Quick Check - Can we run the coach AC units while driving down the road? - RV-Dreams Community Forum

Melnal · RV-Dreams Family Member

Quick Check - Can we run the coach AC units while driving down the road?

Nancy and Bill · RV-Dreams Family Member

As long as you have a generator...

Turn on the generator, crank up the coach AC and enjoy the COOL!!

We run ours all the time:o))

Alie and Jims Carrilite · RV-Dreams Family Member

If you have a generator, then yes you can run an AC while cruising down the road!

Terry and Jo · RV-Dreams Family Member

I looked up the specifications for a 33C online. In the electrical system section, it stated that they came with a 5500 Onan gas generator. As long as there are no other 120V devices running when you are traveling, I don't see a problem with a 5500 having enough power (amperage) to power the two air conditioners.

Onan has two different models of 5500 generator, so you might look to see what differences there might be between the two and what your coach actually has. Onan's website that either of the 5500 models will power two air conditioners with power to spare. There is also a 5500 that is in some way an evaporator for California standards, but I don't know if that one is yours.

Terry

bjoyce · RV-Dreams Family Member

We did it today, ran our generator and both roof A/C units. It was hot in Washington state today, over 100 on some of our route in Eastern Washington. (Yes, it set records).

We have a 7.5KW Generac diesel generator that is water cooled. In our previous gas motorhome we had a 5.5KW gas generator that was air cooled and it would cut out trying to run two A/Cs in hot weather, but would run one.

Barbaraok · RV-Dreams Family Member

We ran ours last fall every day on our way towards Arizona. We normally just run the rear one, which is the smaller of the two and it had no problem keeping the coach comfortable even in 106 weather in Needles, CA as we traveled through. Trick is to turn it on before the coach gets 'hot' so you aren't trying to cool down, but rather 'maintain' temperature. One thing to remember, while it doesn't take a lot of fuel to run the generator, you don't want the fuel level to get to low or the generator will cut out. We always fuel up when we get to about ½ a tank left, so it hasn't been a problem for us.

Barb

TRAILERKING · RV-Dreams Family Member

I ran my Onan Diesel generator for 40+ hours straight, running the front roof air.
Just cuts down on your fuel economy a bit if worried about that...

bjoyce · RV-Dreams Family Member

"Just cuts down on your fuel economy a bit if worried about that... "
Detail oriented people, like myself, account for this in our records. We record each fuel tank fill up and calculate the mpg. Since these generators have hour meters, I record the number at each fill up. I found that for our gas motorhome and the 5.5KW, using 0.7 gallons per hour was about right, and for our 7.5KW diesel, 0.5 gallons per hour is about right.

Melnal · RV-Dreams Family Member

Thank you all! It's a little intimidating the first try. We're holding off until we can pull into a rest area and kick on the generator :) At least now I have confidence that we aren't going to damage the rig! I so appreciate how quickly those replies came in, and we are researching the particular generator type we have, so the links are super helpful!

ItsmeBoo96 · RV-Dreams Community Member

We just bought our motor home and the dealership told us to run the roof unit instead of the air in the cab. He told us it is cheaper to run going down the road. Just saying.......... Chris

bjoyce · RV-Dreams Family Member

"dealership told us" - maybe, maybe not. I have a distrust of the advice from dealers, since many are not RVers and being mostly salespeople, they rattle off a lot he hearsay. The dash air will only keep the front cool, the rear of the motorhome will get no benefit. With our two motorhomes, one gas and one diesel, we did not find any real difference in fuel usage running the dash air but the generator uses between 1/2 and 3/4 gallon of fuel per hour. When the outside is above around 85 to 90, we run the generator and roof air to cool the whole motorhome.

Trabuco · RV-Dreams Family Member

On our diesel running the dash air makes no difference in mileage. If the dash air is not keeping you cool fire up the generator and run one of the house units. You're just not talking about that much fuel.

Melnal · RV-Dreams Family Member

Update: We tried to run the generator but it kept shutting off with an error code that indicates the exhaust was exceeding 1201 degrees Farhenhiet. Too funny! We are now stuck in Carlock, IL, awaiting an appointment to get it fixed. Apparently it's warranty work, so we can't have it fixed just anywhere ;)

TRAILERKING · RV-Dreams Family Member

That's good you tested it, found a problem, and getting it fixed. When working properly you can basically run the generator all day long for days if you want.

cherylbrv · RV-Dreams Family Member

Forgive me if I missed something here or for my ignorance.... is this applicable for a fifth wheel or just a MH? I have an Onan 5500 in my fifth wheel. It never occurred to me to run the genny while towing so that the rig could be cool when I arrived at my destination!