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Ponder's avatar
Ponder
Explorer
Nov 07, 2012

Two AC's with 30 Amp Service ?

Hello...I am a new RV-er and have a million questions but maybe someone can help with one for now.....

I have 30 amp service and two AC's and the two will not run by generator at the same time....but the manufacturer says the Gen will run both but not with 30 amp service in the coach. I found a post that was very complete 6/2/2012 by ""Chaffkeekid"" showing with Pictures and with great detail how to mod wiring (pretty simple)to run two AC's with 30 Amp service....

Does anyone know if this mod was to run off the Generator or one unit off the Gen and the other off shore pwr?? Not sure.

Many Thanks...Ponder
  • Thanks very much for sooo much fast response....

    Here's the link to the post from 2010 that i think may be a good instruction but I am not sure...

    http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/24041285/gotomsg/24042358.cfm


    Anyway, what I have is a 1999 Rexhall Aerbus, XL3550BSL. Two AC units, and a Generac 5KW generator that the manufacturer (Rexhall) says would run the two AC units at the same time but the coach is 30 amps....so there are switches in the coach to select one or the other AC units. I see quite a few discussions on how a mod would allow for the two AC units to be run at the same time from the Generator....but I am just not experienced enough to know for sure what I am looking at with these mods....

    So my question is after you look at the post from 2010 above...Pictures and nice instructions.....will this mod allow me to run the two AC's at the same time with off the generator?
  • Mandalay Parr wrote:
    I run both of mine on 30amps at times. No problem. They pull about 27amps.


    I did too with my winnebago with a decent EMS.
    bumpy
  • What kind of coach and what size genny???

    Seems a bit wierd for the manufacturer to supply 2 AC units and only a 30 service. What does the owners manual say about that??
  • Running one air conditioner off the generator and the other off shore power is not a practical solution... Even if it were possible, if you are in a campground hooked to shore power running a generator would not be permitted...

    Depending on the size of the air conditioners many people report that they are running two off 30 amp service...

    I could not find the post by "chaffeekid" you referred to

    You can help us help you...

    Please state make model year of your motorhome and make, model and size of generator.. Do you have a power managment system in your coach?

    JohnnyT Moderator
  • Depending on the A/C units itself and the capacity of your generator. If your Gen only has a 30amp capacity, I wouldn't rewire it because eventually you'll overload it when you use another appliance at the same time. Even if it does work, the wiring may overheat after a time which could cause you many more problems to the extent of burning the whole rig up.

    Personally, I think the mfg'er knows more than either of us do, in regards to engineering the electrical system.

    Sid
  • There is an aftermarket addon made by Power Solutions that will allow you to interrupt power from the generator on one of the two AC leads and make it a shorepower lead. Now you have two shorepower leads. One is the normal 30 amp that you now have and will power all of your MH and one AC, the other will power only the second AC. Its less than a hundred bucks and makes the conversion somewhat painless.
    You can also find conversions, probably what you have already found, that allow you to do the same thing without the Power Solution unit.
    The generator will indeed power both AC's at the same time.
    Some MH's have an Energy Management System that will allow both ACs to operate at the same time by managing the compressors so that both compressors don't engage at the same time.