SPECIFICATION NO.DIST:01/2005 SPECIFICATION FOR. 200, 315, 500 & 630 kva, 22/0.433 & 11/0.433 kv DISTRIBUTION TRANSFORMERS FOR DISTRIBUTION SYSTEM

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1 SPECIFICATION NO.DIST:01/2005 SPECIFICATION FOR 200, 315, 500 & 630 kva, 22/0.433 & 11/0.433 kv DISTRIBUTION TRANSFORMERS FOR DISTRIBUTION SYSTEM IN MAHARASHTRA MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 1 OF 30

2 TECHNICAL SPECIFICATION FOR 11 & 22 kv Dstrbuton Transformers of 200 kva, 315 kva, 500 kva & 630 kva Capacty. 1 Scope:- 1.1 Ths specfcaton covers desgn, manufacturng, testng and delvery of the ol mmersed, Ol Natural (ON) outdoor/ndoor type, three phase, 50 Hz, 11 & 22 kv Dstrbuton Transformers of 200 kva, 315 kva, 500 kva & 630 kva Capacty 1.2 The equpment offered shall be complete wth all parts necessary for ther effectve and trouble-free operaton. Such parts wll be deemed to be wthn the scope of the supply rrespectve of whether they are specfcally ndcated n the commercal order or not. 1.3 It s not the ntent to specfy heren complete detals of desgn and constructon. The equpment offered shall conform to the relevant standards and be of hgh qualty, sturdy, robust and of good desgn and workmanshp complete n all respects and capable to perform contnuous and satsfactory operatons n the actual servce condtons at ste and shall have suffcently long lfe n servce as per statutory requrements. 1.4 The dmensonal drawngs and the notes thereto are generally of llustratve nature. In actual practce, not wthstandng any anomales, dscrepances, omssons, n-completeness, etc. n these specfcatons and applcable drawngs, the desgn and constructonal aspects, ncludng materals and dmensons, wll be subject to good engneerng practce n conformty wth the requred qualty of the product, and to such tolerances, allowances and requrements for clearances etc. as are necessary by vrtue of varous stpulatons n that respect n the relevant Indan Standards, IEC standards, I.E. Rules, I.E.Act and other statutory provsons. 1.5 The Tenderer/suppler shall bnd hmself to abde by these consderatons to the entre satsfacton of the Employer and wll be requred to adjust such detals at no extra cost to the Employer over and above the tendered rates and prces. 1.6 Tolerances: The tolerance of guaranteed performance fgures shall be as specfed n the (Part-I) table 7 of latest ssue of IS 2026 or relevant Internatonal Standard except wherever specfed otherwse n ths specfcaton. 2 System Partculars:- The transformers shall be sutable for outdoor/ndoor nstallaton wth followng system partculars and they should be sutable for servce under fluctuatons n supply voltage up to 10% as permssble under Indan Electrcty Act Rules there under. 2.1 Nomnal System Voltage : 22 kv /11kV 2.2 Correspondng Hghest System Voltage : 24 kv/12kv 2.3 Frequency : 50 Hz wth ±3 % tolerance 2.4 Number of Phase : Neutral earthlng : Soldly earthed MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 2 OF 30

3 3 SERVICE CONDITIONS: 3.1 Equpment suppled aganst the specfcaton shall be sutable for satsfactory operaton under the followng tropcal condtons:- Max. ambent ar temperature : 50 Deg. C Max. relatve humdty : 100 % Max. annual ranfall : 1450 mm v Max. wnd pressure : 150 kg/sq.m. v Max. alttude above mean sea level : 1000 mtrs. v Isoceraunc level : 50 v Sesmc level(horzontal acceleraton) : 0.3 g. v Clmatc Condton Moderately hot and humd tropcal clmate conducve to rust and fungus growth. x Reference Ambent Temperature for temperature rse : 50 deg C 3.2 The clmatc condtons are prone to wde varatons n ambent condtons and hence the equpment shall be of sutable desgn to work satsfactorly under these condtons. 4 Applcable Standards:- 4.1 The desgn, manufacture and performance of the equpment shall comply wth all currently applcable statutes, regulatons and safety codes. Nothng n ths specfcaton shall be construed to releve the tenderer off hs responsbltes. 4.2 The Dstrbuton Transformers shall conform to IS: 2026 as amended upto date or other Internatonal Standards for equal or better performance. 4.3 Unless otherwse specfed, the equpment offered shall conform to the latest applcable Indan, IEC, Brtsh or U.S.A. Standards and n partcular, to the followng:- a. IS 2026 Dstrbuton Transformer b. IS:1180 Three phase dstrbuton transformers upto and ncludng 100 KVA, 11KV c. IS:335 Insulatng ol for transformers and swtchgear d. IS:2099 Bushngs e. IS:3347 Dmensons for porcelan Transformers Bushngs for use n normally and lghtly polluted atmosphere f. IS 5 Colours for ready mxed pants and enamels. 4.4 Unless otherwse modfed n ths specfcaton the Dstrbuton Transformers shall comply wth the Indan Standard Specfcaton IS 2026 latest. 4.5 In case of conflct arsng out due to varatons between the applcable standard and the standards specfed heren the provsons of ths specfcaton shall preval. MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 3 OF 30

4 5 Specfc Techncal requrement: 5.1 Standard kva Ratngs:- The standard ratngs for transformer shall be 200, 315, 500 & 630 kva. 5.2 Nomnal voltage ratngs Prmary voltage : 22 kv or 11 kv Secondary voltage : kv 5.3 Temperature Rse; The temperature rse for top ol over an ambent temperature of 50 Deg.C should be 50 Deg. C maxmum (measured by thermometer n accordance wth IS 2026 or relevant Internatonal Standard). Temperature rse for wndng over an ambent temperature of 50 Deg. C should be 55 Deg. C maxmum (measured by resstance n accordance wth IS 2026 or relevant Internatonal Standard). 5.4 Over Loadng:- The Dstrbuton transformer shall be sutable for operatng under overload condton as specfed n IS No load voltage rato:- The no load voltage rato shall be 22,000/ Volts or 11,000/ Volts. 6 Desgn & constructon 6.1 Core The core shall be of hgh grade cold rolled gran orented (C.R.G.O) annealed steel lamnaton havng low loss and good gran propertes, coated wth hot ol proof nsulaton, bolted together to the frames frmly to prevent vbraton or nose. All core clampng bolts shall be effectvely nsulated. The complete desgn of core must ensure permanency of the core losses wth contnuous workng of the transformers. The grade of core lamnatons to be used shall be M4 or better. The value of the grade of lamnaton used shall be clearly stated n the offer. The successful bdder, shall be requred to submt the manufacturer s test report showng the Watt Loss per kg and the thckness of the core lamnaton, to ascertan the qualty of Core materals. The Employer reserves the rght to get sample of the core materal tested at any Government recognzed laboratory. The transformer core shall not be saturated for any value of V/f rato to the extent of 112.5% of the rated value of V/f rato (.e / 50 or / 50) (due to combned effect of voltage and frequency) up to 12.5% wthout njurous heatng at full load condtons and wll not get saturated. The bdder shall furnsh necessary desgn data n support of ths stuaton. MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 4 OF 30

5 v v v Flux densty:- Flux densty should not be more than 1.55 Tesla at the rated voltage and frequency. The value of the flux densty allowed n the desgn shall be clearly stated n the offer along wth graph. The No load current shall not exceed 1.5 % of the full load current n L. T. Wndng for transformers of ratng 500kVA and 630kVA, whereas for transformers of ratng 200kVA and 315 kva the no load current should not exceed 2% the full load current n L. T. Wndng. The no load current shall not exceed 2 tmes that at rated voltage when the appled voltage s 112.5% Number of steps of core shall be mnmum of For 200 kva and 315 kva For 500 kva and 630 kva 7 standard steps 9 standard steps v Dameter of core should not be less than ) For 200 kva 155mm ) For 315 kva 170mm ) For 500 kva 195mm. v) For 630 kva 205mm. v Effectve core area of core should not be less than - ) For 200 kva 169 cm sq. ) For 315 kva 200 cm sq. ) For 500 kva 272 cm sq.. x x v) For 630 kva 302 cm sq. Core clampng: On top and bottom M.S channel of sze 100 mm x 50 mm for 200/315 kva and 125 x 65 mm for 500 /630 kva transformer shall be used. 2 X 16 mm. Hgh tensle bolts n parallel at each end wll be used. The top yoke channels to be renforced by adequate sze of M.S flat wth thckness not less than 6 mm, at equdstance f holes cuttng s done for LT lead so as to avod bendng of channel. MS channel are to be panted by varnsh or ol, corroson resstant pant. Te bolts: 8 nos. of effectvely nsulated hgh tensle steel te rods of 16mm. da. n vertcal formaton shall be used. All top and bottom yoke nut bolts, te rods shall be panted wth ol and corroson resstant pant before use. The base channels of the core shall not be cut channel. MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 5 OF 30

6 6.2 Wndng Materals: Double paper covered electrolytc copper shall be used for all ratng except 200 KVA 11/0.433 kv transformer. DPC nsulated alumnum shall be for 200 KVA 11/0.433 KV transformer. Current Densty: Current densty for HV and LV should not be more than 2.8 A / sq.mm. ( However, + 5 % tolerance for LV wndng s permssble) for copper and 1.6 A / sq.mm. for alumnum conductor H.V. cross secton shall not be less than Sr.No..Ratngs 11kV class 22kV class ) For 200 kva 4.16 Sq.mm 1.19 Sq.mm ) For 315 kva 3.75 Sq.mm Sq.mm ) For 500 kva 5.95 Sq.mm 2.97 Sq.mm v) For 630 kva 7.49 Sq.mm Sq.mm. HV wndng resstance at room temperature 20 deg.c. should not be more than Sr.No. Ratngs For 11 kv For 22 kv ) For 200 kva ohms ohms. ) For 315 kva 7.07 ohms ohms. ) For 500 kva ohms ohms. v) For 630 kva 2.88 ohms ohms. However 5% tolerance s permssble. v LV cross secton should not be less than as follows - Sr.No. Ratngs For 11 kv/22 kv ) For 200 kva sq. mm. for 11kV. } mm sq. for 22 kv }5% Tolerance ) For 315 kva 150 mm.sq. } s ) For 500 kva 238mm.sq. } permssble v) For 630 kva 300mm.sq. }. v LV wndng resstance at room temp. at 20 dec. C. not be more than Sr.No. Ratngs 11 kv/22 kv ) For 200 kva ohms for 11 kv ohms for 22 kv ) For 315 kva ohms. ) For 500 kva ohm v) For 630 kva ohm However 5% tolerance s permssble. MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 6 OF 30

7 v v v x x LV wndng shall be n even layers so that the neutral formaton wll be at top. Insulaton of L.V. wndng shall be adequate to wthstand surge voltages appearng across them as a result of transfer due to an mpulse strkng on HV termnals. The stacks of wndngs should be gven adequate shrnkage treatment before and after fnal assembly. Adjustable devces f necessary shall be provded for takng up possble shrnkage of cols f any, n servce. The provsons made n ths respect shall be clearly brought out n the Bd. The conductors shall be transposed at sutable ntervals n order to mnmze eddy current and to equalze the dstrbuton of current and temperature alongwth wndngs. The wndng shall be so desgned that all col assembly of dentcal voltage ratng shall be nterchangeable and feld repars to the wndngs can be made wthout specal equpments. 6.3 Losses : The losses rated voltage for varous ratngs of transformers of 11 & 22 kv class should be as shown below and shall be calculated at 75 deg.c as per lmts specfed. TABLE - 1 Voltage Rato In volts KVA Ratng No load losses n watts. Load losses n watts / / No postve tolerance wll be permtted for No Load and Load Losses. The values guaranteed n G.T.P. for flux densty, no load current at rated voltage, no load current at 112.5% of rated voltage and no load loss at rated voltage shall be ndvdually met. 6.4 Insulaton materal & clearances : Materals - Electrcal grade nsulatng craft paper of Trven / Ballarpur / Cauvery or equvalent make subject to approval of the Employer shall be used. Press MSEDCL of Senapaty, Whtelay or Raman make or equvalent subject to the approval of the Employer shall be used. Perma wood or Hald wood blocks shall be used for top and bottom yoke nsulaton. Radal clearance of LV col to core (bare conductor) shall not be less than - 1 For 200 kva T/F 4.0 mm mnmum. 2 For 315 kva T/F 4.5 mm. mnmum. 3 For 500 & 630 kva T/F 5.0 mm. mnmum. MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 7 OF 30

8 Radal clearance between HV & LV shall not be less than. Sr.No. KVA Ratng For 11 kv For 22 kv & 315 kva 11 mm 14 mm & 630 kva 12 mm 15 mm v Phase to phase clearance between HV conductors shall not be less than v For 11 kv For 22 kv 10 mm 15 mm wth a mnmum of 2 x 1 mm press MSEDCL to cover the te rods. The mnmum electrcal clearance between the wndng and body of the tank (between nsde surface of the tank and outsde edge of the wndngs) should be 30 mm. & 40 mm n case of 11 kv & 22 kv Class transformers respectvely. v Mnmum clearance between end nsulaton to earth shall be 1) 11 kv 25 mm 2) 22 kv 40 mm v No. of cols HV/ phase (mnmum) v 11 kv 22 kv 1 For 200 & 315 kva For 500 & 630 kva 8 10 Thckness of lockng spacers between HV cols - 10mm. mnmum. x No. of axal wedges between LV & HV wndng equspaced around LV - 8 or 12. x 6.5 Impedance Values- 6.6 Tank Inspecton of wndng pror to tankng wll be done. Manufacturng drawng for the transformer showng varous clearances wll have to be got approved from the MSEDCL. Mnmum external clearances of bushng termnals 11 kv 22 kv HV Ph to Ph 255 mm. 330 mm Ph to E 140 mm 230 mm LV Ph-to-Ph 75 mm. 75 mm Ph to E 40 mm. 40 mm The percentage mpedance at 75 º C. shall be 4.5% for dstrbuton transformers The transformer tank shall be of robust constructon and shall be bult of electrcally welded MS plates. All jonts of tank and fttngs should be ol tght and no bulgng shall occur durng servce. The tank desgn shall be such that the core and wndngs can be lfted freely. The tank plates shall be of such strength that the complete transformer when flled wth ol may be lfted bodly by means of the lftng lugs provded. Tank nsde shall be panted by varnsh. Top cover plate shall be slghtly slopng, approxmately 5 to 10 deg. towards HV bushng and ends of cover plate should be bent to 45 to 90 deg. downwards so as to avod entry of water MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 8 OF 30

9 through the cover plate gasket. The wdth of bend plate shall be 25 mm mn. The top cover shall have no cut at pont of lftng lug. Shape of the tank shall be rectangular only. No other shape wll be accepted. The tank shall be fabrcated by weldng at corners. No horzontal or vertcal jonts n tank sde walls and ts bottom or top cover wll be allowed. In addton the cover of the man tank shall be provded wth an ar release plug. Sde wall thckness : 4 mm. (mn.) Top and bottom plate thckness : 6 mm. (mn.) Renforced by welded angle on all the outsde walls on the edge of tank to form three equal compartments. The permanent deflecton s not more than 5mm. upto 750 mm. length and 6mm upto 1250 mm length when transformer tank wthout ol s subject to a vacuum of 760 mm of mercury. Pressure test shall be performed carefully at the tme of 1 st stage nspecton only to confrm the adequacy of renforcement angle and gauge of the tank and certfed by Employer s Representatve Lftng lugs : 4 nos. welded heavy duty lftng lugs of MS plate of 8mm thck sutably renforced by vertcal supportng flat of same thckness as of lug welded edgewse below the lug on the sde wall, upto renforcng angle. They shall be so extended that cuttng of bend plate s not requred. 2 nos. of welded heavy duty lftng lugs for top cover of adequate sze shall be provded. The tank and cover shall be of welded constructon. All seams shall be welded and wherever practcable, they shall be double welded. The tank weld shall be renforced by stffeners of structural steel for general rgdty. The tank shall have suffcent strength to wthstand wthout permanent dstorton under followng condtons: Ol flng under vacuum. Contnuous nternal gas pressure of 35 KPa wth ol at operatng level and Normal Mechancal shock durng transportaton, loadng and unloadng operatons Pullng lugs : 4 nos. of welded heavy duty pullng lugs of MS plate of 8mm thck shall be provded to pull the transformer horzontally Top cover fxng bolts : GI nut bolts of ½ da. wth one plan washer shall be used for top cover fxng, spaced at 4 apart. 6mm neoprene bonded cork ol resstance gaskets conformng to type B/C IS 4253 Part-II wll be placed between tank and cover plate. 6.7 Heat Dsspaton : Heat dsspaton by tank walls excludng top and bottom should be 500 W/sq.m. Heat dsspaton by fn type radator 1.25mm thck wll be worked out on the bass of manufacturers data sheet. The tenderer should submt the calculaton sheet. The sze of the radator shall be such that t covers atleast 50% of bottom yoke, full core and complete top yoke. 6.8 Total Mnmum Ol Volume : Sr.No KVA ratng Ol n ltrs.(nclusve of ol absorbed n core col assembly) 11 kv 22 kv Permssble ol absorpton (ltrs.) KVA KVA KVA MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 9 OF 30

10 KVA Note : If the absorpton of ol n core and wndng assembly s more than permssble value, frst fllng ol of volume should be ncreased accordngly. Detaled calculaton of absorpton should be submtted. 7 Conservator : 7.1 The total volume of conservator shall be such as to contan 10% of total quantty of ol. Normally 3% quantty of the total ol wll be contaned n the conservator. Dmenson of the conservator shall be ndcated on the General Arrangement Drawng. 7.2 Ol level ndcator shall be provded on detachable flange wth sngle gasket and tghtened wth GI nuts and bolts and wll be fxed on the sde of ratng plate and dran valve. 7.3 The ppe from conservator tank connectng to man tank shall be of 30 mm(mn.) da and shall have a sloppng flap so that the ol fallng from the ppe shall not fall drectly on the actve job and shall fall on the sde walls only. 7.4 The conservator shall be provded wth the dran plug and a fllng hole (30mm da) wth cover. 8 Breather : Breather jonts wll be screwed type. It shall have de-cast alumnum body or of Poly carbon materals and nsde contaner for slcagel shall be of tn sheet, n case of alumnum de cast breather. Makes of the breakers shall be subject to Employer's approval. Volume of breathers shall be sutable for 500 gm. of slcagel. The make and desgn of breather shall be subject to approval of C.E.(Dstrbuton). 9 Termnals : 9.1 Brass rods 12 mm da for HT wth necessary nuts, check-nuts and plan thck tnned washers. 9.2 Tnned copper rods 20mm da. for 200 KVA & 315 KVA transformers and 30mm da. for 500 KVA & 630 KVA transformer for LT extenson as shown n the drawng for cable lug connectons, wth necessary nuts, check nuts and plan thck tnned washers. 10 Bushngs & Connectons: 10.1 For 11 kv class 12 kv and for 22 kv class 24 kv bushng shall be used and for 433 volts 1.0 kv bushng wll be used. Bushngs of the same voltage class shall be nterchangeable. Bushngs wth plan shed as per IS-3347 shall be mounted on the sde of the tank and not on the top cover. Only sheet metal pocket shall be provded for mountng of HV bushngs and the same shall not be fxed on ppes. Sheet metal pocket shall be desgned n such a way that all H.T. Bushngs shall reman parallel and at equ-dstance throughout. Bushngs havng type tested as per IS 3347 shall only be acceptable The mnmum creepage dstance for all the bushngs shall not be less than 25 mm per kv. 11 Internal connectons : 11.1 H.V. wndng : v 11.2 L.V. wndng : In case of H.V. wndng all jumpers from wndng to bushng shall have cross secton larger than wndng conductor. Intercol connecton shall be by crmpng and brazng. In case of Al./Cu Wndng Delta jonts shall be wth crmpng and Brazng only. Lead from delta jont shall be connected to bushng rod by brazng only. MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 10 OF 30

11 v L.T. Star pont shall be formed of Al./Cu. flat of suffcent length. Lead from wndng shall be connected to the flat by brazng. Any other arrangement shall be subject to the approval of Chef Engneer(Dst.). Frm connectons of L.T. wndng to bushng shall be made of adequate sze of `L' shaped flat. Connecton of L.T. Col lead to `L' shape flat shall be by brazng. Alternatvely `L' shape lug of adequate capacty effectvely crmped shall be acceptable. `L' shape flat/lug shall be clamped to L.V. Bushng metal part by usng nut, lock-nut and washers. For Alumnum wndngs, L&T Alkapee alumnum brazng rods wth sutable flux shall be used. For copper wndng slver brazng alloy shall be used Connecton n case of ndoor type transformers : In the case of ndoor transformers, the tank shall be ftted wth cable boxes on HV/LV sdes as per the table gven below. The general arrangement for HT & LT cable boxes for varous capacty transformers shall be as per applcable drawng TABLE VOLTAGE KVA DETAILS HV HV LV 433 LV Rollers : 315,500,630 3 P-1G ar flled cable box sutable for 3 core XLPE alumnum cables upto 225 sq.mm. & glands sutable for above cables. 315,500,630 3 P-1G ar flled cable box sutable for 3 core XLPE alumnum cables upto 225 sq.mm. & glands sutable for above cables. 4 nos. 150 mm dameter and 50mm wdth. 13 Tank base channel : P-2G Ar flled cable box sutable to 3.5C 185 sq.mm. PVC alumnum cable wth copper flats ftted on LT studs to connect XLPE cable. 500 & P-3G Ar flled cable box sutable to 3.5C 300 sq.mm. PVC alumnum cable wth copper flats ftted on LT studs to connect XLPE cable. For 200 & 315 KVA transformers - 100x50mm. channel. For 500 & 630 KVA transformers - 125x65mm. channel. 14 Termnal Markng Plates and Ratng Plates : 14.1 Termnals shall be provded wth termnal markng plates showng the relatve physcal poston of the termnal and ther markng as marked on plates. The transformer shall be provded wth non-detachable ratng plate of mnum 8 SWG alumnum anodsed materal ftted n a vsble poston. The entres of the ratng plate shall be n ndelbly marked (.e. by etchng, engravng or stampng) Markng as `MSEDCL' and `Sr.No.' of transformer shall be engraved on transformer man tank below L.T. bushngs The name of the company, order No., capacty, month and year of manufacturng shall be engraved on the tank of transformer just below the nameplate clearly vsble. The engravng MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 11 OF 30

12 can be done on separate plate whch shall be frmly welded to man tank and shall form ntegral part of the tank. 15 Fttngs The fttngs on the transformers shall be as under : 1 Ratng and dagram plate 1 no. 2 Earthng termnals wth crmpng lugs. 2 nos. 3 Lftng lugs 4 nos.(for tank) 4 Ol fllng hole wth cap(on conservator) 1 no 5 Dran valve - 32mm for all T/Fs (It shall be covered wth metallc box spot welded to tank). 2 nos. (for tank cover) 1 no 6 Conservator wth dran plug 1 no 7 Thermometer pocket 1 no 8 Exploson vent 1 no 9 Slca gel breather 1 no 10 Platform mountng channel (wth holes sutable for axle of rollers) 11 Ol level guage ndcatng 3 postons of ol marked as below Mnmum (-) 5 deg.c Normal 30 deg.c Maxmum 98 deg.c 2 nos 12 HT & LT bushng 3 nos. of HT bushng and 4 nos. of LT bushng shall be provded wth connectors. 13 Radators. (18 SWG.) The no. of radators/fns and heat dsspaton calculaton to justfy the no. of radators shall be submtted along wth the offer. 14 Rollers 4 Nos 15 Arcng horns for HT bushngs n case of outdoor type transformer. Each bushng HV & LV should be provded wth 3 nos. of brass nuts and 2 plan brass washer for connectng termnal. Detals shall be gven as per applcable drawng. 6 Nos. 16 Flter value 32 mm da 17 Pullng lugs 4 nos 16 Transformer Ol Transformer ol to be used n all the Dstrbuton transformers shall comply wth the requrements of latest IS 335/1983 wth latest verson thereof. In addton the ol should MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 12 OF 30

13 conform to `Ageng Characterstcs specfed below for New Ol and Ol n Transformers. Type test certfcates of ol beng used shall be produced to Employer s representave at the tme of stage nspecton. New ol - Ageng characterstcs after accelerated ageng (open beaker method wth copper catalyst): Specfc Resstance (Resstvty) a) at 20 º C :- 2.5 x Ohm-Cm (Mn) b) at 90 º C :- 0.2 x Ohm-Cm (Mn) Delectrc dsspaton factor (Max.tan delta) at 90 º C. v Total acdty mg/koh/gm (Max) Total sludge value (%) by weght (Max.) v The method of testng these agng characterstcs s gven n Appendx - C of IS 335. v Ol flled n Transformers: The mportant characterstcs of the transformer ol after t s flled n the transformer (wthn 3 months of fllng) shall be as follows: - Sr.No. Characterstcs Specfcatons 1. Electrc Strength (Breakdown voltage) 30 kv (Mn) 2. Delectrc dsspaton factor (Tan Delta) at 90 deg.c.) 0.01 (Max) 3. Specfc resstance (Resstvty) at27 deg. C (ohm-cm) 10 x Flash Pont, P.M. (closed) 140 º C (Mn) 5. Inter facal tenson at 27 º C. 0.03N/M (Mn) Neutralzaton value (total acdty) 0.05mg.KOH/gm (Max.) 7 Water content PPM 35 (Max) 17 Test and Inspecton: Routne Tests:- All transformers shall be subjected to the followng routne tests at the manufacturer's works. The tests are to be carred out n accordance wth the detals specfed n IS 2026 or as agreed upon between the Employer and the manufacturer. a) Measurement of wndng resstance. b) Rato, polarty and phase relatonshp. c) Impedance voltage. d) Load losses. e) No-load losses and No-load current. f) Insulaton resstance. g) Induced over voltage wthstand. h) Separate source voltages wthstand. All the routne tests shall be conducted n the supplers' laboratory at ther cost. MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 13 OF 30

14 Heat run test shall be arranged free of cost on the unt selected from the 1 st lot by Executve Engneer / Authorzed Representatve. v The calculatons to confrm the thermal ablty as per Clause no. 9.1 of latest IS: 2026 Part-I or equvalent Internatonal Standard, shall be submtted to Executve Engneer / Authorzed Representatve 18 Type Tests: The transformer offered should have been successfully type tested at laboratores accredted by Natonal Accredtaton Board for Testng and Calbraton Laboratores (NABL)n accordance wth IS 2026/1977 as amended from tme to tme and techncal specfcatons, wthn the last 5 (fve) years from the date of offer. The tenderer shall furnsh the followng type tests reports (alongwth General arrangement drawng, Ratng and Dagram Plate and Internal Constructonal drawng). Impulse Voltage wthstand Test on all three LV & HV phases. Dynamc Short crcut Test 18.2 The followng balance type test should be carred at the manufacturer s works nvarably n the presence of Employer s representatve at the tme of nspecton from the frst lot. Temperature Rse Test Ar pressure test as per clause no of IS:1180 (Part I)/1989 Unbalanced current test unbalanced current should not be more than 2% of full load current 18.3 The above type test reports should be submtted n enclosed format and should be got approved from the Chef Engneer (Dstrbuton) before commencement of supply In case of any of the followng, the offer may be consdered for placement of order however, successful bdders have to carry out the sad type tests at the laboratores accredted by NABL before commencement of supply at ther own expense on the sample drawn by the Employer from the lot offered for frst Stage Inspecton. If above tests are carred out beyond 5 years If above tests are carred out on hgher capacty of offered type transformer lmted to 630 kva and 22 kv The type tests carred out are not from NABL approved Laboratory In respect of the successful tenderer, the Employer reserves the rght to demand repetton of some or all the type tests n presence of the Employer s representatve. In case the unt fals n the type tests, the complete supply shall be rejected. The tenderers are therefore requested to quote unt rates for carryng out each type test, whch however, wll not be consdered for evaluaton of the offer For any change n the desgn/type already type tested and the desgn/type offered aganst ths specfcaton, the Employer reserves rght to demand repetton of these tests wthout any extra cost. 19 TEST CERTIFICATES : 19.1 The tenderer shall also furnsh a copy of Accredtaton certfcate ssued by NABL to the Testng Laboratory The successful tenderer shall take approval / acceptance of the type test from the Chef Engneer (Dst.) before commencement of supply. 20 Drawngs:- A set of followng drawngs shall be submtted: MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 14 OF 30

15 v v v General Dmensonal drawng. Core detals drawng. Ratng & Dagram Plate Drawng. HV/LV Bushngs Marshalng Box wth connecton dagram. O&M Manual The drawngs shall be of A-3 (420 x 297 mm) sze only. The tenderer should also supply the pamphlets/lteratures etc. for Ol surge relay, Bucholz Relay, Breather etc The tenderer should confrm specfcally that he wll adhere to the desgn once offered durng executon of the order, f placed wth hm and no changes shall be made wthout pror approval of the Employer Format and Pattern of the drawngs shall be as per applcable drawngs Guaranteed and other techncal partculars of the transformers as per the A/T should also be submtted n A-4 sze for our approval. 21 Rejecton: Apart from rejecton due to falure of the transformer to meet the specfed test requrements the transformer shall be lable for rejecton on any one of the followng reasons. v v v v No load loss exceeds the values mentoned above. Load loss exceeds the specfed values mentoned above. Impedance voltage value exceeds the Guaranteed value plus tolerances as mentoned above. Type test are not carred out. Drawngs are not submtted. GTP not submtted. Heat dsspaton calculaton sheet are not submtted 22 Cleanng and Pantng. v Before pantng or fllng wth ol, the external surfaces of transformer tank and structural steel work shall be completely cleaned and made free from rust, scale and grease by applyng shot blastng or sand blastng. Cavtes on castngs shall be flled by metal depostons. The nteror of transformer tank, other ol flled chambers and nternal structural steel work shall be cleaned of all the scales and rust by applcaton of standard approved methods. There after these surfaces shall be panted wth hot-ol resstant varnsh or pant. Except for nuts, bolts and washers whch may have to be removed for mantenance purposes all external surfaces shall receve mnmum of four coats of pant. The total pant thckness shall be n the range of 52 to 60 mcrons. The 1st and 2nd coats of pantng shall be of prmer and shall be appled mmedately after cleanng. The 3rd coat shall be of an ol and weather resstng qualty, preferably gven a fungcde treatment and of a shade or color easly dstngushable from the prmary coats and shall be appled after the prmary coats have been touched up where necessary. The fnal coats shall be of glossy ol fnsh and weather resstng non-fadng pant of shade dark green conformng to IS 5. Prmer pant shall be ready MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 15 OF 30

16 v mx Znc chromates as per IS 104. Intermedate and fnal coat of pant shall be as per IS The month and year of supply shall be panted n red bold marath letterng at two places, one on conservator and other at sum conspcuous place on the transformer whch shall be clearly vsble from the ground. The heght of letter shall be as per the applcable drawng. 23 Guaranteed & Techncal Partculars: The bdder should fll up all the detals n Annexure H1 and the statement such as as per drawngs enclosed, as per MSEDCL requrement as per IS etc. shall be consdered as detals not furnshed.. 24 Documentary evdence : The tenderer wll have to produce documentary evdence for the purchase of CRGO Sheet, ol and alumnum & copper wre. 25 Submsson Routne Test Certfcate The successful tenderer shall submt the routne test certfcate alongwth documentary evdence for havng pad the Excse Duty for the followng raw materals vz. Ol, copper, alumnum for conductors, nsulatng materals, core materals, bushngs at the tme of routne testng of the fully assembled transformer 26 Stage Inspecton: Suppler shall gve 15 days advance ntmaton to the Chef Engneer (Dst.)/CE (Infra Plan) to organze stage nspecton n whch assembly of core, wndngs and other core materals etc. would be nspected. In respect of raw materals such as core stampng, wndng conductor, ol etc. successful tenderer shall use these materals manufactured/suppled by the standard manufacturers and furnsh the manufacturer's test certfcates, as well as, proof of purchase from those manufacturers (excse, gate passes), for the nformaton of the department Chef Engneer (Dstrbuton)/CE (Infra Plan) wll depute hs representatve at the tme of stage nspecton The transformer wll be tested for acceptance tests at factory, n the presence of Employer's representatve, before dspatch The nspecton may be carred out by the Employer at any stage of manufacture. The successful tenderer shall grant free access to the Employer's representatves at a reasonable tme when the work s n progress. Inspecton and acceptance of any equpment under ths specfcaton by the Employer shall not releve the suppler of hs oblgaton of furnshng equpment n accordance wth the specfcatons and shall not prevent subsequent rejecton f the equpment s found to be defectve If any of the techncal partculars are seen to be n varance than the guaranteed techncal partculars, the whole lot of transformer wll be rejected and rsk purchase resorted to In addton to the above, the Employer may pck up any transformer and decde to get t type tested from any laboratory accredted by NABL. The tenderer wll have to organze packng of the transformer at MSEDCL's Stores for whch they wll be pad necessary charges. If the transformer fals to meet the requrement of type tests, the quantty of transformers ordered on them wll be forthwth rejected and the Employer may purchase these transformers at the rsk and cost of the suppler. 27 Inspecton & Testng of Transformer Ol : To ascertan the qualty of the transformer ol, the orgnal manufacturer's test report should be submtted at the tme of nspecton. Also arrangements should be made for testng of transformer ol, after takng out the sample from the manufactured trasnsformers and tested n the presence of Employer's representatve or n an ndependent laboratory. MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 16 OF 30

17 28 Qualty Assurance 28.1 The tenderer shall nvarably furnsh followng nformaton Certfcates of followng materals. v v v Copper conductor Transformer ol Core Insulatons. Porcelan Bushngs Steel Plate used for Tank 28.3 Names of the suppler for the raw materal, lst of standard accordng to whch the raw materals are tested, lst of test normally carred out on raw materals n presence of tenders representatves, copes of type test certfcates Informaton and copes of test certfcate as n () above respect of bought out accessores ncludng termnal connectors Lst of manufacturng facltes avalable. In ths lst the tenderer shall specfcally menton whether lappng machne, vaccum dryng plant, ar condtoned dust free room wth postve ar pressure for provson of nsulaton and wndng etc are avalable wth hm Level of automaton acheved and lst of areas where manual processng stll exsts Lst of areas n manufacturng process where stage nspecton are normally carred out for qualty control and detals of such tests and nspectons Specal features provded n the equpments to make t mantenance free 28.9 The successful tenderer shall submt the Routne Test Certfcate alongwth central Excse Gate Passes for the followng raw materals vz Ol, Copper for Conductors, nsulatng materals, Core materals, Bushng at the tme of routne Testng of the fully assembled transformer Schedules The tenderer shall fll n the followng schedules whch form part of the tender specfcaton and offer. In schedule `A' the specfc values shall be furnshed and only quotng of IS reference s not suffcent. If the schedules are not submtted duly flled n wth the offer, the offer shall be rejected. Schedule `A' - Schedule `B' - Schedule `C' - Schedule `D' - Schedule `E' - Guaranteed Techncal Partculars. Schedule of Devatons from Specfcaton. Schedule of Tenderer's Experence. Schedule of Devatons from specfed standards. Schedule of Devatons from specfed Test Requrements All devatons from the specfcaton shall be brought out n the schedules of devaton (Schedules `B', `D', & `E') The dscrepances between the specfcaton and the catalogs, Lteratures and ndcatve drawngs whch are subject to change, submtted as part of the offer, shall not be consdered and representaton n ths regard wll not be entertaned The devaton brought out n the schedule shall be supported by authentc documents and clarfcatons, otherwse the offer may be lable for rejecton. MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 17 OF 30

18 28.13 The tenderer shall submt the lst of orders for smlar type of equpments, executed of under executon durng the last three years, wth full detals n the schedule of Tenderer's experence (Schedule `C') to enable the Employer to evaluate the tender. MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 18 OF 30

19 Schedule `A' GUARANTEED TECHNICAL PARTICULARS Sr.No. Descrpton Partculars 1 Make & Manufactured by 2 Voltage rato 3 Ratngs n kva 4 Core materal used & grade 5 Method of connecton for H.V. Wndng L.V. Wndng Connecton Symbol 6. Maxmum temperature rse over an Ambent temp. of 50 C of a) Wndngs by Resstance Method. b) Core by thermometer c) Ol by thermometer 7. Magnetsng (No load) current a) Rated Voltage Amps.e. % of full load. b) Max. Voltage (112.5% of rated voltage) 8. Core loss at normal voltage and frequency (kw) at max. voltage and frequency (kw ) 9. Resstance of wndngs at 20 deg.c. a) H.V. wndng b) L.V. wndng 10. Full load loss at 75 C 11. Current densty used for a) H.V. wndng d) L.V. wndng 12 Cross Secton of Copper used n a) H.V. wndng d) L.V. wndng 13. Clearances a) Core & L.V. b) LV & HV c) HV Ph. To Ph. Amps.e. % of full load. MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 19 OF 30

20 d) End clearance to earth e) Any pont of wndng to tank 14 Effcency at 75 dec. c at a) Unty P.F. & (b) 0.8 P.F. a) b) ) 125% load ) 100% load ) 75% load v) 50% load v) 25% load 15. Regulaton at a) Unty P.F. & (b) 0.8 P.F. a) b) at 75 dec.c. 16. % Impedance at 75 deg.c. 17. Flash test HV 28 kv/50kv for 1 mnute LV 3 kv for 1 mnute 18. Over potental test Double voltage & Double frequency For 1 Mnute. 19. Impulse test value n kvp. 20. Weght of 21 Ol data a) Core lamnaton : Kg. b) Wndngs-Alu/Cu. : Kg. c) Tank and fttngs : Kg. d) Ol : Kg. e) Ol : Ltr. f) Total weght : Kg. 1) Quantty for frst fllng :Ltr. 2) Grade of ol used. 3) Maker's name. 4) BDV at the tme of fllng. 22 Make of Breather & type wth capacty of slcagel flled n gm. Dmensons Overall dmensons of the Transformer In cms Approxmate length: cms MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 20 OF 30

21 Approxmate breadth cms Approxmate heght: cms. Dmensons of Tank In cms Approxmate length: cms Approxmate breadth cms Approxmate heght: cms. Thckness of transformer tank plates Sdes : Bottom mm Cover : Radators 23 Transformers mm mm :mm 1) Overall length x breadth x heght. 2) Tank length x breadth x avg. heght. 3) Thckness of plates for a) Sde Plate b) Top and Bottom plate 24 Inter layer nsulaton provded n desgn for 1) Top & bottom layer 2) In between all layer 3) Detals of end nsulaton 4) Whether wedges are Provded at 50% tuns of the Col. 25 Insulaton materals provded a) For conductors 1) HV 2) LV b) For core. 26. Sze of the wre used 1) HV a) SWG b) Da c) Area 2) LV a) Strp sze b) No. of conductors In parallel. c) Total area of cross Secton. 27. Does the name plate gve all Partculars as requred n tender. 28. Partculars of bushngs. HV LV MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 21 OF 30

22 Maker's name. Materal Wet Flash over voltage at 50 Hz kv Dry Flash over voltage at 50 Hz Impulse Flash over voltage (Statng the wave form adopted) kv Ratng of bushng as per ISS :or equvalent Internatonal Standard Mnmum Creepage Dstance MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 22 OF 30

23 SCHEDULE - B DEVIATIONS FROM SPECIFICATION SR.NO. CLAUSE No. DETAILS OF DEVIATION NAME OF FIRM NAME & SIGNATURE OF TENDERER DESIGNATION DATE MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 23 OF 30

24 SCHEDULE - C SCHEDULE OF TENDERER'S EXPERIENCE Tenderer shall furnsh here a lst of smlar orders executed/under executon by hm to whom a reference may be made by Employer n case he consders such a reference necessary Sr. Name of clent Value Perod of supply Name & Address to No. & Descrpton. Of Order & commssonng whom reference may (alongwth cap. of T/F) be made NAME OF FIRM NAME & SIGNATURE OF TENDERER DESIGNATION DATE MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 24 OF 30

25 SCHEDULE - D SCHEDULE OF DEVIATIONS FROM SPECIFIED STANDARDS Sr. Partculars Stpulaton of Stpulaton of Remarks No. specfed standard adopted Standards. By tenderer Standard Stpula- Standard Stpulatons Ref. tons. Ref NAME OF FIRM NAME & SIGNATURE OF TENDERER DESIGNATION DATE MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 25 OF 30

26 SCHEDULE - E DEVIATIONS FROM SPECIFIED TEST REQUIREMENTS SPECIFIED IN RELEVANT AND PRESENT SPECIFICATIONS Sr. Name of Test Standard Requrement Proposed Reasons No. No. & Cl.No. of standards devaton for devaton TYPE TEST 2. ADDL. TEST 3. ACCPTANCE TEST. 4. ROUTINE TEST. NAME OF FIRM NAME & SIGNATURE OF TENDERER DESIGNATION DATE MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 26 OF 30

27 Annexure I Ar Pressure Test Name of Suppler: Order No.: Capacty & Voltage Rato of Dstrbuton Transformer : kva, /0.433 kv Vector Group Dyn11 Sr. No. of equpment Tested: Date of Testng: Reference Standard All the openng of the transformer tank were closed wth sutable gasket, bushng, valves and plugs. The compressor ppe connected at ol fllng hole on conservator and a pressure guage was ftted at ar vent plug. The paraller strng were places around the tank, the dstance between strng and tank as shown n followng dagram were recorded before applyng the pressure and after releasng pressure. Tank Thckness: Sde mm. Test Pressure : kg/cm 2 appled for 30 Mnutes. Test Pont Dstance before Test A B C D In mm Top & Bottom mm Dstance after release of Pressure n mm Deflecton In mm Permanent Deflecton : mm Permssble Lmt of Permanent Deflecton as per Specfcaton : mm Test wtnessed by Tested by MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 27 OF 30

28 Name of Suppler: Order No.: Annexure II Unbalance Current Test Capacty & Voltage Rato of Dstrbuton Transformer : kva, /0.433 kv Vector Group Dyn11 Sr. No. of equpment Tested: Date of Testng: Reference Standard Transformer Secondary termnals 2U, 2V & 2W are shorted. The shorted 2U, 2V & 2W s connected to 2N through Ammeter. The prmary termnals 1U, 1V & 1W are connected to supply. The rated current A s fed to prmary and unbalance current s noted on Ammeter. Unbalance Current Measured n Ammeter : A Rated current n Secondary Sde : A Permssble lmts as per specfcaton : 2% of the Rated current n Secondary Sde % of Unbalance current wth reference to Rated current n Secondary Sde = = Unbalance Current x 100 Rated current n Secondary Sde = Test wtnessed by Tested by MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 28 OF 30

29 Annexure III Temperature Rse Test Name of Suppler: Order No.: Capacty & Voltage Rato of Dstrbuton Transformer : kva, /0.433 kv Vector Group Dyn11 Sr. No. of equpment Tested: Date of Testng: Reference Standard H. V. Wndng L. V. Wndng Rated Lne Current n Amp Guaranteed No Load Losses Load Losses Total Losses watt watt watt P. T. Rato : / = C. T. Rato : / = Wattmeter Constant = Total Multplyng Factor (MF) = Ambent Temp. TIME T1 C T2 C T3 C Average C Top Ol Temp. C Rse n Top Ol Temp. C Lne Voltage n Volts Lne Current n Amps W1 watts W2 watts W3 watts W1+W2+W3 watt Multplyng Factor (MF) Total Watt Reduced to Rated Current amps MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 29 OF 30

30 Calculaton of Temperature Rse n Wndng LV Wndng : Snce the resstance of LV wndng s less than ohm, Temperature Rse n LV Wndng s taken as temperature rse of ol as per clause no. 4.3 of IS:2026 (Part II)/1977 Temperature Rse n LV Wndng = C HV Wndng Resstance across 1U1V at C = ohm Measurement of Hot Resstance of HV Wndng after Shut Down. Tme Resstance Hot wndng Resstance at Ambent Temperature C (from graph) = Ohm Temperature Rse n H. V. Wndng s Hot Resstance x(235+cold Ambent Temperature) = - (235+Hot Ambent Temperature Cold Resstance = = Results : 1) Temperature Rse n Ol = C 2) Temperature Rse n LV Wndng = C 3) Temperature Rse n HV Wndng = C Test wtnessed by Tested by MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY LTD. PAGE 30 OF 30