| 摘要 |
PROBLEM TO BE SOLVED: To provide a tracking breaker operating at the time point of occurrence of a fine discharge current due to a carbonized conductive path generation. SOLUTION: This tracking breaker has: a current transformer 2 for detecting a current of an electric line 9; a control part 1 for determining a tracking discharge based on current information detected by the current transformer 2; and a trip coil 6 for tripping a contact 7 of the electric line 9 by a tracking discharge detection signal outputted from the control part 1. The control part 1 is equipped with an arithmetic circuit 11 comprising a microcomputer. The arithmetic circuit 11 is used for finding a difference between peak values of adjacent current waves from inputted current wave information. When the number of the differences of the peak values not less than a predetermined current determination value is continuously counted to ten, or intermittently counted to ten for 300 ms, occurrence of the tracking discharge is determined to execute a tripping operation of the contact 7 by outputting the tracking discharge detection signal. COPYRIGHT: (C)2004,JPO
|
