I read the 50 amp explanation hoping I would find my answer in that, However I have not.? I have a 30 amp plug for my Class C rig that works fine when plugged into 30 amps.? The problem occurs if I plug in with the 20 amp pigtail into a 20amp with GFI.? The GFI Pops everytime every where. If I use a 20 amp service with no GFI i am able to run most everything in the rig without any problem.? I'm not an engineer or electrician, I just want to plug in and enjoy?