Forum Discussion

markm's avatar
markm
Explorer
Jul 03, 2018

auto gen start A/C

Anyone using the auto gen start for A/C? I spoke with Cummins rep concerning this feature for Onan 5.5kw generator. Seems like a good way to save on LP when you don't need the generator running all night to power other items.

Application would be for staying overnight at parking lot or rest area. No shore power, only need power intermittently when thermostat calls to kick on A/C.

10 Replies

  • time2roll wrote:
    Yes you would save the fuel while the generator would otherwise be idling.

    Although I plan to have an inverter and enough battery in my next RV to run the A/C 12 to 24+ hours without a generator.


    Never happen
  • Yes have used the AutoStart feature for staying overnight at parking lot or rest areas. Works great!
  • just a thought
    but if you want auto start for A/C
    you are not going to save much fuel over letting the genny run

    the A/C is not going to cycle on for 15 minutes per hour
    you are in a closed box, if you need A/C its going to run and compressor OFF time is going to be LESS than compressor ON time
    and the fan needs 110v to stay on, or the head pressure and start up load for the next cycle is going to be very rough

    auto start can be a life saver for pets, elderly, and your batteries
    but i dont think its an efficient fuel save option for A/C use
  • Yes you would save the fuel while the generator would otherwise be idling.

    Although I plan to have an inverter and enough battery in my next RV to run the A/C 12 to 24+ hours without a generator.
  • We also have an LPG Onan, the fuel cost is so high that if cooling is needed we find a campsite with electric. The campsite typically isn't much more than eight hours of LPG fuel.

    I'm curious how this works out for you. I really doubt the savings will be all that much since the generator fuel usage goes down when the load is cut.
  • DrewE's avatar
    DrewE
    Explorer III
    Big Katuna wrote:
    In Florida, you would wear out the starter.


    Why would the starter wear out when the air conditioner (and thus generator) never cycle off? :B
  • just a thought
    where is the Onan located, can you sleep with it running ?

    we can,, other people can't

    you have a quiet diesel up front ?

    or is under your bedroom like ours
  • We use an Auto Gen Start but do not use it to run the Air Conditioner in the way you are describing. If we have the Air Conditioner on, then we normally have the generator on too. The only exception was when we had pets and were staying at an unfamiliar campground. Then we would set the auto gen start and the AC to come on. The auto gen start was just a back up in case we lost power in the campground.
  • Not going to Florida, so I guess I wont wear out the starter.