Circuit breaker having a trip actuator

摘要

A circuit breaker having a trip actuator which mechanically trips the breaker in response to an electrical trip pulse. The trip actuator includes first and second parallel magnetic circuits, with the first circuit having a lower reluctance than the second circuit. A magnet provides magnetic flux for both circuits. A pivotally mounted clapper has a first position in which it is releasably held in the first circuit by a magnetic force, and a second position. Bias springs urge the clapper towards the second position, with the bias springs providing a biasing force which is less than the magnetic force holding the clapper. The electrical trip pulse creates a magnetic flux which opposes the magnetic flux in the first circuit, switching the magnetic flux to the second circuit. The clapper member pivots to the second position, and a trip link associated with the clapper actuates a trip mechanism.