Most duplex recepticles that are located outside a home will be protected by a GFI circuit. They could be 15amp or 20amp depending on how the home was built. I can't say I've ever seen a 30 amp or 50 amp GFI outlet.  These heavier circuits are always GFI protected at the breaker.

A 15 or 20 amp GFI plug will only support so much downline power draw. Often times even a long extension cord will trip the GFI. And if you add devices that pull lots of power, then you for sure will trip the gfi.

When we wire homes we never install GFI for appliances. i.e. Refridgerators, Freezers, Microwaves, Washers. The appliances pull too much power when the motors kick in and the frequently trip GFI's.

So my first guess, like those posters above is that you have plugged your extension cord into a GFI protected outlet.  You have several choices. Either reduce the load on the receptacle or install a heavier circuit.  If you chose to reduce the load, you can try usings a shorter extension cord, use a high quality cord heavier gauge cord. It will have less current drop than a cheaper cord. Make sure everything is turned off in the trailer.  Only turn on the bare minimum of what you want to run.

If you install a 30 amp circuit, You will probably need to get an electrician out to your home to install a new breaker in the panel, pull a 10 gauge wire from the breaker to where you want to plug in and install the plug receptical.

I was under the ASSumption that this had been working then became a problem. I just came in from using the GFCI outlet on the outside of my trailer to run 100 feet to my block heater on the old Ford 6.9 diesel, thats after the trailer being fed by a 100 feet of 16 gauge plugged into an outside  receptacle GFCI 15 amp and fed by a 15 amp breaker, a very skimpy circuit. The converter in the LQ was on also on line but these switching power supplies don't draw much if not loaded, just a big inrush to initally charge the bus capacitors. Just because the LQ has a 30 or 50 amp plug doesn't mean they need to be connectad to a heavy circuit if the current draw is way under that. Check the simple stuff first.

Whinneyman 

Hi, I want to thank all of the responders for your great advice. After carefully checking off all the various suggestions and not finding any issues; with all appliances turned off, I started the generator, turned all appliances on, everything works; just for courisioty sake, I plugged the trailer into the dedicated receptable and the breaker did not trip this time; so my deduction is that I have a short or breakage in the trailer electrical cord.  This I can fix.  Thank you all again. MS Silver

I had an electrican wire the DR in my trailer. At home, with an adapter on the 30 amp cord, I can plug into a 110 outlet and run everything in the DR. Air conditioner, fridge, fan, etc.  Hauled to a State Park, and went to plug into the 30 service, and tripped the breaker. Will everything shut off inside, still tripped the breaker. Camp host said it was a double ground issue. REALLY want to be able to use my living quarters, any suggestions on what a double ground issue is and what I need to look for? Electrican got a different job and isn't around anymore.

Thanks for any ideas.

  Doesn't sound like a very good electrician.  Either the cord is mis-wired or ...  This article may help ..  Click here >> http://www.mrtrailer.com/hosspuller.htm