On my previous coach, Monaco Diplomat with a Magnum 2000 watt MSW inverter, I added a second 600 watt
Magnum inverter to power just the residential refrigerator.
I knew I wasn't going to save power, but I wanted to isolate the refer to it's own inverter so that all the items that came on with my main inverter wouldn't, unless I wanted them to. Things like the microwave, entertainment center equipment, chargers and so on.
I picked the Magnum because it had automatic power pass thru, meaning when the coach got plugged into shore power, it would automatically switch to power cord power. It came with a small remote for turning it on and off and lights showing that it was on. I mounted the small panel on the side of the refer paneling that houses the refer. It was visible from the driver's seat.
The only issue with the small Magnum is that it's an MSW inverter. On my installation, I was pairing it to a Samsung RF197 refer that was MSW friendly. I mounted the smaller Magnum above my larger Magnum inverter and ran the new wiring alongside the other wiring.
This also gave me a backup if my main inverter went out. When I installed my new Samsung, I left the outlet for the 110 volts, the main inverter (which was powering the ice maker in the Norcold) and added the new outlet for the smaller inverter, giving me three choices for power.