I have that unit and it will power a surprising amount... my well, water heater, 3ton AC (seriously), and the rest of my misc usage. I bought it knowing I needed something right now in my new-to-me country house, and knowing that this would "get me out of jail" until I could get a real whole house unit. It has done the job perfectly. I've been without power 12 days out of the last year and it has got me through it. I'm looking forward to the convenience of an LP whole house system with auto-switch, but this gets it done.
It has a 16gal tank and that runs over 12 hours for me. I got 5 5gal tanks and that lasts a couple days, I always use stabil marine to keep the gas and run hi-test. I lose power enough that I'm not worried about the gas sitting for over a year, and the 3-6month intervals haven't been a problem. Also I pull from the oldest can for filling my oil-mix can which helps too. I tried to run it in a 3 sided covered shed once and almost overheated it. I don't do that anymore, it's a monster of a portable generator and needs to breath.
One other thing: the outputs are as listed in the post above... 50A-220V, 30A-220V, and several 110s at 20A. This means you can't pull the full 15.5kW into a single panel (since that's over 50A-220V). That works ok for me as I have two panels and I can wire the 50A to one (with the AC) and run the rest of the stuff on the other panel off the 30A. It's not perfect, but got the job done. You could hardwire to the main conduit with a 70A breaker if you knew what you were doing, since that is what their breakers and plugs are coming from... but you'd kiss the warranty goodbye.
I've been running it at heavy load for days at a time (sucked a bunch more fuel then, almost 2gal/hr), during the storms on the east coast last summer it was hot and it ran flat out for a week. It's a solid unit. Not what I should get long term, but it's proved its worth no question.
Hope this helps,
Hunter
