Fault indicator having increased sensitivity to fault currents

摘要

A fault indicator for indicating the occurrence of a fault current in an alternating current conductor includes a pair of parallel-spaced reed switches in magnetic communication with the conductor. The reed siwtches are electrically connected in parallel by a magnetically conductive bridging element at one end of the pair and by a non-magnetically conductive bridging element at the other end of the pair. A permanent magnet bridging the non-magnetic bridge establishes a magnetic bias circuit which extends serially through the switches to increase the sensitivity of each switch to a fault current during a respective half-cycle of the alternating current cycle.