Question { 40978 }

what is working of Master trip relay ?

Answer

In Several sub-stations and power houses a special type of
installations is applied i.e. generally O/C relay for B and
R phase and Earth fault relay for Y phase. From there the
three trip connections are coming out and is connected to
the master trip coil. Now this relay output is connected to
the circuit breaker. Thus the other relays works here as
slave(Not mandatory) and the later one as master controlling
the operation of the circuit breaker.