| 摘要 |
PURPOSE:To improve electric cutoff characteristic between fixed and movable electrodes by providing grounding electrodes opposing each other outside a vacuum breaker via an opening-closing device with discharge detector. CONSTITUTION:By the energization of an electrode releasing relay coil TC, a movable electrode 3 begins to part from a fixed electrode 2. The signal given to an electrode controlling relay coil R2 is also given to a retention circuit 19. The retention circuit 19 is energized by a signal and energizes a high dielectric strength relay R1 from the point where the movable electrode 3 begins to part from the fixed electrode 2 to the point where the electrode 3 is in the position most released from the electrode 2. Namely, the normally closed contact point 17 becomes in an open condition from the point where the movable electrodes 3 begins to part from the fixed electrode 2 to the point where the movable electrode 3 is in the position most released for the fixed electrode 2. In this way, a grounding electrode 10 is completely cut off from a grounding potential point G simultaneously with the parting of the movable electrode from the fixed electrode 2. |
