GFCI problem

[RobA]

I recently started having a problem with a GFCI outlet in our horse barn. The electricity in the barn was run 5 years ago and I've never had a problem. There are no moisture problems. The problem circuit starts with a GFCI outlet wired to a switch which controls another 4 outlets. The 4 outlets are used for stall fans in the summer and heated buckets in the winter. My wife found the heated buckets frozen a few weeks ago and noticed the GFCI outlet was tripped. She reset it without a problem and all was good for a week or so. Then it happened again a few more times. 3 days ago it happened but now the GFCI won't reset unless the switch controlling the downstream outlets is off. In order to rule out bad heated buckets I unplugged everything from the outlets but that didn't help. I opened the box with the GFCI and switch in it and all the connections seem OK.

Any thoughts on how to diagnose this? Replace the switch? Replace all 4 downstream outlets?

 

[/pine]

Replace the GFCI...I've had several go bad...

 

[jaxs]

The GFCI is probably bad but you can test it. Disconnect switch at GFCI,if it will reset and carry a load,post back.

 

[B7510HSD]

Also check all plugs and make sure you don't have a lose connection somewhere.

 

[teejk]

My wife was having similar problems with a heater she used on her fish pond. Turned out it was the heater. Not to say that the GFCI might be bad though. I've had that also. Your downstream outlets can be tested with a cheap plug in tester.

 

[rbtjr]

We had the same problem and it turned out to be a short in one of the outlets that were served by the GFI circuit. We diagnosed it by removing the outlets one by one.

 

[RobA]

Thanks. The wiring is conduit, not NM. I can't test the downstream outlets unless I remove the switch since when the switch is on the GFCI trips. I may start with replacing the GFCI. I'll tackle it tomorrow.

 

[bunyip]

We had a similar problem with one tripping and after much investigation found that moist foggy mornings the moisture was getting into an outdoor 'waterproof' GPO, replaced the seal and problem fixed.
Another time we did have a faulty unit and replaced it, the upside is that they are cheap now, I think a new one we installed less than a year ago on a new circuit was about AU$35.00 compared to about $150+ 10 years ago.

 

[quicksandfarmer]

GFCI will trip if the neutral is touching ground somewhere downstream. This is hard to detect because it doesn't cause any problem other than the GFCI tripping. I would start at the switch, disconnect all three wires going downstream, and check for continuity among all three. There shouldn't be any at all. If you find any continuity disconnect the outlets one by one until you find the problem.

 

[JPRambo]

Are the downstream outlets in metal boxes? When you remove them to check, screw in the side wire terminal screws. That is where any moisture will accumulate and short to the box and trip the GFCI.