Posted: 2021-06-30 07:19 AM
This question was originally posted by Adam on APC forums on 2/6/2021
I had this unit for five years now. I always replaced batteries with genuine APC at least two times: not a single issue.
Recently, I have removed the UPS for scheduled maint, cleaned the ventilation holes and then put it back but without connecting any load. When I turned on the device, it performed a self-test which was not successful. The display showed a fault red light and the message: "fault state: output over volt". By attaching all the load back, and cycling the UPS power OFF-ON, the self-test was successfully passed. The load was 12% (120W).
If I attach something lower than 120W, the UPS won't pass the self-test neither is able to provide UPS protection to the outlets if the AC cable is removed (batteries fully charged).
Is there a Minimum load under which the UPS can't operate?
It is normal to get the "fault state: output over volt" without load?
I suspect a system malfunction because other UPS I have installed (different maker) are able to work and perform a self-test with no load attached. In this case, is there something I could do to verify the device?
Thank you very much,
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