Ever had an APC UPS blow up?

Anonymous user · ‎2021-11-16

Nothing wakes you up from a nights sleep like an APC Smart UPS 2200 frying itself at 5:30am. Heard a LOUD bang, rushed to the basement and smelled smoke. Checked my 3 UPS's front lights and 1 unit was shut off. Smell of smoke was the strongest near the back of the rack. This was a second hand unit from a trusted source that I have been runing for 8 months or so. Don't remember exactly how old the unit was. This rack is about 4ft from my saltwater fish tank and about 1 ft away from a 95pint dehumidifier to help make sure humidity is not an issue. The dehumidifier keeps the room in the 30-40% RH.

Thankfully there was no fire or anything. I tried to pull the battery tray out but it wouldn't slide out. The equipment that was plugged into it seems to be all fine.

Anyone ever had this happen? I'm planning on opening the top of the case after I get home from work. I put the unit in the middle of my garage with nothing flamable near it.

We also did have a power outage 4 days ago which completely drained the batteries. My other 2x APC Smart UPS 3000 seem to be fine.

Brad_C · ‎2021-11-22

Yep. Oddly enough to an SU2200. The gate drive circuit for one of the high side MOSFET banks died and caused both high and low sides to conduct simultaneously, putting 48V at lots of amps through them resulting in sparks, smoke and some flame. I ended up rebuilding both high side drivers and replacing about 50% of the MOSFETS. That was 2011 and it has been in service ever since, but there was a bit of cleanup required both in the UPS and my underwear as I was bending over it to plug it in when it went.