Re: onan generator remote start controller
First of all, you don't HAVE to use any 120V AC power when underway. Most (if not all) the systems on a boat work on 12V DC- even the refrigerator.
That switch is called a transfer switch. It controls the source of the 120V AC power. In your case it could come from the shorepower cable, onboard generator, or onboard inverter. It willl only allow current to flow from one source at a time (for safety). You'll have another switch to start the generator.
You need to confirm that you have a good working inverter, which makes 120V power from 12V. A large battery capacity is required with an inverter because it takes a lot of energy to convert. If your inverter is working OK, then you can use it while away from the dock to power smaller 120V appliances, and (depending on the batteries) maybe even the fridge. Unlike a generator, it's nice and quiet. Just be aware that those batteries will be draining so hopefully your boat is setup with separate 'house' and 'engine' banks with switches.
The alternative is the generator. While a bit loud, its advantage is continous 120V power without sacrificing battery reserves. Proper marine generators are water-cooled and draw fuel from the main boat tanks. If your boat isn't rigged that way then the generator is dangerous to use on a boat.
Hope that makes some sense to you. Good luck.
