| 摘要 |
PROBLEM TO BE SOLVED: To judge the presence/absence of power feeding in a present station and an opposite station and to perform a safe maintenance operation by detecting the potential of a feeder as power feeding polarity, comparing it with the output polarity of the present station and judging and displaying the power feeding state of both terminal stations. SOLUTION: A detection means 2 is provided inside a power feeder 1 or near the power feeder 1 and detects the potential of the feeder 5 at a point A reaching the power feeder 1 from the feeder 5 as the power feeding polarity to grounding. That is, in the detection means 2, when either positive polarity or negative polarity is detectable for the output polarity of the present station as a premise, the power feeding state is judged from the relation of the output polarity set in the power feeder and the polarity detected in the detection means 2. For instance, when the output polarity of the present station is positive, when the detected polarity is negative for instance, the power feeding only by the opposite station is judged in a judgement means 3 and the judged result is displayed at a display device 4. |
