PDA

View Full Version : Troubleshooting GFCI Tripping by RV


GStream40
07-01-2007, 08:47 AM
After a member had a problem tripping a GFCI when his RV was plugged into it and some good info was posted on "how to" troubleshoot and locate the culpit circuit by two members, I decided to compile it into one easy to "copy/paste" post for other members so it could be printed for future reference. Hopefully no one will ever need to use it, but if you do be very careful as the procedure descibes the danger of electrical leaks and shorts.
Ron

Troubleshooting GFCI Tripping by RV

1) Turn off ALL breakers in the RV including the main.
2) Plug in the trailer cord to the GFCI, if the GFCI doesn't trip then..
3) Turn on main RV circuit breaker, if okay then...
4) Turn on each individual breaker one at a time until the GFCI trips,

When the GFCI trips, then you have isolated that one circuit that is the cause.

When the culprit circuit is located, you will have to measure for an electrical path to ground. A GFCI trips because the current flowing in the return white neutral lead does not match the current flowing in the black power lead. The only alternative path for that current to have traveled is to green ground.

Not to unduly alarm you, but this is a potentially dangerous condition as well (which is the reason for GFCI). Your unit frame is isolated from earth ground by rubber tires. If the frame, door & step handles, compartment handles are touched while standing on the earth outside, you could complete a better path to ground than the one through the cord to the power pedestal.

You, or service department MUST find out what is going on and correct it. It is not safe.

While you are at the house, do you have the option of plugging into a non-GFCI source? You could do that with all RV circuits off. YOU stay inside while someone else turns your housebreaker on. Follow the top procedure of operating everything, one at a time to determine if the housebreaker trips. That will show you if you have a "short", or if you have the very dangerous "leakage" path to ground. If the NON-GFCI breaker does not trip, then have your assistant turn off the breaker while you exit your unit.

The phone call to your dealer should be to remind him of the liability he risks if he doesn't correct the situation or finds someone understands the problem & can fix it.

BTW, you are under no personal danger running your generator because the generator ground (& RV frame) is not tied to earth outside. No current will flow through your body if you touch both.

Procedure Compiled by Gstream40 & RJ82much [/b]

Disclaimer: The writers of this procedure assume no responsbility as to the users safety.

omaziar
07-10-2007, 02:39 PM
Actually there is other things which will cause tripping of a GFI (GFCI), being an electrician I have seen and caused tripping by keying on the mike of our radio/walkie talkie network. so tripping does not always mean problems with the electrical system.

GStream40
07-10-2007, 03:59 PM
Actually there is other things which will cause tripping of a GFI (GFCI), being an electrician I have seen and caused tripping by keying on the mike of our radio/walkie talkie network. so tripping does not always mean problems with the electrical system.

Can you explain how that happens?

Ron

omaziar
07-11-2007, 01:58 PM
While I'm not an engineer, I would think it has to do with RF being induced onto the wires, ours trip within a 3' radius. you can also trip them with a VOM, if you read from the hot leg to ground (not neutral) it will trip it.

GStream40
07-11-2007, 07:31 PM
That's a first I ever heard of RF from a radio being able to trip a GFCI.

Maybe our electrical engineer, Bob (RJ82much) can explain how the RF from the radio is able to trip the GFCI. Bob, What's your opinion on this? :?:

Ron

The Old Guy
07-11-2007, 10:32 PM
GStream40,
Ron, I have worked in the construction industry since way before GFI's and have worked with and installed them myself. They are extremly sensitive and necessarily so. Radio frequencies are quite strong, some more so than others. That is why there used to be, and probably still are, signs telling us to turn off two way radios near blasting sites. It is also why hospitals and airlines ask us not to use cell phones as they can interfere with delicate electrical equipment. (most hospitals now realize that there is little concern over cell phones anymore.)

That is probably why an RF signal can trip a GFI if close enough. I was testing my new automatic transfer switch at the storage compound a few days ago and just the switching triggered the GFI that supplies low amp service to the unit. We stay "plugged in" to keep the batteries charged.

Curious if Bob agrees with me.

Ralph

GStream40
07-12-2007, 09:10 PM
The first and older cell phones used analog signals and the present day cell phones use digital. That is the difference, No RF to worry about.

I can understand RF interference with a component that uses radio frequencies or if the radio is hard wired getting it's power from the electric line, but I can't understand how a two way radio can interfer with a GFCI and cause it to go into fault/trip.

Ron

The Old Guy
07-12-2007, 10:12 PM
Ron, you have my curiosity peaked. Now I have to go find the answer to that question, if I can.
You are right about the cell phones, that must be the reason for the change and the fact that they still have the signs up for the off chance that someone might still be using analog.

If I find the answer for the RF signal I will post it.

The Old Guy
07-12-2007, 10:13 PM
nothing

mfa
07-13-2007, 07:30 PM
IMO, the construction area warnings to turn off radios were from the era where some folks had large mobile radios/phones that put out maybe 20-40 watts or so. [Pre-cell-phone era where you called the "mobile operator" and asked to be patched into a phone number.] Nowadays cell phones operate around 1 watt.