Faulty GFCI?

[PeterAndMargaret]

We have been away from our 2000 Fleetwood Flair for a few days and returned today to find that the GFCI (located in the bathroom) had tripped and I cannot get it reset. When we left all was well. I have disconnected the shore power and reconnected it (with all the circuit breakers off) and the moment I reset one of the circuit breakers the GFCI trips. The GFCI protects the electric outlets in the bathroom, 2 in the kitchen and 1 outside (these are the outlets that are not working).

 

When I disconnect the shore power I can reset the GFCI but the test button does not pop out as it should.

 

Could it be that the GFCI has failed or should I be looking elsewhere?

 

Peter

 

[mesa]

GFCI are notorious for failing in households so I would expect the same in rv's.

[Alie&Jim's Carrilite]

They can fail, but I would look for a cause. Was there any rain while you were gone? We replaced an outside outlet that was tripping the inside GFCI breaker. Somehow, someway, moisture had worked its way inside the prongs and caused a fault.

[oldjohnt]

I envision a couple of scenarios here.

 

1) A GFCI wont reset BECAUSE THERES A FAULT AND ITS DOING ITS JOB. If there's a fault, it will trip and not reset and hold in.

 

2) If there's absolutely no fault whatsoever (local or downstream) but it wont reset and hold in THE GFCI MAY WELL BE FAULTY as I have seen

so many ESPECIALLY if they are the cheapest bargain barn units.

 

With downstream loads like outdoor receptacles and kitchen etc wired to the GFCI's load side, it may well be that there's a fault in the circuit and

its tripping and working as it should!!!!!!!!! I would completely disconnect the wires on the GFCI's Load side terminals, turn on the breaker, see if

the GFCI will reset and hold in then??????????

 

If so, there's a fault in the downstream circuit or one of the receptacles and the GFCI is working and doing its job.

 

If NOT, with nothing plugged into the GFCI and all load side wiring removed she wont reset I suspect a faulty GFCI.

 

If its set a long time moisture and corrosion may have created a high resistance yet conductive ground fault and a typical GFCI only requires

something like 5 milliamps of fault current to trip and that's not much.

 

John T Short n sweet as I can make it lol Maybe some of the other fine gents can come up with yet more possibilities

[pugsly]

GFCIs can be finicky. If you aren't sure it is working correctly I would spend the couple of bucks and put in a new one.

 

Our house got hit by lightning a few nights ago and every single one of the GFCIs tripped. Never seen anything like that happen before.

[Kirk W]

For one not familiar with electrical trouble shooting, it may well be easiest to try replacing the GFCI first, but don't be too surprised if the new one trips also, as I have seen only a few such failures. If replacing it don't help, look next at the outdoor outlet as they are well known for being the cause due to moisture getting into them from a poorly sealing outlet cover. If you have a plastic one, I'd consider replacing it with a metal one. An easy way to check it would be to open the circuit breaker, then pull the cover off and remove the outlet from the box, disconnecting the wires and leaving them off, just make sure that they don't touch anything while you turn the breaker back on to see if that solves the problem. If it does, there is a very good chance that by using a blow dry you can dry things out to solve the problem and then replace the cover. A GFCI requires only the tiniest amount of electrical leakage to trip as it is there to be quick enough to be able to prevent an electrocution, even if the appliance is dropped into the bathtub with you in it. It is possible that it is some other problem, but my experience has been that with an RV the outdoor outlet is the first suspect.

[oldjohnt]

To add just a bit of hard technical data to Kirks good post....." A GFCI requires only the tiniest amount of electrical leakage to trip as it is there to be quick enough to be able to prevent an electrocution"

 

1) A typical GFCI will trip when there's approximately 5 to 6 milliamps (0.005 to 0.006 Amps) of fault current, the reasons why are:

 

2) The threshold of current which can cause the heart to fibrillate is around 30 to 50 milliamps; At 15 ma muscles freeze in 50% of people;

 

3) A GFCI must trip within 25 milliseconds (0.025 second). At 60 HZ, 1/60 or one cycle = 0.016 seconds (16 milliseconds), therefore it doesn't

take much over one cycle before it must trip;

 

4) Some stationary motors, such as a bathroom vent fan or fluorescent lighting fixtures, may produce enough leakage to cause nuisance tripping.

Another problem may be a long circuit with many splices. If possible, keep GFCI circuits less than 100 feet long. To avoid nuisance tripping, a GFCI

should not supply:

Circuits longer than 100 feet.................Fluorescent or other types of electric-discharge lighting fixtures.............Permanently installed electric motors

 

Best I recall, to avoid potential nuisance tripping, a load such as a freezer on your garages concrete floor is GFCI exempt, provided its

supplied by a SINGLE receptacle in a non easily accessible location such as say a hidden single outlet down behind the freezer etc.

 

In as laymen's terms as I can make it, a GFCI measures the Ungrounded Supply and normal Grounded conductor Neutral return currents, and

if its not all being returned via the Neutral as it should, it must be leaking elsewhere (hope not via your body) and if its more then 5 to 6 ma

IT TRIPS TO SAVE YOUR LIFE.

 

In all my years of engineering and an RV user and dealer I've seen several GFCI failures, but as posted above, outdoor or high moisture

locations are prone to cause a GFCI to trip, NOT because the GFCI is bad, but because its good and doing its intended job, so disconnect and

check all the downstream circuitry.

 

NOTE while I remembered much of the above and the basics, I did a brief internet research (NEMA and other) prior to this post so its not all

based on my failing "recollection" alone lol

 

Hope this helps, yall keep safe now and think of your barefoot grandchild standing in the rain and coming up and touching the RV !!!!!!

 

John T Too long retired and failing "recollection" so NO WARRANTY check with the NEC and rely on their advice NOT mine.

[PeterAndMargaret]

Many thanks for the replies and the advice, they are much appreciated.

 

On the off chance that the GFCI was simply having a bad day, I left it for a few hours and then tried to reset it. Lo and behold, it reset and has been fine since then. I will however check the outside electrical point just to make sure all is well there.

[oldjohnt]

Peter and Margaret, thanks for the feedback. There's a chance some moisture dried out thereby eliminating a small leakage current between Hot and Equipment Ground? or kind of like you indicated, a non perfect mechanical/electrical activated GFCI just had a bad hair day lol stuff happens !!!!

 

It wouldn't hurt to remove, inspect and clean those downstream load side receptacles and circuitry ya know.

 

John T

[Kirk W]

On the off chance that the GFCI was simply having a bad day, I left it for a few hours and then tried to reset it. Lo and behold, it reset and has been fine since then. I will however check the outside electrical point just to make sure all is well there.

That sounds pretty typical for an outside outlet moisture problem. Should you get more rain, it will most likely return. I would go ahead and replace the cover plate on that outlet and seal it with a good caulking material.

[jc2]

I agree with Kirk. The incident that we had several years ago was with a sticks & bricks house outside receptacle. Replaced the cover as the gasket was looking less than optimal; problem solved. Would also applied, as others mentioned, with outside rv receptacles.

[markandkim]

That sounds pretty typical for an outside outlet moisture problem. Should you get more rain, it will most likely return. I would go ahead and replace the cover plate on that outlet and seal it with a good caulking material.

Use that flexseal stuff on the entire box.

[oldjohnt]

Unfortunately, I've seen all the caulking and sealant in the world surrounding an external/outdoor receptacle which didn't help, because the spring loaded trap doors that cover the actual outlets is where water might still enter. Some of the soft gasket material seems to flatten and shrink with age or the doors don't close and seal tightly or leak at the top. The better quality heavy cast outdoor receptacle housing and covers seem to fare better, but such bulky hardware is often seen more in household then RV use. On an RV If the box (even if not a heavy cast type) is well sealed and a good quality waterproof cover is sealed and in place, that's about the best you can do. Also with some brands and styles of weatherproof door/covers a bigger bulky plug just cant fit in because the door/cover is in the way.

 

Since a GFCI has to trip at 0.005 amps (see my reasons why above) nuisance trips due to moisture or contamination just goes with the territory. When trips happen and the external outlet is the cause (as so typical in my experience) about all a person can do is to remove and clean and inspect the outlet and wiring then reseal and use a good tight cover and pray for sunshine...........

 

Regardless, the GFCI could save your life, so pull maintenance to avoid nuisance tripping and use good covers and sealers.

 

John T

[jimhanus]

I've had my TT GFCI trip with just dampness inside the fridge outlet box. Nothing obviously wet, just damp inside the outlet box from a lot of rain while camping (I'm talking deluge), and driving home in the rain. It worked fine once the weather dried up, but I replaced to fridge outlet anyway. Inside the box was dirty and had spider webs, etc. so maybe that was enough of a bridge between wires to trip it.

 

Jim

[Randyretired]

The 50A outlet at or home had the same problem. Cleaned out the spider webs and it has been good for 2+ years.

[Kirk W]

I've had my TT GFCI trip with just dampness inside the fridge outlet box. Nothing obviously wet, just damp inside the outlet box from a lot of rain while camping (I'm talking deluge), and driving home in the rain. It worked fine once the weather dried up, but I replaced to fridge outlet anyway.

That really isn't surprising as it only takes a few micro-amps of current to trigger the ground fault. It is designed to be early enough and fast enough to prevent electrocution if a person is in danger. Your fix was clearly on the right track. About all that you can to do improve on this would be to possibly find a way to seal the electric box to prevent dirt, and moisture from getting into it.

 

I have had our outside outlets trigger the GFI inside of our bathroom that is got power from, when the weather cover got weak or it's seal poor. It was also one that went away as soon as the sun came out and hit the side where the box was. The power loss is so small that it can be difficult to pin down.