HELP! TT not grounded or is there a short?

[V'sGlassSleeper]

Okay, this is the background:

After purchasing our 1988 Bigfoot B19, we plugged it in at a couple of campgrounds along the way home with the 30 amp power cord. We didn't turn on the AC on that trip, but it had worked fine at the dealership and we didn't notice any problems with the travel trailer being plugged in at campgrounds.

At some point, when we had removed the AC unit and I was regluing the skin to the core around the AC roof opening, I had the trailer plugged in to a grounded GFI outlet at home so that I could run the bathroom and kitchen vents to air out the glue fumes, so we everything worked normally then. Around the same time, I replaced 95% of the screws around the bellyband. There were also a few areas where they had not orginally put screws, but where the was a hole for a screw, so I put some screws in, thinking that would help make up for the 5% of rusted screws that I could not remove. I can't remember if I had already put all the new screws in the bellyband prior to plugging in the trailer to vent the fumes. The bellyband is now thoroughly caulked on with marine grade caulk and there is no way it's coming off.

We put the AC back exactly how it was.

The problem now:

When we plug the trailer into the same grounded GFI outlet that we had used without problem earlier, it trips the outlet. We tried plugging the trailer in to a different outlet and everything worked in the trailer including the AC, but the trailer was "hot"... it turned out that the second outlet we tried had the neutral and hot wires reversed (confirmed with a 110 circuit tester). We again tried plugging the trailer into the same grounded GFI and it again tripped the GFI.

We tried turning off all the breakers and removing all the fuses and still, when we plug the trailer into the GFI, it trips.

We tried disconnecting the newly installed LPG detector. Made no difference.

We are scheduled to go out of town next weekend and we have to be able to plug in... HELP!

Questions:

Could one of the newly installed screws underneath the bellyband be causing some short that is tripping the GFI? If so, how can we determine exactly where it is? We cannot reasonably remove the whole bellyband and then remove every screw in order to see if that solves the problem, but if we determine where the problem is, we could maybe remove just the section of the bellyband that is encasing any offending screws (if that is in fact the cause). Or, if that is not feasible, could we run new wires to just bypass the short?

How do we isolate and repair this problem? Shall we just call a repairman in on this one?

Thanks in advance for your suggestions!

[Joe Z]

Try this and see what happens........... unplug the air conditioner from the TT and then plug it into a 12-2 extension cord and then plug the extension cord into the GFI Outlet that keeps tripping on you...... If it trips then you know it's the air conditioner.......if it doesn't trip then you know it's the wiring in the TT and then run a new wire or just run a short extension cord to one of your other outlets in the TT and then fix it at a later time.
Hope this helps.
Joe

[V'sGlassSleeper]

unplug the air conditioner from the TT and then plug it into a 12-2 extension cord and then plug the extension cord into the GFI Outlet that keeps tripping on you...... If it trips then you know it's the air conditioner

Hi Joe, thanks for the suggestion, but the AC doesn't seem to have a plug that I can plug into an outlet... as far as I can see, it's hard wired into the power receptacle behind the fuse/breaker box. Also... if it were the AC causing the GFI to trip, wouldn't flipping the breaker off that serves the AC circuit also stop the GFI from tripping?

I don't understand how, if I took all the fuses out and turned off all the breakers, the TT could still be tripping the GFI outlet? Wouldn't that turn off all the juice, as it would in a house if I turned off all the breakers?

[Darwin Maring]

it turned out that the second outlet we tried had the neutral and hot wires reversed (confirmed with a 110 circuit tester).

A GFI will trip if you have any of the white/black/green wires mixed up. Use your little plug-in tester to figure where it is wrong and fix it.
-----------------------------------------------

White to light and green is ground the world around.

That means that the white wire goes to the silver screw on a receptacle or plug and the black wire goes to the brass screw and that green goes to chassis ground or green screw.

If you did somehow short some wires with a screw then you have a serious situation where you could start a fire and the GFI is tripping so it won't.

[BobB]

Hi Val,

The first thing to do is fix the second outlet so it is wired correctly. Apparently you have an outlet tester, so you can be sure it is right.

Secondly, there are outlet testers for GFI outlets that are only a few bucks more than the basic ones. You may have a defective home GFI outlet that needs to be replaced.

Once you are sure the home outlets are OK, then you can test the trailer again. Your trailer may be OK! Don't jump to conclusions!

If you are uncomfortable with changing an outlet, call an electrician or a competent friend. Be careful!

[V'sGlassSleeper]

Hi Val,

The first thing to do is fix the second outlet so it is wired correctly. Apparently you have an outlet tester, so you can be sure it is right.

Secondly, there are outlet testers for GFI outlets that are only a few bucks more than the basic ones. You may have a defective home GFI outlet that needs to be replaced.

Once you are sure the home outlets are OK, then you can test the trailer again. Your trailer may be OK! Don't jump to conclusions!

If you are uncomfortable with changing an outlet, call an electrician or a competent friend. Be careful!

We aren't using the second outlet right now at all.
But the GFI outlet works fine with other things (a halogen work light, and circular saw, for example)

The home GFI was also working just fine with the travel trailer before I replaced all the bellyband screws, so I do think it's possible that a new screw hit an inside wire.

Question is: is there a way to determine which interior trailer wires were affected without removing all 130 screws that I just replaced? Do all the wires converge at the fuse box and if so, can an electrician use some metering device to determine which wire circuit has the short?

My owner's manual unfortunately doesn't have any wiring schematic for the trailer and Bigfoot has no records of trailers this old, so i don't even know where the wires run.

[brendadave]

I don't understand how, if I took all the fuses out and turned off all the breakers, the TT could still be tripping the GFI outlet? Wouldn't that turn off all the juice, as it would in a house if I turned off all the breakers?

If all your breakers are off and the GFI still trips (and isn't faulty), then it seems to me that the problem lies between the plug and the breaker panel.

[Darwin Maring]

You Said: it turned out that the second outlet we tried had the neutral and hot wires reversed (confirmed with a 110 circuit tester).

Trust me, If you are correct as to what you said above, then you have found the problem.

Reversed Hot and Neutral wires on a GFI circuit will not work.

Be really careful and test all circuits with your tester again and if you still have one with the Hot and Neutral reversed, UNPLUG the trailer from all power and fix the receptacle so all wires are where they should be and then power up and retest with your tester first and if that is OK then connect to the GFI.

[V'sGlassSleeper]

You Said: it turned out that the second outlet we tried had the neutral and hot wires reversed (confirmed with a 110 circuit tester).

Trust me, If you are correct as to what you said above, then you have found the problem.

Reversed Hot and Neutral wires on a GFI circuit will not work.

Be really careful and test all circuits with your tester again and if you still have one with the Hot and Neutral reversed, UNPLUG the trailer from all power and fix the receptacle so all wires are where they should be and then power up and retest with your tester first and if that is OK then connect to the GFI.

Hi Darwin,

The GFI is correctly wired, but it was the second outlet that we plugged the trailer into that was not wired correctly, so there is still something wrong in the trailer. Unfortunately, I suspect that I inadvertently put a screw in where it hit some internal wiring in the travel trailer, creating a short which is what is causing the GFI to trip now, whereas it did not before all the new screws were in. Someone suggested that I used a VOM set to Ohms to test which of the screws is causing the problem, which might save a little time, but I still will have to use a razor blade to cut through most of the lovely caulk job that I did on the bellyband. Sigh.

[colin k]

Im thinking your gonna have to pull screws. It might be less work to fish a new set of wires in and abandoning the old "screwed ones". Pun intended.

[Pete Dumbleton]

You might take a meter probe and sharpen it to a long pin point to pierce the caulk for testing; then put a tiny dab of caulk on the pinhole after the testing is done.

A reverse approach might be easier, however. In most trailers, there really isn't much in the way of 120VAC wiring, so it might be easier to trace the inside circuits to see where they come near the belly band. You can also do some isolation of the branch circuits and wiring at the breaker panel and the neutral and ground connections there, plus disconnecting the convenience outlets.

The belly band screws are a valid suspect, being a change that seemed to result in a problem, but the jury is still out and I personally would be checking the easy stuf first.

[Darwin Maring]

I now understand what you are saying, my bad.

Pete is totally correct in using the pinpoint approach with the multimeter and also in the AC wiring elimination.

Using a pin attached to the test lead will tell U what U want to find out and you will leave no tracks.

DR

[V'sGlassSleeper]

Thanks fo rthe input and suggestions, everyone.

Ironically, when I called Bigfoot and spoke with one of their reps, he was pretty certain that there were no wires near the bellyband that could get hit with screws, but somehow, I think it's still very likely. We bought the voltometer today and definitely want to try the easy way first, though I have to admit, I am totally clueless on how to test the circuits at the breaker box. Maybe I will take a photo tomorrow of the breaker box wires to get some input on what the heck I am looking at and how to test them (will study the voltometer instructions too).

Unfortunately, with the bellyband, there is a black hard plastic band that fits into the crevice of the metal bellyband, over the screws and I caulked the top and bottom of that plastic piece, so that no dirt could get in underneath it (as had previously been the case, evidenced by the gobs of dirt and moss that came out when I initially pulled the plastic piece out of the bellyband crevice). So I can't pierce through the caulk to get to the screws (that was a great idea otherwise).

Kayla just realized that she has an electronic "Studfinder" that also locates electric wires in walls... so we will try that tomorrow too. The juice may have to be running to do that, but we can plug in to a non-GFI outlet for just that test, I think. That,plus testing the circuits if we figure out how, should help at least narrow down the whereabouts of any offending screw(s).

Love the humor Darwin, thanks!

I will post our results.

Val

[Joe MacDonald]

use an outlet tester on the plugged in trailer.(at a non gfci outlet)
and see if a hot/neutral or ground has been switched.
if you have all the breakers turned off, the only thing live should be the power cord.
you said , if I remember, that you had the AC unit out?. the wires for this usually run in the roof, and may have been hit when re-installing it or the wiring might be reversed at the AC unit.

if you use a voltage tester, check the trailer frame, to a ground pin on a plug, (if required, use a three way tap in the plug.) and check for AC voltage between trailer frame and ground. If present, then the trailer has reversed wiring somewhere.

the way the Trillium is set up, there is a remote possibility that you might hit the power cord when putting in a screw in in, the area where the power cord goes into the trailer

[Joe Z]

Val/Kyla
I like the easy simple tests first so unplug the trailer from the original GFI outlet and just try disconnecting the wires for the A/C up at the roof(tape the wires for safety) and plug in the trailer and see if it trips the circuit ( i know you flipped the breakers off but you never know if it's faulty)....hopefully that will do it then you would just reverse the wires at the A/C.....(for some reason i think this will be the problem area because you removed the unit and may have a faulty breaker)
If not and all circuits are flipped off then my next area of interest would be the external plug from there to the converter for any physical damage.
Sure hope one of us here figures it out for you so you can go on your trip.
Joe

[John Perry]

If I read you post correctly you have plugged your trailer into 2 differant outlets at your home, one of which is a Ground Fault interupter outlet. You appareantly do not have a problem when you plug into the non GFI outlet.
Could it be you are OVERLOADING the GFI circuit that your trailer is plugged into?
As Fiberglass is non conductive you would have had to penetrate a hot wire and or a neutral or ground wire, both of which would immediately blow your circuit breakers or fuses.
I have remodeled 4 differant makes of Fiberglass trailers and have never seen wiring at the area of the belly band.

You referred to hot wires, Plural. There is only one hot wire. The other wire that you possibly are assuming is a hot wire is the neutral, white, wire which is only hot when a circuit is completed.

My advice and thoughts are free so take them for what they are worth. Electrical problems are probably the most difficult to correct, so good luck.
John

[V'sGlassSleeper]

Well, I think we have only succeeded in making ourselves more confused.

Upon one forum member's suggestion, we plugged the trailer into a NON-GFI, but correctly wired grounded outlet (we verified it with a circuit tester) that is also an isolated circuit and everything in the TT worked fine: the AC turned on, the two 3 prong outlets in the trailer worked, the lights and fans all worked just fine. And the breaker for that circuit did not trip off. We also plugged the circuit tester into the trailer's three prong outlets while the trailer was plugged in to the NON-GFI grounded outlet and the tester showed no problems.

However, if I understand some of the forum postings correctly, this doesn't mean that we don't have a short, does it? Because the 3 prong outlet we plugged in to this time is not a GFI, it is normal that it wouldn't trip even if there were a problem, right?

We wondered whether or not it would tell us something to disconnect the wires that run from the trailer to the positive and negative posts on the trailer battery and use the multimeter to try to test whether or not there was resistance on the wires coming from the trailer? Would that tell us if there is in fact a short in the trailer wiring, and from there we'd know that we do need to test the individual circuits?

But we are also still confused on how to use the voltometer to test the circuits that go in to the travel trailer breaker and fuse box to determine whether or not any of them are showing resistance. There are big plugs going in to the back of the breaker box. I wish I could post a photo.

One of us thinks that we still need to confirm that there is no problem with the trailer wiring. The other feels that since everything is working on the NON-GFI grounded outlet, there is nothing to worry about.

[Dan M.]

Be Careful!
If you hit a hot wire with one of the Belly Band screws the metal portion of the whole belly could be hot. If plugged into a non-GFI outlet the voltage could be lethal. If you hit a neutral wire or grounded wire the band should be grounded, not good but probably not unsafe.

Try a different power cord. A long or damp power cord can have a small amount of leakage which if added to a small amount of leakage in the trailer can add up to triping the GFI. GFI's on construction sites are subject to nusance tripping especially in damp weather.

Many motorized appliances (ie: an AC unit) can cause a GFI to trip on startup. It's normal, GFI's are not required for refigerators and freezers in houses.

Tracking down nusance tripping can cause electricins to get grey hair, if they have any left, I know.

Good Luck

[Darwin Maring]

You are really at the point that you should pay someone to take a look.
A trained electrician could perform some basic tests and isolate the circuit that is tripping the GFI.

[Joe MacDonald]

try a different gfci in another location, or change the existing one,sometimes they are simply too sensitive for trailers. The ones I plug my car into in the winter are constantly tripping for no reason
If testing inside the trailers shows the plugs as good, I don't think you have a problem.
If you had a short it would still trip the main breaker in the house.