WORK OF REPAIR and OVERHAULING OF 145 KV CBs AT 220 KV S/S NEHTAUR UNDER E.T.D-DHAMPUR.

Amount

Repair & overhauling of 145 KV CGL make CBs installed at 132 KV Bus coupler bay & 63 MVA T/F bay by doing following work in each breaker.

Opening/Dismantling of control valve assembly, cleaning of cap seal cylinder, removal of defective roller, re-fixing of new roller, reassembly of control valve assembly in mechanism. Replacement of control valve seal & bent O-ring, opening of anti-pumping pin assembly cleaning, de-rusting & lubrication of anti-pumping pin assembly. Replacement of spring in anti pumping. Opening and cleaning of closing spring, shock absorber, pneumatic cylinder, cleaning of piston & cylinder including their assembling replacing of oil & O-ring, Opening and reassembling of trip coil assembly after cleaning of its various parts including measurement of resistance adjustment of trip coil gap. Checking of NRV & Drain valve for air leakage with help of soap solution. Replacement of NRV and Drain Valve. Checking of air switch i.e governor switches, low air pressure alarm switch including adjustment. Checking of gas density switch including all adjustment. De-rusting lubrication of horizontal rod assembly & its various linkages, cleaning of bar pins, replacement of cercilip. Show operation of circuit breaker with help of manual jack for checking over stroke, wipe, poles traveling etc. for satisfactory operation of 132 SF-6 CB.

P&H Engineering

TIRUPATI ELECTRICALS