There are charts available that tell how many amps each appliance draw. You can add them up to see if you are pulling at or over 30. When you add the refrigerator, television, water heater, converter, air conditioner, some lights you might go over when you turn on the microwave. We only turn on the water heater on propane when we need it when on 30 amp and don't run it on electric. Also run the frig on propane and that should help.