Circuit breaker

Description of Circuit Breaker

Circuit breaker is a protective device used in power system to protect the system on the event of fault. It isolates the faulty part of the power system in case of the any abnormal conditions. The circuit breaker functions along with a relay which senses
the fault and sends a tripping signal to the circuit breaker.

Functioning of a Circuit Breaker:

The circuit breaker has two contacts namely fixed contact and moving contact. Under normal operating conditions the two terminals are always in contact but when the circuit breaker receives a tripping signal, the moving contact moves away from the fixed contact to isolate the circuit. Upon separation of the two contacts the circuit is not isolated instantly but an arc is formed between the contacts which provide a path for the flow of current. The arc is interrupted by various techniques in various types of circuit breakers for complete isolation of the circuit.