Does F02 indicate misuse?

[Anonymous user]

All,

I'm on my second Back-UPS 1200 and, like the first, it's starting giving me an F02 error (on-battery short). Removing all load and going through the brain-dead steps doesn't help. APC support has been very helpful and so a third unit is on its way to me.

The APC engineer I spoke to after the first unit failed stated this was an internal fault in the unit and he was very apologetic. The engineer I spoke to for second unit told me it's because I've put too much load on the device and was caused by my "misuse of the unit". The implication was that through this supposed misuse, the device now needs to be replaced (and this has been arranged promptly - I've no complaints there). But clearly, I don't want a problem with the 3rd so if this is in my control, I'd like to know more about it.

I've two desktop computers and a small NAS plugged into it which draw around 300w, well within the capabilities of the device. But my question really is this: is it possible to damage the unit by overloading it? The UPS has a separate overload status and I know from many years working in the field with APC UPSs (not this exact model, though), if the load exceeds the max, it enters an overload state which is resolved simply by removing some of the said load. I would be very surprised if a UPS can be irreparably damaged by loading it beyond the max, surely a common-enough event.

Have I been naughty or just unlucky? Any thoughts much appreciated. Thanks.

[BillP]

If the fault was not present during the first few weeks of usage, it is possible that it was caused by the load. On your next UPS, before connecting any load on the UPS I would suggest that you test it first by simulating a power failure. Once the test is done, attach the load one at a time and doing a power failure test on the unit.

To do a power failure test, you would just unplug the UPS from the outlet and letting it run on battery.

[BillP]

Hi ssiltd,

The F02 fault is also known as OnBattery Output Short which may be caused by a true short at the load, an old/weak internal battery or excessive load. Possible damage that it can cause are relay welds or solid state component damage. On your situation, it would help if we could identify if it is the load that creates the F02 fault.

On your third UPS that you'll get, if the same problem would happen again I would start with removing the load attached and power cycle the UPS. Attach the load one a time, giving it an ample amount of time say a day or too before adding additional load. This way we could see if there's a shorted, if in any time that the UPS would show this fault and there's no load connected then the UPS itself is at fault.

[Anonymous user · Accepted solution]

Hi JonPro,

thanks very much for the info. I'll take that approach when the new unit arrives.

Just so I'm clear, my current UPS is giving me an F02 when on-battery even with no load connected (no F02 when utility power connected). Does that mean the fault was always with the UPS or could this current situation have resulted from earlier possible damage?

Thanks.