSMPPTCL/TECH/PROC/07/JULY13Part-8 TECHNICAL SPECIFICATION FOR400/220/132/33KV EQUIPMENTS( 3 BOOKLETS)MPPTCL/TECH/PROC/08/JULY13MPPTCL/TECH/PROC/09/JULY13MPPTCL/TECH/PROC/10/JULY13All the above eight booklets are in the form of separatebooks. This book refers to:-PART-2TECHNICAL SPECIFICATION FOR 400/132/33 KV, 100MVA POWER TRANSFORMERSPlease note that the modifications in technical specificationsare indicated in Appendix-1, enclosed in Volume-I of theTender document.Description of document Page No.Technical specification for transformer 1-76Annexures and appendix for 400KV, 100MVA Power TransformerAnnexure I - Principal Technical particulars 77-81Annexure II - List of Fittings and Accessories 82-86Annexure III - Test certificates to be furnished foraccessories 87-90Annexure IV - Schedule of Inspection Windows 91Annexure V - Schedule of Valves 92-93Annexure VI(A)- Drawings & Data to be furnished 94-96Annexure VI(B)- List of drawings to be furnishedalongwith bid97Annexure VII - Calculations required to be furnished 98-102Annexure VIII - Details of Inspection Program 103-107Annexure IX - List of Hand Tools and Jacks 108Annexure X - Description of equipment forschedule of rates & prices109-110Annexure XI - List of vendors for major items oftransformer111-114Appendix I - Calculation for Hot Spot windingtemperature for EHV transformers

115-116Appendix II - Technical particulars to be filled-inby bidder117List of abbreviations used in technical specification 118-119MPPTCL/TECH/PROC/02/ JUNE 13 Page 1 of 119VOLUME II, PART-2TECHNICAL SPECIFICATION FOR 100 MVA ,400/132/33 KV POWER TRANSFORMERS1.0 SCOPE1.1 This specification covers design, engineering, manufacture,assembly, stage inspections and testing before supply and deliveryincluding unloading on plinth at our substation sites located anywhere inthe state of Madhya Pradesh, of 400/132/33 KV, 100/80 MVA Auto, threephase transformer complete with all fittings, accessories, associatedequipment including oil for first filling including wastage & 10% extra of thatquantity which are required for efficient and trouble free operation asspecified hereunder.1.2 It is not the intent to specify completely herein all the details ofthe design and construction of equipment. However, the equipment shallconform in all respects to high standards of engineering, design andworkmanship and shall be capable of performing the duties specifiedherein. The offered transformers shall be complete with all componentsnecessary for their effective and trouble free operation. Such componentsshall be deemed to be within the scope of Bidders supply irrespective ofwhether those are specifically brought out in this specification or not. Thetransformers should be free from Polychlorinated Biphenyls(PVB/PCB).1.3 The Purchaser will interpret the meanings of drawings andspecification and shall have the power to reject any work or materialwhich, in his judgment is not in accordance therewith. The offeredtransformers shall be complete with all components necessary for theireffective and trouble free operation. Such, components shall be deemed tobe within the scope of Bidders supply irrespective of whether those arespecifically brought out in this specification and/or the commercial order ornot.2.0 STANDARDS2.1 The transformers and associated accessories shall conform tothe latest issues/amendments of standards as given below, and report of thecommittee for standardization of the parameters and specification of class 400KV equipment, except to the extent explicitly modified in this specification.Transformers conforming to any other authoritative standards meeting betterquality and ensuring better performance are also acceptable. Bidder shallspecifically indicate deviations if any from the INDIAN STANDARDS.APPLICABLE INDIAN/INTERNATIONAL STANDARDS FOR POWERTRANSFORMERS AND ASSOCIATED ACCESSORIES ETC.MPPTCL/TECH/PROC/02/ JUNE 13 Page 2 of 119INDIANSTANDARDNUMBERTITLEINTERNATIONALANDINTERNATIONALLYRECOGNISIED

STANDARDIS-2026(Part 1 to 5 )Power Transformers IEC-60076(Part I to 5)CBIP PublicationNo.295Manual on Power TransformersIS-335 Insulating oil for transformers IEC-296,BS-148.IS1866-2000 Electrical maintenance and Supervisionof mineral insulating oil in equipment.IS-2099 Bushings for alternating Voltage above1000V.IEC-60137(2008)IS-2312 Fans (Cooler fans)IS-2705. Current Transformers. IEC 60044IS-325. Three phase Induction motors. IEC-34.IS-375 &IS-996Marking & arrangements for switchgear, bus bars, main connections &auxiliary wiring.IS-3637. Gas & oil operated relays.IS-10028(Part 1to3)Code of practice for installation andmaintenance of transformers.IS-2147. Degree of protection provided byenclosures for low voltage switch gearand control.IEC 60529,IEC60947IS-5. Colours for ready mix paints.IS-6272 Industrial cooling fans.DOC.ETD16(3703)Draft standard by BIS for revision of IS-6600 for Guide for loading of oilimmersed transformers.IEC 60354OLTC IEC 60214IS 8478 Application Guide for OLTC IEC 60542IS 10561 Application Guide for Power Transformer. IEC 60076-8IS 13964 Method of measurement of TransformerSound levels.NEMA-TR1IS 2071(Part 1 to 3)Methods of High Voltage Testing IEC 60060IS 6209 Methods for Partial DischargeMeasurementsIEC 60270IS 2165 Insulation Coordination IEC 60071IS 5561 Terminal connectorsShort Circuit Current – calculation ofeffectsIEC 865(part I & II)MPPTCL/TECH/PROC/02/ JUNE 13 Page 3 of 119INDIAN

STANDARDNUMBERTITLEINTERNATIONALANDINTERNATIONALLYRECOGNISIEDSTANDARDIS-5553 Shunt Reactors, Neutral/EarthingReactor and Arc Suppression CoilIEC 60289IS:335 Insulating oils for transformers andswitchgearsIEC:60296, BS:223IS -1886 Code of practice for installation andmaintenance of transformers.Supervision and Maintenance guide forMineral Insulating Oil in ElectricalEquipmentIEC 60422Method of Sampling of Liquid dielectrics IEC 60475Guide for the Sampling of Gases and ofOil from Oil-filled Electrical Equipment forthe Analysis of Free and Dissolved GasesIEC 60567Digital Recorders and Software for HighVoltage Impulse testingIEC 61083Specification for radio disturbance andimmunity measuring apparatusCISPR 16Guidelines for conducting design reviewsfor transformers 100 MVA and 123 kVand above.Cigre Publication 202Metal oxide surge arrestors withoutgapsIEC 99-4Selection and applicationrecommendationIEC 99-5Indian Electricity Rule 19562.2 In case equipment conforms to other International standards whichensure equivalent or better performance than specified under cl 2.1 thenthe English version of such standards or the relevant extracts of same shallbe forwarded with the bid and the salient features of comparison shall bebrought out separately.2.3 The electrical installation shall meet requirements of Indian ElectricityRules, 1956 and IS-1886,"Code of practice for installation & maintenance ofTransformers" as amended till date.2.4 It has been experienced that the weight of core lamination, weight ofcopper, weight of steel, weight of Transformer Tank along with Fittings andAccessories and quantity of oil for first filling including wastage & 10% extraof that quantity, total weight of core + winding after assembly and totalweight of transformer are indicated in the technical bid by the manufacturerson tentative basis and at the time of submission of drawing, wideMPPTCL/TECH/PROC/02/ JUNE 13 Page 4 of 119

variations in these quantities take place. This is not in order and it willbe obligatory on the part of the Bidder to ensure that all these details areworked out carefully and only correct figures after proper design are offeredin the technical bid. It may be noted that at the time of submission of finaldrawings, variation in these weights beyond the limits of (+) 5% shall not bepermitted.2.5 It will also be obligatory on the part of the Bidders to furnish detailsof calculations for quantity (weight & size) of core material, quantity (weight& size) of copper material, calculations for thermal and dynamic shortcircuit withstand capability of transformer, calculations for pressure reliefvalve, adequacy of size of AIRCELL Bag, volume of oil for adequatecooling with calculations of size of conservator and other details as calledfor in the specification. Furnishing of these calculations along-with technicalbid is a must. All the data should be supported with calculation details. Inaddition, calculations for no. of thermosyphon filter and their adequacy befurnished.2.6 Interconnection : The transformers are meant for service asinterconnecting transformers and shall be capable of being energized eitherfrom 400 KV side or 132 KV side. The auto transformer shall be capable ofbeing loaded at rated power on the 400 KV and 132 KV sides with tertiarywinding loaded at its full rating (lagging or leading or mixed load). On LoadTap Changer and tertiary winding shall be suitable for such operation. TheOLTC shall be suitable for bidirectional flow of power.3.0 SERVICE CONDITIONS3.1 Climatic Conditions : The transformers and its accessories to besupplied against this specification shall be suitable for satisfactorycontinuous operation under the following tropical conditions.1. Location At various substations withinthe State of Madhya Pradesh2. Max. Ambient air temp. (oC) 503. Min ambient air temp (oC) -54. Maximum daily average ambient airtemperature(oC)405. Maximum yearly weighted averagetemperature (oC)326. Maximum Relative humidity (%) 95 (sometimes reachessaturation.)7. Average annual rainfall (cm) 1258. Max. Wind pressure (Kg/sq.m.) 1509. Max. Altitude above mean sea level(Metres)100010. Isoceraunic level (Average number ofthunderstorm days per year)50MPPTCL/TECH/PROC/02/ JUNE 13 Page 5 of 11911. Seismic level (horizontal acceleration) 0.3gModerately hot and humid tropical climate, conducive to rust andfungus growth. Tropical Protection Shall conform to IS:3202 titled “ climateproofing of electrical equipments” and BS: 1014 : titled “protection ofelectrical power equipments against the climatic condition”. The transformertank fittings and radiators including all accessories shall be designed towithstand seismic acceleration equivalent to 0.3 g. Special precautions shallbe taken to prevent mal-operation of Buchholz relay under such condition.3.2 Auxiliary Power Supply : Auxiliary electrical equipment shall be

suitable for operation on the following supply system.a. Power Devices(like drive motors)0.4 KV, 3phase, 4wire 50Hz. neutral grounded ACsupply.b. DC Alarm,control &protectivedevices220 volts DC, ungrounded 2wire(from two supply sources).c. Lighting. 230V, single phase, 50Hz. AC supply.Bidders scope include supply of interconnecting cables, terminalboxes etc. The above supply voltage may vary as indicated below and alldevices shall be suitable for continuous operation over the entire range ofvoltages.i) AC supply : Voltage Variation of –25% to +10%;Frequency+/- 4%ii) DC supply : Voltage Variation of -20% to + 10%.All accessories requiring AC or DC supply shall performsatisfactorily for voltage variation as above.4.0 GENERAL TECHNICAL REQUIREMENTS4.1 Duty Requirementsa) The transformers and all its accessories like CTs etc., shallbe designed to withstand without injury, the thermal andmechanical effects of any external short circuit to earth and ofshort circuits at the terminals considering infinite busarrangement of values specified as under :400KV - 63 KA for 3 secs132KV - 40 KA for 3 secs.33KV - 31.5KA for 3 secs.b) Over Loading : The transformer shall be capable of beingloaded in accordance with IS:6600. There shall be no limitationMPPTCL/TECH/PROC/02/ JUNE 13 Page 6 of 119imposed by windings, bushings, tap changer etc. oftransformer. Transformer & all its accessories shall be liberallyrated to allow 10% over loading at all taps on continuousbasis without exceeding the temperature limits specified inclause 6.0.The transformer shall be capable of being operated withoutdanger on each tapping at the rated KVA with specifiedvoltage variation corresponding to the voltage of thattapping with normal temperature rise. The design adopted toachieve this shall be indicated in detail in the Bid.Transformer shall be capable of operating under the naturalcooled condition up to the specified load i.e. as ONAN rating.The forced air cooling equipment shall than come intooperation by pre-set contacts of winding temperatureindicator and thereafter the transformer shall operate as aforced air cooled unit i.e. as ONAF. Cooling shall be sodesigned that during total failure of power supply to coolingfans, the transformer shall be able to operate at full load forTen(10) minutes without the calculated winding hot spottemperature exceeding 1400C. Also stopping of two coolingfans should not have any effect on the cooling system.Transformers fitted with two coolers (cooling banks) eachcapable of dissipating 50 per cent of the loss at continuous

maximum rating shall be capable of operating for 20 minutesin the event of failure of the blowers associated with onecooler, without the calculated winding hot spot temperatureexceeding 140oC at continuous maximum rating. Thetransformer shall be capable of being operated without dangerat all taps and rated MVA with specified voltage variationcorresponding to the voltage of that tap with specifiedtemperature rise.c) Over Voltage : The transformers shall be capable of beingoperated on continuous basis at 10% excess voltage thanthe rated voltage specified at each tap at rated frequency .4.2 Radio Interference & Noise Level4.2.1 The transformers shall be designed with particular attention forsuppression of maximum harmonic voltage especially the third and fifth soas to eliminate wave form distortion and minimize interference withcommunication circuits.4.2.2 The noise level, when energized at normal voltage andfrequency with fans running shall not exceed, when measured under standardconditions, the values specified in NEMA,TR-I.MPPTCL/TECH/PROC/02/ JUNE 13 Page 7 of 1194.3 Stresses : Transformer shall be capable of withstanding Electrical,thermal and mechanical stresses on any winding caused by forces due tosymmetrical or asymmetrical external fault.4.4 Frequency & Magnetic Induction4.4.1 The transformers shall be suitable for continuous operation for afrequency variation of (+) plus (-) minus 4% from normal 50Hz withoutexceeding the specified temperature rise. For considerations of overfluxing, the transformer shall be suitable for continuous operation forvalues of over fluxing factor up to 1.1.V FNThe over fluxing factor being { -- x -- }VN F4.4.2 The working flux density shall not exceed 1.65 Tesla for offered noload losses and the maximum flux density in any part of core and yoke at110% rated voltage combined with (-) 4% frequency variation shallpreferably not exceed the value of 1.90 Tesla as per CBIP manual no 295.For manufacturing of Power transformer, core laminations of variousspecifications are available and therefore while selecting the working fluxdensity, the Bidders will have to comply with the requirements of cl.4.4.1 &4.4.3.4.4.3 For the selected flux density, the transformer shall haveminimum following over fluxing capabilities , such that while meeting theabove requirement saturation of transformer core shall not take placeunder any circumstances. Transformer shall accept, without injuriousheating, combined voltage & frequency fluctuation, which produces thefollowing over fluxing conditions :Over FluxingFactorPeriod1.50 Less than 2 seconds1.40 5.0 seconds1.25 60 seconds1.10 ContinuousThe Bidder shall also indicate 160% & 170% over voltage/overfluxing withstand capability period. Over fluxing withstand characteristics upto 170% shall be submitted along with the bid.4.4.4 Detailed calculations for maximum flux density and magnetizing

current for core material shall be furnished to substantiate theabove requirement. The Bidder shall enclose details of Core Material withthickness of lamination, type designation and source of raw material and it’scharacteristic curves. All characteristic curves of material including Voltage VsFlux Density and Loss per Kg Vs Flux Density are to be enclosed with BidMPPTCL/TECH/PROC/02/ JUNE 13 Page 8 of 119clearly indicating Flux Density selected for calculation of core losses (No loadloss). On the basis of these data, for the Flux Density and core materialchosen verification of Saturation Flux Density shall be done by thepurchaser, to know the margin considered in operating Flux Density .4.4.5 The maximum current density for design of power transformerswithin specified limits of transformer losses shall not exceed thelimits of 300 amps per sq.cm.4.4.6 All other requirement of magnetic circuit shall be as per latest issue ofCBIP Manual no 295.4.4.7 The transformers shall be either core type or shell type construction,oil immersed, ONAN/ONAF with external heat exchangers and shall besuitable for outdoor service as inter connecting and/or step-downtransformers suitable for parallel operation with the existing transformerhaving tertiary winding already in service at the EHV substation where thesetransformers are to be commissioned. The rating and electrical characteristicsof the transformers shall be strictly as specified in this specification. Formatching the parameters required for parallel operation with existing unit,details shall be intimated to successful Bidder.4.5 All the transformers shall be suitable for continuous operationwith frequency variation of +/- 4% from normal 50 Hz . Combinedvoltage & frequency variation should not exceed the rated V/f ratio by10 %.5. INSULATION5.1 Impulse & Power Frequency Voltage Withstand Values : Forrated nominal system voltage of 33KV, 132KV & 400KV following minimumpower frequency and impulse withstand voltage should be offered for thewindings.SystemVoltageHighestSystemVoltagePowerFrequencyWithstandVoltagesSwitchingSurge/ImpulseWithstandVoltageImpulseWithstandVoltage33KV 36KV 95KV rms - 250KVp132KV 145KV 230KV rms - 550KVp400KV 420KV PD at1.5Um/√3#1050KV rms 1300KVp# The Partial Discharge level should be ≤ 500 pico coulomb at 1.5Um/√3(Method 2) as per IS 2026 part 3 or IEC 60076-3.

5.2 The HV/IV winding of the transformers shall have gradedinsulation. The insulation class of the neutral end of the windingMPPTCL/TECH/PROC/02/ JUNE 13 Page 9 of 119shall be graded to 95 KV. The 33KV winding shall have full insulationfor 33KV i.e. 250 KVp impulse and 95 KVrms power frequency.6.0 TEMPERATURE RISE : Each transformer shall be capable ofoperating continuously at its normal rating & 10% over load conditionwithout exceeding temperature limits as specified below. The maximumambient temperature shall be taken as 50 degree C and type of cooling besuitably adopted to limit the temperature rise within the safe limit ofoperation.Type Of Cooling Temperature-RiseWindings OilONAN (Air natural) 50oC 45oCONAF (Air Forced) 50oC 45oC7.0 FREQUENCY : All the transformers shall be suitable for continuousoperation with a frequency variation of + 4% to -4% from normal 50 Hzwithout exceeding the specified temperature rise.8.0 IMPEDANCE : The percentage impedance of the power transformershall be 12.5%, 30% & 45% between HV-IV, IV-LV & HV-LV respectively onits own highest MVA base i.e 100 MVA base. Bidders shall indicate theguaranteed impedance, tolerances and also the impedance on all taps for theoffered transformers. Impedance shall include positive and zero sequenceand shall be expressed in terms of the branches of the star connectedequivalent diagrams on all the specified MVA base and the range shall begiven for each branch of the equivalent circuit turn. It may be noted that ifrequired the percentage impedance should be designed identical to theexisting transformer of any make in case parallel operation is desired. TheIS tolerance on all matching taps are acceptable. Confirmationregarding requirement of parallel operation should be given in the Bid.It may be noted by the Bidders that for the purpose of matchingimpedance of transformer, included in scope of this Bid, between 400KV,132KV & 33KV main/ tertiary windings , the Bidders are not permitted to usereactor or reactor/capacitor assembly. The design of the main winding shouldtake care of the requirement of impedances as specified in this Biddocument and for this purpose, no reactor or reactor/capacitor should beused.9.0 MAXIMUM LOSSES :9.1 Maximum Losses : While the Bidders may offer their own design, itmay be noted that the transformer losses at 75 deg. C. at rated output,rated Voltage and rated frequency should not exceed the following maximumlimits which include tolerances as per IS :a) No load losses (Iron losses). : 70 KWMPPTCL/TECH/PROC/02/ JUNE 13 Page 10 of 119b) Load(Copper losses) + Auxiliary losses. : 300 KWincluding stray loss in KW9.2 The no load losses in kilowatts ( including BIS tolerance ) at ratedvoltage and rated frequency and the total load losses in kilowatts at ratedoutput, rated voltage and rated frequency at 75oC shall be guaranteed bythe bidder. It may be noted that the losses of the Transformer shall notexceed during final testing of the transformer, if the same exceeds from themaximum ceiling limit of Transformer losses as detailed in 9.1 above then theTransformer shall not be accepted.9.3 Heat run Test:One 100 MVA 400KV power transformer of each manufacturer (ifthere are more than one manufacturer) shall be subject to heat run test(Temperature rise test).

9.4 Tertiary :9.4.1 For 100 MVA transformer, ONAF rating of HV & IV shall be 100 MVAand that of 33 KV tertiary rating shall be 33.33 MVA. The tertiary of 100 MVAtransformer shall be designed for full rated MVA loading of either capacitive orinductive or mixed load. The tertiary winding shall not have taps i.e. Tertiarywinding shall be without tap changer.9.4.2 Tertiary winding may be used for connecting switched type reactors orsynchronous condensers with individual phase ratings of 25 MVAR. Thewinding shall be able to withstand frequent switching in and out many timesevery day of such reactors and synchronous condenser. The tertiary windingis intended to be loaded for the specified rating as mentioned above andaccordingly terminals of delta winding needs to be brought out ontransformer through three bushings.9.4.3 One 33 KV class CT of ratio 400/1-1 Amps suitable for full tertiarywinding having two secondary cores of rating 1Amp , one of accuracy class5P10 and other of accuracy class 1 shall be provided for monitoringcirculating current and also to provide protection against circulating currentbeyond rated capacity. For measurement of circulating current of deltawinding, one Ampere meter of digital /numeric type suitable for specified CTratio shall be provided on the RTCC panel. In case size of CT is large,provision of separate CT with structure shall be included within the offeredprice. The tertiary winding shall be designed to carry the fault current underworst fault condition.10.0 COOLING : The Bidder may offer ONAN / ONAF type of cooling forthe transformer. The ONAF rating for each transformer winding as also fortertiary winding of 400 KV transformers shall be 125% of ONAN ratingachieved by cooling. The ONAF cooling shall be in two groups each of50% capacity. Adequate no. of standby cooling fans shall be provided forMPPTCL/TECH/PROC/02/ JUNE 13 Page 11 of 11920% additional cooling per bank, in line with requirement indicated in clause15.1 ( C ).11.0 CONSTRUCTION DETAILS : The features and construction detailsof power transformer shall be in accordance with the requirements statedhereunder11.1 Tank(A) As required in CBIP manual no. 295, the tank shall be of Belltype construction for 100 MVA transformers covered underthis specification. Top cover of Bell type construction shall bewelded to the tank body .(B) Tank shall be of welded construction and fabricated fromtested quality low carbon steel suitable for welding & offollowing minimum sheet thickness.Tank cover - 20 mm, sides including inspection cover- 10 mm,Base - 20 mm.(C) All seams and those joints not required to be opened at siteshall be factory welded and wherever possible they shallbe double welded. After completion of tank construction andbefore painting, 'Dye Penetration Test' shall be carried out onwelded parts of jacking bosses, lifting lugs and all loadbearing members.(D) Tank stiffeners shall be provided for general rigidity and theseshall be designed to prevent retention of water.(E) The tanks shall be designed to withstand the followingwithout permanent distortion.(i) Mechanical shocks during transportation.(ii) Vacuum filling of oil at 10 milli torr in transformerwith all fittings.

(iii) Continuous internal pressure of 35 kN/m2 over normalhydrostatic pressure of oil.(iv) Short circuit forces &(v) Under seismic condition /events both horizontal/vertical .(F) Where ever possible the transformer tank and its accessoriesshall be designed without pockets wherein gas may collect.Where pockets can not be avoided, pipes shall be provided tovent the gas into the main expansion pipes if any.(G) The shields shall be such that no magnetic fields shall existoutside the tank. They shall be of magnetically permeablematerial. If required impermeable shields shall be providedat the coil ends. Tank shield shall not resonate when excited atthe natural frequency of the equipment.(H) The tank shall be provided with :MPPTCL/TECH/PROC/02/ JUNE 13 Page 12 of 119(i) Lifting lugs suitable for lifting the equipment completewith oil.(ii) A minimum of four jacking pads in accessible positionat 500mm height to enable the transformer completewith oil to be raised or lowered using hydraulic or screwjacks. The location of jacking pads shall be such thatthere should not be any interference with the civilfoundation of rails in either direction i.e. longitudinal ortransverse.(iii) Suitable haulage holes shall be provided.(I) (i) Inspection cover/access windows & Manholes:Suitable man-hole with a welded flange and a properlygasketted bolted cover having of minimum thickness of10 mm shall be provided on the tank cover. The manholeshall be of sufficient size to offer easy access tothe lower ends of the bushings, terminal etc. Therequirement of inspection windows and manholes havebeen stipulated in Annexure-IV & Bidders have toconfirm compliance of the same in their Bid.(ii) Space for free movement in Transformer Tank forinspection:Details of passage & free space provided inside themain tank should be indicated in concerned drawing toallow free movement of at-least two persons forinspection of active parts etc. To be more specific itmay please be noted that minimum clearance fromouter most winding/connection leads/supports totank shall not be less than 300 mm. on all 4 sideswith suitable platform on bottom of the tank tofacilitate free movement of person all around insidethe tank.(J) All bolted connections to the tank shall be fitted withsuitable oil tight neoprene/nitrile gaskets which shall givesatisfactory service under all operating conditions. Specialattention shall be given to the methods of making the hot oiltight joints between the tank and the cover as also betweenthe cover and the bushings and all other outlets to ensurethat the joints can be remade satisfactorily and easily withthe help of semi skilled labour. Where compressible gasketsare used, stoppers/ runners shall be provided to prevent overcompression.(K) Suitable guides shall be provided for positioning the various

parts during assembly or dismantling. Adequate space shallbe provided between the cores and windings assembly andthe bottom of the tank for collection of any sediment.MPPTCL/TECH/PROC/02/ JUNE 13 Page 13 of 119(L) The design of the tank, lifting lugs shall be such that thecomplete transformer assembly filled with oil can be lifted withthe use of these lugs without any damage or distortions.(M) For the complete transformer we have clearly brought out ourrequirement of various types of valves in Annexure Venclosed brings out details of type, size and quantity of valveswhich are to be provided at various locations. Thisrequirement has to be confirmed by the Bidders without anydeviation.(N) Gasketing Arrangement : It may be noted that all gaskettedjoints shall be grooved one using ‘O’ rings of nitrile rubber orbetter, such as the joints between bushing turret and bushingflange, inspection covers of inspection windows and all otheropenings provided for the purpose of inspection of internalparts of the transformer etc. The main bell tank gasketbetween upper tank and bottom tank shall be single piece ‘O’ring cord/gasket of nitrile rubber or material of better quality.The gasketting arrangement shall be grooved one with properstopper to avoid over compression. It is to be noted that oneadditional set of gaskets shall be delivered by the tendereralongwith transformer to replace the used gaskets at the timeof erection of the unit.(O) Ladder : One detachable bolted type mild steel (MS) ladderwith anti-climbing arrangement shall be provided. Ladder forclimbing up to & over top cover of power transformers shall bemechanically sturdy enough to bear the load of healthymaintenance staff without any shake/jerks. The arrangementshall not be detached after erection and commissioning of theunit, hence shall be provided with padlock locking arrangementfor anti-climbing device. On the upper top of the ladder,provision for support shall be made. However, thearrangement of the ladder shall be to purchaser’s approval.Collapsible ladder shall not be acceptable to us.(P) Suitable earthing bridge between upper and lower tank shall beprovided at least on two places each on HV & IV side and oneplace on other both sides.11.2 Tank Cover(a) The tank cover shall be sloped to prevent retention of rainwater and shall not distort when lifted.(b) Inspection cover/man holes shall be provided as perAnnexure-IV.(c) The tank covers shall be fitted with pockets at the positionof maximum oil temperature of MCR (MaximumContinuous Rating) for inserting bulbs of oil and windingtemperature indicators. It shall be possible to remove theseMPPTCL/TECH/PROC/02/ JUNE 13 Page 14 of 119bulbs without lowering the oil in the tank. The thermometershall be fitted with a captive sensor to prevent the ingress ofwater.(d) Bushings, turrets, covers of inspection openings,thermometer, pockets etc., shall be designed to preventingress of water into or leakages of oil from the tank.(e) All bolted connections shall be fitted with weather-proof, hot

oil resistant gasket in between, for complete oil tightness.If gasket is compressible, metallic stoppers shall be providedto prevent over-compression.(f) A minimum of three nos. PRD i.e one each shall beprovided above each phase winding.11.3 Undercarriage(a) The transformer tank shall be supported on a structural steelbase equipped with forged steel or cast steel single flangedwheels suitable for moving the transformer completely filledwith oil. If necessary, the wheel assembly should consist oftwo wheels for each point. Provision shall be made formounting bidirectional flanged rollers with locking and boltingdevice for rail gauge specified below:-Type ofConstruction Shorter axis Longer axisThree Phase 2/3/4 rail combinationaccording to layout andsize of transformerTwo rails with1676 mm gauge(b) Jacking pads/steps shall be provided. It shall be possible tochange the direction of the wheels through 90 deg. when thetransformer is lifted on jacks to permit movement of thetransformer both in longitudinal and transverse direction.(c) The track/rail gauge shall be 1676 mm along the longer side,as well as along the shorter axis. However Rails shall be placedperpendicular to the bushing line.(d) Pulling eyes shall be provided to facilitate movement/pulling ofthe transformers and these shall be suitably braced in avertical direction so that bending does not occur when thepull has a vertical component.11.4 Axles And Wheels(a) The transformers are to be provided with flanged bidirectionalwheels and axles. These shall be so designed asnot to deflect excessively to interfere with the movement ofMPPTCL/TECH/PROC/02/ JUNE 13 Page 15 of 119the transformer. Wheels shall be provided with suitablebearings which shall be rust and corrosion resistant.Fittings for lubrication shall also be provided.(b) Suitable locking arrangement along-with foundation boltsshall be provided for the wheels to prevent accidentalmovement of transformer. The locking arrangement shall besuch that it can be locked with plinth of transformer. Thelength of the arrangement should be adequate to cover heightof the rail. No floating type locking arrangement shall beaccepted(c) The wheels are required to swivel and they shall be arrangedso that they can be turned through an angle of 90 degreeswhen the tank is jacked up to clear of rails. Means shall beprovided for locking the swivel movements in positionsparallel to and at right angles to the longitudinal axis of thetank (i.e. longitudinal & transverse directions).(d) To facilitate uniform distribution of transformer weight twonos. props each on front & rear side along longer axis to beprovided.11.5 Anti Earthquake/Transport Clamping Device(a) To prevent transformer movement during earthquake,

clamping device shall be provided for fixing transformer to thefoundation. The Bidder shall supply necessary bolts forembedding in the concrete foundation. The arrangementsshall be such that the transformer can be fixed to orunfastened from these bolts as desired. The fixing of thetransformers to the foundations shall be designed towithstand seismic events to the extent that a static co-efficientof 0.3g. applied in the direction of least resistance to thatloading will not cause the transformer or clamping devices aswell as bolts to be over stressed.(b) Locking arrangement to eliminate relative movement betweentop yoke/active parts with the transformer tank shall be sturdyenough to bear transport hazards taking in to account the poorroad conditions and also considering that road transportationof transformer will not be on hydraulic trailers .11.6 Conservator Tank(a) The conservator tank shall be of minimum thickness of 10mm and it shall have adequate capacity between highest andlowest visible levels to meet the requirement of expansionof the total cold oil volume in the transformer and coolingequipment from minimum ambient temperature to 100oC.(b) The conservator tank shall be bolted into position so that itcan be removed for cleaning purposes.MPPTCL/TECH/PROC/02/ JUNE 13 Page 16 of 119(c) Magnetic oil gauge (MOG) & prismatic oil level gauge havingthree overlapped windows on one side of conservatorand on opposite side of conservator, plain oil gauge withthree overlapped windows shall be provided to indicate oillevel inside the conservator at each location. Properarrangement to ensure visibility of oil level from ground be alsoensured .(d) Conservator shall be provided in such a position as not toobstruct the electrical connections to the transformer.(e) In order to avoid congestion and to facilitate operation andmaintenance activities, the main conservator and OLTCconservator shall be provided on opposite sides of the maintank. Further, there shall be adequate space for manualoperation of OLTC.(f) Separate conservator tank shall be provided for OLTC.(g) The size of the conservator shall be so designed as toaccommodate approximately 10% volume of total quantity ofoil in the transformer.(h) Suitable arrangement shall be made for providing a foot restwith easy & access arrangement to facilitatemaintenance/operation at top of the conservator, on magneticoil level gauge and buchholz relay.(i) The design of conservator shall be such that the air is nottrapped between air cell and main conservator.11.7 Tank Earthing Arrangement : Two earthing pads complete with twonumber tapped holes M10 bolts plain and spring washer suitable forconnection to 75x8mm GI flat shall be provided each at position close to twodiagonally opposite bottom corners of tank. Earthing strips up to theground level and its connection with station earth pit shall beprovided by the Bidder.11.8 Pressure Relief Device : A minimum of 3 (three) number ofpressure relief devices of reputed make and reliable quality shall beprovided on each transformer and these shall be mounted preferably

on the tank cover above each phase winding. Bidders must submitcalculations to prove that the no and capacity of pressure relief device withlocation of each PRV provided on the transformer will adequately meet ourrequirement. The quantity of three numbers is on the basis that two numberswill be required as per design calculation and one number additional PRD shallbe provided from the point of view of additional safety.Constructional and design details of pressure relief device must be furnishedand it should be proved by calculation that the size and operating pressuresetting of pressure relief device is adequate, considering the rating of thetransformer and quantity of oil in the transformer. Furnishing of thisinformation is a must. These PRD's shall be of sufficient size for rapidMPPTCL/TECH/PROC/02/ JUNE 13 Page 17 of 119release of any pressure that may be generated in the tank and which mayresult in damage to the equipment. The device shall operate at a staticpressure of less than the hydraulic test pressure of transformer tank. Itshall be mounted directly on the tank. One set of electrically insulatedcontacts shall be provided for alarm & tripping along-with therecommendations.11.9 Relays11.9.1 Buchholz Relay : A double float type Buchholz relay along withsuitable moulded type cover to avoid ingress of moisture/ rain water shall beprovided. All the gases evolved in the transformer shall collect in this relay.The relay shall be provided with a test cock suitable for a flexible pipeconnection for checking its operation and for taking gas sample. A copperor stainless steel tube, shall be connected from the gas collector to avalve located about 1200mm above ground level to facilitate sampling ofgas while the transformer is in service. The device shall be provided withtwo electrically independent ungrounded contacts, one for alarm on gasaccumulation and the other for tripping on sudden rise of pressure. Thecontacts of relay shall be properly housed, sealed and gasketted to make thearrangement water proof. Entry of moisture/water in the contact chamberneeds to be eliminated. Cable entry to terminal box of buchholz relay shouldbe made through bottom of relay.11.9.2 Oil Surge Relay (OSR) : From our past experience, it is foundthat undesired tripping of Power Transformers is occurring on oil surge relay(OSR)and Buchholz relay operation actuating due to accumulation of waterinside relay pockets. The water accumulation takes place through entrypoint of cable gland. In view of above, the design and placement of Alarm &trip contact assembly of OSR and Buchholz Relay should be improved totake care of the following requirements:(a) The cable entry to terminal box of OSR should be made throughbottom of relay. Also the OSR relay should be protected from rainwater by providing proper cover on it.(b) In order to ensure exit/drainage of accumulated water from inside therelay, a fine hole should be made in terminal box of relay.Note : The Bidders shall ensure that the compartments housing relaycontacts of Pressure Relief Valve , Buchholz Relay and Oil Surge Relay aremade absolutely water and vermin proof. The compartment housingcontacts of OSR,PRV and Buchholz Relay shall be tested for water proof atthe time of inspection and effectiveness of water proofing shall bedemonstrated at the time of inspection. This should be noted carefully bythe Bidder and specifically confirmed in their bid.11.9.3 Rapid Pressure Rise Relay (RPRR) : The provision for thesame be made on the main tank to operate on rate of rise of pressure. Anelectrically insulated trip contact shall be provided in RPRR relay as perrequirement of NIFPS.MPPTCL/TECH/PROC/02/ JUNE 13 Page 18 of 119

11.10 Temperature Indicator11.10.1 Oil Temperature Indicator (OTI): Transformers shall beprovided with a 150mm dial type thermometer with maximum pointer fortop oil temperature indication. The thermometer shall have adjustable twoelectrically isolated heavy duty alarm and trip contacts, maximum readingpointer and resetting device mounted in the Fan control cubicle (FCC). Atemperature sensing element suitably located in a pocket on top oil shall beprovided. This shall be connected to the OTI by means of capillarytubing. Accuracy class of OTI shall be plus or minus 1.0% or better. The OTIshall be provided with anti vibration mounting .11.10.2 Winding Temperature Indicator (WTI)(a) WTI for measuring the winding temperature of each of thewindings (HV, IV, Tertiary) shall be provided. It shallcomprise of the following(i) Temperature sensing element.(ii) Image coil.(iii) Auxiliary CTs, if required, to match the image coil, shallbe provided.(iv) 150mm dia local indicating instrument with maximumreading pointer mounted in FCC/marshalling box and withfour adjustable electrically isolated heavy duty contacts(two for control of cooling equipment, one for highwinding temperature alarm and other for trip) shall beprovided. The WTI shall be provided with anti vibrationmounting.(v) Calibration device.(b) In addition to the (a) above, repeater dial of WTI for eachwinding shall be provided for Remote winding temperatureindication. It shall be suitable for flush mounting on RTCCpanel. A precision potentiometer mounted inside the caseshall function as a transmitter to operate a repeater forRWTI. For two windings(i.e. HV and IV) the transmitter shallbe directly connected to the repeater. For the third windingi.e. LV(Tertiary) the transmitter shall be connected to aresistance Transducer, which will supply DC for operatingrepeater.(c) Auxiliary supply, if required in RTCC panel for RWTI, shall be220V DC only.(d) Accuracy class of WTI as well as RWTI shall be plus or minus1.0% or better.(e) Any special cables required for shielding purpose forconnection between cooler control cabinet and remote windingMPPTCL/TECH/PROC/02/ JUNE 13 Page 19 of 119temperature indicator control circuit shall be in Bidder’sscope of work.(f) WTI CT ratio shall be embossed on secondary winding terminalbox.Note :- Some of the manufacturers have a practice to directly installwinding temperature indicator (WTI) and oil temperature indicator (OTI) onthe body of the transformer in open. This is not acceptable & it is obligatoryon the part of the Bidders to enclose OTI & WTI and all such accessories ina separate Fan Control Cubicle (FCC) cum Marshalling Box .11.11 Corea) The core shall be constructed from high grade, non- ageing,low loss, Cold Rolled Super Grain oriented (CRGO) siliconsteel laminations of HI-B grade steel or better. All stipulationsunder clause 4.4 should be considered while selecting material

of core. Core shall be preferably 5 limbed construction.Interlamination resistance shall be as per BS 601 Part 5method of July 1973. The Bidder shall furnish thedetails of steel laminations i.e. type alongwithhysterisis loss curve (B-H curve) etc.(b) After being sheared, the laminations shall be treated toremove all burrs and shall be re-annealed to remove allresidual stresses.(c) The design of the magnetic circuit shall be such as to avoidstatic discharges, development of short circuit paths withinitself or to the earthed clamping structure and production offlux component at right angles to the plane of laminationswhich may cause local heating.(d) The core shall be provided with lugs suitable for liftingcomplete core & coil assembly of transformer.(e) Core Belting : The core shall be rigidly clamped by belting toensure adequate mechanical strength. Core and windingshall be capable of withstanding the vibrations & shockduring transport, installation, service and adequateprovision shall be made to prevent movement of core &winding relative to tank during these conditions. Thelocation, size and material of belting shall be clearlyindicated in drawing which shall be submitted with Bid.Bolted type core construction shall not be acceptable.(f) All steel sections used for supporting the core shall bethoroughly sand blasted after cutting, drilling and welding.(g) Each core lamination shall be insulated with a material that willnot deteriorate due to pressure and hot oil.MPPTCL/TECH/PROC/02/ JUNE 13 Page 20 of 119(h) The insulation of core to bolts and core to clampsplates shall be able to withstand a voltage of 2KV RMSfor one minute.(i) The maximum flux density in any part of the core and yoke atrated MVA, 110% voltage and (-) 4% frequency at any tapshall not exceed 1.90 Tesla. The Bidder shall providesaturation curve of the core material proposed to be usedand calculations to demonstrate that the core is not overfluxed under stringent condition of transformer operation.(j) Bidder will offer the core for inspection & approval bythe purchaser during the manufacturing stage.Bidder's call notice for this purpose should beaccompanied with the following documents, asapplicable, as a proof towards use of prime corematerial.i) Invoice of the supplierii) Mill's Test Certificateiii) Packing Listiv) Bill of ladingv) Bill of entry certificate by customs.(k) Core material shall be directly procured either from themanufacturer or through their accredited marketingorganization of repute and not through any agent.(l) Bidder should have in-house Core Cutting facility for propermonitoring & control on quality and also to avoid anypossibility of mixing of prime material with defective/secondgrade material.(m) Oil ducts shall be provided wherever necessary to ensure

adequate cooling. The winding structure and major insulationshall not obstruct the free flow of oil through such ducts.Where the magnetic circuit is divided into pockets by coolingducts parallel to the plane of laminations or by insulatingmaterial above 0.254 mm. Thick, tinned copper strip bridgingpieces shall be inserted to maintain electrical continuitybetween pockets. The design of the magnetic circuit shall besuch as to avoid static discharge development of short circuitpath within itself or to the earthed clamping structure andproduction of flux components at right angles to the plane ofthe laminations which may cause local heating.(n) Considering that the requirement is for three phase autotransformerwith tertiary delta, it is expected that the Biddermay offer transformer design with five limb core. Details inthis respect shall be furnished.(o) Core shall not directly rest on the bottom metal sheet oftransformer tank. Around 5 mm or more free space for oilinsulation shall be made between the core and bottom sheet oftransformer tank. A 5 mm FRP Insulating sheet shall beMPPTCL/TECH/PROC/02/ JUNE 13 Page 21 of 119provided to take care of core earthing due to accidentalslippage of stampings. Also in addition to this extrainsulation thickness of 5 mm or more FRP sheet beprovided at the bottom of resting shoes of end framewith proper fixing arrangement to avoid accidentalslippage, damages etc.11.12 Windings(a) The Bidder shall ensure that windings of all transformers aremade in dust proof, conditioned atmosphere. The Bidder shallfurnish the facilities available at their works alongwith thebid.(b) The conductors shall be of electrolytic grade copper as perrelevant IS. The maximum current density for design oftransformers within specified limits of transformer losses shallnot exceed the limits of 300 amps per sq.cm.(c) The insulation of transformer windings and connections shallbe free from insulating compounds which are liable tosoften, ooze out, shrink or collapse or be catalytic andchemically active in transformer oil during service.(d) Coil assembly and insulating spacers shall be so arranged asto ensure free circulation of oil and to reduce the hot spot ofthe winding. The conductor shall be transposed at sufficientintervals in order to minimize eddy currents and equalize thedistribution of currents and temperature along the winding.(e) The LV (tertiary) winding should withstand short circuitfaults/forces of the transformer upto the prescribed fault levelson HV & IV sides against mechanical and thermal stresses.(f) Best insulating material shall be used and compression ofthe windings after drying out shall be carried out at apressure exceeding one and a half to twice the force whichcan occur in the transformer; to impart greater mechanicalstrength to the windings against heavy short circuitstresses.(g) The windings shall be so designed that all coil assemblies ofidentical voltage ratings shall be interchangeable and fieldrepairs to the windings can be made readily without specialequipment. The coils shall be supported between adjacent

sections by insulating spacers, and the bracings and otherinsulation used in the assembly of the winding shall bearranged to ensure free circulation of the oil to reduce hotspots in the windings.(h) The coil insulation shall be treated with suitable insulatingvarnish or equivalent compound wherever necessary todevelop the full electrical strength of the winding. All materialsused in the insulation and assembly of the winding shall beMPPTCL/TECH/PROC/02/ JUNE 13 Page 22 of 119insoluble, non-catalytic and chemically inactive in the hottransformer oil and shall not soften or otherwise be adverselyaffected under the operating conditions.(i) All threaded connections shall be provided with lockingfacilities. All leads from the winding to the terminalconnectors and bushings shall be rigidly supported to preventinjury from vibration. Guide tubes shall be used wherepracticable.(j) Windings shall be subjected to a shrinkage treatment beforefinal assembly so that no further shrinkage occurs duringservice. Adjustable device shall be provided for taking up anypossible shrinkage of coils in service. After shrinkage process,the windings shall be clamped securely in place so that theywill not be displaced or deformed during short circuits. Theassembled core and windings shall be vacuum-dried andsuitably impregnated before removal from the treating tank.The copper conductors used in the coil structure shall bebest suited to the requirements and all permanent currentcarrying joints in the windings and the leads shall becrimped or brazed preferably by high frequency brazingsystem.It is observed that many manufacturers are using sectoredclamping arrangement at top as well as bottom for clamping ofthe windings. This type of arrangement is considered to be notsuitable for EHV grade power transformers. In this regard, itmay be noted that both top & bottom clamping rings to beprovided for clamping of windings shall be of one piece singlering. The top & bottom clamping rings should be ofminimum thickness 60 mm thk with proper safetymargins based on design and shall be in one piece tomake the clamping arrangement sturdy. Sectoredpressure/clamping rings are not acceptable. The singlepressing/clamping ring shall be provided with adequatenumber of pressure/jacking points as per design. Sincesectored ring arrangement shall not be accepted hencebidder should ensure and confirm this specificrequirement in the technical questionnaire.(k) Bidder will offer the Copper and insulating material forwindings for inspection & approval by the purchaser duringthe manufacturing stage. Bidder's call notice for thepurpose should be accompanied with the following documents,as applicable, as a proof towards use of prime Copper andinsulating material for windings .i) Invoice of the supplierii) Mill's Test Certificateiii) Packing ListMPPTCL/TECH/PROC/02/ JUNE 13 Page 23 of 119iv) Bill of lading

v) Bill of entry certificate by customs.(l) Core, Copper and insulating material for windings shall bedirectly procured either from the manufacturer or through theiraccredited marketing organisation of repute and not throughany agent.(m) Certificate : Supplier shall provide purchaser details ofprocurement of raw materials i.e., core, insulation & copper.Supplier shall also record a certificate as under :" CERTIFICATE "It is certified that the Transformer shall be manufactured by--------- (Name of manufacturer) out of the core,insulating and winding material procured as per detailsindicated in specification. We are agreeable to undertakethird party inspection of Transformer during its manufactureor of raw materials, at the sole discretion of MPPTCL withoutany extra cost.If at any stage it is found that the transformer is notmanufactured out of the raw material indicated inspecification, the transformer shall be liable for rejection byMPPTCL and transformer shall be replaced by (name ofmanufacturer) at no extra cost to MPPTCL.Signature of AuthorisedSignatory with Seal of manufacturer(n) The Purchaser also reserves the right to carry out stageinspections at other stages also, for which advanceintimation shall be given and all necessary cooperationshall be rendered by the supplier.11.13 Bushings(a) The electrical & mechanical characteristics of bushings shallbe in accordance with IS-3347 & IS-2099 ( latest version ) &IEC 60137(2008 or latest version).(b) The bushings shall have high factor of safety againstleakage to ground and shall be so located as to provideadequate electrical clearances between bushings and alsobetween the bushings and grounded parts. Bushings ofidentical voltage rating shall be of similar BCT and interchangeable. All bushings shall be equipped with suitableMPPTCL/TECH/PROC/02/ JUNE 13 Page 24 of 119terminals of approved type and size and all external currentcarrying contact surfaces shall be adequately silver plated.The insulation class of the high voltage neutral bushing shallbe properly coordinated with the insulation class of theneutral of the high voltage winding.(c) All main winding and neutral leads shall be brought outthrough outdoor type bushings which shall be so located thatthe full flashover strength will be utilized and theadequate phase clearance shall be realized.(d) Each bushing shall be so coordinated with the transformerinsulation that all flashovers will occur outside the tank.(e) All porcelain used in bushings shall be of the wet process,homogeneous and free from cavities or other flaws. Theglazing shall be uniform in color and free from blisters, burnsand other defects.(f) (i) For 33KV winding & neutral of common winding, thebushing shall be of OIP condenser of 72.5KV class of drawrod type/solid stem type.(ii) The bushings of 420 KV & 145 KV class shall be of OIP

condenser of draw rod type (DR) only.(iii) Tan-delta of all bushings shall be 0.005 (max.)duringtesting at manufacturer’s works(g) All bushings shall have puncture strength greater than the dryflashover value.(h) Main winding terminals shall be solder-less terminals andshall be of the type and size specified .(i) The spacing between the bushings must be adequate toprevent flashover between phases under all conditions ofoperation. The clearances shall be as follows :S.NoNominalSystemVoltageVoltageClass ofBushingCurrentRatingImpulseWithstandVoltage(Kvp)1 Min. PowerFrequency/SwitchingImpulseVoltageKv (Rms)CreepageDistancein mmClearancein mmPh toPhPh toE1 400KV 420KV 1250A 1425 630/1050 10500 4000 35002 132KV 145KV 1250A 650 275 / - 3625 1430 12703 33KV 72.5KV 1250A 325 140 / - 1813 700 660The Bidders are required to confirm clearances and nochange/reduction in clearances shall be acceptable. Theclearances shall be clear distances in air after accounting forMPPTCL/TECH/PROC/02/ JUNE 13 Page 25 of 119clamps/connectors dimensions to be mounted on the stud ofbushings.(j) Special adjustable arcing horns shall be provided for the HV &IV bushings. For 72.5KV class bushings, arcing horns are notrequired.(k) The Bidder is requested to furnish the guaranteed withstandvoltage for the above and also furnish a calibration curve withdifferent settings of the coordination gap to the purchaserto decide the actual gap setting. Bidder'srecommendations are also invited in this respect.(l) The bushings shall be capable of withstanding without injurythe electrical, thermal and mechanical effects of externalshort circuits. Bushings shall be rated for short time

thermal current rating of 63/ 40/ 31.5 KA for 3 seconds, for400/ 132/ 33 KV respectively.(m) All the transformers covered under this specification shall beutilized in heavily polluted atmosphere. In view of this theBidders while offering prices for the transformers againstthis contract may please note that the offer should be madeout based on the creepage for the bushings @ 25mm per KVbased on the voltage of 72.5KV/145KV/ 420KV. Thus in thequoted prices of transformer cost of bushings should beincluded based on a creepage distance of 25mm per KV.(n) All O.I.P. Condenser bushings shall be provided with :(i) Oil level gauge.(ii) Oil filling plug and drain valve, if not hermetically sealed.(iii) Tap for capacitance/tan delta test.(o) The bushings with current transformers are specified, hencethe bushings shall be removable without disturbing thecurrent transformers.(p) Porcelain used in bushing manufacture shall be homogenous,free from laminations, cavities and other flaws orimperfections that might affect the mechanical or dielectricquality and shall be thoroughly vitrified tough andimpervious to moisture. Glazing of porcelain and bushingshall be of uniform brown color free from blisters and burrs.(q) Bushing turrets shall be provided with suitable vent pipeswhich shall be connected to route any air/gas collectionthrough the Buchholz relay.(r) For Bushings of all voltage class, the arrangement forconnection of winding/neutral terminal shall be indicated .(s) From the end point of the condenser of the bushing whichwill protrude inside the transformer OR the bottomMPPTCL/TECH/PROC/02/ JUNE 13 Page 26 of 119termination point of bushing, sufficient clearance should beavailable so that in case any other make bushing isinstalled problem in this regard may not arise. Maximumlength of condenser portion, which can be easilyaccommodated, should be clearly indicated by the Bidder.(t) The LV take off arrangement within the transformer is ofutmost importance hence due care shall be taken whileproviding this arrangement inside the transformer tank. Theconnecting lug of LV winding with the bushing bottom terminalpad should match with the current rating of the bushing. Thesize of the LV winding lug shall be of suitable rating to matchwith the maximum load current of the transformer to be fedthrough extreme tap of OLTC meeting requirements of IS-6600. In this regard, the clamping arrangement of LVwinding with two lugs having two holes with two holeterminals on counter part of the bushing pad are notacceptable. In case of such arrangement, it will have tobe ensured that the counter part of winding lead/lug i.e.bushing terminal is with four holes or vice versa.11.14 Bushing Current Transformers(a) Current transformers shall comply with IS:2705.(b) One no. bushing CT of Ratio 800/1 on each phase of HVwinding i.e 3 nos, one no. bushing CT of Ratio 800/1 on eachphase of IV winding i.e 3 nos. shall be provided for eachTransformer .(c) Further, 33 KV CT of Ratio 400/1-1 shall be supplied as per

clause no.9.7.3. It shall be possible to remove turret mountedCTs from the transformer tank without removing the tankcover. Necessary precaution shall be taken to minimize theeddy currents and local heat generated in the turret. Also oneno. single phase outdoor mounted 52 KV class CT for neutralside of current ratio 800/1 for REF protection shall be provided.(d) All secondary leads shall be brought to a terminal box neareach bushing. These terminals shall be wired out to coolercontrol cabinet using separate cables for each core.(e) For the thermal image coil of winding temperature indicator,‘CT’ with suitable ratio and class may be used.11.15 Terminal Marking : The terminal marking and their physicalposition shall be in accordance with IS:2026.11.16 The positioning of HV & IV bushings shall be such that skewjumpering is avoided. The middle phase primary & secondary bushing centerline shall be parallel to side axis of the transformer body.12.0 EARTHING ARRANGEMENTMPPTCL/TECH/PROC/02/ JUNE 13 Page 27 of 11912.1 NEUTRAL EARTHING ARRANGEMENT : The neutral terminal ofthe star connected HV / IV winding shall be brought up to the ground levelthrough two tinned copper flat strips of size 50x6mm which shall besupported on transformer tank horizontal/vertical by porcelain insulators of 36KV voltage class. The number of insulators shall be sufficient to provide amechanically sturdy arrangement. Necessary mechanical supports on thetank for mounting of the insulators shall be made. It may be ensured thatconnection of the neutral strips to neutral bushings at one end shall be madeusing a terminal connector suitable for connection to the neutral bushingterminal and to receive 2x50x6mm tinned copper strips on the other side.The connection between the bushing and transformer’s earth pit shall bethrough 2x50x6mm tinned copper strips single run without any jointconnection/brazing/ welding etc. In case of problem in availability of singlerun tinned copper strips, it may be accepted with single joint. However, jointto be provided shall be subject to approval of purchaser. The other end of theearth connection to the earth pit shall also be through terminal connectorsuitable to receive 2x50x6mm copper strips at one end and to receive MS flatand /or twin ACSR Moose conductor on the other end. The length of thecopper strips shall be suitable for providing a joint less connection betweentransformer neutral and earth pit and details in this regard shall be intimatedto the successful bidder based on transformer/substation layout design. Atypical arrangement is shown in drg. No: MPPTCL/100MVA/02 of thisspecification for neutral earthing.12.2 CORE EARTHING ARRANGEMENT : The bidder should note ourrequirement in this regard very clearly. It is required to bring out leads fromcore, end frame and tank to the top of the transformer through onlythree insulated bushings. These Bushings shall be non oil communicating typeof minimum 17.5 KV class Porcelain Bushings. The arrangement shall behoused in a box at the top cover of transformer tank with provision forinterconnection between the studs of bushings. The bushing housing shallhave a suitable cover with gasket to make the arrangement waterproof. Aclear marking (engraved/punched) shall be made to indicate that the housingcontains core/end frame/ tank earthing arrangement. Please note thatstickers/flags/tags/painted marking for identification shall not be accepted. Atypical sketch of general arrangement needed by purchaser is shown indrawing no. MPPTCL/100 MVA/03 of this specification. Arrangement shall besuch that even after removal of connections, oil shall not leak. Removableshorting strips between the three bushing shall be provided. It may be notedthat internal earthing of any nature between core and End frame should not

be provided. Earthing at site shall be done by interconnecting the threebushings through shorting strips. This arrangement is to facilitate checkingof multiple core earthing in the transformer.It may be noted that :a) Any alternative arrangement is not acceptable and thereforebidder must confirm provision of three bushings as desiredabove.MPPTCL/TECH/PROC/02/ JUNE 13 Page 28 of 119b) Once transformer reaches site, before unloading from thetrailer the position of core earthing shall be checked and incase any problem of multiple core earthing is observed,delivery of Transformer will not be taken.The insulated cable to be used for core to Bushing connection & endframe to Bushing connection should be of good quality with propergrounding arrangement. The size and number of strands of cableshall be subject to purchaser’s approval.13.0 AUXILIARY POWER SUPPLY FOR OLTC, COOLER CONTROLAND POWER CIRCUIT13.1 Duplicate(Two) auxiliary power supplies of 0.4 KV, three phase,four(4) wire shall be provided by the purchaser at cooler control cabinet andfor OLTC drive.13.2 All loads shall be fed by one of the two feeders through anelectrically interlocked automatic transfer switch housed in the cooler controlcabinet , for tap changer control and cooler control circuits.13.3 Design features of the transfer switch shall include the following :i) Provision for the selection of one of the feeders as normalsource and other as standby.ii) Upon failure of the normal source, the loads shall beautomatically transferred after an adjustable time delay to thestandby source.iii) Indication to be provided at cooler control cabinet & RTCCfor failure of normal source and for transfer to standby sourceand also for failure to transfer.iv) Automatic re-transfers to normal source without anyintentional time delay following re-energisation on thenormal source.v) Both the transfer & re-transfer shall be dead transfers and ACfeeders shall not be paralleled at any time.13.4 AC feeder shall be brought to the OLTC cabinet (Cooler Control Cabinet)by the Bidder, after suitable selection at cooler control cabinet. The Biddershall derive AC power for control circuit from the AC feeder as mentionedabove by using appropriately rated dry type transformers. If the controlcircuit is operated by DC supply then suitable converters to be provided bythe Bidder to be operated from AC Power source.13.5 Necessary isolating switches and HRC fuses shall be provided atsuitable points as per approved scheme of purchaser.14.0 TAP CHANGING EQUIPMENTMPPTCL/TECH/PROC/02/ JUNE 13 Page 29 of 11914.1 General Requirement(a) OLTC gear shall be motor operated for local as well asremote operation. An external hand wheel/handle shall beprovided for local manual operation. This hand wheel/handleshall be easily operable by a man standing at ground level.(b) Arrangement shall be made for securing and padlocking thetap changer wheel in any of the working positions and itshall not be possible for setting or padlocking the wheel in anyintermediate position. The arrangement shall be such that no

padlock key can be inserted unless all contacts are correctlyengaged and switch set in a position where no open or shortcircuit is possible. An indicating device shall be provided toshow the tap in use.(c) The current & voltage rating of OLTC for the transformersshall be as under. The through current rating of OLTCshall be based on Clause 2.3.2 of IS 8478 and following OLTCrating specified are the minimum requirements. Bidder,however must offer OLTC with higher current rating, asmentioned below:-TransformerRatingOLTC onWinding(IV)Rating of OLTCVoltageRatingMinimumCurrentRatingTap Range(In steps of1.25%)100MVA,400KV132KV(IV)170KV 1000Amp-10 % to+10% of132kV(d) The OLTC motor should be capable of smooth and trouble freeoperation with supply voltage variation of 0.4KV -25% &+10%.(e) The design of the tap changing arrangement shall be such thatthere should be minimum variation of ohmic impedance of thetransformer from minimum to maximum tap. The permissibletolerance on these ohmic values shall be plus minus 10%.14.2 On Load Tap Changing Gear (OLTC)(a) The details of the method of diversion of the load currentduring tap changing, the mechanical construction of the gearand the control features for OLTC gear alongwith detaileddrawings on the inner view and the arrangement ofconnections shall be submitted with the Bid. Informationregarding the service experience on the gear and a list ofimportant users shall also be furnished. The tap changer shallMPPTCL/TECH/PROC/02/ JUNE 13 Page 30 of 119change the effective transformation ratio without producingphase displacement.(b) The current diverting contacts shall be housed in a separate oilchamber not communicating with the oil in main tank of thetransformer.(c) The contacts shall be accessible for inspection withoutlowering oil level in the main tank and the contact tips shallbe replaceable.(d) The Bidder shall indicate the safeguards employed to take care

of harmful arcing at the current diverting contacts in theevent of operation of the OLTC gear under overloadconditions ( overloading capability as per IS 6600 ) of thetransformer. Necessary tools and tackles shall be providedalongwith main supply for maintenance of OLTC gear.(e) The OLTC oil chamber shall have oil filling and drain valves, oilsampling valve, relief vent and oil level gauge/glass. It shallalso be fitted with an oil surge relay. For accommodating oilexpansion of OLTC a separate conservator tank shall beprovided.(f) The diverter switch or arcing switch shall be designed so asto ensure that its operation once commenced shall becompleted independently of the control relays or switches,failure of auxiliary supplies etc. To meet any contingencywhich may result in incomplete operation of the diverterswitch, adequate means shall be provided to safeguard thetransformer and its ancillary equipments.(g) Drive mechanism chamber shall be mounted on the tank inaccessible position. It should be adequately ventilated andprovided with anti condensation metal clad heaters. Allcontactors, relay coils and other parts shall be protectedagainst corrosion, deterioration due to condensation, fungietc.(h) The control feature shall provide the following :i) LOCAL-REMOTE selector switch mounted in thelocal control cubicle shall switch control of OLTC forlower/ raise functions in local or remote mode asselected.ii) The LOCAL-REMOTE selector switch shall have at-leasttwo spare contacts per position which are closed in thatposition but open in the other position.iii) A RAISE-LOWER CONTROL SWITCH shall beprovided in the local control cubicle. The switch shall bespring loaded to return to the Centre "OFF" position andshall require movement to the RIGHT to raise thevoltage of the transformer. Movement to the leftMPPTCL/TECH/PROC/02/ JUNE 13 Page 31 of 119shall lower the voltage. Alternatively push button typearrangement of standard design may be provided.iv) An OFF-ON tap changer control switch shall beprovided in the OLTC local control cabinet of transformer.The tap changer shall be inoperative in the OFFposition. Also the OFF-ON switch shall have atleast onespare contact per position which is closed in thatposition but open in the other position.v) Operating mechanism for on load tap changer shall bedesigned to go through one step or tap change percommand. Subsequent tap changes shall be initiated onlyby a new or a repeat command.vi) On load tap changer shall be equipped with a time delayin complete STEP alarm consisting of a normally opencontact which closes, if the tap changer fails to make acomplete tap change. The alarm shall not operate formomentary loss of auxiliary power.vii) The selsyn units or approved equivalents shall beinstalled in the local OLTC control cabinet to provide tapposition indication for the transformer. Complete

mounting details shall be included with approveddiagram.viii) Transformer load tap changer shall be equipped with afixed resistor network capable of providing discretevoltage steps for input to the supervisory system. Anyother approved / established design for remote indicationof tap position shall also be acceptable.(i) Limit switches shall be provided to prevent over-running ofthe mechanism and in addition, a mechanical stop shall beprovided to prevent over-running of the mechanism under anycondition.(j) Limit switches may be connected in the control circuit of theoperating motor provided that a mechanical-de-clutchingmechanism is incorporated.(k) Thermal device or other means shall be provided to protectthe motor and control circuit. All relays, switches, fuses etc.shall be mounted in the drive mechanism chamber and shallbe clearly marked for the purpose of identification.(l) A permanently legible lubrication chart shall be fitted withinthe driving mechanism chamber.(m) Any "DROP DOWN" tank associated with the tap changingapparatus shall be fitted with guide rod to control themovements during lifting or lowering.(n) A five digit counter shall be fitted to the tap changingequipment to indicate the number of operations performed.MPPTCL/TECH/PROC/02/ JUNE 13 Page 32 of 119(o) All relays and operating devices shall operate correctly at anyvoltage between the limits specified.(p) It shall not be possible to operate the electric drive when themanual operating gear is in use.(q) It shall not be possible for any two controls to be inoperation at the same time.(r) The equipment shall be suitable for supervisory control andindication with make before break multi-way switch, havingone potential free contact for each tap position. This switchshall be provided in addition to any other switch/switcheswhich may be required for remote tap position.(s) Operation from the local or remote control switch shallcause one tap movement only until the control switch isreturned to the off position between successive operations.(t) All electrical control switches and the local operating gear shallbe clearly labeled in a suitable manner to indicate the directionof tap changing.(u) Transfer of source failure of one AC supply shall not affect tapchanging operation.(v) For the purpose of operation of OLTC, based on design ofmanufacturer, transition resistor could be used. However, nocomponent of OLTC including transition resistor shall behoused inside main transformer tank. The design of thetransition resisters should be liberal to ensure suitability duringtap change operation at rated current including over loadingcapability and system short circuits.(w) The location and design of OLTC shall be such that in theevent of any repair / maintenance , it should be possible totake out various parts from the OLTC and other accessoriesand fittings mounted on the transformer particularly equalisingpipes etc do not infringe / obstruct .

14.3 Manual ControlThe cranking device for manual operation of the OLTC gear shall beremovable and suitable for operation by a man standing on ground level.The mechanism shall be complete with the following :i) Mechanical tap position indicator which shall be clearlyvisible to the person operating tap changer manually at thetransformer.ii) A mechanical operation counter.iii) Mechanical stoppers to prevent over-cranking of themechanism beyond the extreme tap positions.iv) The manual control considered as back up to the motoroperated load tap changer control shall be interlocked with theMPPTCL/TECH/PROC/02/ JUNE 13 Page 33 of 119motor to block motor start-up during manual operation. Themanual operating mechanism shall be labeled to show thedirection of operation for raising the voltage and vice-versa.14.4 Electrical Control : This includes Local Electrical control andElectrical remote control from remote control panel. The control circuits shallhave the following features:i. An interlock to cut off electrical control automatically uponrecourse being taken to the manual control inemergency.ii. Reinforcement of the initiating impulse for a tap change,ensuring a positive completion once initiated to the next(higher or lower) tap.iii. Step-by-step operation ensuring only one tap change fromeach tap changing impulse and lock-out of the mechanism ifthe control switch (or push button) remains in the "OperatePosition".iv. An interlock to cut-out electrical control when it tends tooperate the gear beyond either of the extreme tap positions.v. An electrical interlock to cut-off a counter impulse forreverse step change being initiated during a progressing tapchange and until the mechanism comes to rest and resetscircuits for a fresh position. Suitable interlocks shall beprovided to prevent operation of OLTC beyond extreme tapwith a mechanical/electrical lockable switch.vi. Protection apparatus, considered essential by the Bidderaccording to specification.14.5 Remote Electrical Group Control : The OLTC controlscheme offered shall have provision of remote electrical group control duringparallel operation of transformers. This is in addition to independent control ofOLTC.i. A four position selector switch having MASTER,FOLLOWER, INDEPENDENT and OFF position shall beprovided in the remote OLTC control panel for eachtransformers. This shall be wired to enable operator toselect operation of OLTC in either Master, Follower orIndependent mode.ii. Out of step relays with timer contacts shall also beprovided to give alarm and indication in case of tappositions in all the transformers under group control being notin same position.iii. Master Position : If the selector switch is in MASTERposition, it shall be possible to control the OLTC units in theFOLLOWER mode by operating the controls of the MASTER

unit Independent operation of the units under FOLLOWERMPPTCL/TECH/PROC/02/ JUNE 13 Page 34 of 119mode shall have to be prevented. However, the unitsunder independent mode will be controlled independently.iv. Follower Position : If the selector switch is in FOLLOWERmode, control of OLTC shall be possible only from MASTERpanel.v. Independent Position : In this position of Selector Switch,Control of OLTC of individual unit only shall be possible.14.6 Local OLTC Control Cubicle : The Auxiliary devices forelectrical control of the OLTC shall be housed in a weather proof cubicle . Itshall be complete with the following :i) A circuit breaker/contactor with thermal overload devices forcontrolling the AC auxiliary supply to the OLTC motor.ii) Cubicle light with door switch.iii) Space heaters to prevent condensation of moisture.iv) Padlocking arrangement for hinged door of cabinet.v) Cable terminal glands for power and control cables to theOLTC gear.14.7 Remote Tap Changer Control Panel (RTCC Panel) : Remotetap changer control panel to be supplied by the Bidder shall consist of :i) Actuating switch for electrical raise/lower control.ii) Remote tap position indicator.(preferred digital type)iii) Signal lamps for Tap changer in progress and Tap changer outof step.iv) Auxiliary devices for remote electric group control of OLTC.v) Annunciation scheme with the following :- Fan fail (for all fans individual windows).- AC supply fail.- Stand by fan fail.- Stand by fan on.- OLTC motor over loaded.- OLTC control supply fail.- OLTC at extreme position i.e. lowest & highest voltagetap.- Two spare windows.vi) Indicating Devices : Following lamp indications shall beprovided in Remote tap changer control cubicle / panel-- Fan "ON", Fan "OFF"- Cooling system "On Automatic Control".- Cooling system "On Manual".MPPTCL/TECH/PROC/02/ JUNE 13 Page 35 of 119- Selector switch in auto or manual.- 433volts cooler supply auto changeover.- Cooler supply failure for each supply.- Control supply failure main and standby.- one potential free initiating contact for all the aboveindications shall be wired independently to theterminal blocks of cooler control cabinet exclusively forowner's use.vii) Remote OTI with repeater unit.viii) Separate WTI 2 nos. for HV, one no. for IV and one no. for LVwinding operated by signal transmitter.ix) Voltmeter for indicating HV, IV and tertiary voltage.x) Schedule of equipments for RTCC panel shall be as under:- Name plate – “remote OLTC and cooler control cubicle’’- Indicating lamp-“OLTC control supply on ’’ ( red)

- Indicating lamp-“tap change in progress ’’ ( yellow)- Indicating lamp-“OLTC out of step’’ ( red)- Indicating lamp-“OLTC motor trip ’’ ( red)- Cooler mode selector (auto-off-on)- OLTC sequence selector switch.(OFF-INT-FOLL-MAST.)- Emergency stop push button for tap change operation. (red)- Auxiliary contactor for OLTC out of step monitoring.- Out of step timer.- Voltmeter for HV ( 0 ~ 500kv )- Voltmeter for IV ( 0 ~ 150kv )- Voltmeter for LV ( 0 ~ 40kv ) for ‘tertiary winding’- Terminal blocks.- Cubicle lamp.- Door switch.- HRC cartridge fuse holder with link for cubicle illuminationcircuit.- Neutral link.- Earth bus.- HRC cartridge fuse holder with link for HV volt meter.- HRC cartridge fuse holder with link for IV volt meter..- HRC cartridge fuse holder with link for LV volt meter..- HRC cartridge fuse holder with link for RWTI and ROTI circuit.- Selector switch for HV volt meter.- Selector switch for IV volt meter.- Selector switch for LV volt meter.- Remote winding temperature indicator. ( for HV , IV , LV )- “OLTC control switch’’MPPTCL/TECH/PROC/02/ JUNE 13 Page 36 of 119- Tap position indicator (digital).- Remote oil temperature indicator.- Ammeter for delta winding circulating current ( digital)- Online monitoring device parameters indication.xi. a. HV digital Voltmeter of accuracy class 0.5 provided forindicating HV voltage shall be scaled for voltage range 0-500 KV (phase to phase) and shall be suitable for usewith PT ratio 400KV/220 volt. The HV digital voltmetershall be precisely calibrated so as to indicate 400KVVoltage on voltmeter scale corresponding to input voltageof 220 Volt (phase to phase).b. IV digital Voltmeter of accuracy class 0.5 provided forindicating IV voltage shall be scaled for voltage range 0-150 KV (phase to phase) and shall be suitable for usewith PT ratio 132KV/220 volt. The IV digital voltmetershall be precisely calibrated so as to indicate 220KVVoltage on voltmeter scale corresponding to input voltageof 220 Volt (phase to phase).c. LV digital Voltmeter of accuracy class 0.5 provided forindicating LV voltage shall be scaled for voltage range 0-40 KV (phase to phase) and shall be suitable for use withPT ratio 33KV/220 volt. The LV digital voltmeter shall beprecisely calibrated so as to indicate 33KV Voltage onvoltmeter scale corresponding to input voltage of 220 Volt(phase to phase).xii. One 33 KV CT of ratio 400/1-1 having two secondary cores ofrating 1Amp , one of accuracy class 5P10 and other of accuracyclass 1 shall be provided for monitoring circulating current andalso to provide protection against circulating current beyond rated

capacity. For measurement of circulating current of delta windingone Ampere meter of digital /numeric type suitable for specifiedCT ratio shall be provided on the RTCC panel.xiii. Over current relay having setting range from 10% to 200% andwith high set feature having range 50% to 3000% in step of0.5%.15.0 COOLING EQUIPMENT15.1 The design shall take into account the following requirementsa) The oil cooling system of transformer shall be designed using2x50% radiator banks. The radiator banks shall be mountedon two different sides of transformer tank. The arrangementshall be subject to approval by the purchaser based onsubstation layout and positioning of other neighboring switchMPPTCL/TECH/PROC/02/ JUNE 13 Page 37 of 119yard equipments. Coolers/radiators shall withstand pressure /vacuum conditions specified for the tank. All coolers/ radiatorsshall be attached on the transformer tank through headerhaving suitable expansion joints (flexible coupling) toensure adequate mechanical strength against vibrationetc. subject to specific approval from the purchaser. Radiatorsdirectly mounted on transformer tank are notacceptable.b) Each radiator bank / block shall have its own set of coolingfans, shut off valves, lifting lugs, top and bottom oil fillingvalves, air release plugs, drain valves and if considerednecessary based on design thermometer pocket fitted withcaptive screw cap on the inlet and outlet, in line with valveschedule as per Annexure-V.c) Each radiator bank shall be provided with at least 20%standby (spare)cooling fans. These spare fans shall be dulymounted and shall also be wired up complete with requiredprotective devices and be identified with each radiator bank.While working out number of spare fan for 20% additionalcooling per bank, if 20% quantity works out in fraction , thespare fans to be provided shall be next whole number. Coolingfans shall be designed to meet overloading requirements asper clause 4.1 (b).d) Cooling fans shall be suitable for operation from 433 Volts, 3phase 50-Hz power supply and shall confirm to IS:325.e) The exhaust air flow from cooling fan shall not be directedtowards the main tank in any case. Cooling fans for eachradiator bank shall be located so as to prevent ingress of rainwater. Each fan shall be suitably protected by galvanised wireguard.f) The cooler and its accessories shall preferably be hot dippedgalvanised or corrosion resistant paint shall be applied to it.g) Each cooling fan shall be provided with starter thermaloverload and short circuit protection and also single phasepreventor.h) Each radiator shall be provided with suitable lifting lugs andshut off/air release/sampling valves as per Annexure-Vi) Expansion joints, one each on top and bottom cooler pipeconnections as per ‘a’ above.j) Air release device/plug and oil drain plug on oil pipeconnections.k) The cooling Fans shall be mounted on separatefoundation. Mounting of Cooling fans directly on

Radiators or on transformer tank is not acceptable .MPPTCL/TECH/PROC/02/ JUNE 13 Page 38 of 119The radiator’s mounting arrangement is to be indicatedby the Bidder in his Bid.l) Cooling fan support shall be of adequate strength to avoidbending etc. The mounting arrangement of cooling fans shallbe subject to approval be purchaser.15.2 Cooling Equipment Control (ONAN/ONAF Cooling)a) Automatic operation control (switching in and out) of fansshall be provided (with temperature change) from contacts ofwinding temperature indicator. The Bidder shall recommendthe setting of WTI for automatic change over of coolercontrol from ONAN to ONAF. The setting shall be such thathunting i.e. frequent start stop operations for smalltemperature difference do not occur.b) Suitable manual control facility for cooler fans shall beprovided.c) Selector switches and push buttons, shall also be provided inthe cooler control to disconnect the automatic control andstart/stop the fans manually.15.3 Indicating devices- Fan ‘ON’ , Fan ‘OFF’- Cooling system ‘on automatic control’.- Cooling system ‘on manual’.- Selector switch in auto or manual for cooler .- A.C. auxiliary cooler supply auto change over.- Cooler supply failure for main /standby.- Cooling fan failure for each fan.- Control supply failure for main and standby.One potential free initiating contact for all the above indicationsshall be wired independently to the terminal block of cooler controlcabinet exclusively for purchaser’s use.16.0 LOCAL OLTC CONTROL CABINET, COOLER CONTROL CABINET& REMOTE TAP CHANGER CONTROL PANELa) Each three phase transformer unit shall be provided with localOLTC control cabinet, cooler control cabinet OR fan controlcubicle (FCC) and RTCC panel. The total height of RTCCpanel shall be 2250mm to match with the height of othercontrol & relay panels. Local OLTC control cabinet shall bemounted on the transformer. The thickness of front panel,door frame etc. shall be 3mm (10 SWG),while doors &side panels may be 2 mm (14 SWG) and gland plate shall be ofminimum thickness 4 mm.b) The cooler control cabinet or FCC shall not bemounted directly on transformer tank .Please note thatMPPTCL/TECH/PROC/02/ JUNE 13 Page 39 of 119FCC shall be grouted away from the main tank thus the lengthof capillary tubes of all oil and winding temperature indicatingmeter shall be sufficient to connect OTI and WTI meters inthe FCC. The cooler cabinet shall have all necessary devicesmeant for cooler control and local temp. indicators. All thecontacts of various protective devices mounted on thetransformer shall also be wired up to the terminal Board inthe cooler control cabinet. All the secondary terminals of thebushing CT's shall also be wired upto the terminal Board atthe cooler control cabinet.c) The cooler control cabinet shall have two (2) sections. One

section shall have the control equipment exclusively meantfor cooler control. The other section shall house thetemperature indicators, aux. CT's and the terminal Boardsmeant for termination of various alarm and trip contacts.Alternatively the two sections may be provided as twoseparate panels depending on the standard practices of theBidder.d) The cooler control cabinet, Local OLTC cabinet and RTCCPanel shall be provided with non disconnecting stud typeterminal blocks. Each of the terminal blocks in the abovepanels should have 20% spare terminals exclusively forpurchaser’s use. All the necessary terminals for remoteconnection to purchaser’s panel shall be wired upto the coolercontrol cabinet. Necessary shorting of terminals shall bedone at the cooler control cabinet, local OLTC cabinet andremote OLTC panel. All the CT secondary terminals in thecooler control cabinet shall have provision for shortcircuiting to avoid CT open circuit while it is not in use.e) The local OLTC control cabinet shall house all necessarydevices meant for OLTC control and indication.f) Following cabling are specifically excluded from the scope ofthe Bidder. However, interconnection drawings for the sameare to be submitted by the Bidder.i) Cabling between Remote OLTC Panel to Cooler ControlCabinet.ii) Cabling between Remote OLTC panel to Local OLTCCabinet.iii) Cabling between Remote OLTC to Purchaser's Panel.iv) Cabling between Cooler Control Cabinet to Purchaser'sPanel.v) Cabling between Local OLTC Cabinet to Purchaser's Panel.16.1 The degree of protection shall be IP-55 in accordance with IS-2147.16.2 The temperature indicators shall be so mounted that the dials arenot above 1600mm from ground level. Glazed door of suitable size shall beprovided for convenience of reading.MPPTCL/TECH/PROC/02/ JUNE 13 Page 40 of 11916.3 A space heater and cubicle lighting with ON-OFF switch shall beprovided.16.4 Terminal Blocksa) The terminal blocks to be provided shall be fully enclosedwith removable covers and made of moulded, noninflammable plastic material with block and barriers mouldedintegrally .Such block shall have washer and binding screws forexternal circuit wire connections, a white marking strip forcircuit identification and moulded plastic cover. Allterminals shall be clearly marked with identificationnumbers or letters to facilitate connection to external wiring.b) All internal wiring to be connected to the external equipmentshall terminate on terminal blocks, preferably verticallymounted on the side of each panel. The terminal blocksshall be 1100 V grade and have 10 amps continuousrating, moulded piece, complete with insulated barriers,non-disconnecting stud type terminals, washers, nutsand lock nuts. Terminal block design shall include a whitefiber marking strip with clear plastic, slip-on/clip-on terminalcover. Markings on the terminal strips shall correspond to wirenumber and terminal numbers on the wiring diagrams.

c) Terminal blocks for current transformer secondary leadsshall be provided with test links and isolating facilities. Alsocurrent transformer secondary leads shall be provided withshort circuiting and earthing facilities.d) Unless otherwise specified, terminal blocks shall besuitable for connecting the following conductors on eachside.For all circuits except current transformer circuits minimum oftwo nos. 2.5 mm2 copper.For all CT circuits minimum of four nos. 4.0 mm2 copper.e) There shall be a minimum edge to edge clearance of 250mm between the first row of terminal blocks and theassociated cable gland plate. Also the clearance between tworows of terminal blocks shall be a minimum of 150 mm.f) Arrangement of the terminal block assemblies and the wiringchannel within the enclosure shall be such that a row ofterminal blocks is run parallel and in close proximity alongeach side of the wiring duct to provide for convenientattachment of internal panel wiring. The side of theterminal block opposite the wiring duct shall be reserved forthe owner's external cable connection. All adjacent terminalblocks shall also share this field wiring corridor. A steel stripMPPTCL/TECH/PROC/02/ JUNE 13 Page 41 of 119shall be connected between adjacent terminal block rows at450mm intervals for support of incoming cables.g) The number and sizes of the owner's multi core incomingcable will be furnished to the successful Bidder.16.5 One Cooler Control Cabinet and OLTC local control cabinetshall be tested for IP-55 protection in accordance with IS-2147.16.6 The gaskets shall be of neoprene rubber.17.0 PAINTING17.1 It has been observed that certain units received in the pastby us are not having good quality painting on inside & out side andwith passage of time peeling of flakes of paint takes place. In view ofthis the Bidders are requested to furnish in a separate sheet paintingprocedure adopted by them for internal & external surfaces of thetank. This is an essential requirement and details should be confirmedby the Bidders in their offer. The internal and external surfaces includingoil filled chambers and structural steel work to be painted shall be shot orsand blasted to remove all rust and scale of foreign adhering matter orgrease. All steel surfaces in contact with insulating oil shall be painted withtwo coats of heat resistant, oil insulating varnish.17.2 All steel surfaces exposed to weather shall be given a primarycoat of zinc chromate, second coat of oil and weather resistant varnish ofa colour distinct from primary and final two coats of glossy oil and Epoxy lightgray paint in accordance with shade no.631 of IS-5.For each transformer oilpaints should be obtained from same source to ensure compatibility & properfinish.17.3 All paints shall be carefully selected to withstand extremes ofweather. The paint shall not scale off or crinkle or be removed by abrasiondue to normal handling. The process of painting should be clearly described.17.4 The minimum thickness of each coat of outside painting of tankshall be 20 microns and the total thickness shall be minimum 80 microns.17.5 Bolts & Nuts :All bolts and nuts exposed to weather shall be hotdipped galvanised/cadmium plated.18.0 WIRING & CABLING(a) All external cabling will be carried out by the purchaser based

on wiring diagram & interconnection schedule to be suppliedby the Bidder . Cable box/sealing end shall be suitable forfollowing types of cables :-MPPTCL/TECH/PROC/02/ JUNE 13 Page 42 of 119i) POWER SUPPLY 0.4 KV : 1100 volts grade PVCinsulated armouredaluminum cable .ii) CONTROL CABLE : 1100 volts grade PVCinsulated 7/0.737mmstranded armoured coppercable .Size of the Purchaser’s cable will be intimated to thesuccessful Bidder after detailed engineering.(b) Compression type cable glands shall be provided fortermination of power and control cables.(c) All controls, alarms, indicating and relaying devicesprovided with the transformer shall be wired upto theterminal blocks inside the Cooler Control Cabinet.(d) All devices and terminal blocks with the Cooler ControlCabinet shall be clearly identified by symbols corresponding tothose used on applicable schematic or wiring diagrams.(e) Not more than 2 wires shall be connected to one terminal.Each terminal shall be suitable for connecting two 7/0.737mmstranded copper conductors from each side.(f) All internal wiring shall be securely supported, neatlyarranged, readily accessible and connected to equipmentterminals and terminal blocks.(g) Engraved code identification plastic ferrules marked tocorrespond with schematic diagrams shall be fitted at bothends of wires. Ferrules shall fit tightly on wires and shall notfall off when the wire is disconnected from terminal block.(h) The schematic diagrams of circuitry shall be available in therespective cabinets (local OLTC control cabinet , local fancontrol cubicle and RTCC panel). The diagrams shall bemounted on the inner side of door of cubicle/cabinets. Thearrangements shall be such that it is not be possible to removethe diagram from its place and diagrams are long lasting(engraved type).19.0 TERMINAL CONNECTORS19.1 Terminal connectors for HV/IV/LV side bushings shall be suitablefor double (twin)/ double (twin)/ Single Moose ACSR (31.77 mm) conductorrespectively and suitable for horizontal and/or vertical take offarrangement i.e. universal type. All terminal clamping arrangement shall besubject to Purchaser’s approval.MPPTCL/TECH/PROC/02/ JUNE 13 Page 43 of 11919.2 Bushing terminals shall be provided with terminal connectors ofapproved type and size for connection to external parts. Terminal connectorsoffered must have been successfully type tested as per IS-5561.19.3 All terminal connectors shall be manufactured out of gravity dyecasting process only and shall be free from blow holes, surface blisters,cracks and cavities. All sharp edges and corners shall be blurred androunded off. The aluminum alloy castings, if used, shall conform torelevant IS.19.4 No part of the clamp shall be less than 12mm thickness.19.5 All bolts, nuts and washers shall be of Hot Dip Galvanised.19.6 For bimetallic clamps , bimetallic strip of not less than 2 mmthickness shall be provided.

19.7 Flexible connectors, if provided shall be made from tinned coppersheets.19.8 Size of terminal (bushing stud)/conductor ( ACSR Moose ) for whichthe clamp is designed and also rated current under site conditions shall beembossed/ punched on each part of the clamp, except hardware.19.9 All current carrying parts shall be designed and manufactured to haveminimum contact resistance.19.10 Clamps shall be designed corona controlled.19.11 The nominal current rating and short time current rating of terminalconnectors shall match the corresponding rating of respective bushings i.e.,63KA for 3 seconds for 400KV, 40KA for 3 seconds for 132KV & 31.5KA for 3seconds for 33kV. Test Reports to substantiate this requirement should befurnished alongwith the Bid.20.0 INSULATING OIL REQUIRED FOR TRANSFORMERS20.1 Transformer oil shall be supplied by the Bidder. The offered Price oftransformers therefore, should include first filling of oil( including wastage &10% extra of that quantity). The quantity of oil for first filling includingwastage and 10% extra of that quantity should be indicated by the Bidder inkilo-liters and in kg. The design of the transformer shall be based on thecharacteristic of EHV transformer oil as per relevant IS , IEC, ASTMstandards.20.2 Although oil for the transformer is included in the scope of supply, butit may be noted that the transformer shall be supplied duly N2 gas filled withsuitable arrangement to ensure that the pressure of gas is regularlymaintained during transit and upto the date of filling of oil. For thispurpose, necessary gas cylinders with regulator shall be supplied on nonMPPTCL/TECH/PROC/02/ JUNE 13 Page 44 of 119returnable basis. Additional gas cylinders required for recouping andmaintaining of positive Nitrogen pressure upto filling of oil should besupplied by the manufacturer of Transformers and the offered priceshould take into account this requirement.20.3 The quality of the oil supplied with transformer shall conform to theoil parameters specified in this clause. No inhibitors shall be used in the oil.The oil samples of transformer will be drawn for the oil used at factory &site as follows.i. Prior to fillingii. Before and after heat run test / pre-commissioning testiii. Before energizing.All tests as per IS:335 (latest revision) , IEC, ASTM standards shallbe conducted on oil samples.20.4 Sufficient quantity of oil necessary for first filling of main tank, coolers,radiators and conservators etc. upto the proper level plus anticipatedquantity of wastage of oil during first filling shall be supplied in tankers. Pleasenote, wastage means quantity of oil absorbed during initial filling at works fortesting. In addition to the oil needed for first filling, 10% extra quantity of oilfor topping up in future, shall be supplied in non-returnable containerssuitable for outdoor storage. Therefore, total quantity of oil required for firstfilling shall be measured at works at the time of testing on unit subjected toheat run test.20.5 The supplier shall dispatch the transformer in an atmosphere ofpressurised Nitrogen. In this case, necessary arrangement shall be ensuredby the supplier to take care of pressure drop of nitrogen during transit andstorage till completion of oil filling during erection. A gas pressure testingvalve with necessary pressure gauge and adapter valve shall be provided.20.6 The supplier shall warrant and confirm that oil to be used for thetransformer testing at Works & oil to be supplied for the transformer is freefrom Polychlorinated Biphenyls (PVB/PCB). The transformer oil to be used

and supplied by the bidder for first filling at site shall be new oil of EHV Grade-I having technical specification mentioned hereunder . Hence Oil to be usedby the manufacturers at factory for the purpose of testing at theirworks shall be of similar or better quality having parameters matchingwith the parameters specified in the specification. Specific approval ofoil test results of oil proposed to be used for testing of transformer infactory shall be obtained by the manufacturer from the purchaserbefore first filling in the unit. MPPTCL shall not accept any other oil fortesting purposes having lower parameters than those specified in theBid. Bidders should specifically confirm this requirement in their offer.Sl.NoCharacteristics Requirement Method of TestMPPTCL/TECH/PROC/02/ JUNE 13 Page 45 of 119Sl.NoCharacteristics Requirement Method of Test1. Appearance The oil shall be clearand transparent andfree from suspendedmatter or sedimentA representativesample of oil shall beexamined in a 100mm thick layer atambienttemperature.2. Density at 29.5oC(maximum)0.89 gm/cm3IS:14483. Kinematics viscosity at27oC (maximum).27 CST IS:14484. Interfacial tension at27oC (minimum).0.04 N/mIS:61045. Flashpoint PenskyMarten (closed)(minimum).140oC IS:14486. Pour point. (maximum) -6 oC IS:14487. Neutralization value(Total acidity maximum)0.01 mg KOH/gIS:335 Appendix`A’, IEC 620218. Corrosive Sulphur Non-corrosive IS:335 Appendix `B’9. Electric strength(breakdown voltage)Minimum.a. New unfiltered oil (asreceived condition).b. After filtration40 KV (rms)60 KV (rms)

IS:679210. Dielectric dissipationfactor (tan delta) at90oc Maximum.0.002 IS:626211. Specific resistance(resistivity)a. at 90oC Minimum.b. at 27oC Minimum.100x1012 ohm.cm1500X1012 ohm.cmIS:610312. Oxidation stabilitya. Neutralisation valueafter oxidation,maximum.b. Total sludge, afteroxidation Maximum0.20 mg KOH/g0.02 percent byweightIS:335 Appendix `C’13. Presence of oxidationinhibitorThe oil shall notcontain antioxidantIS:335Appendix `D’MPPTCL/TECH/PROC/02/ JUNE 13 Page 46 of 119Sl.NoCharacteristics Requirement Method of Testinhibitors .14. SK value 6% maximum IS:33515. Water content,maximum.10 ppm IS:2362,IS 1356716. Ageing characteristicsafter accelerated ageing(open Breaker methodwith copper catalyst)a) Resistivityi. 27ocii. 90ocb) Tan delta at 90occ) Total acidityd) Sludge contentby weight2.5x1012 ohm.cm(min.)0.2x1012 ohm.cm(min.)0.15 (max.)0.05 mgKOH/gm(max.)0.05% (max)As per ASTM-D

1934, IS 12177,IEC6202117. Oil sample taken fromthe transformer afterthe completion of siteprocessing and tested inapproved manner shallhave the followingvalues beforecommissioning of thetransformer.i. Break downstrengthii. Moisture contentiii. Resistivity at 90ocminimumiv. Interfacial Tensionat 27ocv. Dielectricdissipation factor at90 oCMinimum 70 KVwithstandMaximum of 10 ppm35x1012 ohm.cm(min)0.04 N/M (min)0.002 (max.)Tested in accordancewith IS :33518 N-dm analysisCA%CN%CP%4 –6%40-43%51-54%MPPTCL/TECH/PROC/02/ JUNE 13 Page 47 of 11920.7 AIR CELL: Our technical specification calls for supply of powertransformers with air cell type oil preservation system of PRONOL,make only. It is obligatory on the part of the Bidders to clearly submitcomplete constructional and technical details of sealing arrangement, dulysupported with technical details, pamphlets and dimensional drawings.While furnishing details for the above sealing arrangement the Biddersmust confirm clearly that the size and capacity of sealing arrangement isadequate for the transformer and for the quantity of oil required for thetransformers. Necessary calculation/documentary proof shall be furnished.20.8 Air cell type oil preservation system included with each transformers hall ensure as under :(a) The air inlet of COPS (Conservator Oil preservation System) shallbe properly fitted on the conservator for leak proof arrangement toensure that the air does not come in contact with oil under anycircumstances.(b) The size and capacity of the COPS (Conservator Oil preservationSystem) shall be selected to suit the design of Conservator and toensure proper operation for the quantity of oil in the unit with theproper allowances. The COPS shall be of reputed make, proven

design and of established performance. Details in this regard are tobe submitted with the offer by the Bidder for verification . TheBidder is required to submit calculation with bid to proveadequacy of air cell & its size.(c) The Bidder shall clearly indicate in the manual the procedurefor installation of COPS and precautions to be taken at the time offirst oil filling under vacuum in the transformer.20. 9 SPECIFICATION OF FIRE PROTECTION SYSTEM : Nitrogeninjection type fire prevention & extinguishing system with flow sensitiveconservator isolation valve shall be provided for all the transformers.20.9.1 Nitrogen Injection Fire Protection System (NIFPS) shall be designedto prevent explosion of transformer tank and the fire during internal faultsresulting from arc and also to extinguish the external oil fires on transformerdue to tank explosion and/or external failures like bushing fires, OLTC firesand fire from surrounding equipments, etc. The system shall work on theprinciple of Drain & stir. On activation, it shall drain a pre-determined quantityof oil from the tank top through drain valve to reduce the tank pressure,isolate conservator tank oil and inject nitrogen gas at high pressure from thebottom side of the tank through inlet valves to create stirring action andreduce the temperature of oil below flash point to extinguish the fire. Thequantity of oil removed from the tank shall be such that adequate amount ofoil shall remain to cover active part, i.e. core coil assembly even afterstoppage of oil drain. Electrical isolation of transformer shall be an essentialpre-condition for activating the system. The NIFPS shall conform to NEPAMPPTCL/TECH/PROC/02/ JUNE 13 Page 48 of 11970 standard titled “ Fire protection of transformers & transformervaults” and Tariff Advisory Committee (TAC) regulations .20.9.2 OPERATIONAL CONTROLS: The system operation shall be fullyautomatic and activate from the required fire and other trip signals. Inaddition to automatic operation, remote operation from control room/ remotecentre and local manual control in the fire extinguishing cubicle shall also beprovided. System shall operate on following situations.20.9.3 PREVENTION OF TRANSFORMER EXPLOSION AND FIRE: Toprevent transformer explosion and fire in case of an internal fault, signalsgiven by operation of Electrical protection relays and tripping of circuit breakerof transformer and operation of either Buchholtz relay, or pressure relief valve(PRV) alongwith Rapid Pressure Rise Relay (RPRR) shall be used toactivate the system and logic for RPRR for system activation shouldinclude for operation of Electrical protection relays and tripping ofcircuit breaker of transformer. The exact logic for system activation shallbe finalized during detailed engineering.20.9.4 FIRE PROTECTION: In case of fire, sensed by fire detectors, thesystem shall be activated only after electrical isolation of the transformer,confirmed by breaker trip. If the fire detection is not associated with any otherfault, the system activation shall be only manual. Manual operation switchshall be provided in the control room/ remote control centre with a cover toavoid accidental operation of it.20.9.5 OPERATION OF SYSTEM: On receiving activation signal, thefollowing shall take place:i. Open the quick opening drain valve to drain the top layer oilii. Shut off the conservator isolation valve to prevent flow of oil fromthe Conservator tank to the main tank.iii. Open the Nitrogen regulator valve to inject Nitrogen into thetransformer tank to create stirring of oil.There shall be interlock to prevent activation of the system if the transformeris not electrically isolated. There shall also be provision for isolating thesystem during maintenance and/or testing of the transformer.

20.9.6 TECHNICAL PARTICULARS: The supplier shall be responsible forthe design of the complete system and shall submit the drawings and designcalculations for the number of fire detectors, pipe sizing of drain pipe andNitrogen injection pipe, Nitrogen cylinder capacity, number of injection points,etc. and get approval from purchasure. Facility shall be provided to test thesystem when the transformer is in service, without actually draining the oiland injecting Nitrogen. The Nitrogen regulator valve shall be designed in sucha way that the Nitrogen shall not enter the transformer tank even in case ofpassing/ leakage of valve. The system shall work on station DC supply.MPPTCL/TECH/PROC/02/ JUNE 13 Page 49 of 119MPPTCL shall give two distinct DC feeders in control. The control box of fireprotection system shall have facility to receive these feeders for auto changeover of supply. It shall be the contractor’s responsibility to further distributepower to the required locations.Following indications and alarms shall be provided in the cubicle as well as thecontrol box:-• Nitrogen cylinder pressure indication.• Nitrogen cylinder pressure low.• Fire in Transformer/ Reactor.• Oil drain started.• Conservator oil isolation valve closed.• Nitrogen injection started.20.9.7 DETAILS OF SUPPLY & WORK FOR SYSTEM EQUIPMENTS ANDOTHER RELATED ACTIVITIES: The scope of supply shall include thefollowing items, any other items required for safe & trouble free operation ofthe system and the scope of works include complete earthwork (i.e.excavation, backfilling etc.), scope of supply also includes services to beavailed by the purchaser for erection and commissioning of NIFPS at EHV substationsof MPPTCL in MP. , civil work with civil material for the entire open/buried piping for the fire protection system, construction of safety wall,construction of oil pits with provision of oil storage tank of MS and pipesupports for open/ buried, entrenched and overground piping. The systemdesign shall also conform to TAC/NFPA norms.(i) Fire extinguishing cubicle with base frame and containing at least thefollowing:• Nitrogen gas cylinder of sufficient capacity with pressure regulator andmanometer with sufficient number of adjustable NO contacts.• Oil Drain Assembly including oil drain pipe extension of suitable size forconnecting pipes to oil pit.• Mechanical release device for oil drain and nitrogen release.• Limit switches for monitoring of the systems.• Panel lighting.• Flanges on top of the panel for connecting oil drain and nitrogen injectionpipes for transformer.• Limit switch for pressure switch/sensor.• Pressure indicators for Nitrogen pressure in the cylinder and afterNitrogen regulator.(ii) Control box to be installed in the control room of the station for monitoringsystem operation, automatic control and remote operation, with alarms,indication light, switches, push buttons, audio signal, suitable for trippingand signaling.(iii)Conservator isolation valve which shall be flow sensitive and shut off whenthe flow in the pipe is more than the flow expected in the permissiblenormal operating conditions. It shall be provided with position indicatorremote alarm indication.MPPTCL/TECH/PROC/02/ JUNE 13 Page 50 of 119(iv) Required number of fire detectors to be located in strategic locations to be

finalized during detailed engineering.(v) Flow Sensitive Conservator Isolation Valve.(vi)All controls, alarms, panels, cables, cable trays (if required), junctionboxes, Valves etc.20.9.8 INSTALLATION AND PRE-COMMISSIONING TEST: Afterinstallation the system pre-commissioning tests shall be carried out jointlywith the MPPTCL representative before the system is put in service.20.9.9 In order to restrict the supply of oil in case of a fire in transformer,provision shall be made to isolate the conservator oil from the main tank.20.9.10 A valve which shall be flow sensitive and shut off when the flow inthe pipe is more than the flow expected in the permissible normal operatingconditions. This valve shall be located in the piping between the conservatorand the buchholz relay and shall not affect the flow of oil from and to theconservator in normal conditions.20.9.11 When the flow from conservator to main tank is more than thenormal operating conditions, the valve shall shut off by itself and will have tobe reset manually. It shall be provided with valve open/close positionindicator along with alarm indication in control room during closing operationof valve.20.9.12 Necessary switches shall be provided in cooler control cabinet /common marshalling box for manual open / close operation of the valve.Bidders shall offer Transformers completely fitted with NitrogenInjection Fire Protection Systems and also indicate cost of completesystem, separately in their offer in Schedule of prices.20.10 ON LINE MONITORING DEVICE FOR TRANSFORMER:20.10.1 The Bidder should offer for a suitable on line monitoring devicefor regular monitoring of 3 key gases and moisture for conditionassessment and fault detection of the 400 KV 100 MVA transformer . Thedevice should measure 3 key dissolved gases viz. Hydrogen, Acetylene,Carbon mono oxide with accuracy of ±10%. The minimum range ofmeasurement of dissolved gases shall be Hydrogen :5 to 500, Acetylene : 3to 5000, Carbon mono oxide : 10 to 5000 . The moisture content shall bemeasured from 0 to 100 % RS (in ppm). The device shall have non volatilememory storage to prevent loss of data. The device shall be provided withuser configurable at least six alarm contacts & two front panel LED arrays.The alarm setting screen shall be available for setting alarms based on level of3 Key gases or moisture and rates of change for Key gases. For configuringthe six alarm settings, suitable PC software shall be provided with the device.The device shall be supplied with two separate channels for remotecommunication plus local USB and Ethernet connections. The device shouldsupport communication Protocol viz. MODBUS, DNP 3.0 and IEC-61850. ItMPPTCL/TECH/PROC/02/ JUNE 13 Page 51 of 119shall be possible to configure sampling rates to hourly/ daily. The alarm &Caution thresholds shall be user configurable. The device should support Loadmonitoring by analyzing results with loading of Transformer and device shallbe provided with suitable software for graphical trending & diagnostic analysisof results. The device shall have minimum maintenance requirements.On line monitoring unit shall not be mounted on the body of the transformer.A separate mounting arrangement near the transformer body with properprotective sheds & covers for protection against sun and rains be provided.The mounting cubical shall have provision for ventilation/cooling and alsoprovision for reading of parameters by operators without opening the box. Online monitoring unit shall be complete with provision for remote monitoringalarm and indication in RTCC panel in control room. Complete details ofoffered device shall be submitted by the Bidder and explained by suitablemanual/pamphlets.External temperature range : 0 to 55 o C

Operating Humidity : 10 to 95% RH non condensingEnclosure : IP55Input Power requirement : Voltage 120 to 260 V AC, Frequency 47 to60 Hz; The power supply should be able towithstand electrical surges & disturbancesprevalent in EHV substation.20.10.2 Bidders shall offer Transformers completely fitted with OnLine Monitoring Device for Transformer of Kelman or equivalentmake, suitable for monitoring of 3 Key gases .20.11 THERMOSYPHON FILTER: Atleast four Nos. of Thermosyphon filterarrangement each of capacity 1/5th of the total oil flow in the cooler shall beprovided with rigid support (i.e., slotted one not acceptable) on thetransformer along with connecting piping, isolating valves at either end, drainplug shall be mounted on the transformer. It will have Alumina trap and willbe designed in such a way that 1/5th of the forced oil circulation passesthrough it. The quantity of absorbent will be 0.25% of the total weight of totaloil in the transformer, cooler, conservator etc. Spare alumina for one timereplacement shall be also supplied by the supplier. The location ofThermosyphon filter should be in such a way that same do not interfere withany of the existing equipments. The Thermosyphon filter shall be located atdiagonally opposite points of transformer and out of four filters, two filtersshall be with pumps .The connecting pipes of Thermosyphon filter to tankshall be provided with flexible couplings. It may be noted that rigid supportsshall be provided for thermosyphon filter i.e., slotted type of fixingarrangement is not acceptable.20.11.1 SILICAGEL BREATHER: Minimum 3 (Three) nos. dehydrating filterSilica Gel Breathers each of 100% breathing capacity are required and thesame shall be provided. Size of breather & its pipe connection is to beindicated. However, each breather of minimum capacity of 8 Kg. having itsMPPTCL/TECH/PROC/02/ JUNE 13 Page 52 of 119pipe connection of minimum size of one inch dia shall be preferable. Suitablearrangement for parallel mounting of breathers shall be made for connectingSilica Gel Breathers to the main conservator. The passage of air should bethrough dual filter & Silica Gel. Silica Gel shall be isolated from atmosphere byan oil seal. Adequate supports are required to be provided for pipe connectionto avoid any swing in air.The capacity of dehydrating silicagel breather shall be adequate to ensuresupply of dry air only for the volumetric expansion/contraction of oil keepingin view the total quantity of oil in the unit. The container of the breathershall be made of metal with glass enclosure along its periphery to ensure thatthe transparency (to verify the colour of dehydrating agent) is maintainedduring operation directly under sunlight (ultra violet rays) for long life. Thequantity of the dehydrating agent shall be sufficient keeping in view theclimatic condition specified and that the breather will be maintained generallytwo times in a year. This applies to all the breathers provided with thetransformer.20.12 SURGE CAPACITORS: The Bidder has to provide with each 400 KV100 MVA transformer , three (3) nos 40 KVrms , 0.125 mocro farad SurgeCapacitors with mounting structure & terminal connectors for connection to72.5 KV tertiary bushings. The complete technical particulars of capacitor unitshas been specified in Annexure I. The constructional features of the surgecapacitors shall be as under :a) The dielectric fluid within the capacitor unit shall be environmentally safeand biodegradable. PCB type fluid shall not be used. The capacitorelements shall be vacuum dried inside the case prior to impregnationwith dielectric fluid. After impregnation, the capacitor unit shall be sealedimmediately upon removal of impregnating reservoir.

b) The capacitor shall include bushings, discharge resistor, capacitorelements connected in series and/or parallel, internal connections etc. Alljoint of casing shall be tested for leaks.c) Each capacitor unit shall be provided with lifting eyes or similar provisionfor lifting or placing the unit into its position.d) Each capacitor unit shall be provided with discharge device whichreduces the residual voltage from the crest value of rated voltage to lessthan 50 Volt within one minutes after the capacitor is disconnected fromthe source of supply.e) Surge capacitor shall be mounted on a support structure to be suppliedby the Supplier.f) The surge capacitor shall have adequate strength to withstand withoutdamage or loss of life the mechanical load both in operation andtransportation, handling and erection. The loads shall includeelectromagnetic forces including those during fault external or internal tothe capacitors, wind loading forces due to expansion and contraction dueto ambient temperature, load variation and seismic efforts.MPPTCL/TECH/PROC/02/ JUNE 13 Page 53 of 119g) The capacitor units shall be interchangeable in order to reduce sparerequirements and simplify maintenance procedures.h) The bushings of the capacitor shall be of porcelain or oil communicatingtype. The bushings and other insulators shall have creepage of 25 mmper KV of phase to earth voltage. Bushing terminals shall be providedwith terminal connectors for interconnection with adjacent equipment orbus bars.21.0 FITTINGS & ACCESSORIES FOR THE POWER TRANSFORMERS21.1 The transformers will be supplied complete with all fittings andaccessories exactly in line with various requirements indicated in Annexure IIin this technical specification. The basic offered cost must take intoconsideration cost of all fittings and accessories as under and indicatedelsewhere in this specification .21.2 The equipments and accessories furnished with thetransformer shall be suitably mounted on the transformer for ease ofoperation, inspection and maintenance and the mounting details shall besubject to the approval of the purchaser. All valves shall be provided eitherwith blind companion flanges or with pipe plugs for protection.21.3 Indication, alarm and relay equipment shall have contacts suitablefor operation with 220V DC supply. Any other accessories or appliancesrecommended by the manufacturer for the satisfactory operation of thetransformer shall also have 220V DC as input.a) OLTC and its controls shall be as per clause 14.b) All cabinets & panels shall be conforming to stipulationsunder Clause-16 .c) All 420KV, 145KV, 72.5KV phase bushings and 72.5 KV neutralbushings shall be of OIP condenser type and as per Clause 11.13 .21.4. Equalizing pipes for maintaining equal pressure between main tankand OLTC and at various other locations as per design shall be provided.These equalizing pipes shall be routed such as not to create any obstruction.21.5 Accessories which are necessary for satisfactory operation ofTransformer shall be deemed to have been included in the accepted pricewithout any extra cost to the Purchaser.21.6 It may be noted that all the name plates/rating plates/diagramplates on transformer shall be engraved type/anodized type and shall be fixedusing rivets/spot welding method. The method of printing of letters on theR&D plate shall be such that inscriptions shall not fade by ultra violet rays andother adverse weather conditions under which the same is subject to duringservice life of transformers.

MPPTCL/TECH/PROC/02/ JUNE 13 Page 54 of 119(a) Rating & Diagram Plate: In the R&D plate following additionalinformation over & above as specified in the IS/CBIP specification shallbe provided.- Weight of the copper for windings- Weight of the core laminations for core- Weight of insulation- Weight of steel- Untanking weight (Core & Coil)- Transport weight- Total weight of Transformer Tank along with Fittings &Accessories and oil- Percentage Impedance at all taps- HV & IV winding resistance of all phases at all taps- LV winding resistance of all phases- Weight of the oil for first filling in Kg/Liters- Total quantity of oil (including wastage) and 10% extraquantity in Kg/Liters- If required two separate R& D plates may be used.(b) Valve Schedule Plate: In the valve schedule plate, at least two viewsshould be inscribed so that location of all the valves provided on thetransformer could be indicated/visualised. In the table of valveschedule plate, details of valves viz. type, material, size & positionduring transportation and after commissioning shall be clearlyindicated. The size of the letters shall be such that the same be visibleclearly to a person standing away at a distance of one meter from therespective vertical face of the transformer.(c) Instruction Plate For Oil Filling in the Conservator with Air Cell:An instruction plate shall be provided for oil filling in the conservatorhaving air cell type breathing arrangement. In addition to theinstructions for oil filling on this plate, a diagram indicating mountingdetails of MOLG, oil level gauges, air cell inside the conservator with apictorial view of conservator including make, type & size of air cell shallalso be inscribed. The location of plate should be such that same isvisible to operating personal from a distance as mentioned in (b)above.22.0 CENTRE OF GRAVITY : The centre of gravity of the assembledtransformer shall be low and as near to the vertical centre line as possible.The transformer shall be stable with or without oil. If the centre of gravity iseccentric relative to track gauge either with or without oil, its location shallbe shown on the outline drawing.23.0 PACKING23.1 The packing may be in accordance with the Bidder's standardpractice but Bidder should give full particulars of packing for the approval ofthe purchaser. Special arrangements should be made to facilitate handlingand to protect the projecting connections for damage in transit.MPPTCL/TECH/PROC/02/ JUNE 13 Page 55 of 11923.2 The transformer shall be transported filled with inert gas preferablyNitrogen gas. The Bidder shall ensure that adequate pressure of gas ismaintained inside the tank throughout during transportation by sendingescorts and required apparatus and equipment with the transformers.23.3 All parts shall be adequately marked to facilitate field erection.Boxes and crates shall be marked with the contract number and shall havea packing list enclosed showing the parts contained therein. however theverification of accessories shall be done in presence of suppliersrepresentative.

24.0 TESTS24.1 The manufacturer shall carryout routine test ,additional routinetests and type tests on the transformers as per the relevant IndianStandard IS-2026 with latest amendments , IEC 60076, CBIP Publication No295, IEEE or any equivalent International Standard .The details of tests arespecified hereunder. It should be specifically noted by the Bidder that testingof each & every transformer included in this Bid specification shall be carriedout at the manufacturer’s works in fully assembled condition complete with allfittings & accessories.24.2 ROUTINE TESTS AND ADDITIONAL ROUTINE TESTS: All routinetests and additional routine Tests detailed under clauses 24.2.1 & 24.2.2herein under will be carried out on each transformer on "free of cost" basis, inaccordance with IS:2026 part-I.24.2.1 ROUTINE TESTSa) Measurement of winding resistance as per cl.16.2 of IS 2026Part I. The winding resistance shall be measured on all tapsand of all the three phases and values be recorded inrespective test certificates.b) Measurement of voltage ratio at all taps and checking ofvoltage vector relationship as per cl.16.3 of IS 2026 Part I.c) Measurement of Impedance voltage/ short circuit impedance(at all taps) & load loss (at principal tap & extreme taps) asper cl.16.4 of IS 2026 Part I, IEC 60076.d) Measurement of no load loss at 90%, 100%, 110% of ratedvoltage & no load current as per cl.16.5 of IS 2026 Part I.e) Measurement of insulation resistance as per cl. 16.6 of IS2026 Part I.f) Dielectric tests shall be carried out as per IS 2026 (part I, II &III) & IEC60076 as under:i. 400 KV winding- Lightning impulse on all the line terminals (routine test)MPPTCL/TECH/PROC/02/ JUNE 13 Page 56 of 119- Induced over-voltage with partial discharge indication Onall the line terminals (routine test)- Separate source AC on neutral terminal (routine test)- Switching Impulse testThe test voltage between line and neutral shall be broughtupto 420 KV and held for 5 seconds. It shall then bereduced to 364 KV. This shall be held for 30 minutes whereafter the voltage shall be reduced to zero. During the 30minutes period at 364 KV between the line and neutral,observation of partial discharge shall be carried out at lineas well as neutral terminals of the winding under test.Further, following conditions shall be specifically verifiedNote : There shall be no breakdown during short applicationof higher voltage i.e 420 KV and the continuous level ofpartial discharge during the long application of lower testvoltage shall not exceed 500 pico-Coulomb in any of themeasuring channels.ii. The 132 KV winding- Lightning impulse on all the line terminals (routine test)- Induced over voltage test with partial discharge indication(routine) .This test gets simultaneously done when 400KV winding is tested, therefore, no separate test needs bedone.iii. The 33 KV winding- Separate source AC on all the line terminals (routine test)

- Lightning impulse on all the line terminals (type test)Note : No separate induced over-voltage test need to bedone. The winding gets tested as a consequence of theinduced over voltage test with partial discharge indicationon 400 KV winding.g) All tests on OLTC as per cl.16.9 of IS 2026 Part I, IEC 60214.h) Measurement of Tan-Delta, Capacitance & IR values ofHV,IV,LV & Neutral bushings before & after tests ontransformer .i) Low voltage AC, magnetic balance and magnetizing currentthree phase & single phase at normal tap for field reference.The test shall be carried out only after ensuring properdemagnetizing of the core so as to achieve proper results.Note : DGA test of oil of main tank of transformer before (initial) &after completion of all testing shall be done and test resultsshall be submitted to the purchaser .MPPTCL/TECH/PROC/02/ JUNE 13 Page 57 of 11924.2.2 ADDITIONAL ROUTINE TESTS(A) Insulation Resistance : Insulation Resistancemeasurement shall be done for 15 Secs. , 60 secs. and 600secs. Duration. Polarization Index (PI) shall be clearlyrecorded on test report for 600 sec /60 sec values and D.A.R.for 60 sec/15 sec values.PI value : PI value (i.e. ratio of IR Values for 600 sec /IR Values for 60 sec) for winding should be greater than2.0. This requirement is to be confirmed specifically bythe Bidders in their offer.(B) Magnetic Circuit Test :After assembly, core shall be testedfor 1 minute at 2 KV AC between all bolts, side plates &structural steel work. Immediately prior to the despatch of thetransformer from works of manufacturer, the magneticcircuit shall be tested for one minute at 2 KV AC between theCore & Earth and leakage current shall also be recorded.(C) Oil Leakage Test on Tank : All Transformer tank with itsactive part as assembled for type test (i.e. including pipe workand cooling equipment and excluding PRV and conservatorwhen air cell is provided) shall be subjected to apressure corresponding to twice the normal head of oil or tonormal pressure plus 35 kN/ m.sq.(5psi) whichever is lowermeasured at the base of the tank and will be maintainedfor 12 hours during which time no leakage shall occur. Beforeconducting the pressure test, the following are to be takencare of :(i) Pressure relief valve are to be removed and the openingblanked .(ii) Transformer and tap changer conservators are to bedisconnected.(iii) Diverter switch compartment of tap changer to beconnected with transformer tank for equalising thepressure on both sides.(iv) Oil should be completely filled and all trapped airreleased.(D) Capacitance & Tan-delta Test on winding : Themeasurement of capacitance and tan delta to determinecapacitance between winding & earth shall be carried outbefore and after series of dielectric tests by Ampere turnmethod. For temperature correction factors IEEE C.57.90 shall

be referred.The measured Tan delta values of winding shall notexceed 0.45% at 200C (degree Centigrade) temperature.In case Tan delta of transformers during testing atMPPTCL/TECH/PROC/02/ JUNE 13 Page 58 of 119works of manufacturer is measured above maximumceiling of 0.45% at 200C (degree Centigrade)temperature, then MPPTCL reserves right not to acceptsuch of the transformer. This requirement is to beconfirmed specifically by the Bidders in their offer.(E) Test Results of calibration & measurement reports of WTI CTand ratio test for bushing CT..(F) Checking & recording of following:a. IR valuesi. Between Core and End frameii. Between Core and Tankiii. Between End frame and main Tank.The measured IR values should be more than 1000 MOhms.This requirement is to be confirmed specificallyby the Bidders in their offer.b. Measurement and recording of currents withapplication of 400 volts, 3phase, AC supply on HVside with IV side shorted, as underi. Between Core and Tank.ii. Between Core and End frameiii. Between End frame and Tankiv. Between neutral and short circuited links with neutralgrounded and ungrounded conditions.NOTE: The details of arrangements provided outside themain tank for connecting core, end frame and main tankbody shall be indicated on a diagram , to be attached withthe test reports.(G) Test results of CT provided in one phase of tertiarywinding before delta formation.(H) Magnetising current measured with LT supply.No Particulars With Single phasesupplyWith Three phasesupplyVolts. Amps. Volts. Amps.a On HVsideb On IV sidec On LV side(I) Magnetic balance test on HV , IV and LV side.(J) Pressure Relief Device Test :All pressure relief devicesprovided in each transformer shall be subject to test for itssuccessful operation. It shall operate before reaching the testpressure specified in clause 24.3 (C) of this specification. TheMPPTCL/TECH/PROC/02/ JUNE 13 Page 59 of 119device shall seal off after the excess pressure has beenrelieved.(K) Frequency Response Analysis (SFRA) Test onTransformer : The SFRA test shall be conducted by themanufacturer at manufacturers works using his own SFRA testset and also SFRA test shall be conducted by the manufacturerat site using same SFRA test set at the time of erection &

commissioning of unit.(L) Measurement of Dew point prior to despatch of the unit,filled with N2 gas: Dew point is the temperature at whichwater vapours present in the gas filled in the transformerbegins to condense. The transportation of transformer from thefactory of manufacturer’s works upto the purchaser’s site isdone with dry Nitrogen gas filled condition, due to weightlimitation. Positive gas pressure say 0.25 kg/cm2 is normallymaintained during transportation as well as during storage. Incase positive pressure is not maintained then due tohygroscopic properties of insulation used in transformerpossibility of absorption of moisture in insulation can not beoverruled. Therefore to check the dryness of insulation,measurement of dew point at factory prior to despatch and atsite prior to oil filling is necessary and to be carried out. Itmay be noted that dew point shall be measured at factory priorto despatch. Temperature, pressure and dew point at the timeof gas filling (reading taken after stabilisation) shall be takenand painted on the transformer tank. The minimumpermissible value of dew point shall be (–)25oC at normaltemperature and pressure.(M) Functional tests on auxiliary equipments i.e. Air cell,OTI,WTI , valves , Filters etc as per CBIP publication no295.(N) Supplier’s test certificate in respect of on linemonitoring device (OLMD) , NIFPS, Surge capacitor asper IS , IEC, CBIP publication no 295.24.3 TYPE TESTS : Following Type Tests shall be conducted on onetransformer of each manufacturer (if there are more than one manufacturer)as per IS:2026 Part I, IEC , CBIP publication no 295.(A) Temperature Rise TestThis test as per cl. 16.8 of IS:2026(Part- II) shall be conductedat the lowest voltage tap having maximum current with 10%overload conditions. The supplier before carrying out suchtests, shall submit detailed calculations showing thealternatives possible, on various taps and for different ratingsMPPTCL/TECH/PROC/02/ JUNE 13 Page 60 of 119(ONAN/ONAF), of the transformer and shall recommend thecombination that results in highest temperature rise, for thetest.Since 100 MVA transformer is a auto transformer thetemperature rise test shall be conducted for the condition ofsimultaneous loading of all three windings for their respectiveONAF rating i.e 400 KV and 132 KV winding corresponding tocurrent of 100 MVA and 33 KV winding for 33.33 MVA. Loadingon two windings for 100 MVA transformer for the measuredlosses will not be accepted. Gas chromatographic analysis of oilshall be conducted before and after heat run test and thevalues shall be recorded in the test report. The samplingshall be in accordance with IEC-567. For the evaluation of thegas analysis in temperature rise test, a method will beproposed which is based on the rate of increase of particulargases and the permissible limits of minimum detectable valueof gases and the maximum limit will be mutually discussedand agreed upon between the Purchaser and Supplier. Thisshall be treated as reference during maintenance oftransformer in future.

The calibration of OTI and WTI shall be done by TransformerManufacturer and these calibrated OTI,WTI shall be used duringtesting of transformer. The Sr. No. of WTI,OTI shall berecorded during testing of transformer and these indicatorsonly shall be supplied with the transformer. During test, themanufacturer selects suitable tap from CT based on gradientbetween the reading of WTI & OTI . This tap position is to beclearly recorded on test report so that selection of correct tapcould be done at site to avoid discrepancy in temperaturegradient recorded during factory test and the value recorded atsite.(B) Impulse Test on line terminals as per IS 2026 part III, on onetransformer of Bid(C) Tank tests : Following Vacuum and Pressure tests shall becarried out on one transformer tank.(a) Vacuum Test (Fabrication stage)One transformer tank of each design shall be subjected tothe vacuum of 760 mm of Hg. The tanks designed for fullvacuum (760 mm of mercury at sea level or the barometricreading at the location of test) shall be tested at a maximuminternal pressure of 3.33 kN/m.sq. (25 mm of Hg) for onehour i.e. 760-25=735 mm of Hg at sea level and (Barometricreading -25mm Hg) at other location. The permanentdeflection of flat plates after vacuum has been released shallnot exceed the values specified below:MPPTCL/TECH/PROC/02/ JUNE 13 Page 61 of 119Horizontal Length of flat plate (inmm)Permanent Deflection (inmm)Up to and including 750 5751 to 1250 6.51251 to 1750 81751 to 2000 92001 to 2250 112251 to 2500 12.52501 to 3000 16Above 3000 19(b) Pressure Test (Fabrication stage)One transformer tank of each design , its radiator, conservatorvessel ,and other fittings together or separately shall besubjected to a pressure corresponding to twice the normalhead of oil or to normal pressure plus 35 kN/m2, whichever islower, measured at the base of the tank and will bemaintained for 1 hour during which time no leakage shall occur.The permanent deflection of the flat plate after the excesspressure has been released shall not exceed the figures specifiedabove for vacuum test as per clause 24.3(C)(a).24.4 SPECIAL TESTS : Following special tests other than type and routinetests shall also be carried out as per IS:2026 Part-I on onetransformer of each manufacturer (if there are more than onemanufacturer) .a) Measurement of zero seq. impedance as per CL.16.10 ofIS:2026 Part-I.b) Measurement of acoustic noise level as per CL.16.12 ofIS:2026 Part-I, NEMA TR1 & IEC 60076-10. Detailed calculations& conditions outlined in the IEEE standard C 57.12.12.90 shall

be followed.c) Measurement of power taken by fans as per cl.16.14 ofIS:2026Part-I.d) Measurement of harmonic level of no load current and totalharmonic distortion of voltage & current as per CL.16.13 ofIS:2026 Part-I. Details of rms voltage applied & print out ofHarmonic Analyser shall be enclosed with report.e) One Cooler Control Cabinet and OLTC cabinet of each type oftransformer shall be tested for IP:55 protection inaccordance with IS:2147.f) Test to prove over fluxing capability of transformer.MPPTCL/TECH/PROC/02/ JUNE 13 Page 62 of 11924.5 To summarize the requirement of tests for 400KV 100 MVApower transformers covered in this Bid specification, are asunder :ClauseNo.Nature of testsNumber oftransformers tobe testedTest charges1 2 3 424.2.1&24.2.2.Routine tests &additional routinetestsOn each unit While offering for the Bid, costof all these tests for specifiedno. of units as per column ‘3’should be included in the totalBid price. Thus no additionalcharges shall be payable forany of the tests andtherefore, offered Bid priceshould account for all thecosts to be incurred for thispurpose24.3 Type test:(A)Temperaturerise testOn one unitincluded in Bid(B)Impulse test On One Unit ofBid(C)Vacuum andpressure testOn One unit ofBid24.4 Special tests On One unit ofBid24.7 Tests at site On each unitincluded in BidNote : It is to be noted that after complete final testing of the unit ,it should be kept charge at rated voltage for adequate time to ensure

proper demagnetization of core i.e. demagnetization of core shall beensured prior to dispatch of the unit.24.6 Oil to be used by manufacturers at factory for the purpose oftesting at their works shall be of similar or better quality havingparameters matching with the parameters specified in thespecification. Specific approval of oil test results of oil proposed to beused for testing of transformer in factory shall be obtained by themanufacturer from the purchaser before first filling in the unit.MPPTCL shall not accept any other oil for testing purposes havinglower parameters than those specified in the Bid. Bidders shouldspecifically confirm this requirement in their offer.25.0 TESTS AT SITE :On delivery /receipt, after erection at site, thetransformer shall be subject to the following tests, in presence ofsupplier's engineer.(i) Immediately upon receipt of transformer at site and beforeunloading of transformer from trailer, core earthing , endframe earthing & tank earthing shall be checked . Only aftersatisfactory verification that there is no multiple coreearthing in transformer, unloading of transformer shall beundertaken.MPPTCL/TECH/PROC/02/ JUNE 13 Page 63 of 119ii) Insulation resistance test and polarisation index.iii) Ratio and polarity test.iv) DGA of oil and Dielectric, Tan-Delta, resistivity & moisturecontent test of oil .v) OLTC operational test at each tap for lower and raise operationof tap changer.vi) Magnetic balance test and measurement of magnetizingcurrent.vii) Vector group test.viii) Percentage Impedance test at all taps.ix) Short circuit current measurement at low voltage and at alltaps.x) Measurement of winding resistance at all taps.xi) Tangent Delta, capacitance and insulations resistance tests ofbushings.xii) Leakage current between core & tank, core & end frame , endframe & tank and between short circuited links & neutral ingrounded and un grounded conditions.xiii) Dew point measurement & recording of pressure of Nitrogengas.xiv) SFRA testxv) After receipt of transformer at site physical inspection shall bedone for checking any physical damage to transformer tank &accessories. Further data of Impact recorder shall be analysedfor any changes before unloading of transformer.26.0 CHECKS & TESTS : Following checks & tests shall be carried out byManufacturer at different stages of manufacture & supply of transformer andthese reports shall be sent to the purchaser for records :(i) Assembled Transformer:a) Check completed transformer against approved out linedrawing, provision for all fittings, finish level etc.b) Jacking test on the assembled Transformer.c) Measurement and recording of temperature and drying time duringvacuum treatment.d) Check for completeness of drying by measuring IR values & TanDelta.

e) Certification of all test results.(ii) Preshipment Checks at Manufacturer's Works:a) Check for interchangeability of components of similar Transformers formounting dimensions.MPPTCL/TECH/PROC/02/ JUNE 13 Page 64 of 119b) Check for proper packing and preservation of accessories likeradiators, bushings, explosion vent, dehydrating breather, rollers,buchholz relay, control cubicle, connecting pipes, conservator etc.c) Check for proper provision of bracings to arrest the movement of coreand winding assembly inside the tank.d) Gas tightness test to conform tightness.e) Derivation of leakage rate and ensure adequate reserve gas capacity.(iii) Commissioning Checks at site :a) Check the colour of silicagel breather.b) Check the oil level in the breather housing, conservator tank, coolingsystem, condenser housing etc.c) Check the bushings for conformity of connection to the line etc.d) Check for correct operation of all protection and alarms.i) Buchholz relayii) Excessive winding temperatureiii) Excessive oil temperatureiv) Low oil flowv) Low oil level indicatione) Check for adequate protection on electric circuit supplying theaccessories.f) Insulation resistance measurement for:i) Control wiringii) Main windingg) Check for cleanliness of the Transformer and the surroundings.27.0 TEST REPORTS : After all tests have been completed sevencertified copies of each test report shall be furnished. Each report shallsupply the following information :-i) Complete identification data including serial number of thetransformer.ii) Method of application, where applied, duration andinterpretation of results for each test. Complete diagram oftest circuits and details of test equipments including auxiliarytransformer, Instrument transformer shall be furnished.iii) Where ever applicable parameters to be corrected to 75º Ctemperature.iv) Test certificates of all the accessories and stageinspections.28.0 TOOLS : The transformer shall be supplied with a full outfit of tools,spanners, special tools for assembling and dismantling transformers with arack for holding them as per Annexure IX. All spanners shall be doubleended & case hardened. The quantity of each item of tools shall be indicatedby the Bidder in Bid.MPPTCL/TECH/PROC/02/ JUNE 13 Page 65 of 11929.0 DRAWINGS & INSTRUCTION MANUALS29.1 SPECIFIC REQUIREMENT FOR GENERAL ARRANGEMENTDRAWING: For our 400KV switch yard, the bay width adopted is 27 metres.Following points shall be kept in view while finalizing General Arrangementdrawing of the transformer.i. Along transverse direction (i.e. the parallel to the Bushing line) spread ofthe transformer from one extreme end to the other extreme end shall belimited to 27 meters. This spread shall be distributed symmetrically withrespect to the centre line of the transformer ( i.e. 13.5 meters on either

sides) This is an essential requirement to avoid encroachment of thetransformer body in the adjoining bay.ii. Along the longitudinal direction the 400KV lightning arrestor are locatedat a distance of 11.0 meters from centre line of the transformers. Whiledeciding arrangement of location of the accessories, this requirementneeds to be kept in view from consideration of clearances.29.2 The drawings for each items of transformer and its accessories are tobe submitted to MPPTCL at the time of obtaining approval of manufacturer.29.3 As soon as possible after the award of the contract themanufacturer shall supply Instruction Manual. This Instruction Manualshall be hard bound manual shall contain set of all approved drawings,instruction books, manufacturer’s catalogue of all bought items & fittings,operation & maintenance manuals , spare part bulletin.(a) Two copies of each drawing mentioned above and InstructionManual shall be sent along with the transformer & its accessories tosite. Further a CD containing soft copy of all drawings in AutoCAD ,instructions manuals and other relevant details in acrobat or MS wordshall be sent with transformer to site . This CD shall contain AutoCADsoftware and acrobat reader software also.(b) Ten (10) sets of hard bound folders containing copies ofapproved drawings, instruction manuals shall be sent to order placingauthority within a fortnight of approval of drawings. Further, Six (6)CDs containing soft copy of all drawings in AutoCAD , instructionsmanuals and other relevant details in Acrobat or MS word shall besent to order placing authority. These CDs shall contain AutoCADsoftware and acrobat reader software also.30.0 The offered price shall include cost of drawing / manuals asdetailed out in Annexure VI(A).31.0 DESIGN CALCULATIONS & DESIGN DATA TO BE ENCLOSEDWITH BID : All the important data of the transformer i.e. Net weight of barecopper in each winding , Weight of core without clamping fixtures , Weight ofMPPTCL/TECH/PROC/02/ JUNE 13 Page 66 of 119core and windings, Cross section of the core, Flux density calculations ,Calculations for short circuit current and its duration , Current density duringshort circuit , Calculations showing withstand capability of windings forthermal & mechanical stresses during short circuit conditions , MechanicalDesign of transformer tank etc should be invariably submitted by the Bidder .After placement of detailed contract the final design calculations shall besubmitted for our verification and records .Submission of design calculations and data with technical bid is anecessary requirement and those Bids will be rejected whereinthese data & calculations is not found . It may be noted by the Biddersthat no correspondence with the bidder in this regard shall be madeafter opening of technical & commercial offer. All responsibility forSubmission of design calculations and data with the Bid is thereforeof the Bidder & non furnishing of same may run the risk of rejection/non responsiveness of the Bid.31.1 DESIGN CALCULATIONS & DRAWINGS31.1.1 Short Circuit Withstand Capabilities : The calculations to provedynamic and thermal short circuit withstand capability of transformer shallbe submitted by the B i d d er for the fault level indicated as under400KV - 63 KA for 3 secs.132KV - 40 KA for 3 secs.33KV - 31.5KA for 3 secs.The design of winding assembly , which is to be furnished in thedrawing as per Sr. No. (e) of Annexure VI(A) should be commensuratingwith these calculations. The details of clamping ring shall be indicated in the

drawing .It may be noted by the Bidders that calculations for short circuitwithstand capability for two winding transformer is not acceptable under anycircumstances and these calculations shall be submitted for 3 winding autotransformer. The computer output for calculations of short circuit forces withminimum of 7 iterations with limiting values shall be submitted during DesignReview as per Cigre Guidelines.31.1.2 Design of Tank : Complete mechanical design of transformer tankincluding details of stiffeners shall be submitted . The tank shall be designedto withstand the following without permanent distortion.(i) Mechanical shocks during transportation.(ii) Vacuum filling of oil at 10 milli torr in transformer with all fittings.(iii) Continuous internal pressure of 35 kN/m2 over normal hydrostaticpressure of oil.(iv) Short circuit forces &(v) Under seismic condition /events both horizontal/vertical .MPPTCL/TECH/PROC/02/ JUNE 13 Page 67 of 119The calculations for tank stiffeners shall be submitted to prove no. & size ofstiffeners are adequate to withstand full vacuum & pressure . Drawing of tankshall be submitted indicating stiffners .31.1.3 Design of Static End Rings (SER) and Magnetic Shunts : Detailsof Static End Rings (SER) and magnetic shunts , if provided , shall besubmitted with calculations . A drawing indicating locations , size ,material ofSER and magnetic shunts shall be submitted with the Bid .31.1.4 Overfluxing Capability: A curve to prove suitability of transformerto withstand various Overfluxing conditions for the duration indicated in clause4.4.1 to 4.4.3 without core saturation shall be furnished with the Bid .31.1.5 Cooling Calculations : Calculations of tank surface for heatdissipation, details of radiators , fans for ONAN & ONAF cooling shall besubmitted.31.2 DESIGN DATA : On the basis of offered flux density and currentdensity, the Bidder shall furnish following design calculations & data.Calculations regarding wt. of core & copper and also calculations for losseswill be brought out to justify the offered transformer losses. :31.2.1 Core Data: Details of core material i.e Name of Manufacturer,Manufacturer’s type designation for core , thickness of core, curve for Loss VsFlux density, No of steps of Core & No of limbs, gross core area , stackingfactor , Net core area ,height & width of core window, center to centerdistance of limb, voltage per turn, wt. of core material, working flux density ,core loss in watts per kg marked on graph for grade of core material &selected flux density, building factor and calculated no load loss in watts,guaranteed no load loss.Design data for core shall be submitted with the Bid. A drawing indicatingdetails of core i.e. limbed construction, step width & thickness , core belting,top & bottom yoke plate etc shall be submitted with the Bid .31.2.2 Winding Data: wt. of copper for windings ie. for HV(series),IV(common) ,tap, LV(tertiary), cross sectional area , current density, type ofcoil, ID/OD/mean dia of coils, size of winding conductor including parallels,no. of turns per phase, no of spacers, length of mean turn, weight of copperwithout paper covering, resistance per phase of winding at 75 deg C, I2R lossat 75 deg C & normal tap, eddy current & stray loss at 75 deg C , total copperloss at 75 deg C , guaranteed transformer losses at 75 deg C.Complete details of Insulation components i.e. Top & Bottom clamping rings,washers , Pressboard blocks & cylinders, Pressboard spacers & Phase barriers,Pressboard segments etc shall be submitted indicating qty , thickness in mm,width & height , wt. Design data for winding shall be submitted with the Bid.MPPTCL/TECH/PROC/02/ JUNE 13 Page 68 of 119

Dimensioned drawings indicating details of winding , ducts, insulation , takeoff arrangement, clamping ring , pressure points etc shall be submitted withthe Bid .31.3 QUANTITY OF OIL : Complete calculations of oil quantity to be utilizedin transformer for first filling shall be submitted. The calculations shall indicate(i) Volume of tank including turrets, conservator main & OLTC ,volumeof headers & Radiators, oil quantity in OLTC & thermosyphon filter.(ii) Oil displacement by Active parts i.e. core - coil assembly,31.4 CAPACITY OF CONSERVATOR & SIZE OF AIR CELL : Whilefurnishing details of conservator & air cell type sealing arrangement, theBidder shall submit details & calculations for adequacy of size and capacity ofPronal make air cell for the rating of the power transformer and also for thequantity of oil required. Catalogue of Pronal should be enclosed with the Bidclearly marking type designation of selected size of Air cell. A drawingindicating complete details of conservator with Air cell shall be submitted .31.5 CAPACITY OF PRESSURE RELIEF DEVICE : Our specification callsfor supply of pressure relief device for all power transformers. Biddersmust submit calculation with the Bid to prove that the capacity/rating ofpressure relief device and locations of the same for the transformer willadequately meet our requirement. Constructional and design details ofpressure relief device must be furnished and it should be proved bycalculation that the size and setting of pressure relief device isadequate considering the rating of the transformer and quantity of oil in thetransformer.A drawing indicating complete details of PRDs & their locations on tank shallbe submitted .31.6 LIMITS OF TEMPERATURE RISE & HOT SPOT WINDINGTEMPERATURE : The limits of temperature rise for windings, oil and hotspot have been specified. Temperature rise calculations at rated full load,110% load and 125% load considering 100% cooler banks, 50% cooler banksand without coolers shall be furnished as indicated below :(a) 100 % Loading : (i) 20 minutes duration - 100 % cooler bank- 50 % cooler bank- without cooler bank(ii) 10 minutes duration - 100 % cooler bank- 50 % cooler bank- without cooler bank(b) 110 % Loading : (i) 20 minutes duration - 100 % cooler bank- 50 % cooler bank- without cooler bank(ii) 10 minutes duration - 100 % cooler bank- 50 % cooler bank