Originally Posted by Bama Rambler
The biggest issue is that if you're tripping the GFCI part of the receptacle you need to find out why. The size of the cord won't have an affect on that, and somethings not right. Either it's wired wrong from the factory or something has happened to cause a problem (i.e. water heater element).
OR he has plug something new in the trailer that maybe tripping it in the TT I agree you need to check in to it more, But the size & length can be big issue with GFCI sometime, most all house GFCI are 15amp. The greater the voltage drop the higher the current load & surge. IT may not trip right away, but it will. This don't even take in to account the heating of the cord,plug Or the GFCI.
Manrialee are you using anything new in the trailer. (Elect. heater). Since you post it just started, You can do this simple thing to trouble shoot. Turn all breaker off in trailer & then plug in cord. Turn your breaker on one at a time. The 30 amp first & work your way down ,check your GFCI every time to see if it holds. IF it dose trip when you turn on a breaker. Check and see what on the breaker. IF it the GFIC holes then it is most likely a surge tripping . The combination of converter, refg, & anything else that may be on. IF the breaker trip the GFCI , runs the outside outlets on the trailer, check for water inside the cover (it should trip the tt GFIC, but sometimes the house GFIC trip first.)