8425 CERATIN REPAIRS TO 33 KV POWER TRANSFORMERS AND 11KV DISTRUBUTION TRANSFORMERS, 2/ 4 POLE STRUCTURES (33/ 11 KV) INCLUDING DEHYDRATION/ ROUTINE MAINTENANCE AT NSTL AREA UNDER AGE (I) R n D NSTL, VISAKHAPATNAM

Amount

M&L for filteration of transformer oil of step down 33 KV /11 KV indoor/outdoor type Transformer installed at different sub stations/locations,testing of dielectric strength of transformer oil of indoor/outdoor type transformer,33 KV/11 KV filteration of transformer oil by passing through filtration plant to remove moisture, impurities and improving di-electic strength to above 60 KV for 1 minute at 2.5 mm gap between terminals including new transformer oil for toping up & testing after filtration complete as specified. (Note: Extra Transformer oil will be measured & paid seperately.)

M&L for filteration of transformer oil of step down 11 KV / 0.433 KV indoor/outdoor type Transformer installed at different sub stations/locations,testing of dielectric strength of transformer oil of indoor/outdoor type transformer,11KV/433 volt, filteration of transformer oil by passing through filtration plant to remove moisture, impurities and improving di-electic strength to above 60 KV for 1 minute at 2.5 mm gap between terminals including new transformer oil for toping up & testing after filtration complete as specified. (Note: Extra Transformer oil will be measured & paid seperately.) Notes for Item Nos 1&2: (a) The contractor will take shut down orders in working before commencement of the work from Engineer-in-charge. (b) The contractor shall ensure no wastage at transformer oil. (c) The Contractor is solely responsible for any damage to the transformer during filetration operations. He is responsible for making good any damage to the transformer at his own cost without any extra cost to the department (d) The contractor shall ensure that the conservator tanks are full to its level before starting the dehydration. (e) The di-electric strength of oil shall be tested before & after filtration. Test results shall be submitted to Engineer-in-charge

Material and labour for Spray painting with Silicon Acrylic heat resistant paint of approved quality & colour to indoor/outdoor type, step up/ down transformer of capacity up to 500 KVA, installed at different locations at NSTL after thoroughly scrapping the existing corroded paint/ rust, filling of cavities complete without disturbing/ damaging the electrical network system including writing the details such as SM/ MES No, Capacity/ Rating/ Incoming and outgoing details all as specified and directed.

All as per item No 3 above but from 750 KVA to 1600KVA

All as per item No 3 above but from 2000 KVA to 5000KVA

Supply and fix in repair silica gel breather assembly transparent type with first fill of silica gel suitable for upto 1000 KVA Transformers complete including connecting with proper rubberized gasket complete including necessary GI fitting complete all as specified and directed. Make : Patel Electrical Industries or equivalent recommende by OEM

Supply and filling Silica gel in Breathers of Transformers all as specified. Note: The Silica Gel shall be brought in Air-tight container.

Supply and filling of new Transformer Oil in sealed drum with di-electric strength of 60 KV for topping up the transformer complete all as specified and as directed. Make : Power Oil/ Electrol/ Servo/Savitha

Supply and replacement of burnt transformer oil with new Transformer Oil in sealed drum with di-electric strength of 60 KV for topping up the transformer & Extra oil required for repaired transformers complete all as specified and as directed. Make : Power Oil/ Electrol/ Servo/Savitha.Note for item Nos.8 & 9 : (a) The transformer oil shall be type EHV confirming to IS - 3351983. (b) Mineral oil grade shall be used.(c) The transformer oil should have a high dielectric strength not less than 60 KV/Min

Supply & Fix new Gun metal gate valve of 32 mm dia bore [Class-II, 1.6 Mpa] with ISI mark an diron wheel head, screwed both ends to GI pipes including taking down old unserviceable valve all as specifeid and and as directed.

M&L for disconnecting the existing HT/ LT electrical connections of defective transformer terminals and shifting the transformer of any capacity from existing position to workshop for repairs, and reinstalling the same after repairs in position including necessary testing after reinstalling the transformer complete all as specified and as directed. Notes :- (i) Repair/ replacement of transformer parts shall be measured and paid separately under respective items of BoQ. (ii) The unit rate quoted shall be deemed to include for the cost of shifting of transformer to workshop and back to position.

M&L for opening the transformer cover along with the conservator by removing the nuts,bolts then after removing the internal HT & LT connections by taking them out by removing studs,bushings,taking out the core winding assembly out of the tank,removing out burnt HV& LV windings from the core assembly,cleaning of core assembly with CTC including necessary repairs for the unserviceable transformers having ratio 11/.433 KV ,draining & decanting of burnt transformer oil and cleaning of sludge deposited in the tank with CTC for the transformers.Rewinding of HV & LV coils with suitable turns & size of super enamelled copper wire/strip winding material measured separately(As existing) having suitable class insulation material.Heating of core winding assembly as per existing procedure & removing the moisture present in it,removal of leakage of tank if any by welding,refilling transformer oil to tank,after putting the core winding assembly in to tank,reassembling making the internal HT & LT connections by fixing the studs,bushings,fitting the top cover by replacing the cork sheet gasket along with conservator ,testing the trnsformer in the workshop duly filled with oil all as specified and directed by Engr-in-charge. Notes: (i) The unit rate quoted shall be inclusive of varnish sleeving of insulating material, taking down the clamps, upper channels and core & HT links and re-clamping, positioning with separators, brazing etc complete. (ii) Weight of copper coil, HT & LT insulation shall be considered for payment. (iii)Replacement of of u/s items such as HT & LT bushings,studs,nut,bolts & washers shall be paid separately. (iv)Extra Transformer oil will be measured & paid seperately. (V)Synthetic rubber cork sheet gasket will be measured & paid separately.

Supply and Fix in replacement of LV Porcelain bushing with insulator,stud,nuts & washers of rating 1.1 KV, 400 to 100 Amps complete suitable for indoor/ outdoor type, step up/ step down transformers of any make/ model complete all as specifieed and as directed.

Supply and Fix in replacement of HV Porcelain bushing with insulator,stud,nuts & washers of rating 12 KV, 250 to 630 Amps complete suitable for indoor/ outdoor type, step up/ step down transformers of any make/ model complete all as specifieed and as directed.

Taking down unserviceable sheet gasket (Cork sheet), Supply and fix synthetic rubberized cork sheet gasket 6mm thick for top cover HT/LT bushes at places existing and tighting all the bushings and top cover to avoid any oil leakages of capacity 100 KVA to 500 KVA complete all as specified and directed

All as above item but no.12 of capacity 750 KVA to 1600KVA

Supply & replacement of super enamealled copper winding wire/strip of suitable gauge as per existing for H.T & L.T coils of transformer of capacity 11/0.433 KV including providing HT & LT insulation complete all as specified and directed by Engr-in-charge.

M & L for Low voltage testing of 11KV/433V 100 to 1000 KVA distribution Transformer ie open circuit test short circuit test, magnetizing current, Magnetic balance & IR Value test complete all as specified and directed by Engr-in-charge.

M & L for Shifting of Transformer of any capacity from variours substations/Locations at NSTL area by road using and removing the faulty transformer by fxing/errecting of the healthy tansformer with the hydraulic crane support making the necessary HT/LT cable connections earth connections and restoration of power supply all as specified and directed.

Material and labour for earthing complete with galvanised steel earth plate electrode 60 x 60 cm and 6 mm thick burried directly in ground (earth pit not less than 2.25 m deep below ground level) with top edge of plate not less than 1.5 m below ground level connected to galvanised GI earth strip 32 x 6 mm size by means of nuts, bolts, check nuts and washers of the galvanised iron or steel all as shown in electrical plate No 5 connected to earthing test point including watering arrangement with PCC 1:3:6 type C1 chamber, MS Funnel, Wire Guage, 50 mm thick precast RCC Coverin Type B1 including necessary excavationin any type of soil, returning, filling in, removal of surplus soil to a distance n exc 50 m, char coal and salt complete all as shoen in electrical Plate No. 3of SSR Part-1 2009 and conecting to earth test point all as specified and as directed. Note : Contractor should submit test results of earthings.

Material & Labour of GI earth strip of size 32 x 6 mm in trenches/fixed to walls/ transformer/LT panel /2 pole/4 pole with saddles and fixing screws etc., from earth pit to test point all as specified and directed.

Supply and Replace Danger notice plate of 1.6mm thick mild steel sheet, vitreous enamelled white, with letters, figures and conventional skull and bones in signal red colour and fixed with M.S. clamps, bolts and nuts of approved size, for HT, 25x20cm size including taking down of old plate all as directed.

M&L for Preparation of old painted surface of HT 11/33 KV Panel boards, Cable duct of any size by scrapping including hinges, doors and applying two coats of synthetic enamel paint over a coat of zinc chrome primer on new steel surfaces complete all as specified and directed.

SRI SAI KRISHNA ENGINEERING WORKS