Home gfi trips when I try to plug in RV

harvestmac · 06-09-2020, 09:21 AM

New Outlook 25J. Preparing for short trip to get refrigerator cold. Just got house current to 30amp adapter. When I plug in to dedicated gfi it trips immediately. It has 20amp breaker. When I plug back to generator on RV everything seems to work fine. Same with a neighbors adapter. Also tried closing breaker after plugging in. Have only used campground 30amp once and had no problem. Is this a weak home gfi or an RV Problem?

AZAspect · 06-09-2020, 10:09 AM

I haven't checked my fridge on startup, but it typically takes 4 amps of power to run. Startup would be higher. A home GFI is typically rated at 15 amps (you want it to trip before the 20 amp breaker) so if startup amperage is higher than that, it should trip. But if startup is less, then you may have a faulty GFI.

harvestmac · 06-09-2020, 10:15 AM

Thank you. To be complete I should mention nothing in the RV was turned on when I make the connection to the RV plug adapter. I guess the next test will be to plug in at my neighbor or at a campground.

AZAspect · 06-09-2020, 10:19 AM

If nothing was turned on and the GFI is immediately tripping, I would check that the GFI was properly wired. If it is, then the GFI is most likely defective. Good luck!

Al

Goodspike · 06-09-2020, 10:33 AM

Quote:

Originally Posted by AZAspect

I haven't checked my fridge on startup, but it typically takes 4 amps of power to run. Startup would be higher. A home GFI is typically rated at 15 amps (you want it to trip before the 20 amp breaker) so if startup amperage is higher than that, it should trip. But if startup is less, then you may have a faulty GFI.

GFCIs do not trip based on load. They trip based on ground fault conditions, or Arc faults but those are more typically part of a GFCI/ARC circuit breaker in the breaker box. Not sure if there are stand alone GFCI/ARC protection outlets.

Most likely there is a wiring defect with the trailer wiring. I would try turning off all the circuit breakers and then turn them on sequentially to see which trips the GFCI.

The reason there's no problem at a 30 amp park connection is those do not typically have GFCI protection.

AZAspect · 06-09-2020, 10:51 AM

Quote:

Originally Posted by Goodspike

GFCIs do not trip based on load. They trip based on ground fault conditions, or Arc faults but those are more typically part of a GFCI/ARC circuit breaker in the breaker box. Not sure if there are stand alone GFCI/ARC protection outlets.

Most likely there is a wiring defect with the trailer wiring. I would try turning off all the circuit breakers and then turn them on sequentially to see which trips the GFCI.

The reason there's no problem at a 30 amp park connection is those do not typically have GFCI protection.

I stand corrected! Thank you...learning stuff everyday!

Al

Goodspike · 06-09-2020, 03:39 PM

Quote:

Originally Posted by Goodspike

GFCIs do not trip based on load. They trip based on ground fault conditions, or Arc faults but those are more typically part of a GFCI/ARC circuit breaker in the breaker box. Not sure if there are stand alone GFCI/ARC protection outlets..

BTW, if this is a GFCI/Arc circuit breaker that is tripping, it very well could be the device, not the trailer. Early Arc detection sucked, and would trip frequently. Personally I don't understand the need for such devices and am glad my house doesn't have such "protection." But I thought I would mention that possibility before the OP tears their RV apart looking for a fault there.

al1florida · 06-13-2020, 11:14 AM

Just to be clear, it is the GFI at the household outlet that is tripping, not a GFI in the RV, correct?

If you have an inverter that may be the cause. I don't recall exactly why the inverter causes the problem, but is not caused by a failure.

As others wrote, the GFI trips because the current going back on the neutral wire does not match the amount of current coming in on the hot wire. So anything that would bleed off any current would cause the house GFI to trip. Inverter installs usually have a green wire ground from the inverter to the frame ground. I have never researched why this wire is there, but if any current travels down this wire to frame ground the GFI would sense the miss match in current between the shore power 120V AC hot lead and the neutral return lead.

Morich · 06-13-2020, 11:37 AM

Quote:

Originally Posted by al1florida

Just to be clear, it is the GFI at the household outlet that is tripping, not a GFI in the RV, correct?

If you have an inverter that may be the cause. I don't recall exactly why the inverter causes the problem, but is not caused by a failure.

As others wrote, the GFI trips because the current going back on the neutral wire does not match the amount of current coming in on the hot wire. So anything that would bleed off any current would cause the house GFI to trip. Inverter installs usually have a green wire ground from the inverter to the frame ground. I have never researched why this wire is there, but if any current travels down this wire to frame ground the GFI would sense the miss match in current between the shore power 120V AC hot lead and the neutral return lead.

I would suspect that this is at least part of the problem. We often think of ground as one firm solid item but it is not all the same. We would like for it to be all the same and it would solve a lot of problems but it is not and that may be part of what is causing the GFCI to trip.
Most of the US uses a system called multi grounded neutral, meaning it has many, many, grounding points knowing that all ground is not the same, so we ground it at many points hoping to get closer to correct. Looking at many power poles, you may see a ground wire running down the side for grounding.
In our house, we ground many ways, depending on location, plumbing type and local codes which dictate how to ground. You don't get the same quality of grounding in hot dry ground like Texas as we do in wetter areas where the ground stays moist deeper down. Some places use a ground rod at the entrance and call it good while other places use the metal pipes in plumbing. But where other materials are used than metal in plumbing the codes require different methods.
We know grounding is different so what do we get in an RV? We get a frame connection and call it ground but the whole thing is isolated from "true" ground by the tires! So if we try to connect a house GFCI to an RV, we are quite likely to get a difference in ground potential and it can get weird.
This case could be a defective GFCI or it could be that the RV needs to be grounded to the same ground as the GFCI?
Just theory with no proof until tested!

Goodspike · 06-13-2020, 11:53 AM

Quote:

Originally Posted by Morich

We know grounding is different so what do we get in an RV? We get a frame connection and call it ground but the whole thing is isolated from "true" ground by the tires! So if we try to connect a house GFCI to an RV, we are quite likely to get a difference in ground potential and it can get weird.
This case could be a defective GFCI or it could be that the RV needs to be grounded to the same ground as the GFCI?
Just theory with no proof until tested!

Interesting theory, but I'm not sure it holds up, although given RV wiring anything is possible!

I'd throw another possibility out there that may connect with your theory--the charger. It clearly grounds to the trailer frame because that's where the battery grounds. Seemingly though if either of our theories was right this would be a problem with every RV connected to any GFCI outlet. I've never tried to connect mine to a GFCI, so I don't know about my trailer.

Edit: Mine you could perhaps test by connecting a battery charger plugged into a GFCI outlet to a battery outside a vehicle and then connect the ground of the battery to a second true ground.

harvestmac · 06-13-2020, 12:26 PM

Appreciate all the replies. I went to the dealer who could find nothing wrong. While there met someone who had similar problem which went away with a dedicated 30 or 50 amp outlet installed. Then went to state park where options were 20amp and 50amp and I had no problem using the 20amp running ac, tv, lights and a little bit of microwave for 2 days. The inverter question is interesting, should it be off or on when I plug in or does it matter?

Goodspike · 06-13-2020, 01:01 PM

Quote:

Originally Posted by harvestmac

The inverter question is interesting, should it be off or on when I plug in or does it matter?

Per Creativepart's answer in this other thread, it draws power from your battery whenever it is on, so I would say you should have it off unless you are using it. That would likely mean it would be off when you plug in.

https://www.winnieowners.com/forums/...ml#post3863885

Morich · 06-13-2020, 01:04 PM

I keep my RV plugged to a GFCI. In this area any outside outlet is required to be GFCI so it is right next to the RV parking space and handy. I could add a 30 or 50 amp outlet but not worth the effort for the small number of times we would want to use the AC. We just use it to pre-cool the frig and to keep batteries up, etc. We have found the AC will start and run on the 15 amp but I would not want to do it often.
GFCI are like anything else and they can wear out or begin to trip too easily but if it happens more than a few times, I like to look for the cause.

al1florida · 06-13-2020, 07:37 PM

Quote:

Originally Posted by harvestmac

Appreciate all the replies. I went to the dealer who could find nothing wrong. While there met someone who had similar problem which went away with a dedicated 30 or 50 amp outlet installed. Then went to state park where options were 20amp and 50amp and I had no problem using the 20amp running ac, tv, lights and a little bit of microwave for 2 days. The inverter question is interesting, should it be off or on when I plug in or does it matter?

Many people carry a 30amp to 50amp dog bone adapter to connect their 30amp RV to 50amp shore power.
Be sure to buy the correct one. There is also a dog bone adapter to connect a 50amp RV to 30amp shore power.

Both adapters look much the same at a first glance.

Goodspike · 06-13-2020, 09:38 PM

Quote:

Originally Posted by al1florida

Many people carry a 30amp to 50amp dog bone adapter to connect their 30amp RV to 50amp shore power. .

Which is an unsafe practice, unless it's fused. There's a thread on that here somewhere.

al1florida · 06-14-2020, 06:46 AM

Quote:

Originally Posted by Goodspike

Which is an unsafe practice, unless it's fused. There's a thread on that here somewhere.

Yes indeed, there could be a dangerous situation if there was something to happen, which would cause more than 30amps to flow, but less than 50amps to flow, from the shore power pedestal, along the power cord and inside the RV up to the point of the 30 amp main power CB. After that any short should trip the 30 amp CB in the RV's main power panel.

This is not a disagreement with the quote, but to add more detail & information in regards to the safety issue.

Goodspike · 06-14-2020, 07:58 AM

Quote:

Originally Posted by al1florida

This is not a disagreement with the quote, but to add more detail & information in regards to the safety issue.

I agree with what you wrote. In a way it's analogous to using extension cords inside the house and those catching on fire because of being too small of gauge.

To some extent the last link of the power chain is often the most dangerous. An ordinary lamp cord could overheat and catch fire before even a 15 amp breaker would trip. And many surge protector devices have components that can overheat and catch fire.

But in this case you're dealing with two systems of questionable wiring safety--the RV park and the RV itself. I'm just not in favor of compounding the problem without people knowing of the risk.

tsut · 06-14-2020, 05:42 PM

Had a similar tripping Issue. Found out it was a “feature” with the hard wired Surge Guard protector in our Vista. It would trip in conflict with a GFI on the house. Any GFI, all GFIs. As soon as the 2 minute Delay start circuit would transfer power to the RV. I now have a non-GFI 20A outlet near the RV. Problem solved.

pobstlmo · 06-14-2020, 08:26 PM

I would try a non-gfci plug, just a regular plug and see if that works.
As a side note gfci plugs are not used on refrigerators, washers, dryers, dishwashers etc. they work by sensing an increase in the amperage, it’s a very small amount which keeps you alive if you drop a very old hair dryer in the sink, or a toaster in your tub.
Ground fault circuit interrupters, odd name since they don’t use a ground. They interrupt the circuit if there is short and a ground fault.

n9wdq · 06-14-2020, 11:38 PM

good chance that your outlet is not rated for the power that you are trying to draw. Even with a 30 amp circuit - that is the total amount for the circuit, not each outlet. It is probable that you are overloading the outlet. Some are only rated for 10 amp. Fortunately for you, you are tripping it rather than overloading the outlet wiring and possibly causing a fire. I would recommend having a dedicated 30 or 50 amp outlet installed.