Mountain View, CA
|reply to PeeWee |
Regardless of what any "status LEDs" show, try taking the batteries out of the system and examining them for any kind of bulging (sides, top, bottom, etc.).
I myself just replaced two TrippLite UPSes of my own (not SMARTxxxSLT models, lower-end stuff) due to them mysteriously kicking over to battery power for no reason. They worked great for about 4 years. I ended up debunking that situation by purchasing a new UPS (see my profile for what brand/model) and hooking up the TrippLite "behind" that, with no devices hooked up to it, and waited. After a few days the TrippLite units (at separate times) would kick on battery power for a few seconds then kick back onto AC power -- while the UPS providing AC power showed no AC power loss whatsoever. The things just went bad from what I can tell.
At my previous workplace we had a high-end (datacenter-grade) APC UPS with 11 external batteries linked/chained together for a multi-workstation NOC. So that's 12 batteries total.
After many years our UPS began to kick its fans on (very loud) on occasion. After 3-4 months of this (because nobody ever cares to do maintenance on things these days, sigh), the situation worsened when the area where the UPS + batteries were began to emit a high-pitch squealing noise that lasted 3-4 seconds, followed immediately by a very strong, nauseous smell which made a lot of people sick (of which I was one). I know it sounds funny, but it sounded like a fart. Once things got to that point I took matters into my own hands.
I examined the UPS + batteries found that of the 12 batteries we had, 5 were blazing hot to the touch (including the one which was inside the UPS). All 5 required using use of a prybar to bend the steel housing just to get the batteries out (due massive bulging), and one battery had what appeared to be a hole in it of some sort (still not sure from what; there was no white acid leaking from it).
We ended up replacing the 5 batteries which were in this condition and the UPS no longer kicked on its fan. The fan issue was caused by what VegasMan stated -- heat. The heat was caused by the batteries -- they were hot even when they weren't being charged, or possibly they thought they needed to be charged 24x7x365, I don't know. I just know that they were preposterously hot even when the last power outage was months prior.
However, the high-pitch noise continued, as did the toxic smell shortly afterwards.
It wasn't until we replaced the UPS entirely (giving me a chance to open it up and look at it) where we found many of its internal capacitors were bulging. My theory was that the capacitors would hold a charge most of the time, but occasionally would (quite literally) leak electrolyte, which is highly toxic. Leaking caps often tend to emit a high-pitch noise.
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.