20 amp service and furnace

20 amps will run one of the following
1 Air conditioner
1 Microwave
1 Water heater
And up to 120 amps of converter (That's 120 amps at battery voltage) if the batteries are HUNGRY.

If the batteries are well fed, Well.. The converter does not count.

The furnace, runs on battery power.

Are you also aware you will need a RV30A-15A long ADAPTER to connect your trailer 30A SHore Power Cable to the 20AMP Service 120VAC receptacle at their pedestal.

If you dont have this adapter you can pick this up from WALMART
looks like this... Make sure all three prongs are in good shape - this is the only frame ground you 30A Trailer will have...


I have never had good luck using the small round type RV30A-15A adapters like these. They always get hot on me...


This is what you "don't" want to happen to your RV30A shore power plug due to poor adapter connections...


Again you can run all of the 120VAC items in your 30A trailer using the camp ground 20AMP Service connection including your air conditioner. You just can't have two high wattage items on at the same time as it will trip the pedestal breaker.

I use this type connection to my garage 120VAC receptacle at home all the time with my t30AMP trailer. It might be a good idea to bring along a RV 120VAC VOLTMETER like this one plugged into a easy to see 120VAC receptacle inside your trailer to keep an eye on the 120VAC VOLTAGE. This is a neat AC meter to have as it has the SAFE ZONE SCALE printed in "GREEN". DO not run hig high wattage items if your 120VAC level is outside this printed safe zone.


Roy Ken

20 amps is plenty to run your single AC on.

Thanks, that may be the dumbest question Ive ever asked. After you guys answered I remembered running the furnace on the battery in the driveway once just to see if it would work.

You could even have your fridge(3a) and water(12a) on electric with the heat(3a).
Worst case you turn something off electric and reset the breaker.

Agree, no problem with furnace.
And you can run the AC on 20 amps as long as you do not run much else at the same time. If you check your breaker box you will most likely find the AC is on a 20 amp breaker It probably pulls around 15 amps running.

No problem, the furnace runs off the house battery 12-volt system for ignition & fan and 20-amp is sufficient to keep the battery charged through the converter system.

The furnace still runs on gas. Only the fan motor is 12vdc that comes from the battery and charging system which should have enough power with 20 amp service.

Furnace runs completely on 12V power.....so if your batteries are good and stay recharged then furnace will run.