SUA2200I - Random high pitched whine

[Anonymous user]

Hi,

Over the past 2 weeks my UPS has begun to emit a sound - a short high pitched whine lasting 2 seconds, the kind you hear when a camera flashgun charges up but this is much louder.

It happens about 2-3 times a day and is not related to load or time. I have heard it when the UPS is switched off or in use. Ambient temp is pretty warm at around 28 deg Celcius as we head into the Indian summer.

I had set the data logs to update at 1 minute intervals. Everything seems normal - including line voltage (232-243VAC) battery charging voltage (54.5-54.8 VDC), output voltage and frequency (230-240VAC, 49.5-50 Hz), internal temperature (32-35.5 deg celcius, 89.6-95 deg F).

Can someone shed some light on this peculiar noise?

Thanks!

Viv

[BillP]

Is the whining sound accompanied by a visual indicator on the UPS? Is it somehow similar to what our UPS could produce when it is operating on battery and is there any possible that the event is logged on the APC software?

[Anonymous user · Accepted solution]

Hi,

There's no visual indication of any change in the UPS status. I have set the monitor logs to update at 1 minute interval but everything seems normal. I mentioned the range of operational parameters from the log in my 1st post.

I took a flash light and shone it into the UPS via the side ventilation grill - and I could see 2 large black capacitors between 2 heatsinks. Could it be one of those capacitors or something else in the battery charging circuit, MOSFETs for example?

Will forcing UPS to go 'braindead' (by disconnecting the batteries, switching off the power supply/mains, disconnecting load at the outputs and pressing the Off Button till you hear a click) reset the UPS and its microprocessor to factory defaults?

Regards,

Viv