I just had an electrician wire my house with an interlock kit so that I can use my new 6600 watt generator for power backup. Unfortunately, the GFCI in the generator's panel trips as soon as I attach the cable to the house. My electrician says that there is absoultely nothing wrong with the wiring in my house and that the problem is with the GFCI. He says that most generators with built in GFCI's won't work for power backup. He also says that there is no way he'll touch the generator to disable the GFCI for liability reasons. How do I use this brand new $2,200 generator to power my house if the GFCI keeps tripping and can't be disabled? Thanks in advance for the advice!