CBI-electric (Circuit Breaker Industries)

A circuit breaker transforms a change in an electric current to a mechanical movement that interrupts the circuit. A thermal circuit breaker does this through a bimetal element that heats up and bends. Therefore, heat trips the circuit breaker.

In a hydraulic-magnetic circuit breaker, the current travels through a coil that generates a magnetic field that trips the circuit breaker. Therefore, heat is not a factor in tripping a hydraulic-magnetic circuit breaker. This means that a hydraulic-magnetic circuit breaker is always tripped by rated current, regardless of the ambient temperature. Other benefits include smaller module size and lower critical resistance.