| 摘要 |
PURPOSE:To always certainly specify the machinery generating an accident at first, by performing the cut-off operation of a breaker after the holding operation in a recording holding apparatus is completed by the current detector interposed between the metal on an earth side and a receiving metal container. CONSTITUTION:A signal receiver 54 is equipped with a selector circuit selectively receiving one of signals different in frequency and specifies the machinery generating a flashover accident at first and uses the received high frequency signal to close the electric contact 54a connected to the trip coil 55a of a breaker 55 in series. A protective relay 57 is operated by the secondary current of a current transformer 56 and, when the operation of the relay 57 is faster than the operation up to the closure of the contact 54a of a flashover order discrimination apparatus constituted using a current detector 50, a recording holding apparatus 51, a signal output device 52 and the signal receiver 54, the breaker 55 immediately enters cut-off operation by the closure of the contact and, when the operation of the relay 57 is later, the breaker 55 enters cut-off operation after the operation of the relay. Since the operation of the breaker 55 is performed after the holding operation of a storage device in both cases, the machinery generating an accident at first is certainly specified.
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