Research on closing coil protection of low-voltage circuit breaker

A scheme to solve closing coil burnout of low-voltage circuit breaker is proposed. A kind of protection circuit in allusion to closing coil of low-voltage circuit breaker is designed in combination with concrete requirements. A protection unit is added to closing coil circuit so as to cut off closing coil circuit by 4060 chip to protect closing coil when breaker can't trip in time. Closing coil of low-voltage circuit not only monitors running conditions of low-voltage main circuit, but cuts off closing coil circuit to avoid closing coil burnout of low-voltage circuit breaker in accident state. Phenomena of closing coil burnout which can't trip in time can be avoided because operating mechanism is jammed or auxiliary contacts of breaker toggle anomaly.