Transfer Switch Question

[Maks]

Today visiting a relative, the shore power quit in our trailer. We were not spending a lot of time in the trailer so the power requirement is quite low. Fridge and water heater is on propane.

The shore power is plugged into our relative's garage via a simple 15 amp wall plug. (Via 50/30/15 adapters)

Shore power was fine for a couple days but today the GFI on the garage wall plug kept tripping. I can hear the trailer transfer switch try to lock in but the wall plug GFI would immediately trip.

Started up our Yamaha 3500 generator. I have it set up via the 30 amp generator plug through the factory installed transfer switch. After 30 seconds the generator side of the transfer switch locks in and everything works fine.

I then shutdown the generator and unplugged the 30 amp from the Genset. Took the long extension cord that was previously plugged into the garage wall plug (shore power) and plugged it into the 15 amp plug on the Genset. Fired up the Genset and the shore power side of the transfer switch locked in and AC power in the trailer ....again, everything works fine.

My question...... Do you think there's a problem in our trailer or a problem with the "shore power" garage 15 amp plug?

[Foldbak]

Check the shore power receptacle on the trailer. Mine had all the lugs loose and wires cut too short. Fried the TS!

[Carl n Susan]

My first guess would be the GFCI shore power plug. Do you have access to another outlet?

[Old_Salty]

Tend to agree with Carl. Make sure when you try another outlet that it is on an different circuit than the GFI that is giving the problem. Multiple outlets can be protected by a single GFI in some cases.

It's easy to test. Plug into the different outlet and trip the GFI that is giving the problem. If the power stays on, it is on a different circuit.

[BB_TX]

I read an article about potential problems plugging an RV with GFCIs into a shore power outlet that is GFCI. The reasoning is that when the downstream GFCI outlet (the one in the RV) performs a self test, the upstream one (shore power) may see that as ground fault. The GFCI self test sets up a current imbalance to test itself, and that imbalance may also be detected by the other GFCI. But others say that it is not a problem to plug an RV into a GFCI outlet. So, who knows ??????? May be due to the age and style of GFCI outlets being used.

And, as stated above, it may simply be the shore power GFCI outlet be going bad.

[Maks]

Well BB_TX......you were exactly correct. I changed out the "shore power" GFI plug to a standard type (non GFI). And everything worked perfect.
We are now in a campground in Cedar City Utah and transfer switch / shore power works like it should.
I guess the trailer didn't have the problem. Thankfully.
And by the way, once we left, the GFI plug was replaced with a brand new GFI plug.
Thanks to all who replied.