Fridge electric while traveling.
I put a relay in that has a 12V coil. I have the 12v controlled by the solenoid. When the engine is running the solenoid sends 12v to the relay coil and closes it. The relay is a three pole double throw with 10 amp 120v contacts. I run from the house panel and the relay uses that power when we are on shore power. The other poles are from the inverter panel and when the 12v is on this circuit is used. I use a 3 pole because the sine wave inverters switch the neutral so it is best to keep the whole circuit separate. I put the fridge on auto so when we stop the fridge automatically goes to gas until I plug into shore or start the engine or generator. I don't want the inverter to run it when the engine is not running so it does not run the batteries down. This way I get ice making on the road and we are not using the propane.
2008 Winnebago Itasca Latitude 37'
Workhorse UFO/Gas Pusher 8.1
2008 Ford Escape Hybrid, Portland, OR