| 摘要 |
PURPOSE:To confirm uninterruptible switching reliably by a method wherein a circuit breaker belonging to a power source, which is not feeding power, is opened and an AC switch belonging to that power source is automatically turned ON and then the voltage at the output of the AC switch is detected. CONSTITUTION:When a second circuit breaker 23 is opened, contact 23B of the second circuit breaker is closed. Consequently, a logic H signal is fed from an inverting element 42 to an OR element 43 and a gate drive circuit 28 feeds an ON signal through an OR element 27, based on a logic H signal fed from the OR element 43, thus turning a second AC switch 22 ON. Furthermore, second relay contact 44A is closed because the second relay 44 is excited by a logic H signal fed from the OR element 43. Since the second AC switch 22 is turned ON at that time and the voltage of a backup power source 21 is produced at the output side, an indicator 45 is operated by that voltage through the second relay contact 44A thus indicating normal function of the second relay 22. |
