FAULT INDICATOR HAVING AUXILIARY FAULT SENSING_WINDING

摘要

A fault indicator is described which indicates the occurrence of a fault current in a monitored electrical conductor. The fault indicator includes a magnetic pole assembly which mounts the housing of the fault indicator to the monitored electrical conductor. The magnetic pole assembly includes both a main outer magnetic core assembly and an auxiliary inner magnetic core assembly. As described, an auxiliary fault sensing winding is disposed on the inner magnetic core assembly so that it becomes energized and provides power for fault circuitry within the fault indicator upon the occurrence of a fault current in the monitored electrical conductor. The fault circuitry positions a flag indicator within the module to visibly acknowledge the occurrence of the fault current in the electrical conductor. As disclosed, two air gaps prevent the inner magnetic core assembly from communicating magnetic flux from the main core assembly to the auxiliary fault sensing winding while a current sufficiently less than a fault current flows within the monitored electrical conductor.