GFI Tripping When I Plug RV into Shore Power

[AHarris]

Anyone seen this before. When I try to plug the RV into shore power (a 20A service using an adapter from the 30A cord) it trips the GFI on the camproud power connection. Tried several different outlets even two different campgrounds. It's not the cord and it's not the adapter.



Has anyone ever run into this issue before? It's a 25' TT and has not had anything done to it recently.



This ruined a good weekend camping beside the river at Big Sur. Even an electrician at the campground looked at it and couldn't figure it out.



Any ideas appreciated...

 

[kenny61]

You got a voltage leak somewhere. gfi's work by making sure the same amount of voltage going out comes back in. you need to narrow down where to look. i would start by turning off all the breakers / fuses and seeing if it still trips. if it does the problem is probaly in the charger circuit. if not turn breakers / fuses on one by one until it trips and then check that circuit. electrical problems are a pita

 

[AHarris]

You got a voltage leak somewhere. gfi's work by making sure the same amount of voltage going out comes back in. you need to narrow down where to look. i would start by turning off all the breakers / fuses and seeing if it still trips. if it does the problem is probaly in the charger circuit. if not turn breakers / fuses on one by one until it trips and then check that circuit. electrical problems are a pita

We tried that... it might just be the charger is bad :{

 

[jjordan1]

I had the same problem in my 2005 Carriage Cameo 35`. Firts time it ever happened. The cam,pground remove the ground fault in tere box & all worked well. Also you shoiuld put @ leats one of your jacks directly on the ground . Not boards our the plastic pads. I dont know for sure But that is what i was told. Good Luck

 

[kenny61]

you can unhook the charger and measue resistance with an ohm meter between the power wires (feed) and the ground or metal case



From the xantrex site



Where does Ground Fault Current come from?



Ground fault current can result not only from a direct metal to metal short, but also from deteriorated electrical wiring on a boat. Ground fault current is often referred to as leakage current. Every wire and electrical connection on a boat has the potential to leak a small current due to dampness, oil/dust contamination in sockets, and wire insulator breakdown due to weathering including prolonged ultraviolet exposure (sunlight). The more wiring and connections there are in the boat the greater the cumulative leakage may be. If your boat has several leaky AC sockets, or connection boxes that total up to 4 mA, adding one more appliance (ie. battery charger), or leaky wiring connection could trip the GFCI. GFCI's are not to trip at 3 mA (>40 kR leakage resistance, hot to ground), may trip at 4 mA (30 kR), should trip at 5 mA (25 kR), and must trip at 6 mA (20 kR). If you isolate and test the GFCI itself using the above information and find that either of these tests fail, the GFCI is defective and should be replaced. There must be no connection to the GFCI for this test to be valid, since the boat's wiring can add leakage to the above test resistor leakage currents.

 

[HBarlow]

I had a problem with a breaker tripping in my previous Travel Supreme fiver. It was a '95 model I had bought used. I'd had it parked up in IN for a couple years while I was transporting trailers. The problem showed up after a period of frequent heavy rains and turned out to be an outside receptacle at the end of the string of receptacles on the back wall of the kitchen counter. I guess the heavy rains had caused water to migrate into the outside receptacle. I didn't take it apart to try to learn how the water caused the problem. After I cut that receptacle loose from the string the breaker never tripped again.

 

[R C Cola]

Gfci

With the specs mentioned above and a good meter you can find any problem you might encounter. Most of us can use the first method of turning everything off and then turning circuits or appliances on one at a time until the problem recurs. Then by looking and checking closely ascertain the exact problem, be it loose connection, damaged wire, moisture, etc.

 

[DBentley]

As an electrician i can feel your pain with GFCI tripping. I have had to remove the gfci plug for my truck because during a heavy rain the cord caps would get wet and trip. Also I have lost $$$ of food in my camper when plugged into gfi and raining

Dont get me going on AFCI breakers as there worse.

 

[AKAMAC]

Just a quick check you can do if you have an Ohm meter. All breakers on to start.

Run your service into RV with a good extension cord.

Connect the meter to the service plug at the N (neutral) prong and check resistance to N bus.

Connect the meter to the service plug at the G (ground) prong and check resistance to G bus.

Check resistance between N bus and G bus.

If you have a non-isolated ground system all values should be close to zero ohms. If there is a difference check the extension cord then check the N wire from panel to exterior connection.

If good there try this.



Connect the meter to the service plug at the L (line) and N prongs.

Record ohm value then turn off breakers one at a time recording the value as you go. Leave no change breakers off but mark them.

Now connect the meter to L and G. The R value should be the same on a non-isolated ground system. Now turn off (the remaining on) breakers in previous order and record values. Are they the same?

If they are, leave them off as you go and when finished start turning on the "marked off" ones to see if there is a measured resistance. If there is, the circuit with resistance will have a bad N.

Give it a try and let us know. Mike

 

[WOT]

Had a similar issue - after doing a bunch of looking I figured out is was a short in the electric heating element. I disconnected the wires on it and the problem went away. What was surprising to me is that even when the water heater switch was off it would do it. At least it only cost me a heating element and some time to fix it.

 

[AHarris]

Just a quick check you can do if you have an Ohm meter. All breakers on to start.

Run your service into RV with a good extension cord.

Connect the meter to the service plug at the N (neutral) prong and check resistance to N bus.

Connect the meter to the service plug at the G (ground) prong and check resistance to G bus.

Check resistance between N bus and G bus.

If you have a non-isolated ground system all values should be close to zero ohms. If there is a difference check the extension cord then check the N wire from panel to exterior connection.

If good there try this.



Connect the meter to the service plug at the L (line) and N prongs.

Record ohm value then turn off breakers one at a time recording the value as you go. Leave no change breakers off but mark them.

Now connect the meter to L and G. The R value should be the same on a non-isolated ground system. Now turn off (the remaining on) breakers in previous order and record values. Are they the same?

If they are, leave them off as you go and when finished start turning on the "marked off" ones to see if there is a measured resistance. If there is, the circuit with resistance will have a bad N.

Give it a try and let us know. Mike

I just might pick up an Ohm meter and give this a try before spending $$$ at the dealer... thanks! Will let you know.

 

[R C Cola]

Dealers ?

Just had a similar problem with a dealer. In for repairs we were told $89 would be the repair bill, came back to pick up to face a repair bill for $250 and could tell they had worked on it but the problem was not fixed. Final outcome was we had to learn how to make the repairs ourselves and repair is made and still feuding with the dealer over the $250 bill

 

[E2360]

Agree with WOT, had a similar issue and went over the trailer circuit by circuit. It was the water heater element.

 

[CUMMINZ]

I had on and off problems over the last year with the outlets on one side not working. Was also having problems with the refrig not working on battery. I changed single battery for 3 batteries and finally found a loose wire in the converter. After fixing that the GFI in bathroom failed. Swapped out GFI--same problem. My dealer finally thru process of elimination found a bad wire from one recepticle to another one. Rewired and no more trouble.

 

[AHarris]

Agree with WOT, had a similar issue and went over the trailer circuit by circuit. It was the water heater element.

How do you test the water heater element? Was your water heater element still working when you discovered the problem?

 

[WOT]

How do you test the water heater element? Was your water heater element still working when you discovered the problem?

It's been a while, but I THINK I disconnected the wires on it and then put a meter from the terminals to ground (frame). One of them was shorted (had some resistance; enough to leak current.



I guess the element inside was somehow shorted to the case and leaking back through the ground where it the element was screwed in.

 

[kenny61]

You can test it the same way as the charger with a ohm meter you can also just unhook the wires and see if it still trips

 

[MrFixit]

My Brother-in-law had this same problem on a brand new trailer. He was plugging into a 20A GFI outlet at his house. We ran new wire and a 30A recepticle and the problem went away. We thougt maybe one should not plug into a GFI source when you have GFI breakers in the rig... not sure about this though.



Looking back. . he did have a water heater element that was shorted from the factory.

 

[AHarris]

I think the first thing I'll check is that darn WH element--seems that comes up as a common problem.



I'm going to to do the troubleshooting tomorrow morning on the camper. I'll lot you guys know what I find out. Thanks for all the helpful suggestions.

 

[AHarris]

I gave up

Well I spent about 5 hours yesterday morning. Followed the suggestions above using an ohmmeter I picked up at Radio Shack and didn't find the problem. The camper was in an accident 5 years ago where my brother was driving the truck and the A/C unit snagged an overhang. It did about $6K worth of damage to the camper and the insurance company repaired it. I got on the phone with a good RV place near me in Salinas (lots of other NPS students take their campers there) and he thinks something is wrong with the wiring for the A/C since turning on the A/C trips the GFI. I'm not even going to try to mess around the rooftop A/C so it's at the dealer for what is hopefully a quick and inexpensive fix. Getting some other things fixed in the camper too... if this thing doesn't turn out to be a maintenance pig we might just keep it for a while... it's paid for.



Thanks for all the helpful suggestions.