My customer has a private (family and friends - no rentals) RV park - for use by family and friends during the summer - seasonal only. The site has provisions for 3 campers, complete with septic hook-up.

He asked me to upgrade the 3 20A 120v GFCI outlets to 30A. Not having a copy of the 2011 NEC with me, I called the State Inspector to get a reading on the requirements. He referenced me to 551 III - 551.40 (C) and said they must be GFCI protected.

I ordered the GFCI's (special order with my supply house, and Square D doesn't make a single pole Homeline 30A GFCI, so I had to convert the panel to Square D QO). Swap went fine, with 30A 120 "RV" receptacles. Then the campers started arriving, and every one of them tripped the 30 A GFCI breakers! My cost for the QO GFCI's is $68.00 - expect a customer dispute.

I believe my State Inspector was wrong. 551.40 (C) references the requirements for inside the RV; 551 VI 551.71 references RV Parks, and the only mention there is for GFCI protection on 15 and 20 amp circuits; references to 30 A and 50 A do not mention GFCI protection. 551.71 also proscribes that I must have some 50 A receptacles as I have 3 sites....

QO 30A GFCI's trip at 5 ma, and these campers have air conditioners and refrigerators, which have capacitors on the motors, and over time they leak......

Any comments or guidance here?

Thanks guys (and gals).

Grov

I expect you're about to make a major tuition payment in the "University of Life."

Let's start with a few observations that ought to be vommon knowledge by now:
1) These days, GFCI's generally trip because there's a problem;
2) RV parks more than a few seasons old are wildly overloaded and badly degraded; and,
3) The RV's themselves are invariably a vipers' nest of worn, damaged, and improper wiring.

Need I go into detail?

What I suggest you do is that you hook up a nice big electric heater (or, better yet, a 'wall shaker' air conditioner) to each circuit to demonstrate that the problem is NOT with the breaker.

Next explain, using small words and short sentences, that it's likely there is something in each RV that is trying very hard to kill someone.

Grover:
This took some reading on my part. I agree with you..551.40 is for receptacles within the RV IMHO.

Again, 30-50 GF is not required. You may want to politely request the inspector to please re-read 551.

As to the 50 amp locations, yes they are required, BUT...your clients site may not comply with the NEC definition. See the wording '...vehicles of the general public'. IF the site is private....then you have no reason to comply with the 50 amp requirements, although you may choose to do so for convenience.

OK, Reno slipped in above me.

Yes, there may be internal issues in the RVs, no doubt that is what is tripping the GF. As Reno more than likely has seen more RVs than me, I believe him that they can be ratty.

My point being, reading 551 I offered my opinion on the requirements as I read it.

I would not be surprised if RVs regrounded the neutral. A couple of minutes with a meter would confirm that

The other thing I will tell the owner of that place to have some of the RV the inverter or converter connection can screw up the RCD { GFCI } I have see this over in France once a while as well espcally with either inverter or converters they can shunt them up pretty good and pay attetion to the DC side espcally the inverter or comverters they not always float it the negtive cable typically grouned to the frame and some converter or inverter will leak thru the negtive cable and can cause false singal in there.

Merci,
Marc