How its wired
Rob, it depends on how your invertor is wired in your boat. I have a Heart 2000 and it is wired in series with the A/C input. Anytime the 110 volt A/C is disconnected from the input, the invertot kicks in and supplies A/C. This is the easiest way to wire it in. There is a problem with this means of wiring it in. If the air conditioner is running at the dock and A/C power fails, then the invertor tries to run the air unit. Two things are wrong with this, you exceed the amperage of the invertor and air units don't like square waves. Either way, the breaker trips, but not before the compressor makes some strange sounds. I now leave the invertor turned off except when using it at anchorage.