Undervoltage release device for a circuit breaker

摘要

A direct acting undervoltage release device utilizes stored spring energy to trip a circuit breaker when the control voltage reduces to a critical level (the "undervoltage"). The device includes a solenoid that senses the undervoltage, and a charging motor that automatically resets the device after a tripping operation (provided the control voltage recovers to its normal level). The direct acting feature is achieved by providing a chargable trip spring and a trip pin in the circuit breaker which directly drives the latch bar of the breaker to trip the breaker.