LEAKAGE RELAY, ZERO-PHASE CURRENT TRANSFORMER, AND LEAKAGE RELAY UNIT

摘要

PROBLEM TO BE SOLVED: To provide a leakage relay technique with high safety in a leakage relay and a zero-phase current transformer for detecting the leakage state of a main circuit.

SOLUTION: In addition to a leakage detection coil, a connection state checking coil for checking the connection state between the leakage relay by flowing a checking current is provided on the zero-phase-sequence current transformer side, and in addition to a leakage detection output, a connection state checking output is made possible to output on the leakage relay side. Furthermore, the leakage relay not only outputs the above checking current, but also outputs a contact point signal for giving an alarm in the case at least any of these is abnormal by carrying out abnormality judgement of the leakage state of the main circuit or the above connection state based on the output of the above zero-phase-sequence current transformer.

COPYRIGHT: (C)2005,JPO&NCIPI