Back-UPS 850 start-up - intermittently fails with continuous whistling noise.

[pete99]

I have a APC Back-UPS 850 uninterruptible power supply. Sometimes when I switch it on it goes through the normal testing sequence but then all the leds go out and it makes a continuous whistling sound. If I switch it off and repeat, it normally starts up correctly.

PowerChute self-test passes.  The last battery replacement date, which must be when I bought the device, is September 2022.  The average load on the battery is consistently below 150 watts and the estimated battery time is over 20 minutes, which is pretty much what I remember it being when the device was new.

It's irritating but I can work round it.  Just wondering if there is an explanation or solution?

Thank you.

[Teken]

Connect the unit to a computer running APC Power Chute Software. The system should indicate any active faults / error codes provide that information here for review.

You also have the ability to provide the data, event, ups logs. Upload them here for review so better insight can be given.

Questions Ask . . . 👍

[pete99]

Thanks for this.  I would say that my original post did say Iwas using APC Power Chute and that there is no indication anywhere of any failure.  The only "ups logs" I can find in the software are the PowerChute Technical Data, which I have attached and which reports "Result of last manual self-test: Passed".

To clarify my initial post, I press the power button on the UPS, it goes through the self test routine, then all the leds go out and it makes what I can best describe as a whistling sound from the internal speaker of the ups.

The only non-informational Windows Event Viewer events for APC Data Service or APC UPS Service are a couple of older "PowerChute not communicating with the battery backup." errors.

However, now I think about it, this is all irrelevant as the issue I'm reporting is when I'm pushing the power button of the UPS on in the first place - i.e. before the computer is booted.

[Teken]

You can install SPC PCSS software for better insight for event, data, ups logs. In the interim remove AC Mains and report back how long the system operates for on battery power.

Report back what the system indicates the battery voltage is prior and after the lights out test.

Once the UPS shuts down disconnect the battery and measure the voltage. Report back if it matches what Power Chute indicated.

Questions Ask . . . 👍

[pete99]

SPC PCSS software does not work for me.  The browser says the (self-signed) certificate is invalid.

[Teken]

You just need to ignore the error message and say yes to proceed. 

[pete99]

Thank you, but not in latest versions of Edge and Firefox on Windows 11.  Ridiculous that a piece of software would have this obvious gotcha.  (Possibly the issue with PCSS is due to time zones and the self-certification : I am in UK, it was morning and possibly it relies on US time zones?)

In any case, I posted the question thinking my issue would be something others had experienced and solved.  It seems that's not the case.  The issue only happens fairly occasionally so, rather than trying for a second time to get into PCSS and more determinedly work round the https issue (to collect data, not solve my issue), I think at this stage I'll just live with the issue.

Thanks to everyone for their responses.