BX1000 (intermittently) constantly switching on and off battery

[justmatt_apc]

I've got a 10 year old BX1000.  About a month ago, I was awakened to the sound of constant clicking.  The switches were within 1-2 seconds of each other, such that they didn't even really register in PowerChute.  PowerChute might indicate "On Battery" for a split second, but often didn't, and even then it would not be long enough to sound the alarm or increment the "Unit switched" counter on the Performance page.  Occasionally it would trip for long enough to register and increment in PowerChute, and when it did, it indicated Blackout for the reason.  But those registered, incremented trips were outnumbered easily 5-6:1 by the "so fast it didn't register" trips.  Once it starts, it usually goes on for a couple hours before it quits again, and then it might be 24 hours before it does it again.

The batteries are 8-10 months old, and the UPS passes self tests.  I can't see any power fluctuations on a multimeter.  An ES 725 on the same circuit has never tripped.  I've checked all my connections, and they're all tight.  I'd really prefer not to replace this, as it's been good to me for a decade, and I just put $70 worth of new batteries into it.  Turning the sensitivity down to Medium has cut the clicking by maybe 20%, and I'm not willing to run my system on Low.  I'll replace the UPS first.

[justmatt_apc]

I've got a 10 year old BX1000.  About a month ago, I was awakened to the sound of constant clicking.  The switches were within 1-2 seconds of each other, such that they didn't even really register in PowerChute.  PowerChute might indicate "On Battery" for a split second, but often didn't, and even then it would not be long enough to sound the alarm or increment the "Unit switched" counter on the Performance page.  Occasionally it would trip for long enough to register and increment in PowerChute, and when it did, it indicated Blackout for the reason.  But those registered, incremented trips were outnumbered easily 5-6:1 by the "so fast it didn't register" trips.  Once it starts, it usually goes on for a couple hours before it quits again, and then it might be 24 hours before it does it again.

The batteries are 8-10 months old, and the UPS passes self tests.  I can't see any power fluctuations on a multimeter.  An ES 725 on the same circuit has never tripped.  I've checked all my connections, and they're all tight.  I'd really prefer not to replace this, as it's been good to me for a decade, and I just put $70 worth of new batteries into it.  Turning the sensitivity down to Medium has cut the clicking by maybe 20%, and I'm not willing to run my system on Low.  I'll replace the UPS first.

[Anonymous user]

What is the environment you are using this in ...  assuming home office ? ...need to know or look around to see if there is anything on the local electrical grid or in your home or even your  neighbourhood that is causing power glitches like things with a motor, or fridges, or welders ? If that is not the issue, it could be as components in the ups age (such as the circuitry that is watching for glitches) it could cause the thresholds for detection to drift over time...upwards or downwards.

[justmatt_apc]

There's nothing coincidental to the clicking in my house, but I live in an apartment, so I can't speak to the people around me.  However, it'd have to be pretty significant, I'd think, for me to see problems because of them.  Significant enough, I'd think, for the power company to notice, since I had them out here to look at it.

[BillP]

Seeing your using PowerChute you can try and adjust the sensitivity to low or medium and see if that makes a difference. As the unit might be responding to small power fluctuations that the other UPS is not able to detect. If you have PowerChute on the ES you can see what its current sensitivity settings are.

[BillP]

From everything that you have said so far it sound very much like the in coming power is at fault but its hard to say without seeing the unit in operation personally. The fact that the switching dropped when you reduced the sensitivity to med would suggest mains in is out of tolerance. When you say you had the power company out do you know what they tested for? One thing you could look into is getting someone to install a voltage logger which can monitor the slightest changes and record it, they can then give you a report with recommendations as to what might be causing the faults.

[justmatt_apc]

Thanks for the reply.  I didn't actually have the power company out to my location, as I apparently wasn't able to convince them there was an issue.  I presume they have some sort of monitoring system in place because the support person I talked to on the phone (tier 2?  I don't know, but I got referred to a "supervisor") indicated that their equipment didn't show any issues in my area.  It's possible that their equipment only shows issues of a gross nature, and mine is clearly a "fine" issue.

I've been trying to figure out a voltage logger, but they're not cheap, and I've had no luck so far finding a loaner.

Thanks again for the reply.  I continue to chase it.  The tripping has gotten less frequent in the last 3-4 days, but it does still happen.  It's gone from 5-6 times a minute for 2-3 hours at a time down to 4-5 times in rapid succession and then nothing for several hours.  My settings are still at Medium sensitivity and 104 volts for a low voltage limit.

[justmatt_apc · Accepted solution]

I'm already running on medium, and I'm not willing to subject my equipment to Low.  My ES 725 has no sensitivity settings, just voltage.