GFCI Problems

[seanb02]

Hey folks, I have a tough one you may or may not be able to help me out with. My GFI outlet in the bathroom is having issues, for the last few weeks it has randomly tripped here and there, now it trips a few seconds after resetting it. This is a 2018 Nash 26N travel trailer, only a year and a half old which I full time in.

I spent the day doing some troubleshooting, and have not found an issue yet. It appears to feed 4 downstream outlets through that single GFI outlet above the sink in the bathroom, one down underneath the dinette, one near the floor next to the couch, one slightly above the kitchenette counter, and one outside for the patio area.

I took each outlet apart one at a time and reset the GFI, it made no difference removing any of the outlets from the circuit it tripped again right away. Disconnecting the downstream circuit directly at the GFI outlet allowed me to reset it and it worked fine when plugging an item into it. This leads me to believe that the GFI outlet itself is not the problem, and the problem must be downstream of that.

But if removing the downstream outlets one at a time did not remedy the issue then that points me towards it being a wiring problem somewhere between the GFI and the first downstream outlet. Is this correct?

What other testing can I do to narrow things down that I have not already tried?

Thanks

[Dropthejacks]

Sounds like the outlet side of the GFI is shot and needs to be replaced. It's either there or the wiring running to the first outlet downstream. I'd change the outlet first, if it doesn't fix the issue you can always return it.

[Old-Biscuit]

YEP.....
1st downstream outlet/wiring
If GFCI does NOT trip with that outlet removed you have narrowed the search to the wiring going from GFCI to that outlet.
(with that outlet removed ALL outlets are not in circuit----daisy chain wired)

Chaffed wire SOMEWHERE between GFCI & 1st downstream outlet

[seanb02]

Originally Posted by Dropthejacks

Sounds like the outlet side of the GFI is shot and needs to be replaced. It's either there or the wiring running to the first outlet downstream. I'd change the outlet first, if it doesn't fix the issue you can always return it.

I don't see why the outlet itself would work fine and not trip if the downstream is disconnected if it was the GFI outlet that is the problem? But I am thinking I will probably throw one at it anyway, because that is the cheapest way to proceed at this point. Easy enough to replace so may as well just try it.

[seanb02]

Originally Posted by Old-Biscuit

YEP.....
1st downstream outlet/wiring
If GFCI does NOT trip with that outlet removed you have narrowed the search to the wiring going from GFCI to that outlet.
(with that outlet removed ALL outlets are not in circuit----daisy chain wired)

Chaffed wire SOMEWHERE between GFCI & 1st downstream outlet

This is my worst fear, because I have no idea how I would proceed with attempting to find how the wire is routed, or where the actual problem is. I do have an extended warranty on the trailer, but I don't know (and doubt) that it would cover finding electrical problems.

[cavie]

Are you pluged into a GFI cidcuit in the house. 2 GFI's do not play nice. Pug into a non gfi circuit and try it again.

[seanb02]

Originally Posted by cavie

Are you pluged into a GFI cidcuit in the house. 2 GFI's do not play nice. Pug into a non gfi circuit and try it again.

I am not, I wired a 30amp RV service plug to the side of the house about 10 years ago, it is on it's own breaker not shared with anything else.

Interesting thing about that though, I did find a burned up pin where the trailer plugs into the 20' extension cord that gets it the rest of the way to the side of the house. It was obviously still working fine, but was definitely an accident waiting to happen. I don't think it was related to the GFI problems though as I purchased a new 50' extension cord, cut the female end off of it and hardwired it to the trailer replacing the original cord.

[twinboat]

Looks like you have a slide in that trailer. That is the first place to start looking for chaffed wiring.

If there are outlets in the slide, find to flexible cable that supplies them. Make sure its not pinched or cut into.

[Finance]

If you have a good multimeter disconnect the segment of wire between that GFCI and the next outlet downstream and measure the resistance between the conductors, it should read infinity. If not there's your problem. Also I'd check carefully to try and find out if the wiring between those two points takes a detour to some other hidden outlet or appliance you don't expect. RV wiring techs do some odd practices at times, not what you'd expect.

Now it's also possible there's a high impedance leak in the cable that a multimeter won't detect, because it's measuring the resistance using very low voltage. There's a specific tool to test insulation called a megohmmeter, which tests using higher voltage.

Another work around using the common multimeter would be to isolate that suspect cable at both ends, connect one conductor at a time to 120v line voltage, then use the multimeter to test for voltage leakage into the other conductors. But this is less precise and harder to interpret the result because the AC voltage will induce a small amount of stray voltage in parallel conductors anyway.

It should be noted this is the sort of work that is best left to professionals for safety reasons.

[NRR]

The fact it first was intermittent and now trips all the time when hooked up the other outlets points to a bad GFI or bad wiring.

I would change the GFI just because it is easy to do and hope that is the problem.

If it is not the problem I would call Northwood and arrange to have them fix it. I am guessing it is under warranty still. I realize they are across your state. But it would be fixed right.

[AnotherMike]

Originally Posted by seanb02

Hey folks, I have a tough one you may or may not be able to help me out with. My GFI outlet in the bathroom is having issues, for the last few weeks it has randomly tripped here and there, now it trips a few seconds after resetting it. This is a 2018 Nash 26N travel trailer, only a year and a half old which I full time in.

I spent the day doing some troubleshooting, and have not found an issue yet. It appears to feed 4 downstream outlets through that single GFI outlet above the sink in the bathroom, one down underneath the dinette, one near the floor next to the couch, one slightly above the kitchenette counter, and one outside for the patio area.

(rest of original posting deleted for brevity)

I'd replace the GFI. If any of the downstream outlets are in a slide-out I'd look real carefully at the flexible cables that feed them.. one may be chafed.

And downstream outlets from GFIs are a pet peeve of mine, they've always caused me problems, and are a case of the builder shouting "See just how cheap I am?.
I always rewire the load side wiring to the line side and replace the downstream outlets with GFI outlets. This way a failed GFI only affects one device (or maybe two, if both sides of the duplex outlet are in use).

[seanb02]

I changed out the GFI today with no difference. Talked to my local dealer, only advice they could offer was to check the slide area, I haven't moved the slide in well over 6 months. I checked anyway, but can't find where the wires go from the wall to the slide, must be hidden very well inside somewhere, but I honestly don't think that is the issue in this case. I am just about out of options, I am going to try and get in contact with the manufacturer and perhaps get an idea of how the GFI circuit is wired, but if that fails I am pretty much down to the last option of taking it in to the dealer for them to figure out. Labor rate is $115 an hour, and the extended warranty will likely not cover any of that since it is mostly diagnostics and probably very little parts replacement.

[seanb02]

Originally Posted by Finance

If you have a good multimeter disconnect the segment of wire between that GFCI and the next outlet downstream and measure the resistance between the conductors, it should read infinity. If not there's your problem. Also I'd check carefully to try and find out if the wiring between those two points takes a detour to some other hidden outlet or appliance you don't expect. RV wiring techs do some odd practices at times, not what you'd expect.

Now it's also possible there's a high impedance leak in the cable that a multimeter won't detect, because it's measuring the resistance using very low voltage. There's a specific tool to test insulation called a megohmmeter, which tests using higher voltage.

Another work around using the common multimeter would be to isolate that suspect cable at both ends, connect one conductor at a time to 120v line voltage, then use the multimeter to test for voltage leakage into the other conductors. But this is less precise and harder to interpret the result because the AC voltage will induce a small amount of stray voltage in parallel conductors anyway.

It should be noted this is the sort of work that is best left to professionals for safety reasons.

Unfortunately I don't know which outlet is the one next inline downstream from the GFI, it must split somewhere as there are two downstream on one side, and two downstream on the other side. And one on each side has wires going in and wires going out, but the second one on each side only has wires going in with nothing going out. This tells me it splits somewhere before any of the downstream outlets and branches off to each side of the unit. That is where I would probably start looking for where it branches off if I could get my hands on a wiring schematic for this particular model. I am out of luck even trying until Monday though with it being the weekend now.

[Paul R. Haller]

The very first place I would look is the outdoor duplex outlet and just replace it. Most RVs use offshore made outlets and this outdoor outlet is exposed to moisture. Most Chinese made outlets are of poor quality and can easily get a small ground fault due to moisture. You can buy a household approved duplex outlets that are UL approved at the big box stores in bulk for less then a dollar each. Simply replace all outlets downstream of your GFCI with UL approved duplex outlets starting first with your outdoor outlet. My guess is you have a moisture problem with your outdoor duplex outlet and don’t use the built in slide in connectors on the back of the outlet. Use the screws to tighten your connections down on the sides of the outlet. If you have ever disassembled an offshore made duplex outlet you would see first hand their incredibly very poor quality. The very first thing I did with my new rv, as a former county electrical inspector, was to replace every duplex outlet in my rig with ul approved duplex outlet. They are inexpensive and will easily carry the current they are rated for. Not so with offshore made outlets. Check each outlet in the output chain and remove the outlet and strip and connect each conductor together with a wire nut mechanically twisted together tightly before applying the wire nut. Strip more insulation off then you need and twist the conductors together with a lineman’s pliers so you have a solid mechanical connection between conductors before applying the wire nut and cut the twisted conductors to the right length and cap tightly with a wire nut so you have a solid mechanical air tight connection and only buy quality built wire nuts that have a spring steel copper plated insert that creates an air tight connection between conductors inside the wire nut. Only then, can you be assured of good air tight connections. Good luck and keep us posted on finding your ground fault.