| 摘要 |
PROBLEM TO BE SOLVED: To ensure positive power supply even if failure occurs in either of backup power supplies or at the time of maintenance test. SOLUTION: In this uninterruptible power supply system, if failure occurs in either of uninterruptible power supplies 1 or 2 parallel-connected to a bus-bar panel 6 outputting AC power, a controlling circuit 13a or 13b stops no- instantaneous switching operation of a no-instantaneous break switching circuit 7a or 7b on the side of failure occurrence and switches the nobreak switching circuit 7a or 7b on the side of no failure occurrence to the direct power supply side. When overcurrent occurs in either of the uninterruptible power supplies 1 or 2, power supply is switched to direct feeder lines 12a, 12b side. At the time of maintenance test for the uninterruptible power supplies 1 or 2 on either side, backup power is supplied from the other uninterruptible power supplies 1 or 2.
|
