| 摘要 |
<P>PROBLEM TO BE SOLVED: To highly precisely determine tracking short circuit and to guarantee security of an electric path with a simple and small structure equipped with one current detector. <P>SOLUTION: A home distribution board 1 includes a main breaker 3 connected to main circuit 6, a branch breaker 4 connected to a load circuit 8, ZCT9 for detecting current flowing in the load circuit 8 near the main breaker 3, and a control circuit 5 for controlling the main breaker 3 based on output of ZCT9. A peak value measuring part measuring a peak value of a current waveform, a determination part for determining the tracking short circuit based on a change amount of the peak value, and a breaker driving part for making the main breaker, perform an interception operation in accordance with determination results. <P>COPYRIGHT: (C)2008,JPO&INPIT |
