MAINTENANCE WORK AT 220KV SUB-STATION AZAMGARH

To attend SF-6 Gas leakage of 145kV SF-6 CB (CGL make S.No. 16936C Type 120 SFM-32B) of 132kv Mubarakpur bay at 220kV S/S Azamgarh.

A:- Detect gas leakage by SF-6 Gas leakage detector. B:- Extract SF-6 gas from pole units by help of SF-6 extraction plant and keep it into empty SF-6 gas cylinder. C:- Dismantle all top covers from pole units and opening of fixed contact chamber from pole unit. D:- Cleaning of all fixed & Moving contacts, polishing the contacts and applying micro carbon grease on contact surface. E:- Replace pole top cover O ring P-170, absorbent and re-fitting the same. F:- Apply Vacuum in all poles by help of vacuum pump up to specified value and keep it for 4/5 hour & check no loss of vacuum. G:- Complete overhauling of Spring charging Mechanism assembly, cleaning & lubrication. H:- Dismantling of close & trip coil assembly, opening its parts, cleaning. lubricating and adjustment of air gap of this plunge. 1. Checking electrical connection in the marshalling box and tightening all electrical connection. J:- Check Close/trip operation of this breaker satisfactory. K. Check Close/Trip timing by digital timer. K:- SF6 gas fling in all poles at desired Level for satisfactorily completion of work.

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.