At an Not For Profit/Charity I volunteer for occasionally we were very fortunate to be provided (donated) with a brand new 3Kva APC UPS. This is total overkill for our modest server rack (four mid-range servers and a switch!) but hey, I'll take what I can get!
Pressing the TEST button on the front indicates that yes, the UPS does work. Brilliant. But it only tests it for about 15 seconds.
My question is – will I degrade the UPS by unplugging it from the wall to see how long it will last? My plan is to unplug it, and wait until the battery meter reaches its last LED before plugging it back in, so that I know about how long I will have in the event of a power outage.
Do people do this on a regular basis? I'm guessing no (Lead Acid is very different to Li-Ion batteries)… but what kind of harm would it do if this were to happen (on purpose) every 6 months?
Best Answer
You should consider turning off the circuit breaker to the outlet running the rack in lieu of unplugging the cord from the wall. The UPS is losing its electrical ground when you unplug it from the wall. While it's unlikely that anything would go wrong, the UPS designers "expect" that path to ground to remain available at all times, and if something did short during your test you might see sparks (smoke, flame, etc) when the electricity takes another path to ground. I've unplugged UPSs from the wall for testing before, but seeing a flash of "lightning" and hearing a loud "bang" coming out of a UPS during one such test gave me "religion" about not doing that again. After talking to an electrician friend I decided that, from then on, I'd do UPS tests that didn't interrupt the ground to the UPS.
BTW: The PowerChute Network Shutdown software from APC is garbage. You might have a look at apcupsd. It runs under a variety of operating systems (Windows included) and is much easier to configure (and to replicate the configuration on multiple servers via copying files) than the APC alternative.