| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent unnecessary electric cutoff as a result of the fact that a generating position where tracking short circuit occurs can be determined. <P>SOLUTION: A tracking breaker 10 in which electric cutoff is carried out by occurrence of the tracking short circuit is provided with a directivity determination circuit 23 and a circuit 24 for determining cutoff element. When the tracking short circuit occurs, noises occur. Based on the noises, the generating position where the tracking short circuit has occurred can be identified by the directivity determination circuit 23, and when the tracking short circuit has occurred on the load side, the electric cutoff is carried out by the circuit 24 for determining the cutoff element. <P>COPYRIGHT: (C)2007,JPO&INPIT |
