Moisture/Cold resulting in GFI Tripping

[BellaandKing]

as a result of the current cold spell (upper 20's at night) and a few days of rain, there is a build up of moisture in our 1988 29ft Excella. We also sleep with very cold inside temperature (45-55) - under an electric blanket of course - that results in the interior moisture. Over the past few nights the GFI is tripping. Per the wiring diagram this breaker supports the bedroom and bathroom outlets. There is also a polarity light on the diagram which I cannot locate and have read that the GFI has replaced that (not sure is the polarity light was removed or covered up). When the TT dries out / warms up - the breaker starts to hold longer and eventually works. when it does start to hold - upon inserting a circuit tester into an outlet it trips. The strange part is when i insert it into a non-GFI outlet the GFI also trips which leads me to the polarity connection. Although this problem may go away on its own when the weather shifts back to warmer / drier - I do not to ignore it as this is our future and I need it to be safe.
Any suggestions or directions towards resolution would be beneficial.
BTW - I am fairly handy as I have remodeled with hot water tank, axles, AC and awning - but electrical is a bit confusing for me.

[BellaandKing]

forgot to add - I did see in a forum on tripping that moisture in the outlet could be the cause and a hairdryer was the solution. As I do not have a hair dryer due to the lack thereof I have yet to try that solution

[dznf0g]

Do you have an exterior outlet on the curbside? That would be my first check.

[AtomicNo13]

I experience the exact same condition in my 91 Classic 34'. We get loads of moisture too.
As soon as the sun comes up and we open the vents, the GFI stops tripping.
A real pain!

[BellaandKing]

took the curb side exterior outlet cover off and it was dry. Circuit tested and it is part of the GFI breaker loop.

[BellaandKing]

that is the approach we are heading in although not one i am happy with - thanks

[Hyo Slvr]

We camp in southern Indiana every year until the middle end of November hunting season. We, as all TT owners who camp in cooler climates can attest to condensation issues. Unfortunately one of the byproducts of using the furnace (newer Classic withstanding) to keep warm is moisture from propane heat. To reduce our former issue we limit or cease indoor cooking, use the heat pump as much as possible, leave the vents cracked and purchased a 30 pint dehumidifier. Also found leaving the blinds open some does help. Since you mentioned an electric blanky, I am guessing you have shore power? Try cracking the vents and seriously look into a dehumidifier. Night and day difference!

[Hyo Slvr]

Originally Posted by Hyo Slvr

We camp in southern Indiana every year until the middle end of November hunting season. We, as all TT owners who camp in cooler climates can attest to condensation issues. Unfortunately one of the byproducts of using the furnace (newer Classic withstanding) to keep warm is moisture from propane heat. To reduce our former issue we limit or cease indoor cooking, use the heat pump as much as possible, leave the vents cracked and purchased a 30 pint dehumidifier. Also found leaving the blinds open some does help. Since you mentioned an electric blanky, I am guessing you have shore power? Try cracking the vents and seriously look into a dehumidifier. Night and day difference!

Sorry, also forgot to mention not to shower inside the cmpr. Since we boondock (w/generator) we use disposable scent free wipes. They're fairly inexpensive and work very well to keep the Mrs and Me from becoming funky monkies.

[BayRat]

A GFI works by measuring the current in the hot (usually black) wire and compares it to the current in the neutral (white) wire. If the difference in the two currents is more than about 5 milliamps (mA), it will trip.
Tripping means there is current bleeding off to ground somewhere. Your tester can trip the GFI if you measure voltage to ground instead of to the neutral.
Tiny bits of leakage throughout the trailer can add up, causing nuisance tripping. One solution would be to add additional breaker(s) and split up the circuit into several circuits, so that less wiring is on a single GFI. Adding one GFI breaker with only one (added?) outlet for the blanket would likely not trip, keeping you warm at night.

[gklott]

Originally Posted by BellaandKing

When the TT dries out / warms up - the breaker starts to hold longer and eventually works. when it does start to hold - upon inserting a circuit tester into an outlet it trips. The strange part is when i insert it into a non-GFI outlet the GFI also trips which leads me to the polarity connection.

Does this mean when you insert the circuit tester on another branch circuit, served by a non-GFCI breaker (like the bedroom), the GFCI breaker on the bathroom & kitchen circuit trips?

If so, as you say, this sounds like a mis-wiring. This could be a serious safety issue. Recommend you check each outlet on a single branch circuit, with the other branch circuits turned off at their breakers. Make sure to check all the outlets.

Have you considered replacing the bathroom, kitchen, and outdoor outlets with a tamper-resistant and weather-resistant (TR/WR) outlet? Ours are the Eaton Model TWR270W. We got these at Home Depot for $2 each. It has a blue WR on the front, and hot and neutral openings have the plastic shield. We also put one in for the refrigerator outlet.

We have Eaton AFCI/GFCI combo breakers (CHFAFGF120) on all branch circuits in our trailer - including the A/C. We've not experienced any ghost tripping.

Originally Posted by BellaandKing

I do not to ignore it as this is our future and I need it to be safe.

Agree! Hope everyone has the same viewpoint.

73/gus

[BellaandKing]

thanks - will look into the weather resistant outlet and breaker. as these outlets are not the self-contained type used in RVs - do household electrical boxes fit within the walls of AS???

[A W Warn]

When someone replaces a breaker it should be made by the same manufacturer and be the same breaker type as the breaker box. If someone has not used exactly the correct breaker as a replacement it can create problems.

(example: if the original panel was manufactured by Square D and is a type QO panel, then it requires Square D type QO breaker)

When it is cold outside I loosen the latch on the window that is furthest from the location I am occupying so that the window is slightly open. Then I raise the bath vent about 1/4 inch. That small amount of air exchange helps a lot in removing moisture.

Running the furnace does not create moisture/humidity inside the trailer, because combustion air intake is from outside the trailer and the exhaust gas is expelled outside of the trailer.

However, using the cooktop/oven and/or using a heater that has unvented interior combustion does create moisture and other combustion waste/pollution. These types of propane burners definitely require ventilation, regardless of brand or type!

[gklott]

Originally Posted by BellaandKing

thanks - will look into the weather resistant outlet and breaker. as these outlets are not the self-contained type used in RVs - do household electrical boxes fit within the walls of AS???

For the electrical box, I used a 8 cu. in., 1-1/4 in. deep, flanged shallow old work box from Home Depot. Cost $1.25. To match the AS stainless steel cover (SKU: 39760W), I had to use a "decorator" style TR WR outlet - which are hard to find. The one shown is a Hubbell DR15WHIWRTR. I used stainless steel screws to mount the outlet in the box.



Airstream's opening was so poorly cut, they installed the original "self-contained RV outlet" at an angle. AS also stuffed the original wire within the wall, passing through the self-contained outlet, into really tight bends, far tighter than the NM-B allowed bend radius. I tried to straighten the new outlet best I could without cutting a larger hole. AS has no quality control, as shown by the non-rectangular, crooked cuts with over cut.

Because AS so poorly cut the opening, though not in the picture, I used 2 flat head stainless steel #6 screws to hold it in - upper left and lower right.



With the shallow box, you don't have a positive grab on the wire. You need to support the wire coming into the box within the distance specified on the box (12 inches). As you can see in the upper right corner, I also used a wire tie on the inside.

Where I could, I replaced the old NM-B #12 solid wire AS used with Ancor Triplex Cable, 12/3 AWG (3 x 3mm²), Flat.



This is the AS stainless steel cover - BEFORE I cleaned up the Sikaflex-221 sealant. I had to get the stainless steel cover plate screws, because AS does not provide them with the cover. As shown, recommending including the NEC-specified AFCI/GFCI label.

Hope this helps.

73/gus