RV electrical

[astraelraen]

We just built a new house and I had a 20amp breaker put in. Went with a 20amp because the electrician said that should run 95% of RV's just fine, including AC... hindsight tells me I should have gone with a 30amp, but that's done and gone at this point.

My 20 amp outlet has GFI on it and the RV trips the GFI every time it is plugged in. My old house had a 15 amp outlet with GFI and the RV would at least plug in without tripping GFI.

I calld the electrician who wired the house and he mentioned maybe the GFI was "extra sensitive." In my old house the GFI outlet was only about 5 years old, so I would guess they would be of similar "sensitivity."

I tried a variety of combinations of turning the different breakers off inside the RV and plugging the outlet into the wall.

There are six breakers, main, general #1, general #2, microwave, water heater, and A/C.

I could plug it in without tripping GFI by turning on any TWO breakers except for main & general #2. If main and general #2 were on in the RV, it would always trip GFI. This made me think general #2 has issues, but, any time I turned on any combination of three breakers the GFI would trip.

Any tips?

[astraelraen]

Sorry guys, we finally moved and I have been unable to check anything since then. I ran an extension cord from the Non-GFCI 20amp washer outlet and everything in the RV works fine, AC unit will run for a long time, etc.

The last thing I am going to check before having the electrician out to change the RV outlet to a non-GFCI outlet is to unhook the water heater element.

Can someone tell me where to look? I tried searching the internet and didn't come up with anything. Here is my water heater housing:

RV water heater

I suspect its behind the black rubber boot in the bottom left handish corner? There is an on/off switch there as well?

Thanks for all your help!

[aruba5er]

I recently serviced a motorhome that was kicking the gfci. The water heater element was bad and by turning off the breaker did not clear it. Needed to disconnect the neutral wire (white)

[Gene_Ginny]

teddyu wrote:
... ... Even though the GFCI tripped because of a few drops of water inside the converter box, there was in little danger until the component was openned when engerized. ...

This was a direct leakage of AC to the grounded converter box. My ohmeter showed it was a high resistance but it still was a leakage. If the trailer did not have a proper ground then the trailer skin and frame would be "hot". Without the proper ground anyone standing on damp grass outside and touching any metal part of the trailer would get a tingle or a jolt. We have seen that happen often in these forums.

[riggsp]

Several years and another RV ago, I had a case of GFI circuit tripping every time I plugged in the RV, but it wouldn't trip a non-GFI circuit breaker...after much work and frustration it turned out the water heater element was shorted. This was caused by plugging in to shore power with the water heater on and empty (this was my first RV and I didn't know the water heater even had an electric element in it)...try disconnecting the wire to the water heater to see if the gremlin goes away...if it does, replace the element in the water heater

[teddyu]

X2

[Wayne_Dohnal]

teddyu wrote:

No where in my posts do I say to ignore a problem.

I mis-interpreted what you said and apologize for that. Possibly another way to state my point-of-view is that if the rig trips the GFCI, it gets unplugged and stays that way except as needed to isolate the problem. If a voyage gets delayed over it, so be it. I've never encountered a 30 amp GFCI protected outlet so based on this the likelihood of seeing a GFCI trip on the road is close to nonexistent. If it does ever happen I'd most likely isolate it on the spot or just stay off of shore power until returning home.

[enblethen]

The RV is a sub-panel. It receives the power through a feeder circuit.
The circuits with in the rig are branch circuits.
The GFCI receptacle being used is seeing a fault in the wiring between the cord body and somewhere in the rig. It should be tested and corrected before something more major happens.
NEC article 551 tells electricians and other trained persons how it is supposed to be wired. It is not a training manual for "untrained persons" as specified in Art 90.1(C)

[teddyu]

Wayne Dohnal wrote:
My 2 cents is opposite of the previous post: If the GFCI that the RV is plugged into trips, there is something wrong with the RV's electrical system. I want to know about it as soon as possible, and get it fixed. I actively seek out GFCIs for powering the RV.

No where in my posts do I say to ignore a problem. It seems like you are a capable individual who could build a GFCI breaker box to plug into the pedestal then plug the RV into the "protection box" since the 50A or 30A are not proteced. You can treat your RV as the load or you can treat the RV as a sub-panel of the pedestal. As for me, I'll rely on NEC Article 551 for my coach. JM2¢...

[Wayne_Dohnal]

My 2 cents is opposite of the previous post: If the GFCI that the RV is plugged into trips, there is something wrong with the RV's electrical system. I want to know about it as soon as possible, and get it fixed. I actively seek out GFCIs for powering the RV.

[teddyu]

Gene&Ginny wrote:

teddyu wrote:
... In my garage, I have ONE dedicated non-GFCI receptacle just for the RV. ....

I will give you one example of why that would have been a bad idea in my case.

This Spring I was doing my routine cleaning including washing down the bathroom shower. Evidently a tiny amount of water went into my converter. When I noticed the clock on my microwave was dark I checked the GFI outlet that feeds my shore power. It was tripped. ... long story short ... turning on the converter breaker tripped the GFI. When I pulled the converter board I found a few drops of water between the circuit board and the metal case of the converter. Some current from the switching mode converter circuit board was leaking to frame ground. A dangerous situation.

As part of a previous post, I said that a GFCI protects people not equipment. I still stand by that statement. Think about this, in my (and probably your) RV, only the circuits where I can come in contact with water and an electrical circuit have this protection: kitchen, bath, and outside receptacles. My converter is not protected, neither is my TV, refeer, or hotwater heater. Even though the GFCI tripped because of a few drops of water inside the converter box, there was in little danger until the component was openned when engerized. The tripping did help to very quickly determine that the convertor was compromised. You will read in this and other forums of the common items causing GFCIs to trip are hotwater and refeer heater leakage currents. Again most people are not in danger when these items fail. The protection in the RV is not compromised by using a dedicated non-GFCI receptacle in the garage since it is no different that a CG pedestal 30/50A receptacle. The 15/20A GFCI in the pedestal is there for protection when using an electrical device outside an RV, bypassing the RV GFCI protection. JM2¢...

[diveman52]

astraelraen wrote:

enblethen wrote:
Is your clothes washer in the vicinity? It should be on a non-GFCI receptacle.
Connections do not show anything that jumps. out. Only thing I can see is that with the plastic stop on the buss, I cannot see that the conductors are completely under the screw.

I will take the plastic stops off and check the connections underneath them this evening or tomorrow morning and will see if my extension cord will work to the washer. It's got to be at least 25ft away and the only extension cord I have available is at best 14 gauge, it may be a 16 gauge cord. I can't remember off the top of my head since most of our stuff is in storage.

That appears to be the 12 volt DC connections in your pictures.
Not the 120 volt ac side

[diveman52]

Lynnmor wrote:
My tip would be to get a better electrician.

That's a big X_2 on that!!!!

[Gene_Ginny]

teddyu wrote:
... In my garage, I have ONE dedicated non-GFCI receptacle just for the RV. ....

I will give you one example of why that would have been a bad idea in my case.

This Spring I was doing my routine cleaning including washing down the bathroom shower. Evidently a tiny amount of water went into my converter. When I noticed the clock on my microwave was dark I checked the GFI outlet that feeds my shore power. It was tripped. ... long story short ... turning on the converter breaker tripped the GFI. When I pulled the converter board I found a few drops of water between the circuit board and the metal case of the converter. Some current from the switching mode converter circuit board was leaking to frame ground. A dangerous situation.

[Wayne_Dohnal]

myredracer wrote:

The link to a page from a hot tub supplier isn't exactly something I'd call credible.

OK, I'll stay out of tech stuff. The linked GFCI article on the hot tub supplier's site was originally on codecheck.com. It was removed some time ago from codecheck.com but survives on other sites. The author is a prof at U of Pennsylvania, has published hundreds of tech articles, and is a principal contributor at sci.electronics.repair and repairfaq.org. His GFCI article is referenced often on the Mike Holt forum, and I have not found any rebuttal to it there. For me, I consider it credible.

Breaking the "no tech stuff" on edit, there's a newer GFCI chip from Fairchild that doesn't use the 120 Hz. signal. It still uses a 2nd coil which is normally not energized. When there's a downstream ground-neutral fault, the interaction of the 2nd coil with the main sense coil results in the sense amplifier oscillating, indicating the ground-neutral fault. I have a fairly new Leviton GFCI that uses a Fairchild chip. Older Leviton GFCIs used the LM1851 chip that uses the 120 Hz. signal. I don't know when the chip change occurred or if anybody uses the LM1851 any more. Here's a "How GFCIs work" powerpoint presentation that describes the 120 Hz signal technique:
McGraw Hill GFCI presentation

Slides 9 & 10 cover the grounded neutral detection.