bids are invited for estimate for overhauling of 145kv sf 6 circuit breaker of abb make installed at 132kv substation usawan under e.t.d., budaun.; a to attending sf-6 gas leakage of 145kv sf 6 circuit breaker (abb make) sl. no. 17002186, type ltb145d1/b) installed at 132kv substation usawan under etd, budaun 1 detect pole leakage by sf6 gas leakage detector 2 extract sf6 gas from pole units by help of sf6 gas extraction plant and keep it into empty, sf6 gas cylinder. 3 dismantle all top covers from pole units and opening of fixed contact chamber from pole unit. 4 cleaning of all fixed & moving contacts, polishing the contacts and applying micro carbon grease on contact surface. 5 replace pole top cover o ring p-170, absorbant and re-fitting the same. 6 apply vacuum in all poles by help of vacuum pump upto specified value and keep it for 4/5 hour & check no loss of vacuum. 7 complete overhauling of spring charging mechanism assembly, cleaning & lubrication. 8 dismantling of close & trip coil assembly, opening its parts, cleaning, lubricating and adjustment of air gap of this plunge. 9 checking electrical connection in the marshalling box and tightening all electrical connection. 10 check close/trip operation of this breaker satisfactory. 11 check close/trip timing by digital timer. 12 replacement of main nrb with pipeline (if required) work consist of dismantling of main nrb with pipeline & replace it with new one & fitting at its original place in cb sf6 gas filling in all poles at desired level for satisfactorily completion of work.