Does anyone have any experience with a model igen4500 Westinghouse brand generator. It has 3700 watts running power and seems to hit that sweet spot for adequate power. Also this looks to be the same unit as the Onan Cummins p4500i just in a different package. Is it accurate that a 15k AC unit needs 3600 watts to run? Would this generator be ok to use with the 15k AC unit and/or are there other "draws" on current that would make this choice to small of a power source. Thanks for the input.