SmartUPS 1500 drops load during power glitch

[lunadesign_apc]

I have a few SmartUPS 1500 (SUA1500) units and an older SmartUPS 1400 (SU1400NET) unit.

They have worked flawlessly for many years.  Primarily, they help with sub-second power glitches that we get (usually during windy weather) and occasional multi-minute outages.

Earlier today we had one of those sub-second power glitches during a wind event and I was surprised that one of the SmartUPS 1500 units dropped its load, somewhat like if it had no battery.  The load was probably about 50% of capacity.  The battery on this particular unit was replaced less than a month ago and is known to be good.  I also ran a Self-Test after the event with a similar load connected and it had no problems.

Any idea what happened?  Does the power glitch detection circuitry and/or relay go bad over time?  Or are there certain kinds of glitches that these boxes can't protect against?

[BillP]

Hi,

A UPS along with all other electric equipment will degrade over time. We recommend replacing unit ever 7 to 10 years depending the usage and environment. I will admit I just recently replaced 2 BP700 that where manufactured in 2004 so they were way past the recommend dates. 

[SamirD_apc · Accepted solution]

If the units weren't able to calibrate the replacement batteries they may have miscalculated the run times.

The other thing that can happen is that if the replacement battery wasn't a genuine APC, I've seen issues like this with third party batteries.