30amp RV using 20amp Blows GFI

[rubysamm]

I read the 50 amp explanation hoping I would find my answer in that, However I have not.? I have a 30 amp plug for my Class C rig that works fine when plugged into 30 amps.? The problem occurs if I plug in with the 20 amp pigtail into a 20amp with GFI.? The GFI Pops everytime every where. If I use a 20 amp service with no GFI i am able to run most everything in the rig without any problem.? I'm not an engineer or electrician, I just want to plug in and enjoy?

 

[Ned]

You either have some device in your RV that has a fault, or the neutral and ground are tied together.? Disconnect as many 110v devices as you can and if the GFI then does not trip, plug them in one at a time until it does.? If disconnecting all 110v devices doesn't stop the GFI fault, then there is a problem in your RV wiring.? Check the circuit breaker panel and see if the neutral and ground are tied together.? They should not be but it's not uncommon to find an RV wired that way.

Most 30A circuits don't have a GFI so you don't see the problem in those cases.

If you have any doubts about the above procedure, please have an electrician take a look.

 

[rubysamm]

I have brought it to the dealer and they said it never tripped there 20 amp circuit breaker.? I explained it won't trip your circuit breaker only your gfi plug will pop out.? (very aggravating when they don't listen to the full concern) Anyway I will try another dealer and provide your description.? When you say Disconnect 110 devices do you mean to simply pull the fuse on those circuits? (i did try that) still popped.? ?Thank you so much for your response I was beginning to think this was "normal operation"? (kind of a pain when you have to run the extension chord in the window for a piece of toast? ? )

 

[Ned]

Don't just turn the breakers off, unplug the 110v devices.  Turning off the breaker just opens the hot leg, it doesn't affect the neutral or ground and that's where the problem is.

This is NOT normal operation and may indicate a serious hazard.

 

[John From Detroit]

Some years ago the standards for wireing changed,,, Back when I was a wee little lad it was fairly common practice for the nuteral and ground wires to be connected together.

This will pop a GCFI 9 times out of nine.

The standard today is different.  I'm not absolutely sure what the standard is for the power pole in fact (i'm a bit out of date) but for the trailer it should be seperated all the way to the plug.

This was pointed out to me some  years ago... I'd re-wired my trailer for 30 amp service (3 wires all the way back to the plug, nothing common) and was used to using 30 amp outlets.

However at one place I parked the box was 20/30 amp, the other camper had 15/20 amp cord plugged in to the 30 amp via a pigtail adapter (such as you are using but the other way around) because in his rig the nuteral and ground were common and it popped the GCFI's

Now.. personally... I would rather he had fixed his trailer, and not just so I could have had the better outlet (I got by with the 20 just fine that trip, I only need 30 when extending my stay by using electric heat, which I used in the trailer, or electric grill and ac and a few other things all at once (electric hot water heater + AC + Grill + "Burner" = tripped 20 amp breaker, any 3 of them won't trip)

As someone else said, it is a safety issue, I would endevor to have it fixed.

I got one circuit on my new MH (The one I added) where I have to track a gound fault... Tester shows good ground... Trust me. it's wrong

 

[rubysamm]

Just a quick update, I've been told the problem with my gfci popping is the power converter.  I had it at a dealer for a recall and they diagnosed the issue, however there replacement price seemed quite pricey so I am going to try another local place not so big.Thanks again for your input, hope this power converter is the problem. Time will tell ???

 

[Ned]

The converter most likely has the neutral and ground tied together.  They shouldn't be.  Simple test is to disconnect the ground wire, if you can, on the converter and see if the problem goes away.

 

[John From Detroit]

Just a quick update, I've been told the problem with my gfci popping is the power converter.  I had it at a dealer for a recall and they diagnosed the issue, however there replacement price seemed quite pricey so I am going to try another local place not so big.Thanks again for your input, hope this power converter is the problem. Time will tell ???

You might try talking to either the converter's manafacturer or the coach's manafacturer.  As someone else said the problem is most likely a design issue (Nuteral and ground tied together) and this is a safety issue.  A serious safety issue in fact.  Thus they may be willing to replace either no-charge or reduced charge.

Also.. It's possible that the error is correctable if you know anything about electrical/electronics

If you do not.. I won't try and describe how to do it,  and if you do, I don't need to

 

[Jim Godward]

There can be another issue.  In the RV are electronic devices like the TV etc.  Many in the last few years have a surge suppressor built in to them.  It only takes a few to cause a GCFI to pop.  You don't normally see the problem as few outlets in a house haf GCFIs on them, primarily the bathrooms, kitchens, garages and outdoor ones.

 

[fredethomas]

I never could plug in to a GFI 20 amp circuit with our 1998 Dutch Star.  Have worked many hours on trying to isolate the cause with no success.  I must and do use a 20 amp adapter with the third wire ground cut off.  Does not sound safe but I read no voltage or current between the coach and ground.  I do have the jacks down on bare ground.  Might help??

 

[Karl]

John:

You don't normally see the problem as few outlets in a house haf GCFIs on them, primarily the bathrooms, kitchens, garages and outdoor ones.

If the GFCI is wired properly and is the first one in a circuit string, it will protect all downstream outlets.

 

[rubysamm]

I brought it to another technician and explained the GFI problem.? He diagnosed it and fixed it!!! It turns out it wasn't the power converter at all it was the element in the Hot Water Heater.? The Hot water heater has the option of gas or electric and at one point the electric must have been left on with no water in the tank so it shorted the electric element.? Sure enough I got it home plugged it in and VOILA fixed!!!
I was a bit sceptical and almost mad at myself that I didn't just have the original dealer fix it.? But now I'm glad I went with my instincts for a second opinion. (even if it was the price that drove me to it)?
Just wanted to share in case anyone else has a similar problem

 

[fredethomas]

We have always tripped the ground fault when our 50/30 amp Dutch Star is plugged into 20 amp GFI outlets.  I have unhooked all the 120 volt and 12 volt appliances including the inverters and chargers.  Can not stop it.  I now have to use a 20 amp adapter with the ground cut off and ground the coach using a nail and wire.  I have never [with or witout the ground wire] been able to measure any current from the coach to ground.  Electricians say don't do it but the 20 amp is all the park here has for storing the RV's.

 

[Ned]

Fred,

You'll trip 30A GFCI outlets too.? We have the same problem.? I believe it's the inverter that has the ground and neutral tied together incorrectly but haven't attempted to diagnose that yet.? It's always on the list to do at QZ but I just never seem to get around to it

 

[John From Detroit]

We have always tripped the ground fault when our 50/30 amp Dutch Star is plugged into 20 amp GFI outlets.  I have unhooked all the 120 volt and 12 volt appliances including the inverters and chargers.  Can not stop it.  I now have to use a 20 amp adapter with the ground cut off and ground the coach using a nail and wire.  I have never [with or witout the ground wire] been able to measure any current from the coach to ground.  Electricians say don't do it but the 20 amp is all the park here has for storing the RV's.

Rather than trying to measure current (there shoudl be none) try this

Unplug EVERYTHIGN, and I mean EVERYTHING, if you have hard wired stuff like a water heater or AC, unwire it BOTH LEGS (make sure to mark everythign so you hook it back up right)

Now measure for continunity between nuteral and ground,  Again, there should be none, I'll bet that is not the case

Ground should show continutiy to the chassis (mine does) but not to nuteral (mine does not) or hot (likewise)

I've had hardware where there was a short, and folks installed a 3-2 wire adapter,,, And I came very close to sueing them for trying to kill us because that's what very nearly happened.  To say the least, that situtation was "Shocking" (Very shocking)

 

[Karl]

Fred and Ned,

Can't say for sure, but it almost sounds like the shore power/inverter cutover circuitry may be causing the problem; not the relay itself but the shore power sensing part of it???

 

[Gary RV_Wizard]

The problem could well be in either the inverter's internal switch or the shore/genset auto transfer switch. Both are ahead of the main power panel and unaffected by shutting off breakers or disconnecting appliances.

 

[fixitman]

Had the same problem with my rig, after a lot of time tracing found it to be a bad heating element in the water heater, although it was working fine heating up...