Building wiring fault red light is always on!!!

[BillP]

I have a Backups 750 and the red wiring fault light is always on even when nothing is attached to the UPS.  I have also checked the outlet with tester and it is fine.  I have checked the ups on different outlets which have shown no fault on tester as well.  What should I do????

[BillP]

Hi Sasan,

The Site Wiring fault LED is indicating that at least of three electrical issues is present in the circuit. 

I would recommend you review the following document which explains what may be wring.

Site Wiring FAQ# FA158817

If you feel the LED is on in error, I would recommend trying the unit in a completely different location such as a neighbor or at work. 

Secret Squirrel

[Anonymous user · Accepted solution]

Good day to all.

I have 3 APC Back-UPS 550 that all exhibit the same condition described in the subject line.  When powered up, the Building Wiring Alarm activates. I removed them from the original job-site where the fault occurred & replaced all 3 with new ones.  These do not indicate any wiring faults in the same wall sockets that the original 3 units were connected.

After powering up the "old" units in a different building/location, all 3 continue to show the fault light & emit the warning tone.  I've confirmed the building wiring at the current location is correct. Replacing the batteries has no positive effect on eliminating the alarm condition.

Is there any "reset" procedure that I can run on these units to allow them to work properly again or are they damaged beyond further use?

Thanks for any feedback/suggestions that the forum members can provide

Regards,

WTG21953

[BillP]

As with my case and the way I see your case too, your devices are faulty and either have to be replaced or sent for repair.

[FincaPinguino]

I just recieve our new UPS and it is acting up with the wiring fault light, especially at night. 
We are deep into the country side and our electricity is jumpy at best. The wiring is in check but we have the ever so often lows in the electricity supplies. 
Could the reason why the wiring fault light  is on, when it is or am I  looking at a need to replace it entirely? 

[dnchrist]

LED on constantly on a 1500.  First I used a circuit tester on the receptical.  No problem.   Tested the UPS on multiple recepticals through-out the house.  LED was on at each location.  I bought a new UPS and it did not have a problem  Turned the UPS power off and uplugged everything and unpluged it from the wall.  Carefully removed the 6 screws on the back cover and looked inside.  Notice the little circuit board in close proximity to the fault LED.  I removed a large dust deposit and blew the whole UPS out with compressed air.  Reassemble.  For Me - Problem Solved!