[Techtalk] mysterious pops driving me nuts

Akkana Peck akkana at shallowsky.com
Tue Apr 14 21:00:03 UTC 2009

Carla Schroder writes:
> That's the APC unit, a cheapo backup battery and surge protector. Not a real 
> uninterruptible power supply. Dunno if it even has a vent. I shall look.

We have a cheapo APC UPS too, and it makes loud relay clicking
noises sometimes. Same noise you hear from the big relays in your car.
When I start hearing a lot of those clicks (a couple times a minute
or more for several minutes or all day) it means either

(a) we're having power problems (the relay clicks when power drops
below some threshold, and during windy/stormy days sometimes that
happens repeatedly even though there's no power outage), or

(b) the battery is dying and will need replacing soon.

When it's (b), you typically don't have much time -- maybe a week,
maybe less -- from when the relays start clicking a lot to when the
unit will stop working at all.


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