COMPREHENSIVE MAINTENANCE OF TRANSFORMER VCB VOLTAGE STABILIZER AND CONNECTED ITEM AT AGE(I) R AND D MANALI

Amount

Disconnecting cable and Earthing connections of Servo voltage stabilizer of capacity 400 KVA , 3 phase to carry out overhauling of stabilizer comprising of the following:- (i) Draining out oil from chamber. (ii) Opening top cover, disconnecting winding connection from bushings and taking out carefully core assembly complete with winding (iii) Checking compactness of core and tightening the same where required. (iv) Chemical washing of winding to remove dirt, dust and carbon particles. (v) Cleaning of oil tank to remove oil sludge followed by painting of inner surface of tank with zinc chromate base paint (vi) Refixing of core & winding assembly and making connection with HT /LT bushing. (vii)Replacement of worn out gaskets & nut/bolts. (viii) Refilling of oil duly filtered /dehydrated /fresh oil. Removing of old damaged unserviceable Burnt dimmer coil and replacement new dimmer coil of 400KVA rating complete all as specified and as directed by Engineer-in-Charge. Material and labour for in replacement of carbon brush of all dimmer coils 400KVA stabilizer complete all as specified and as directed by Engineer-in-Charge.

Disconnecting cable and Earthing connections of Servo voltage stabilizer of capacity 250 KVA, 3 phase to carry out overhauling of stabilizer comprising of the following:- (i) Draining out oil from chamber (ii) Opening top cover, disconnecting winding connection from bushings and taking out carefully core assembly complete with winding (iii) Checking compactness of core and tightening the same where required (iv) Chemical washing of winding to remove dirt,dust & carbon particles (v) Cleaning of oil tank to remove oil sludge followed by painting of inner surface of tank with zinc chromate base paint (vi) Refixing of core and winding assembly and making connection with HT /LT bushing. (vii) Replacement of worn out gaskets and nut /bolts. (viii) Refilling of oil duly filtered /dehydrated /fresh oil. Removing of old damaged unserviceable Burnt dimmer coil and replacement new dimmer coil of 250 KVA rating complete all as specified and as directed by Engineer-in-Charge. Material and labour for in replacement of carbon brush of all dimmer coils 250KVA stabilizer complete all as specified and as directed by Engineer-in-Charge.

Removing of old damaged unserviceable Burnt dimmer coil and replacement new dimmer coil of 400KVA rating complete all as specified and as directed by Engineer-in-Charge.

Removing of old damaged unserviceable burnt dimmer coil and replacement new dimmer coil of 250KVA rating complete all as specified and as directed by Engineer-in-Charge.

M&L for in replacement of carbon brush of all dimmer coils 400KVA /250 kva stabilizer complete all as specified and as directed by Engineer-in-Charge.

M&L for in replacement of finger set 400/250 kva stabilizer complete all as specified and as directed by Engineer-in-Charge.

M&L for in replacement of motor of 250 kva stabilizer complete all as specified and as directed by Engineer-in-Charge.

M&L for earthing complete with galvanized earth plate electrode 60 cm x 60cm x 6mm thick buried directly in ground to the depth of not less than 2.25 mtr below ground level with top edge of earth plate or a depth not less than 1.50 m below ground level connected to GI strip 32 x 6mm as earth lead by means of galvanized bolts, nuts check nuts and washers and necessary excavation and earth work PCC 1:2:4 type B-1 using 20mm graded brick aggregate for earth pit RCC cover, charcoal & common salt filled in alternate layers funnel with 20mm bore light grade watering pipe, 40mm dia GI pipe light grade for protection of GI strip, wire mesh and connected to earth point including testing on all as specified and shown in electric plate No. 3 of SSR part I. complete all as specified and as directed by Engineer-in-Charge.

M&L in replacement silica gel breathers assembly transparent PVC body with top and bottom posn pressed with metallic cover filled with silica gel blue in colour and suitable for fixing on existing size 15/20/25 mm dia as per situ requirement for transformers of capacity up to 400 KVA. complete all as specified and as directed by Engineer-in-Charge.

Disconnecting and taking down of transformer indoor/outdoor type 11000/415 volts having capacity 250 to 400 KVA, transportation to contractor’s workshop for repairs, strip opening of transformer after unscrewing nuts /bolts screws and connected accessories such as breather, conservator tank, temp gauge, taking out the core for replacement of defective parts and transportation back to the site after repairs and installing, connecting up, testing and commissioning at the site complete all as specified and directed. Notes: - (a) Transformer oil shall be drained out by the contractor in suitable capacity MS drums to be arranged by the contractor. The said drained out transformer oil shall be refilled in the transformer duly dehydrated after repair and the cost thereof shall be included in unit rate quoted against the respective item of this schedule. (b) Rewinding of both HT & LT coils shall be measured and paid for separately under respective item of this schedule. (c) Transportation charges for transportation of transformer from site to workshop and after repair, workshop to site shall be borne by the contractor and cost thereof shall be deemed to be included in the unit rate quoted for this item. (d) The said transformer shall be repaired in reputed workshop as decided by the AGE. (e) Note:– Coil to be replaced shall have same number of turns, gauge insulation value matching with manufacturer’s design. (f) Testing of transformer after repair shall be carried out with the following test and the cost of testing shall deem to be included in unit rate quoted against this item :- (i) The IR value of the dried winding before inserting the core in the shell shall not be less than 750 mega ohm with 5000 volts megger and record of the same shall be maintained. (g) Painting of transformer with one coat of super enamelled paint after cleaning the oil from transformer body complete all as specified and as directed by Engineer-in-Charge.

Supply and replacement of HT coils made out of super enameled HT copper winding wire of transformers having capacity 250 to 400 KVA complete all as specified and as directed by Engineer-in-Charge.

Supply and replacement of LT coils made out of super enameled LT copper strip of transformers having capacity 250 to 400 KVA complete all as specified and as directed by Engineer-in-Charge. Note:- Coil to be replaced shall have same number of turns, gauge insulation value matching with manufacturer’s design.

Strip opening of transformer of capacity 250 TO 400 KVA, 11 KV /433 volts indoor /outdoor type of any make after unscrewing nuts & bolts, screws and connected accessories such as breather, conservator tank, temp gauge etc. for replacement of defective parts such as replacement of leaking gaskets, replacement of worn out/burnt out studs, checking and cleaning of contacts of tap changer and re-assembling the transformer after replacing the defective parts/repair complete all as specified and as directed by Engineer-in-Charge. Notes:- (i) Payment of defective parts to be replaced shall be measured and paid for separately under respective item of this schedule (ii) The cost for replacement of packing material such as top gasket, shall deem to be included in the unit rate quoted by the contractor against this item (iii) The repair/strip opening of transformers shall be carried out at site of its installation without taking down/removal of transformer from the site of installation.

Supply only LT porcelain bushing and heat resistance gasket with brass/copper studs washer and rubber bush etc for Transformer of Cap up to 250 KVA complete all as specified and as directed by Engineer-in-Charge.

Supply only LT porcelain bushing and heat resistance gasket with brass/copper studs washer and rubber bush etc for Transformer of Cap 400 KVA complete all as specified and as directed by Engineer-in-Charge.

Supply only HT 11 KV porcelain bushing with brass/copper studs and gaskets and rubber bush etc for Transformer of Cap upto 400 KVA complete all as specified and as directed by Engineer-in-Charge.

Supply and Replace Gun metal gate valve ISI marked with Iron wheel head, screwed both ends for iron pipe or for socket or union for 25 mm bore pipe including taking down existing gate valve in existing transformers of any capacity complete all as specified and as directed by Engineer-in-Charge. Note:- Draining out and refilling of transformer oil shall be deemed included in quoted rate.

M&L for painting the transformers complete by two coat of approved colour synthetic enamel spray painting after preperation of the surfaces and one coat of red oxide paint and writing SM/MES No, capacity of transformer and date of oil testing etc Transformer of capacity 400 KVA complete all as specified and as directed by Engineer-in-Charge.

Supply and filling up of fresh transformer oil as in topping up/levelling up after dehydration having dielectric strength not less than 60 KV at 2.5 mm gap conforming to IS -335/1993 complete all as specified and as directed by Engineer-in-Charge.

Dehydration of transformer oil having dielectric strength not less than 60 KV at 2.5 mm gap conforming to IS -335/1993 complete all as specified and as directed by Engineer-in-Charge.

Overhauling/ servicing of HT VCB 400 to 630 Amps 11 KV of any make by carrying out following job:- (i)Taking out VCB trolly from the panel board (ii) Removal of dirt,dust & carbon particles by air blower (iii) Cleaning of all moving and fixed contacts of VCB with dry cloth and CRC solution and greasing of moving contacts and gears (iv) Checking and setting of VCB ON/OFF operation mechanism through TNC & push button (v) Checking tightness of all control wires (vi) Checking leakage in vacuum interrupter by Hi-Pot test (vii) Assembly of trolly and testing complete. Opening of VCB/Ring main unit) 11 KV of Capacity up to630 Amps for servicing, cleaning, tightening of loose mechanical mechanism, greasing, inspection of Busbar, CTs/PTs internal wiring of control panel, indicators, measuring of IR value, callibration of relays matching with 66 KV Grid replacement of unserviceable spare parts testing of tripping system and removing all type of dust and settled dirt by means of required T&P complete all as specified and as directed by Engineer-in-Charge. (spares shall be measured & paid separately) and testing complete all as specified and driected. List of spares as under :-

Ashida numerical OC/EF protection relay ADR241S in repair complete all as specified and as directed by Engineer-in-Charge.

ON/OFF button complete all as specified and as directed by Engineer-in-Charge.

Linking between K&A mechenism in repair complete all as specified and as directed by Engineer-in-Charge.

Supply and filling silica gel blue colour in existing breather assembly after taking out old silica gel all complete all as specified and as directed by Engineer-in-Charge.

Supply and fix cable jointing kit for 11 KV (Earthed) grade cable for indoor termination cold shrink type join complete with jointing material and accessories suitable for 3 core XLPE armoured aluminium conductor cable of size 50 sqmm to 95 sqmm complete all as specified and as directed by Engineer-in-Charge.

M&L for repair /replacment of U/S LT APFC panel board, indoor/outdoor type at site of any capacity after disconnecting electrically including discharging all the capacitor banks, dismantling, fault finding and locating the defective items, dismantling unserviceable items from circuit and removing burnt out wiring, cleaning with carbon tetrachloride, painting the panel by scrapping off the old paint and polishing rusted surfaces, and repainting with two coats of synthetic enemal paint over a coat of redoxide primer complete all as directed at site including shifting from one location to another and connecting complete all as specified and as directed by Engineer-in-Charge. Note:- Rates are deemed to include miscellaeous items to be repalced such as capacitor, indication lamps, connector, PF relay, copper cable multi core above 2.5 sqmm, and contactor included in the job.

Material and labour of danger notice plate of 1.6 mm thick confirming to IS : 2551 of 1982 mild steel sheets vitreous enamelled white with letters figures and conventional skull and bones in signal red colour and fixed with MS clamps, bolts, and nuts of approved size for LT 25 cms x 20 cms complete all as specified and as directed by Engineer-in-Charge.

Supply and fix in repair battery power bank 24 volt for VCB incl inverter complete all as specified and as directed by Engineer-in-Charge.

Standard engineers