OVERHAULING OF 33kV VACUUM CIRCUIT BREAKERS AT 220kV SUB-STATION BASTI AND 132kV SUB-STATION HARRAIYA UNDER ETD-I, BASTI.

FOLLOWING WORKS ARE TO BE CARRIED OUT FOR MAJOR OVERHAULING & REPAIRING OF VARIOUS TYPE OF 33KV VACUUM CIRCUIT BREAKERS OF DIFFERENT 33 KV FEEDERS AT 220 KV SUBSTATION GIDAHI BASTI AND 132KV S/S HARRAIYA.

Cleaning of Porcelain of drive insulator and porcelain of vacuum interrupter from outside of each pole and sealing the vacuum pole by applying anabond.

Checking & adjustment of snatch gap, travel of drive insulator rod & tie rod of each pole.

Opening, repairing of breaker mechanism including welding, drilling, machining and filling of material if required and proper fitting of it in breaker cubicle.

Oiling & greasing of crank gears by opening of lock pin etc.

Replacement of worn out parts such as bushes, ring, lockpins and trip latch etc.

Checking & adjustment of oil dashpot of breaker for its damping action.

After major overhauling & repairing VCBs, following tests are to be carried out

Opening & closing time of each pole of circuit breaker.

Contact resistance measurement by CRM test kit of each pole of circuit breaker.

Checking of insulation Resistance of each Pole of Circuit Breaker.

Checking of circuit breaker tripping at 70% of DC voltage.

Checking the Close/Open of operation of circuit breaker from remote and local.

Prepare and submit site overhauling report of each CB in 02 numbers copies (One in subdivision office & One in Division Office).