| 摘要 |
PROBLEM TO BE SOLVED: To detect an overheat state of many screw connection parts provided on a cable run by a single detector, and to secure safety by disconnecting the cable run on the detection.SOLUTION: A master breaker 5 and an overheat detector 7 are separately provided inside a power distribution board case. A detection line 74 is wired to a case 73 of the overheat detector 7, and a sensor circuit 75 and a first switch 76 are provided on the detection line 74. An output line 77 of the sensor circuit 75 is connected to an average value circuit 79 through an integrated input circuit 78. A determination circuit 80 compares an average value with a threshold to determine an overheat state of screw connection parts of various in-board apparatuses including the master breaker 5. Once an overheat state is determined, the output circuit 82 excites an electromagnetic coil 84 to open the first switch 76 and to close a second switch 87 on a pseudo-leak circuit 86, and thereby supplies a pseudo-leak current to the master breaker 5 to open a main contact 57, thereby disconnecting the cable run. |
