What is circuit breaker and its function?

Circuit Breaker

A circuit breaker is a switching device that interrupts the abnormal or fault current.

It is a mechanical device that disturbs the flow of high magnitude (fault) current and in addition performs the function of a switch.

The circuit breaker is mainly designed for closing or opening of an electrical circuit, thus protects the electrical system from damage.

Tripping and Auxiliary Supplies

Trip Circuit

A relay provides a potential free contact, which is shown in the figure as Trip Contact', at the time of fault sensed by the relay.
The auxiliary supply goes through this contact to the Trip Coil of the circuit breaker.

Types of circuit breaker and its operations

circuit breaker trip circuit

Auxiliary Supply

All the circuit breakers are DC (Direct Current) operated.
Because DC power can be stored in battery and at the time of total failure of incoming power Occurs, still the circuit breakers can be operated for restoring the situation by this battery.
Hence, the battery is another essential item of the power system.

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