Maharashtra State Electricity Distribution Company

Transcription

1 Maharashtra State Electrcty Dstrbuton Company SPECIFICATION NO.DIST: MM-II 01/2006 SPECIFICATION FOR 630 kva, 11/0.433 kv THREE PHASE (I.D.) DISTRIBUTION TRANSFORMERS FOR DISTRIBUTION SYSTEM IN MAHARASHTRA Page 1 of 31

2 I N D E X Clause No. Contents Page No. 1 Scope 4 2 System Partculars 4 3 Servce Condton 5 4 Applcable Standards 5 5 Specfc Techncal requrement 6 6 Desgn & Constructon Core Wndngs Losses Insulaton Materal & Clearances Impedance Value Tank Heat Dsspaton Conservator Vessels, Ol Gauges & Breathers Breathers Termnals Bushng and connectors Internal Connectons Rollers Tank base channel Termnal Markng Plate & Ratng Plate Fttngs Transformer Ol Tests & Inspecton Type Tests Drawngs Rejecton Cleanng & Pantng Guaranteed Techncal Partculars Testng facltes Submsson of Routne Test Certfcate 18 Page 2 of 31

3 25 Stage Inspecton Testng of all dstrbuton transformers for no load and full load losses. 27 Random Sample Testng Inspecton & Testng of Transformer Ol Qualty Assurance Qualfyng Requrements Fnal Inspecton Cost Data Sheet Schedule 22 Schedule A Guaranteed and Other Techncal Partculars 23 Schedule B Devaton from specfcaton 24 Schedule C Tenderer s experence 25 Schedule D Devatons from specfed standards 26 Schedule E Devatons from specfed test requrements specfed n relevant and present specfcaton Annexure-I Ar Pressure Test 28 Annexure-II Unbalance Current Test 29 Annexure-III Temperature Rse Test Page 3 of 31

4 1 Scope:- MAHARASHTRA STATE ELECTRICITY DISTRIBUTION COMPANY TECHNICAL SPECIFICATION FOR 630 KVA, 11/ kv Three Phase Dstrbuton Transformers (I.D.) 1.1 Ths specfcaton covers desgn, manufacturng, testng and delvery of the ol mmersed, Ol Natural (ON) ndoor type, three phase, 50 Hz, 11 kv Dstrbuton Transformers of 630 kva. 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 desgn and constructonal aspects of materals shall not wthstandng any anomales, dscrepances, omssons, n-completeness, etc. n these specfcatons and 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 Bdder/suppler shall bnd hmself to abde by these consderatons to the entre satsfacton of the purchaser and wll be requred to adjust such detals at no extra cost to the purchaser 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 ndoor nstallaton wth followng system partculars and they should be sutable for servce under fluctuatons n supply voltage as permssble under Indan Electrcty Rules 2.1 Nomnal System Voltage : 11kV 2.2 Correspondng Hghest System Voltage : 12kV 2.3 Frequency : 50 Hz wth ±3 % tolerance 2.4 Number of Phase : Neutral earthlng : Soldly earthed Page 4 of 31

5 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 bdder off hs responsbltes. 4.2 The Dstrbuton Transformers shall conform to IS: 2026 as amended up to date or other Internatonal Standards for equal or better performance. Unless otherwse modfed n ths specfcaton the Dstrbuton Transformers shall comply wth the Indan Standard Specfcaton IS 2026 latest. 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 up to and ncludng 100 kva, 11KV c. IS:335 Insulatng ol for transformers and swtchgear d. IS:2099 Bushng e. IS:3347 Dmensons for porcelan transformer bushng for use n normally and lghtly polluted atmospheres f. IS 5 Colours for ready mxed pants and enamels. 4.4 In case of conflct arsng out due to varatons between the applcable standard and the standards specfed heren the provsons of ths specfcaton should preval. Page 5 of 31

6 5 Specfc Techncal requrement: 5.1 Standard kva Ratngs:- The standard ratngs for transformer shall be 630 kva. 5.2 Nomnal voltage ratngs Prmary voltage : 11 kv Secondary voltage : kv Wndng connectons:-. H.V. Wndng : Delta ( ). L.V. Wndng : Star (Y) The neutral of the L.V. wndng shall be brought out n a separate nsulated termnal. The voltage group shall be Dyn 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:- 5.6 Taps: The no load voltage rato shall be 11,000/433 Volts No taps are requred for these transformers. 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. 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 purchaser reserves the rght to get sample of the core materal tested at any Government recognzed laboratory. Page 6 of 31

7 v v 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) (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. 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 at rated voltage shall not exceed the percentage gven n Table below. The no load current shall not exceed 2 tmes that at rated voltage when the appled voltage s 112.5%. Sr. No. kva Ratng At Rated Voltage 1.5 % of the full load current n L. V. Wndng v Number of steps of core shall be mnmum of For 630 kva 9 standard steps v Dameter of core should not be less than ) For 630 kva 205 mm v Effectve core area of core should not be less than - x x ) For 630 kva 302 sq cm Core clampng: On top and bottom M.S channel of sze 125 x 65 mm for 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. Page 7 of 31

8 6.2 Wndng Materals: Double paper covered electrolytc copper shall be used for 11/0.433 kv transformers. Current Densty: Current densty for HV and LV should not be more than 2.8 A / sq.mm. However +5 % tolerance for L.V. wndng s permssble for Copper conductor. H.V. col cross secton shall not be less than Sr.No. Ratngs For 11 kv ) For 630 kva 7.49 sq. mm v HV wndng resstance at room temperature 20 deg.c. should not be more than Sr.No. Ratngs For 11 kv ) For 630 kva 2.88 ohm/phase 5% Tolerance s permssble v LV col cross secton should not be less than as follows - Sr.No. Ratngs For 11 kv ) For 630 kva 300 sq.mm 5% Tolerance s permssble v LV wndng resstance at room temp. at 20 dec. C. not be more than Sr.No. Ratngs 11 kv ) For 630 kva ohm/phase However 5% tolerance s permssble. v v x 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 along wth 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. Page 8 of 31

9 6.3 Losses : The losses at rated voltage for 630 kva 11 /0.433 KV transformers should be as shown below and shall be calculated at 75 deg.c as per lmts specfed. TABLE - 1 Voltage Rato n volts KVA Ratng No load losses n watts. Load losses n watts / No 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 purchaser shall be used. Press Board of Senapaty, Whtelay or Raman make or equvalent subject to the approval of the purchaser 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 630 kva T/F 5 mm mnmum. Radal clearance between HV & LV shall not be less than. Sr.No. KVA Ratng For 11 kv 1 For 630 kva T/F 12 mm v Phase to phase clearance between HV conductors shall not be less than v For 11 kv 10 mm wth a mnmum of 2 x 1 mm press board 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. v Mnmum clearance between end nsulaton to earth shall be 1) 11 kv 25 mm v No. of cols HV/ phase (mnmum) v Sr.No. KVA Ratng 11 kv 1 For 630 kva T/F 8 Thckness of lockng spacers between HV cols - 10mm. mnmum. x No. of axal wedges between LV & HV wndng equspaced around LV - 8 or 12. Page 9 of 31

10 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 company. Mnmum external clearances of bushng termnals 11 kv HV Ph to Ph 255 mm. Ph to E 140 mm LV Ph-to-Ph 75 mm. Ph to E 40 mm. The percentage mpedance at 75 º C. shall be 4.5% for dstrbuton transformers. The mpedance values are subject to tolerance of ± 10% 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 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 50X50X5 MM on all the outsde walls on the edge of tank to form two equal compartments. The permanent deflecton s not more than 5mm up to 750 mm length and 6mm up to 1250 mm length when transformer tank wthout ol s subject to ar pressure of 35 KPa above atmospherc pressure for 30 mn. 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 E.E.(IW) 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, up to 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: Page 10 of 31

11 Ol flng under vacuum. Contnuous nternal gas pressure of 35 KPa wth ol at operatng level 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 The heght of the tank shall be such that mnmum clearance heght up to the top cover plate of 120 mm s acheved from top yoke. 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 Bdder should submt the calculaton sheet wth the offer otherwse the offer shall stand rejected. The sze of the radator shall be such that t covers at least 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 Permssble ol absorpton (ltrs.) kva Note : The transformer shall be suppled complete wth frst fllng of ol and 10 % extra of total volume of ol(of all the transformers whch wll supply to the stores) n separate contaner/ drum to the concerned stores. 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 slca gel shall be of tn sheet, n case of alumnum de cast Page 11 of 31

12 breather. Makes of the breathers shall be subject to purchaser's approval. Volume of breathers shall be sutable for 500 gm. of slca gel. 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 30 mm da. for 630 kva transformers 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 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 L.T. and H.T. bushng rod shall be provded wth bmetallc connectors. 11 Internal connectons : 11.1 H.V. wndng : v 11.2 L.V. wndng : v In case of H.V. wndng all jumpers from wndng to bushng shall have cross secton larger than wndng conductor. Inter col connecton shall be by crmpng and brazng. In case of Copper Wndng Delta jonts shall be wth crmpng and Brazng only. Lead from delta jont shall be connected to bushng rod by brazng only. L.T. Star pont shall be formed of Copper flat of suffcent length. Lead from wndng shall be connected to the flat by crmpng and 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 crmpng and 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 crmpng and slver brazng alloy shall be used Connecton of ndoor type transformers:- In the case of ndoor transformers, the tank shall be ftted wth cables boxes on HV/LV sdes as per the table gven below. Page 12 of 31

13 TABLE VOLTAGE KVA DETAILS H.V L.V P 1-G ar flled cable box sutable for 3 core XLPE alumnum cables up to 225 sq. mm and glands sutable for above cables P-3G ar flled cable box sutable to 3.5 core 300 sq. mm. PVC alumnum cable wth copper flats ftted on L.T. studs to connect XLPE cable. 12 Rollers : 4 nos.150 mm Dameter and 50mm Wdth. 13 Tank base channel : For 630 kva transformers x 65 mm. 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 mnmum 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 `M.S.E.D.C.L'S 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 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 Conservator wth dran plug 1 no 6 Thermometer pocket 1 no 7 Exploson vent 1 no Page 13 of 31 2 nos. (for tank cover)

14 8 Slca gel breather 1 no 9 Platform mountng channel ( wth holes sutable for axle of rollers) 10 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 11 HT & LT bushng 3 nos. of HT bushng and 4 nos. of LT bushng shall be provded wth bmetallc connectors. 12 Radators. (18 SWG.) The no. of radators and number of fns per radator and heat dsspaton calculaton to justfy the no.of radators shall be submtted along wth the offer. Detals shall be gven as follows. 1. Total losses 2. Losses to be dsspated by the tank. 3. Losses to be dsspated by radators. 4. LXBXH of tank. 5. Formula for calculaton of surface area of tank. 6. Surface area of radators 7. Total radatng surface area 8. Number of radators 9. Number of fns 13 Rollers 4 Nos 14 Dran valve-32 mm (It shall be covered wth metallc box spot welded to tank). Each bushng HV & LV should be provded wth 3 nos. of brass nuts and 2 plan brass washer for connectng termnal. 1 No. 15 Flter valve 32 mm da. 16 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 conform to `Ageng Characterstcs specfed below for New Ol and Ol n Transformers. Type test certfcates of ol beng used shall be produced to EE (IW) at the tme of stage nspecton. Page 14 of 31

15 New ol - Ageng characterstcs after accelerated ageng test 96 hrs at 115 C (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) 6. 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 purchaser 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. Page 15 of 31

16 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 (IW). 18 Type Tests : In addton to routne test as above Impulse voltage Wthstand test and Dynamc Short Crcut Test as under shall be successfully carred out 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 pror to the date of offer. The bdder shall furnsh the followng type tests reports (along wth General arrangement drawng, Ratng and Dagram Plate and Internal Constructonal drawng) along wth the offer. Impulse Voltage wth stand Test on all three LV & HV phases chopped on tal. Dynamc Short crcut Test 18.2 The followng balance type test should be carred at the manufacturer s works nvarably n the presence of M.S.E.D.C.L 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 type test reports should be submtted and 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. If above tests are carred out beyond 5 years. Impulse Voltage Wthstand test and Dynamc Short Crcut test carred out not from NABL approved Laboratory. If there s any change n the desgn/ type of the type tested transformers suppled n the past and to be offered aganst ths specfcaton. However, successful bdders should carry out type tests as per Clause No and 18.2 before commencement of supply at ther own expense on the sample drawn by purchaser from the lot offered for frst Stage Inspecton In respect of the successful bdder, the purchaser reserves the rght to demand repetton of some or all the type tests n presence of the purchaser s representatve. In case the unt fals n the type tests, the complete supply shall be rejected. The bdders are therefore requested to quote unt rates for carryng out each type test, whch however, wll not be consdered for evaluaton of the offer. Page 16 of 31

17 19 Drawngs :- A set of followng drawngs shall be submtted by the Bdder along wth the offer: v v v General Dmensonal drawng. Core detals drawng. Ratng & Dagram Plate Drawng. HV/LV Bushngs Marshalng Box wth connecton dagram. Operaton and Mantenance Manual The drawngs shall be of A-3 (420 x 297 mm) sze only. The bdder should also supply along wth hs offer the pamphlets/lteratures etc. for fttngs / accessores The bdder should confrm specfcally that there wll not be any change n desgn offered aganst ths tender. No changes shall be made wthout pror approval from purchaser Guaranteed and other techncal partculars of the transformers as per the A/T should also be submtted n A-4 sze for approval of C.E. (Dstrbuton). 20 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 n Sr. No.6.3 above. Load loss exceeds the specfed values mentoned n Sr. No.6.3 above. Impedance voltage value exceeds the Guaranteed value plus tolerances as mentoned at Sr.No.6.5 above. Type test are not carred out as per clause no. 18 of the specfcaton. Drawngs are not submtted as per clause no. 19 of the specfcaton. GTP not submtted as per clause no. 22 of the specfcaton. Heat dsspaton calculaton sheet are not submtted as per clause no.6.7- of the specfcaton. 21 Cleanng and Pantng. 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. Page 17 of 31

18 v v 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 nonfadng pant of shade dark green conformng to IS 5. Prmer pant shall be ready 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. 22 Guaranteed & Techncal Partculars: The bdder should fll up all the detals n GTP parameter lst, the statement such as as per drawngs enclosed, as per MSEDCL S requrement as per IS etc. shall be consdered as detals are not furnshed and such offers shall lable for rejecton. 23 Testng faclty The bdder should have adequate testng faclty for all routne and acceptance tests and also arrangement for measurement of losses, resstance, etc. detals of whch wll be enumerated n the tender. 24 Submsson Routne Test Certfcate The successful bdder shall submt the routne test certfcate along wth 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. 25 Stage Inspecton : Suppler shall gve 15 days advance ntmaton to the Chef Engneer (Dst.) and S.E. (Store/Adm) 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 bdder 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 documentary evdence for havng pad the excse duty for the nformaton of the department Chef Engneer (Dstrbuton) wll depute hs representatve at the tme of stage nspecton The transformer wll be tested for acceptance tests at factory, n the presence of purchaser's representatve, before dspatch The nspecton may be carred out by the purchaser at any stage of manufacture. The successful bdder shall grant free access to the purchaser's representatves at a reasonable tme when the work s n progress. Inspecton and acceptance of any equpment under ths specfcaton by the purchaser 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 The purchaser may at ts opton open a transformer suppled to the Stores, n presence of suppler at ste or at Stores. If any of the techncal partculars are seen to be n varance than Page 18 of 31

19 the guaranteed techncal partculars, the whole lot of transformer wll be rejected and rsk purchase resorted to In addton to the above, the purchaser may pck up any transformer and decde to get t type tested from any laboratory accredted by NABL at purchaser's cost. The Bdder wll have to organze packng of the transformer at company'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 purchaser may purchase these transformers at the rsk and cost of the suppler Heat Run Test wll be carred out on 10% of ordered quantty of transformers. 26 Testng of all Dstrbuton Transformers for no load and full load losses After nspecton of new transformers at factory for acceptance of the lot, all dstrbuton transformers from the lot wll be tested for no load and full load losses at all stores. Tenderer has lberty to be present at the tme of testng. 27 Random Sample Testng (RST) The tenderer should ntmate to C.E. (Dst.), M.S.E.D.C.L of completon of dspatches of whole lot of Dstrbuton Transformers to stores aganst ths tender. C.E. (Dst.), M.S.E.D.C.L for wll select the stores for Random Sample Testng (RST) and depute E.E. (Testng) to carry out RST of the lot. E.E. (Testng) wll select a transformer from the lot of transformers, tested for No load & full load losses.15 days advance ntmaton wll be gven to tenderer for jont nspecton. The date of RST wll not be altered to the convenence or request of suppler. If suppler s representatve fals to attend on the date fxed for RST, the RST wll be carred out n hs absence and results of RST wll be bndng on suppler. In case the selected transformer fals n any of the tests, complete lot of transformers wll be rejected. 28 Inspecton & Testng of Transformer Ol : The tenderer shall make arrangements for testng of transformer ol to be used n the transformers and testng wll be done n presence of purchaser's representatve. To ascertan the qualty of transformer ol, orgnal manufacturer's test report should be furnshed to EE (Testng) at the tme of factory nspecton for acceptance of the lot. 29 Qualty Assurance 29.1 The bdder shall nvarably furnsh followng nformaton along wth the offer falng to whch the offer wll be rejected Certfcates of followng materals. v v v Copper conductor Transformer ol Core Insulatng paper. Porcelan Bushngs Steel Plate used for Tank Page 19 of 31

20 29.3 Names of the suppler for the raw materal, lst of standard accordngly to whch the raw materals are tested, lst of test normally carred out on raw materals n presence of bdder s 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 bdder shall specfcally menton whether lappng machne, vacuum 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 29.9 Lst of testng equpment avalable wth the bdder for fnal testng of transformers and test plant lmtaton, f any, vs-à-vs the type, specal acceptance and routne tests specfed n the relevant standards and the present specfcaton. These lmtatons shall be very clearly brought out n Schedule D.e. schedule of devatons from specfed test requrements The successful bdder shall submt the Routne Test Certfcate along wth documentary evdence havng pad for the excse duty 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. 30 Qualfyng Requrement 30.1 The bdder should have proven experence of not less than 5 years n Desgn, Manufacture, supply and Testng at work for equpment / materals offered for equal or hgher voltage class /capacty. The equpment/ materal offered by bdder should be n the successful operaton, at least for two years as on the date of submsson of the tender The bdder should have adequate n house testng facltes for conductng acceptance tests n accordance wth relevant IS Bdder should have a mnmum turnover of 60% of the value of the materal offered n any one fnancal year durng the prevous 3 years. However, beng a commercal aspect ths pont may be verfed by CPA The Bdder should furnsh all the relevant documentary evdence to establsh the fulfllment of the above requrement The bdders not meetng the requrement at clause No can also partcpate, provded they have vald ongong collaboraton wth a manufacturer who has at least 10 years experence n the Desgn, manufacture and testng of the equpment of the type and class offered whch have been n satsfactory servce for a perod of at least seven years. In such an event the bdder shall furnsh along wth the bd the documentary evdence for the same and undertakng from the bdder and collaboraton acceptng jont and several lablty for all oblgatons under the contract The bdder who does not meet the above Qualfyng requrement of experence ( Clause No )may be consdered for a Tral Order subject to fulfllng the followng requrements along wth Clause Nos to Page 20 of 31

21 30.7 The bdder shall have the basc nfrastructure for the desgn, manufacture and supply of the tems offered, lke machnery, techncal know-how, capacty etc The purchaser s satsfed wth the desgnng, manufacturng, supplyng and fnancal capacty of the bdder after nspectng the suppler s works Notwthstandng anythng stated above, the purchaser s decson n ths regard wll be fnal. 31 Fnal Inspecton 31.1 C.E. (Dstrbuton) wll depute hs representatve at the tme of fnal nspecton along wth CPA s representatve, 32 COST DATA SHEET:- The bdders shall submt the cost data sheets ndcatng the break up prces and quantty of each raw materal and components along wth the unt rates requred for manufacture the offered transformers along wth the offer. The cost data sheet format s enclosed herewth.. If the rates quoted are not justfed wth the cost data sheets, the offer shall not be consdered for evaluaton and placement of the order. The cost data sheets shall be scrutnzed by CPA secton. ITEM Sr. No. FORMAT FOR COST DATA KVA, KV DISTRIBUTION TRANSFORMER PARTICULARS UNIT UNIT RATES Rs. 1 CORE (M4) KG 2 ALUMINIUM /COPPER WITH DPC KG 3 OIL LTRS 4 TANK NO 5 RADIATOR KG 6 CHANNELS KG 7 INSULATORS/BUSHINGS KG 8 OTHERS LUMP SUM % QUANTITY TOTAL AMOUNT (Rs.) Page 21 of 31

22 33 Schedules The bdder shall fll n the followng schedules whch form part of the tender specfcaton and offer.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 33.1 All devatons from the specfcaton shall be brought out n the Schedule 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 Authentc documents and clarfcatons shall support the devaton brought out n the schedule, otherwse the offer may be lable for rejecton The Bdder 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 purchaser to evaluate the tender. Page 22 of 31

23 Schedule `A' GUARANTEED TECHNICAL PARTICULARS As ndcated n E-Tenderng GTP Parameter Page 23 of 31

24 SCHEDULE - B DEVIATIONS FROM SPECIFICATION SR.NO. CLAUSE No. DETAILS OF DEVIATION NAME OF FIRM NAME & SIGNATURE OF TENDERER DESIGNATION DATE Page 24 of 31

25 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 Purchaser 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 (along wth cap. of T/F) be made NAME OF FIRM NAME & SIGNATURE OF TENDERER DESIGNATION DATE Page 25 of 31

26 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 Page 26 of 31

27 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 Page 27 of 31

28 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 parallel 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 A B C D Dstance before Test 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 Page 28 of 31

29 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 Page 29 of 31

30 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 Page 30 of 31

31 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 Page 31 of 31