| 摘要 |
PURPOSE:To detect the degree of vacuum deterioration at any time in the operation state over a wide range by opening a vacuum switch in the operation state for a fixed time and detecting the current flowing between electrodes of the vacuum switch during this time. CONSTITUTION:When a detection control device 6 is operated and a vacuum switch 1 is opened for a fixed time, 1sec at the longest, the load current having been flowing by that time is out off, the current change at this time of a sound vacuum switch differs from that of a vacuum-deteriorated switch. The difference of this change is judged with a vacuum deterioration judging device. For the vacuum-deteriorated switch, the current is not cut off and an arc is continued, thus the deterioration of a vacuum bulb can be detected. The vacuum deterioration can be detected at any time in the operation state if a system, and the degree of vacuum deterioration can be detected over a wide range. |
