House GCFI keeps Tripp

[KATYBELLE]

I have a frustrating issue. I have a totally gutted 72 airstream. There are no appliances inside. I used my drill plugged into the interior outlets all this week.

All of a sudden, my shore power cord keeps tripping my GFI in the garage. I tried several outlets throughout the house and it keeps tripping out. I’ve change the 30 amp power cord and it still keeps tripping. I tried to turn on my power one by one on the Rv till I get to the one that trips the House GCFI. The problem seems to be the outlets. Should I change out all the outlets? I am getting so frustrated as I have been working on this issue for Two days!!!! Thanks for any help!

Paul

[azflycaster]

Other possibilities that might be an issue.
Is there a converter in the trailer? If so, disconnect it
Also, there should be a reverse polarity light. It was located on the rear skin of the outside of the trailer. It would light if hot and neutral were reversed.
Any GFI outlets or breakers in the trailer? I have heard of GFI feeding another GFI can be an issue.

[KATYBELLE]

Thanks for responding Azflycaster. There is nothing in my trailer....no converter, no frig, no ac....nothing. The polarity light is missing and there are no GCFI outlets in trailer. The perplexing thing I was drilling for almost a week until the house GCFI trippped. I am at wits end trying to figure this problem out!

[azflycaster]

Have you tried using an ohm meter at the cable end. You should have an open between any two of the 3 prongs on the power cord.

[KATYBELLE]

No I haven’t tried the Ohm meter.

[azflycaster]

If the meter shows some sort of a connection between hot. neutral or ground you could go from outlet to outlet and possibly eliminate something.

One of the rules I use when trouble shooting issues is the theory that you work backwards from when the problem occured. You stayed that you were using a corded drill. Have you examined the outlet you used before the problem? Maybe it got too hot.

[Ultraclassic]

Do you have a GFI tester? Maybe your extension cord was to long and you melted the plug in the house? (Due to current draw with the drill).

I will assume here you tested the plug with just a lamp or light. And it still blows or trips.

[47WeeWind]

Could it be your drill? Plug your drill into an outlet inside your garage and see if the drill trips the GFI (in the subpanel or in the outlet?) in the garage.

If your garage GFI is part of the outlet (usually a button between the outlets), plug the drill into that garage GFI outlet and into a different garage GFI outlet and see if you get identical or different results. Different results would suggest the GFI in the outlet that is tripping might be the problem. Identical results would suggest the drill is causing the GFIs to trip. If your garage outlet GFIs do not trip in either case, that suggests your power extension cord (or perhaps an outlet inside your gutted Airstream) is causing the garage GFI to trip.

If the GFI is in a breaker installed in your garage subpanel, take the drill into your house and plug it in a house outlet and see if it trips a GFI breaker in your main panel. Identical results would suggest your drill is causing the GFI breakers everywhere to trip. Different result would suggest the GFI breaker in your garage might be at fault.

[KATYBELLE]

Thank you all for your responses! No I checked three different extension cords and several outlets in the kitchen and the fuses trips. When I plug in the 30amp rv plug (shore power) with nothing plugged in no drill it still trips the house GCFI. In other words, it trips just by plugging in. So do I need to replace all the outlets in the airstream? Thanks again for your help.

[47WeeWind]

Hi Paul:

As a short term work-around to keep on drillin' on, can you plug your drill directly into a long (or linked) extension cords and wholly bypass the outlets in your '72 Airstream? That way you can get holey again.

I recall that early 1970s Airstreams, and so perhaps your '72, were wired with aluminum wiring due to a shortage of copper back then. Over time the connections of aluminum wiring can oxidize, increasing resistance and heat.

With your trailer totally unplugged from shore power, disassemble one outlet in your '72 and see if it has aluminum or copper wiring. If aluminum, maybe all the trailer needs is for you to disassemble and clean up (polish the aluminum wires at) every electrical connection. Using the drill for a week may have heated up an old oxidized connection in a trailer outlet to the extent it now causes your GFI to trip. If the wiring is aluminum, a search in these Forums should reveal many threads that address the issues with aluminum wiring.

If the wiring is copper, then you may have an unintentional ground or near short somewhere.

Knowing how GFI breakers work is well above my pay grade, so I can't help you with any ideas as to why they now trip. Best wishes with your project.

[BayouBiker]

First the unlikely causes:

Is it possible you drilled into or sunk a screw into a wire feeding the outlets? Are any of the outlets loose and you shifted it causing neutral and ground to touch?

Now the most likely cause:
The 120VAC Neutral bus is almost certainly "grounded" the to trailer frame. And if it is there are three possible neutral routes back to the house distribution center. The primary and intended route is the power cord neutral. But if any of the neutral current returns on either of the two alternate routes, the GFCI will trip. One alternate path is device neutral to trailer distribution neutral bus to trailer frame to the ground wire through the 30A power cord. The trailer generally has a poor ground as the tires won't provide continuity, but the tongue jack and the stabilizers can possibly offer decent continuity if the points of contact have become damp. Thus some of the neutral current could be returning via earth ground between the trailer and then back to the electrical transformer directly.

Now why did this just start? 1) Change in earth ground continuity possibly do to a weather change or 2) Change in continuity of the trailer supply power neutral wire to neutral bus connection. Maybe it is corroded or loose.

So what to do? If you want to use a GFCI protected circuit while working on your trailer, while working isolate the neutral bus from the trailer frame ground. Ensure the power cord ground goes to trailer frame and not the neutral bus. If you cannot ensure this, temporarily ground the trailer to your house copper grounding rod or house copper water pipe or gas pipe.

[KATYBELLE]

Thanks for your response 47weewind. Yeah mine is copper . ...so no worries about that. Yeah I am almost done with the drilling. I am about to install the water pump and fridge and will be camping by April 1. But this CCFI issue has stalled my progress out of the blue.

[BobnGayl]

GFI breakers are tricky and easily messed up when a ground is not connected properly. We had a problem with our hot tub where the breaker would trip every now and then. Couldn't figure it out until I checked the wiring in the control box. For some reason, probably vibration, the neutral was slightly loose. It felt tight when I pulled on it, but the connection screw was not as tight as originally. I tightened it and no further problems for a few years. Then the problem started again. This time, the first thing I checked were the connection screws. They were all very tight. Once again I double checked everything and finally I just bought a new GFI breaker. 50 Amp, 220 Volt breakers aren't cheap. But, this solved the problem. Since then I learned that breakers, esp. GFI breakers are not designed for multiple trips and are supposed to be replaced when one trips. Of course most people don't do this, but when all else fails, give it a try.

[JayTheCPA]

Maybe it is not the GFCI.

Given the description of plugging-in the umbilical as the sole cause-and-effect, perhaps the umbilical has gone bad and is allowing a current leak betwen the hot / neurtral / ground.

[cazual6]

KISS: Replace GCFI. Easiest process of elimination.

[Wazbro]

Hows the weather? I have heard of a couple people having the GCFI trip repeatedly for a couple days after a rain storm. Water leaking in.

[KATYBELLE]

Thank you all for your responses. It has been raining a lot but I have tried other outlets and it still trips. I have replaced the shore power cord and it still trips. I changed the Romex and the plugs and still trips....I have done everything and yet it still trips! I don’t know how hat else I can do but call an electrician!! Ugh!

[Al and Missy]

IF you have an exterior outlet on the trailer it may have insect detritus in it that gets wet and causes a GFCI trip. Also, if you have a leak in the trailer shell that is allowing water into an outlet, that could cause it. First thing I would do is pull the exterior outlet, if you have one, and look for problems there.

Al

[aftermath]

Have you tried using a different drill? There might be something wrong with it, something that just recently happened.


I have a 2006 25FB and it does not have GFCI outlets inside but they are Ground Fault protected by a GFCI fuse in the panel. Mine started acting up and this was the cause.


Of course that is not your situation. If the GFCI is in your garage and it isn't tripping until you plug the drill in then I would suspect that. You have tried different cords, you have checked the wiring in the trailer and it is good. Does this GFCI in the garage trip with different appliances plugged in? If yes, then perhaps the GFCI is bad. They do go bad. If no, then maybe it is time to look at the drill itself.

[BobnGayl]

There have been lots of posts since the original so I went back and read it and all the rest. Based on the original post it’s only the trailer outlets that are tripping the GFI in the garage. Not the trailer lights? Trailer lights are normally 12 volt power supplied by the converter. You said there is no converter so that means no lights at this point? I may be asking same questions again and if so just ignore me. But just in case, did you try plugging the drill directly into GFI outlets? No trip? Then it’s the trailer although the garage GFI might be compromised. You said you tried different ones In the garage and kitchen so that’s probably not the case. Is the garage 30 amp outlet a GFI RV outlet or what? I have a 30 amp RV outlet on a post by my driveway wired directly to a 30 amp GFI breaker in my house panel. I don’t know how you have your shore power set up but I would really look at that. You said you tried different 30 amp shore cables. If the outlet source is faulty different cables won’t make any difference.

If the problem isn’t the shore power feed from the house then it’s something in the trailer. How many circuits are the trailer outlets on? Only one or multiple? If one then replacing the fuse or breaker IN the trailer may solve the problem. Breakers do go bad. If multiple then maybe all the breakers and/or outlets are bad. It is an old trailer. I think this is unlikely however. I think the problem is probably due to the alternate neutral path BayouBiker mentioned. As he said and you probably know, GFIs trip when they sense ANY neutral current going back in the wrong leg. Hard to believe but an alternate path to ground from your post jack or stabilizers or any other metal part between the trailer body and a garage floor will do it. The floor may not feel wet but cold cement causes condensation and you might have a thin film of water between your jack and the floor. Put a dry block of wood or better yet a dry piece of rubber under you post jack and make sure nothing else is bridging the trailer to the ground. And if possible pull your trailer up onto dry 2 by 10s just to be sure. For what it’s worth.

Bob