| 摘要 |
<P>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 of a load-side circuit by disabling current to flow to the detector if a master breaker performs breaking operation. <P>SOLUTION: A master breaker 5 and an overheat detector 7 are 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 sensor 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. An operating mechanism 91 is provided between the master breaker 5 and the overheat detector 7, and when the master breaker 5 disconnects the cable run, an electromagnetic coil 93 opens the sensor switch 76 and places the sensor circuit 75 in an open-circuit state to disconnect the overheat detector 7. <P>COPYRIGHT: (C)2013,JPO&INPIT |
