Ground Fault outlet will not trip when converter is running

[Hogan]

NEED HELP! I have chased this problem the better part of 2 days and $300 and had no luck!
When my 2008 HHII 32.5UKTG fifth wheel is plugged into 110V. and the converter is running the ground fault outlet in the kitchen will not trip when the test button is pressed. If the converter is not running and still plugged in the test button works correctly. The converter is on the same circuit as the ground fault outlet which is a good thing.
If I remove the batteries from the system by removing the chassis ground wire or one of the positive post wires with the converter running the outlet works just fine. If appears I have an open ground when the batteries are connected and the converter is running.
I have replaced both the outlet and the converter with no change other than to my bank account.
Do I have to chase every 12v circuit checking for open grounds?

HELP I am at a loss.

[Hogan]

Just got back from a practice round at the "Masters". I flew since I didn't have the RV fixed yet. Had fun but flying last minute is more expensive than diesel fuel!
Spent the day running a new circuit from the spare slot in the breaker box mounted under the fridge and ran it thru the basement in flexible conduit. Really pretty easy access. Ground fault circuit breaker works correctly (trips when test button is pushed). Converter works fine since it is on another circuit now. Smart move since the converter will draw up to 13 amps and had been on the same circuit with ceiling fan and light and 4 outlets.
Had to have been a slight drain in the circuitry of the converter that was enough to energize the trip solenoid but not trip it. The GFCI needs about 4-6 milliamps to trip.

[MrWizard]

i'm sorry but it sounds like you have a kitchen outlet on the "INVERTER"
a converter is a 12v charger
the inverter will NOT do its job if the batteries are disconnected there fore you are on shore power, and have a continuous ground wire circuit thru the shore power cord and transfer switches
but when using inverter mode there IS no earth ground link because the RV is NOT grounded to the shore power system because the transfer switches break that circuit and you are on INTERNAL power not External shore power, so there is NO link for the GFI to detect any leakage, because there is NO leakage when you push the test button, because there is No external ground potential, only battery negative, which is chassis grd

[Gene_Ginny]

teddyu wrote:
... Check my source - www.mikeholt.com. ....

The specific page is HERE. One line: This is done by connecting the load side hot terminal to the line side neutral terminal through a resistor calibrated to conduct a small amount of current at 120V (approx. 8-10 ma). - That would allow current to flow through one winding only in the diagram. My early experience with GFIs (I still use the old term) was that the test did not work without a ground.

[BFL13]

I wonder if the 120v white wire to the converter input is on the power centre negative buss instead of the neutral buss. Or maybe the converter white wire insulation is cut somewhere so that exposed part touches the metal case of the power centre (which is grounded to the Rv frame) on the way to the neutral buss.

[wa8yxm]

I kind of wonder about that. Also the test button should work even on inverter power since, as I think you pointed out it need not be a ground.

I suspect.. he is loosing power to the outelt,, but that is not what he is saying.

[teddyu]

wa8yxm,

Check my source - www.mikeholt.com. When in the site, query GFCI test button. Other discriptions discuss the test button as connecting to the WHITE wire in a household circuit. In my house house, black is HOT, white is NEUTRAL, bare/green wire is GROUND. Please note the OP keeps stating converter not inverter. JM2¢...

[wa8yxm]

Gene showed the answer to your question Teddy. His diagram is very accurate as to the external to the GFCI wiring,, I suspect it is correct as to the inside as well.

The GFCI is a teeter totter.. So long as the "Weight" (Current) in the neutral and the hot wire are the same, Nothing happens (it passes power) but as soon as you introduce a 2nd return path (A ground fault normally) the thing trips.

As Gene showed. that path is your body in many cases.

If you are hooked to MAINS power (SHore) then the ground and neutral wires are bonded in several places actually.. At the power teransformer, at the main service box and at the park pedestal. (In theory, in practice, Do not count too heavily on that last one) Thus if there is a hot wire to case short and you touch the case YOU become a return (neutral) path via the ground. Not a good thing, Been there, Done that, Tossed the hand grinder across the room. (I tend to THROW when that happens, most Clinch).

The GFCI does not need, or care about, a ground, It only looks to see that the teeter totter is balanced.

NOW: if you are using a power source that has no ground (IE: INverter not bonded) THEN a ground fault will not trip the GFCI, because the current in the hot and neutral legs remains balanced, there being no 2nd return path.

[BFL13]

Hogan wrote:
NEED HELP! I have chased this problem the better part of 2 days and $300 and had no luck!
When my 2008 HHII 32.5UKTG fifth wheel is plugged into 110V. and the converter is running the ground fault outlet in the kitchen will not trip when the test button is pressed. If the converter is not running and still plugged in the test button works correctly. The converter is on the same circuit as the ground fault outlet which is a good thing.
If I remove the batteries from the system by removing the chassis ground wire or one of the positive post wires with the converter running the outlet works just fine. If appears I have an open ground when the batteries are connected and the converter is running.
I have replaced both the outlet and the converter with no change other than to my bank account.
Do I have to chase every 12v circuit checking for open grounds?

HELP I am at a loss.

The GFCI receptacle needs power to make the test button work AFAIK. So first question is whether, with the converter on and the test button not working, is there any power in that receptacle (plug something in and see)

If no, then turning on the converter is killing the receptacle, they are on the same circuit, so the GFCI is doing its job and there is something not right with the converter wiring.

Disconnecting the battery fixes that. Battery and converter meet at the DC lugs on the DC fuse panel and also via the frame where the 120 and 12v share the frame as "ground"

Swapping the converter to another circuit would stop the problem with that receptacle, but then what would happen if you plugged the RV into shore power that has a GFCI? Trip that? You could try that now at home by running an extension cord into the bathroom GFCI receptacle in the stick house.

My converter 120 only has black and white, no green wire. As suggested above, maybe your white wire is not in the right place.

[teddyu]

Gene&Ginny,

I'm trying to determine what is in error in my post. I agree a GFCI will work without a ground attached to the receptacle. If there is no ground to the receptacle, how does the test button trip the circuit? Answer, the same as a GFCI breaker in a distribution box - no ground attachment there either. I try to be very accurate when posting concerning 120V electrical problems since many members are electrically challenged and bad advice can be dangerous to the less knowledgable. Check your sources. Mine is www.mikeholt.com JM2¢...

[Gene_Ginny]

teddyu wrote:
Something is wrong with the GFCI receptacle or its wiring. Pressing the test button DOES NOT induce a ground into the system to trip the GFCI. The test button shunts current from the hot side to the neutral through a current limiting resistor. Conclusion: the GFCI is bad, the neutral is open, or the neutral and ground are reversed - in other words the wiring to the GFCI is messed up. JM2¢...

Close but with a few errors. The test DOES connect the hot side through a resistor to ground. The actual operation of a GFI does not depend on a ground, only the test function requires a ground. If the hot and neutral are reversed then the test button will not trip the GFI. The GFI works by detecting a difference of current flow between the hot and neutral. Here is a link to more info that goes with the picture below.

http://gfciplug.com/index.php/how-does-gfci-work

[Hogan]

It sounds like everyone is as perplexed as me!
I e-mailed NU-WA (which by the way isn't in the manufacturing business any longer just a service center and dealer) and think I have a solution.
My trailer was built in a transition year when they were moving manufacturing from one facility to another and evidently were trying new things. The service man I talked to on the phone was very knowledgeable about HHII trailers. He was very surprised that the converter was on the same circuit as the GF outlet and said it shouldn't be. He told me to find another circuit (easier said than done) to power the converter.
By the way-after working with the trailer a little I found that the test button on the GF outlet worked just fine if the converter was not running(batteries fully charged), converter is unplugged, or the 12v batteries were disconnected.
Does anyone out there have a converter on a GF circuit?

Thanks for the input. I'll let you know the outcome when it gets a little warmer and I can work on it. I'm in Iowa and its been a fun winter!

[teddyu]

Something is wrong with the GFCI receptacle or its wiring. Pressing the test button DOES NOT induce a ground into the system to trip the GFCI. The test button shunts current from the hot side to the neutral through a current limiting resistor. Conclusion: the GFCI is bad, the neutral is open, or the neutral and ground are reversed - in other words the wiring to the GFCI is messed up. JM2¢...

[wa8yxm]

You said Converter, on most RV's the converter is working any time you are plugged into shore power so how did you test it when it was not running?

Now.. on some RV's there is a device called an INVERTER, this is optional.. I have one.. An inverter may be wired two different ways, Ground bonded to neutral, or unbonded. It matters not..

On the MAINS power. it is bonded, so an inverter with power pass through switches all 3 leads. Hot, Neutral and Ground. thus when it's "Not Running" neutral and ground are bonded and a ground fault is possible.

If the inverter is hooked up so that the ground is NOT bonded. then when you trip the breaker that feeds the inverter and let it power the down-line devices, one of which is often said GFCI, it is not possible to generate a ground fault, for there is no ground to fault to.

[ScottG]

Is there any chance the Ground and Neutral are tied together at the breaker panel in your RV? Or that the battery ground is connected to the Neutral bus?