circuit bkrs. names related with arc quenching medium which
is used in breaker. mostly air ckt. bkr used for LT system
and arc quenching mwdium is only air but vaccume ckt. bkr.
used for HT system and arc quenching medium is vaccume
which is created in separate vaccume bottles where contacts
make and break .
ACB: As name it is Air circuit breaker, and it is used in
LV side of transmission, air as a arc quenching medium.
VCB: vaccume circuit breaker it used in HT side of
transmission there is not any medium for arc quenching so
it is vaccume circuit breaker
ACB means "AIR CIRCUIT BREAKER" it is a Electrical power
supply protection equipment when fault occur in the system.
It is used in the Low Voltage application. The power supply
mechanical contacts are kept in the atmospheric air at the
time of fault, the breaker will trip the generated electric
arc ia quenched by the air.
VCB means " VACCUM CIRCUIT BREAKER " it is also same
equipment but used in the High Voltage application ( 11kv -
33kv ), here the power supply mechanical contacts are kept
in the vaccum sealed bottle, the vaccum will quench the arc
at the time faulty trip. The electric arc generation is
high when comparing with the ACB
sir , what happen if we decrease ( approx 3 inch ) the
lenth of shaft in 110KW Induction , three phase motor.
actually a 110KW motor is couppled with star couplling to
120TR compressor. When we doing maintenance in compressor
it is required to skid the motor backword and resulting dis-
alightnment . so we want to change the tyre coupling in
place of existing coupling. so it is required to cut off
the rotor aprox 3 inch form driving side.