| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a reliable uninterruptible power supply unit, which can previously prevent overloading and operation stop in a standby uninterruptible power supply unit, and can reliably supply power to a load, even if abnormality simultaneously occurs in pluralities of uninterruptible power supply units that are being used, or even if the uninterruptible power supply units that are being used are stopped for maintenance, inspection, and renewal. SOLUTION: When a first feeder circuit 11 of each uninterruptible power supply unit 1 that is being used is normal conduction is made from the standby uninterruptible power supply unit 51 to a second feeder circuit 16 of each uninterruptible power supply unit 1 that is being used. When abnormality occurs the first feeder circuit 11 of either one of the uninterruptible power supply units 1 being used, conduction is continuously made only to the second feeder circuit 16 of the uninterruptible power supply unit 1, being used and has abnormality from the standby uninterruptible power supply unit 51, and conduction from a commercial AC power supply 30 is made to the remaining second feeder circuit 16 of the uninterruptible power supply unit 1 being used.</p> |
