Smart-UPS 1000XL shuts down unexpectedly

[Anonymous user]

I have a Smart-UPS 1000XL connected to a UXBP24 battery pack with four batteries. The UPS battery and all four batteries in the battery pack are brand new, fully charged with about a 31% load. Twice in the last three months this UPS has shut down unexpectedly. The first time, I was right next to it and it shut down completely with no beeps or lights flashing, as though I had manually shut it off. This of course immediately cut power to the entire rack that it powers. Any idea what the cause could be? Unfortunately, I did not have PowerChute running at the time (I do now). I know the UPS unit itself is 10 or 11 years old. Is it time to replace the UPS unit, and if so, is there an available one that would work with this same battery pack?

[BillP]

This is tough to say without looking at log data to see what is reported. It could be either be batteries (is the external battery connector connected securely) or the UPS unit and based on what you said and described, it does not make me lean towards one more than the other unfortunately.

After making arrangements with a non critical load, you could trip the upstream breaker to simulate a power outage to the UPS as one test to see what happens when the UPS loses AC input. If that works, then that's one thing to rule out but it still wouldn't necessarily rule out the UPS as the culprit but is at least a start to verify a part of the UPS's operation.

We do have a Smart-UPS XL compatibility charge for battery packs here if you do end up going with a new or different UPS (only older models will likely work with this XL BP)-> http://www.schneider-electric.us/support/index?page=content&country=US〈=en&locale=en_US&id=FA156524 

[Anonymous user]

Thanks for your reply. This happened again a few days ago and I'm seeing a few interesting facts.  This issue has happened exactly 28 days apart, three times in a row (although at different times of the day). This last time it happened I found the "Battery Charge" lights on the right side of the panel were all lit - can't remember if other lights were lit or not, but it was not making any sound or providing any power.  That is, everything plugged into it was powered down.  I hit the power button and the unit powered off, then I hit the Test button and the unit and everything plugged into it powered up.  The log files don't show much.  I see a week or so before that it did a self-test and passed.  It doesn't show any lost communication until I powered it down and back up. I failed to mention earlier that we have occasionally experienced very brief power outages to the building, during which the unit has responded appropiately and switched to battery power. Does this make any sense?  Thanks.

[BillP]

Hi Rick,

I am just as puzzled as you unfortunately. I am not sure what the every 28 days part means either. It does not align with anything I know of on the product side and I assume it did not mean anything to you regarding something in the environment, regular building maintenance schedule (beyond planned power outages), etc?

[Terry_Kennedy_apc · Accepted solution]

The only thing I can think of is that 28 days is exactly twice the standard self-test interval of 14 days. It might be that there is something happening which causes the self-test to fail some of the time. It might be worthwhile to temporarily set the self-test to "never" and see if the problem stops happening. If that is the case, then there's something wrong which is causing a total failure ("lights out") during the self-test which will need to be investigated further. If the problem keeps happening, then this wasn't the cause of it. In either case, you definitely want to re-enable scheduled self-tests or the first time you'll know the UPS doesn't work is during the next power outage.