Hi, Funpilot -
I think I finally traced down the "other forum" that you have referenced. There was a recent discussion in the Airstream forum - was that it?
There are some misunderstandings in that discussion. The first post relates that the neutral and ground points are connected somewhere inside the trailer. This is the problem - the owner needs to find the connection, and open it.
His photo shows that "Hooking up a Honda generator gives a normal indication." In fact, that is an abnormal indication when the trailer is powered by a generator, and the fact that it looks "normal" is a second indication that the neutral and ground are connected within the trailer. The reason? In a campground power post, the neutral and ground are connected together, according to code. But in a generator, the neutral and ground are NOT connected together (again per code), so the neutral light on the tester should NOT light. This is clearly stated in the Honda generator manual, which I guess he did not read. This is also stated in the electrical code under a heading like "Independent Power Sources" - I can dig up the specific reference if it would help.
The second post in that Airstream thread, by IDROBA, contains the proper answer when he says "Your neutral and ground wires in the trailer should not ever be connected together. You will have to trace where that is happening and then your problem will be solved." The thread should have died there.
Here on this forum, we had a couple of extensive discussions on this issue, which came from the same problem - GFI trips when it isn't expected to trip. They ended with this tutorial
http://www.trailmanorowners.com/foru...ead.php?t=8101
The purpose of the tutorial was to answer in concrete terms the question of WHY it trips, not simply to say "Yup, it trips". Six years later, this discussion is still the first hit on a Google search for "neutral to ground short GFI", although the pictures, which are included in the link above, went missing on the Google link.
The neutral-to-gound short thread started with a discussion of GFI nuisance trips
http://www.trailmanorowners.com/foru...ead.php?t=7220
and continued as a more in-depth picture was developed.
The generator issue is discussed near the end of another thread
http://www.trailmanorowners.com/foru...ad.php?t=11398
where the Honda generator manual says that the neutral light on the tester should NOT light.
The pdf document that you referenced in post #10 above says the same thing about isolating neutral from ground within the RV, so I'm not sure where the misunderstanding is coming from. The only error I see in the article is that the diagrams show a generator with its neutral and ground connected internally, which is not correct.
Sorry to be so wordy, but this is an often-misunderstood issue, and owners spend a lot of time trying to diagnose it. Did I find the right forum?
Bill