I have 3 APC UPS (Uninterupted Power Supply) units in my house. Tonight, two of them started beeping as though the power were out, but the power was on. Pressing the reset button on one of them stopped both of them from beeping. Any idea what might cause this?
How old are they?
The two that were beeping are less than 1 year old. The one that did not beep is about 2 years old. They are all the same model (BF 500).
I have a Tripplite UPS, and it is routinely tripped by brownouts that are almost imperceptible. I’ll see the lights flicker just slightly and the UPS will start beeping, but other devices are unaffected (other computers not on UPS, TV, etc.). After a few moments, the UPS resets and all is normal. I assume it just has its threshold set very low and “overreacts” to changes.
Is it possible that your UPSs reset on their own, and it was only coincidentally tied to you pressing the reset button? Perhaps the two new units have tighter standards and tripped on a minor brownout that didn’t trip the older unit.
Wow, never thought this old knowledge would help anyone else. I worked on Exide UPS systems for about 5 years. So I have a detailed knowledge of thier operation. What probably happened, assuming that the power didnt bump or go out, was on over voltage or undervoltage situation. In that case the UPS system will see that the AC power coming out of the outlet ia above the threshhold, say 130V or so, then it kicks the UPS on for a bit and disconnects the device from the commercial power. This will happen frequently when you have power flux’s. Especially those cheapo APC UPS systems. Those things are pretty much glorified surge suppressors. If it does it on an consistent basis, try to plug it into a different outlet. If it still does it, the UPS may be bad.
Hope that helped!
Micco’s got it IMHO. I have 5 APC UPS’s near me, 3 of them generally come one once every two months or so. My PC prior to being protected by a UPS, would reboot when the other UPS’s would come one. No other machine in the shop (40 PC’s) would.
It’s possible that 2 of the 3 UPS’s you have are one one side of the AC line, and only that side drops out.