| 摘要 |
PROBLEM TO BE SOLVED: To provide a small and low cost circuit breaker provided with a checking device capable of checking operations of a judging circuit comprising a microcomputer of a tracking short circuit and cord short circuit occurrence time; a tripping means and an open-close mechanism not by applying a current falsely flowing into a current detecting means at the time of a tracking short circuit but by inputting a voltage value serving as a judging condition of a microcomputer corresponding to a cord short-circuit current in a judging means. SOLUTION: This circuit breaker is provided with a current detecting means detecting the current flowing in a cable way, a judging means incorporating a microcomputer prestoring a program judging occurrence of a short circuit by a tracking phenomenon of a plug or a cord short circuit by insulation deterioration by a voltage signal obtained by converting a current value outputted by the current detecting means into a voltage value by a current voltage conversion means, the tripping means driven by the output of the judging means, a switching means blocking the cable way by driving the tripping means and an operation checking means. The operation checking means checks operations of the judging means, the tripping means and the switching means, but not the current detecting means. COPYRIGHT: (C)2005,JPO&NCIPI
|
