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Lance M · 05-20-2011, 08:39 PM

I have a small problem. Whenever it rains, the A/C circuit pops the GFCI of the house circuit I'm plugged into. It only happens when it rains. When it dries out, it works just fine. If I shut off the A/C breaker at the box, I can reset the GFCI and all the other 110 outlets work fine in the trailer. Even with the A/C off at the thermostat, when I turn on the CB at the CB box it will trip the GFCI. Not the main CB, just the GFCI at the outlet. I have removed the A/C shroud and opened up the little wiring box and tightened all the wire nuts and made sure everything was in order. I found one wire a tad loose the other day so I thought I had the culprit, but It just rained and did it again. I sealed the little Jbox with sealant when I closed her up. The A/C is the original Armstrong unit. Any ideas?

barts · 05-20-2011, 10:25 PM

GFCI breakers trip when a imbalance exists between the current in the hot leg and the current in the neutral leg. Some things to check:

1) make sure relay/starter on A/C is interrupting hot leg, not neutral leg.
2) look for leakage paths on any of the wiring to the relay/starter. Note that dirt, wetness, etc. can easily conduct the milliamp necessary to trip the GFCI.

Another way of doing this is to get a mister bottle on a dry day and gently mist connections, etc. to find the leakage path. Plug something into the 110 outlet in the trailer so you know exactly when it trips. Of course, be careful while doing this....

- Bart

Aage · 05-20-2011, 10:33 PM

Wonder if the GFCI unit is marginally defective?

Did you try replacing it?

NevadaGeo · 05-20-2011, 10:56 PM

I had that problem in a buried line once. When it rains, it trips. Best bet is to find the wire that collects rain and replace it or waterproof it. Probably be a small slit in the protective covering from a siding nail that you can't find.

Silver Goose · 05-20-2011, 11:18 PM

Do you have an outside 110v outlet? Considering your symptoms I would start there and inspect the gaskets to be sure moisture isn't getting in.

Lance M · 05-21-2011, 05:11 AM

Thanks for the help guys.

Barts,
I'll try those things you mentioned.

Aage,
I haven't replaced the outlet. I don't have any problems from it any other uses. Just when I have the trailer A/C circuit breaker on and it rains. When it trips I can shut off the A/C CB, reset the GFCI and everything else works fine.

NevadaGeo,
I have it isolated to the A/C circuit of the trailer. I don't think it is anything with the house or the house wiring. I have a 100' extension cord that I use to plug the trailer into an outlet inside the house.

YankeeDoodle,
My trailer doesn't have an exterior outlet.

I guess I need to do some more trouble shooting.

overlander63 · 05-21-2011, 07:44 AM

You'll want to pull the shroud off the A/C unit. Check the capacitors and make sure they aren't in a position to get water on top of them, where the connections are. Our '72 had this problem, I found out about it one day when it had rained, and I touched a metal part of the air conditioner.

Lance M · 05-21-2011, 09:36 AM

Thanks for the help y'all. I think I've fixed it. These two wires were draped down over the blower motor sitting in a puddle of water. The black rubber boot for the (capacitor? Relay?) Is all torn up and was puddling water where these two wires connect to the componnent.
I cut off the old blade connectors and used two of these $1.10 crimp/solder/heat shrink super connectors I bought at Fastenal. I did my best to seal up the top and sides of the rubber boot. I'll have to keep an eye on it. It seems to be working fine right now.
Thanks guys. Once again the Forum knowledge base comes through!

Aage · 05-21-2011, 01:27 PM

Congratulations on finding the fault, Top. It does sound logical, that the wires that got a soaking would trigger the GFCI.

Here's a tester that I think I will put in my toolbox for future questions like you were going through. It tests for seven conditions and indicates faults by simple LEDs, hopefully it would have given you a hint as to what was going on.

"GFCI and receptacle tester tests ground fault receptacles by overloading circuit and tripping GFCI."

Lance M · 05-21-2011, 05:19 PM

Quote:

Originally Posted by Aage

Congratulations on finding the fault, Top. It does sound logical, that the wires that got a soaking would trigger the GFCI.

Here's a tester that I think I will put in my toolbox for future questions like you were going through. It tests for seven conditions and indicates faults by simple LEDs, hopefully it would have given you a hint as to what was going on.

"GFCI and receptacle tester tests ground fault receptacles by overloading circuit and tripping GFCI."

Thanks Aage! I'll see if I can find one of those. I'm not an electrician, but I do make them do push ups now and then. Electricians are always the ones in the smoke break area at the hangar. Whenever you see three Soldiers in my unit wasting time, two of them are electricians. The third is usually a pneudraulics (aircraft plumber) mechanic. You know what I think of plumbers these days!

wasagachris · 05-21-2011, 05:35 PM

Quote:

Originally Posted by Top

Thanks Aage! I'll see if I can find one of those. I'm not an electrician, but I do make them do push ups now and then. Electricians are always the ones in the smoke break area at the hangar. Whenever you see three Soldiers in my unit wasting time, two of them are electricians. The third is usually a pneudraulics (aircraft plumber) mechanic. You know what I think of plumbers these days!

Lance I'm LMAO about the pushups. Electricians are the only ones that get paid to pull their wire all day long.

Plumbers only need to know the two rules of plumbing.
1) poop flows downhill
2) Payday is Friday.

Farmer Dan · 05-21-2011, 05:44 PM

Chris,
I heard the same plumbers admonitions with one more bit of advice : Don't chew your nails !!!!

Dan

Lance M · 05-21-2011, 06:03 PM

Quote:

Originally Posted by wasagachris

Lance I'm LMAO about the pushups. Electricians are the only ones that get paid to pull their wire all day long.

Plumbers only need to know the two rules of plumbing.
1) poop flows downhill
2) Payday is Friday.

My Dad always said that about plumbers when I was a kid. After actually trying to find a good plumber, I know what he was talking about!

overlander63 · 05-21-2011, 06:08 PM

Quote:

Originally Posted by wasagachris

Plumbers only need to know the two rules of plumbing.
1) poop flows downhill
2) Payday is Friday.

I have always heard:
Hot on the left
Cold on the right
Crap flows downhill
Most plumbers around here only have one out of those three correct

Lance M · 05-21-2011, 06:19 PM

Ha Ha! That's a funny one! So Terry, what is the little thing on the top of the motor called?

overlander63 · 05-21-2011, 07:53 PM

Quote:

Originally Posted by Top

Ha Ha! That's a funny one! So Terry, what is the little thing on the top of the motor called?

That's a capacitor. If you grab the terminals, it can really "light up your life".

Lance M · 05-21-2011, 07:59 PM

Quote:

Originally Posted by overlander63

That's a capacitor. If you grab the terminals, it can really "light up your life".

It did just that a few days ago when I was prodding around with the juice on!

soldiermedic · 05-21-2011, 09:57 PM

Cardiac Dysrhythmias.....shocking

Lance M · 05-24-2011, 08:12 PM

Looks like another problem with the A/C and popping the GFCI. Today after having the A/C on for about six hours, the GFCI popped again. No rain. Just a lot of heat. I shut off the A/C and moved the thermostat to the hottest setting. I reset the GFCI and turned on the A/C/ The blower fan came on and ran fine. When I turned the thermostat down, the compressor kicked in and immediately the GFCI popped. That pretty much narrows it down to the compressor and compressor wiring. Maybe something melted. Any ideas?