03/ETD-II(L)/2025-26

Amount

Major overhauling of machanism assembly of 145 KV SF-6 CB CGL make installed at 132 KV Bus Coupler bay at 132 KV S/S N.K.N. work include overhauling control valve assembly by replacement of control valve seat, O-ring P 80 and roller C/D. Overhauling of holding latch. Opening of pneumatic cylinder, closing spring etc. De-Rusting and greasing of the same. Rectification air leakage through NRV, safety valve, opening of reservoir, cleaning of reservoir along with replacement of 06mm and 12mm gas pipe assembly. Checking and adjustment of air pressure switches and gas pressure swithches. The work also includes overhauling of compressor, replacement of bearing and seals if required. Checking and re-tightening of all electrical connections. Measurement of closing and tripping time of Circuit breaker. Measurement of contact resistance of circuit breaker.

Rectification of SF6 gas leakage from 01 pole (B phase) and NRV valve of 145KV SF-6 CGL Make circuit breaker of 132KV Hardoi Road bay at 132KV Sub-station NKN. Work consist of (a) To identify SF-6 Gas leakage with the help of Sf-6 gas leakage detector and pole non-operating problem (b) Dismentle identified pole from breaker structure by help of hydra (c) Dismentle all components of poles and replace all 'O' Rings / Gaskit by applying Anabond 661 (Gas Sale Out) after through cleaning part (d) Replacement of pull rod for pole moving contact (e) Re-assemble all parts of the pole (f) Apply vacuum and keep it for 24 hrs and check no loss of vacuum (g) Erection of poles at structure using hydra (h) Fill SF-6 gas upto specified value (i) check satisfactory Close and trip operation both by local and remote.

M/S T R TRADERS (BID ID -5257893)

M/S YASHVARDHAN ENGINEERING WORKS (BID ID -5257734)