| 摘要 |
PROBLEM TO BE SOLVED: To solve the grabber in which conventionally the ground current election uses the power supply at ground fault time as the ground fault current, so that ground fault current sensitivity could not be set low for causing the ground fault detection circuit or permant-display device to operate or that means were not avail for finding out the contents of the past foults on the measurements of the cable changing current, which always flows at times other than at the fault times. SOLUTION: A sensor 5, which detects a ground fault current, is installed regarding every phase of a cable 2. A ground fault detection circuit 71, which detects a ground fault using the ground fault current as a circuit power supply when the ground fault current exceeds a prescribed value, is provided. A display unit 72, which holds a permanent display by a battery power supply 73 in response to the operation of the ground fault detection circuit 71, is provided.
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