RV Air Conditioner Question

Q. Mark, We are looking at the Winnebago Sightseer 35J. The model we are looking at has two roof air conditioners, but only has 30 amp service with an Onan 5.5 KW generator. Will these two air conditioners be able to run at the same time with only 30 amps? Thanks!

Mark Says: Most RV manufacturers use some type of energy management system so both roof A/C's can operate at the same time on a 30 amp system. Our 2006 Bounder 35E is a good example. It will power up one A/C and then the other. Once they are both running it can sense if there is a requirement for more power placed on the system, like somebody making a pot of coffee, and it will shut one A/C down or both depending on the power requirement. When there is no longer a requirement the A/C units automatically start back up.

Something else many manufacturers are doing is to use smaller BTU air conditioners. It was no good to have two 15,000 BTU units if you can only run one, so now they might use a 13,500 and an 11,000 BTU unit which a 30 amp system can run at the same time.

Basically what I am saying is most of today's manufacturers offer some type of power management system to operate both A/C units with a 30 amp system. On the other hand most manufacturers have a built in system to prevent you from using both A/C units and attempt to use the microwave or other power consuming appliance. It is a combination of modern technology and learning to live with 30 amps.

I recommend calling a Winnebago dealer and ask them how Winnebago deals with this issue and to send you some literature on the topic.

Copyright 2008 by Mark J. Polk, owner of RV Education 101

RV Expert Mark Polk, seen on TV, is the producer & host of America's most highly regarded series of DVD's, videos, books, and e-books. http://www.rveducation101.com/

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  1. I want to find out why white styrofoam would blow out of our roof top airconditioner. It is a 2007 Georgetown motorhome. This airconditioner has been used maybe 30 times in the three years we have owned this. It isn't driven all winter and the last time we used it was August 2009.

  2. Lots of RV manufacturers use styrofoam for the a/c duct work routed through the ceiling. It's possible that some styrofoam is in the duct work from the initial installation or possibly the duct work is damaged and some of it comes out when the A/C is running.