| 摘要 |
PURPOSE:To shorten recovering time by opening only zone opening/ closing means of a zone to be monitored under the conditions that power supply is interrupted and a fault occurs at a load side from own monitoring zone, and then sequentially reclosing only the means of an open state. CONSTITUTION:A zero-phase current Io, a zero-phase voltage Vo are detected at zone units D1, D2, and a circuit breaker CB is tripped. In this case, the fact that a ground-fault accident is located at a load side from the monitoring zone of the fault in the units D1, D2 is detected. When power supply is interrupted and the output of a rectifier REC is reduced, a zone switch DM is opened. In this case, the switch DM is held in a closed state in the units D3-D6. Thereafter, when the breaker CB is reclosed after predetermined time, the units D1, D2 are sequentially energized. In this case, since data indicating a fault is stored in a memory, the switch DM is reclosed in the designated order according to a time limit sequential energization system. |
