REPAIR / MAINTENACE OF VCB and SERVO VOLATAGE STABILISER AND CONNECTED ITEMS AT DGRE UNDER AGE (I) R and D MANALI.

Earthing complete with galvanized steel earth plate electrode 60 cm x 60 cm x 6 mm thick buried directly in ground (earth pit not less than 2.25 metres deep below normal ground level) with top edge of plate not less than 1.5 metres below normal ground level, connecting to the Galvanised iron strip 25x4 mm by means of bolts, nuts , check nuts and washers of galvanized iron and steel earth wire protected by provision of GI light grade pipe 40 mm bore including provision of concrete pit made from PCC ( 1:2:4) type B-1 (using 20 mm graded stone aggregate) with 40mm thick cover of RCC 1:2:4 reinforced with XPM (Weight not less than 4 Kg/Sqm) and frame of angle iron 40 x 40 x 6 mm and handle of 6 mm dia MS bar made to shape, GI light grade 20 mm bore pipe for watering perforated at bottom, 1.50 metre long placed on top edge of earth plate, common salt & charcoal filling, with fixing arrangement , funnel, wire mesh and earth work in hard/dense soil , returning filling in and removal of surplus soil to a distance not exceeding 50 metres, all as per electrical plate No 5 of SSR 2009 Part-I and connecting to Transformer / Poles all as specified or indicated including testing on complete all as specified and as directed by Engineer-in-Charge.

Earth continuity conductor or main earthing lead fixed to wall on batten or recess or chases or buried in ground or drawn in conduit/pipe or fixed to poles or any other indicated situation for loop earthing/connecting as required 25x4 mm galvanised iron strip complete all as specified and directed by Engr-in-charge.

M&L in replacement of synthetic insulating mat of size 2m x 1m x 12 mm complete all as specified and directed by Engr-in-charge.

Material and labour for servicing /testing of breaker/control panel including CT, PT and relays in control panel of VCB of capacity 630 Amps and rating 11 KV complete as details mentioned as under:- (a) Details of servicing of breaker :- (i) Adjustment of mechanism if required. (ii) Clean the circuit breaker to remove dust and dirt. The envelope of the vacuum interrupter and insulating materials shall be wiped with a clean cloth. (iii) Apply a small amount of oil to rotary sections, sliding surfaces, pins, coupling section, etc.use grease for the operating shaft and bearings, and machine oil for other parts. (iv) Check for rust and wear. (v) Check Spring Tension and pitting of the Cluster Contacts. (vi) Visual check for rust and deformation. (vii) Check for loosened bolts and nuts, broken spring washers and snap pins etc. (viii) Check for loosened connections, rust, damaged lead wires. (ix) Check whether the contacts are damaged by arcing. (x) Checking of control circuit & tighten the connections if any. (xi) Check close & trip coil. (xii) Checking of Jaw Contacts Conditions and repair/adjust. (xiii) Replace the jaw contacts,If required. (xiv) Improvement of resistance of epoxy insulator and epoxy body by applying post heated varnish. (xv) Replacement of Dashpot/shock absorbers . (xvi) Replacement of carbon brush of spring charging motor

(b) The following test shall be carried out:- (i) Primary Injection Test of CT / PT (ii) Closing & Opening Timing Test for all three poles. (iii) IR Test with megger in open and closed condition. (iv) Contact resistance test for all three poles (v) Closing coil resistance (vi) Tripping coil resistance. (c) Testing of following relays of control panel with Secondary Injection Kit ,checking and programming of relay :- (i) Over current and earth fault relay (d) Testing of followig Aux relay (i) DC Supply supervision relay. (ii) Master trip relay

S&F in repairs of tripping push button as per sample suitable for VCB/OCB11 KV, complete all as specified and directed by Engr-in-charge.

S&F in repairs of closing coil assembly suitable for VCB 11 KV, complete all as specified and directed by Engr-in-charge.

S&F in repairs of tripping coil assembly suitable for VCB 11 KV , complete all as specified and directed by Engr-in-charge.

S&F in repairs of earth contact assembly suitable for VCB 11 KV, complete all as specified and directed by Engr-in-charge.

S&F in repairs of spring charging mechanism assembly suitable for VCB 11 KV, complete all as specified and directed by Engr-in-charge.