I have a 2008 travel trailer that has a 30 amp 120 volt plug. When using an RV adapter to go to 15 amps and plug it in to a house hold 120 volt ground fault plug, It trips the ground fault plug. Also if I plug it into a small 10 amp 120 volt generator it won't work. I am not sure why. The generator just idles, not producing any power. When I plug the trailer into a regular house hold 120 volt plug in it works just fine. Is there something wrong with the trailer wiring or is this normal?