Ground fault circuit breaker for detecting fault current, has fictive signal generator circuit that produces alternating fictitious current signal according to determined direct voltage produced by DC electrical supply circuit

摘要

The breaker has a zero phase current transformer (5) detecting a fault current caused in a polyphase main circuit (2), and a fault detector circuit (6) determining whether fault is caused or not based on output of a fault detector winding (51). A fictive signal generator circuit (12) produces alternating fictitious current signal according to a determined direct voltage produced by a DC electrical supply circuit (4).