UPS Failure

UPS failed while I was checking the batteries after the vendor finished battery maintenance. This was my last walk-through of the day. I checked the battery voltage and current at the UPS panel, inspected each battery for signs of leakage or post swelling. I was going to print a battery report when I noticed the battery monitor printer was near the end of the paper. I looked for a new roll of paper and just as I closed the door, the UPS failed releasing a fireball into the room. The failure tripped one of the three 3000 AMP main feeders, the battery breaker and the UPS input breaker. My first concern was all the smoke even though the fire sensors in this room are heat detecters. By the time I got the door open to vent the smoke and add light to the room, my phone was blowing up with alarms. Though I was quite busy for the next few hours, none of the computers in the center were affected.

I learned that the failure in the UPS was a phase-to-phase short on the input 480 VAC circuit, apparently through the diodes or SCRs in the input AC side.

Видео UPS Failure канала TheDennisChannel