JPS6463232A - Remote control circuit for circuit breaker - Google Patents

Abstract

PURPOSE:To make the state of a circuit breaker inexpensively monitorable without entailing any special wiring by making a judging device judge a trip of the circuit breaker in the case where a current sensor detects a fact that a current of an exciting circuit becomes less than the specified value. CONSTITUTION:A trip switch 20 is normally closed, and thereby a current flows by way of a continuous current sensor 21, a bypass circuit 23, and a bistable type electromagnet 12. At this time, the current flows into this bistable type electromagnet 12 as well, but since it is abated to small enough by impedance of the bypass circuit 23, the bistable type electromagnet 12 will not do its unnecessary motion. When a circuit breaker 1A is tripped for some reason or other, the trip switch 20 is opened, so that an operating current is cut off. At this time, a judger 22 judges the trip of the circuit breaker 1A by what output of the current sensor 21 runs short. Consequently, the bypass circuit 23 can abate the current enough so as not to cause the bistable type electromagnet 12 to do its unnecessary motion, thus a specific terminal is no longer required, and wiring is also enough with two pieces, securing a good remote control circuit.