CGFI Tripping

This morning my wife was running the electric heater on high and the GFCI tripped in our RPOD 176.  I reset it and it tripped again.  I unplugged the heater.  I reset it and it seem to work.  Moved to another campground and found the GFCI would instantly trip after a reset.  I replaced the GCFI switch thinking it was faulty.  I even unplugged the refrigerator because it was also not working and and unplugged all other 110 plugs.  Still can't get the GFCI to stay on.  It instantly trips.  i have even reset the circuit breaker thinking it might be the issue.  Any thoughts one where else I might check and whether there are any other GCFI plugs besides the one next to the dinette, right next to the slide out.  

Since it has been raining hard for a number of days I do suspect the outside plug.  I'm going to just have wait until it stops raining to verify that one.  Does anyone know if all plugs are wired thorough the GFCI plug, or a some not.

I’m assuming from your post that the gfci is tripping with nothing at all connected to any receptacles, but power is otherwise still available in the trailer? If you have any receptacles powered separately from the gfci it should be easy to tell, those will be the ones that are still hot. In theory any ground fault upstream of the gfci should not trip it. So your fault should be in one of the dead receptacles or possibly in damaged insulation on the wires leading to the receptacles. Moisture is the number 1 cause. Gfci’s will trip with a few milliamps of ground fault current so it doesn’t take much.

As I said before, in theory it shouldn’t. The gfci is comparing the current flowing through the hot (black or red) and neutral (white) wires feeding that circuit and trips if they are different. To be different there needs to be an alternative return path for the current besides the neutral (white) wire. That is the ground fault and the gfci is there to be sure the ground fault isn’t your body.

So no matter what’s happening upstream the gfci should be ok as long as you don’t have a ground fault downstream. In practice though gfci’s have to be really sensitive to slight current changes (they are supposed to trip at 5 milliamps) so have been known to trip from electrical noise on circuits, so anything is possible.

You should get a circuit analyzer if you are going to be on shore power much. Campground electrical service is notorious for being messed up in lots of different ways.

There are many options available for RVs, lots of variation in price range too. Some are portable and connected to the pedestal and some are permanently installed in the trailer. As a minimum you want one that will check the RV park circuit for open ground, open neutral, low and high line voltage, and has surge protection. At least one also has an auto transformer which will bump up the voltage if it’s getting too low, fairly common in RV parks with long circuit runs.

I’d suggest doing a search on the forum for circuit analysers, surge suppressors, auto transformers, and similar keywords. I don’t personally own one (I very rarely camp with shore power) so can’t recommend one over another. Lots of folks on the forum have them and can comment or answer specific questions.

I’d get one and start using it, see if the problem reoccurs. With all the condensation you’ve been having inside your trailer you likely got some moisture condensing in your electric receptacles as well. That could definitely trip a gfci because the water creates a path from line (hot) to ground. It only takes 6 milliamps to trip. If you have your ventilation under control now you might not see the problem again.