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Willie_Jim's avatar
Willie_Jim
Explorer
Jun 26, 2023

Generator won't start camper air conditioner

Year old Bullet camper, AC General Electric unit lists three model numbers, with a square the manufacturer was supposed to mark the appropriate square, but didn't. It draws 13.2 amps running load which agrees with the smallest model.
On house power it starts & runs fine. On the occasion I can get it started, it runs fine on the generator.
Generator is a new Generac GP3300I rated 2500 watts continuous & 3300 starting power (20.8 & 27.5 amps)

Hard start capacitor sets are available on line, but little information is given about installation or applications.

Any help would be appreciated.
  • Mike134's avatar
    Mike134
    Explorer
    Jun 26, 2023
    Willie Jim wrote:
    I'll try disconnecting battery. I see no circuit labeled battery charger in the breaker panel, guess it is powered through the main breaker.


    If you do that than all the 12V loads will need to be powered from the generator via the 120/12V inverter.
    If you could disconnect the inverter, then any 12V loads would be supplied by the battery.
  • Willie_Jim's avatar
    Willie_Jim
    Explorer
    Jun 26, 2023
    CA Traveler wrote:
    Motors and especially heavier duty motors can draw substantial amps during startup. I just bought a 3,200 watt rated inverter gen with a 4,000 watt peak. I would not expect a problem with one A/C starting, 2 at the same time could be a problem. Will do some testing with the RV A/Cs because I want to know. I don't expect any issue with it's intended application of 2 household refers.


    I'm intimately familiar with extra load starting motors, Air Conditioning tends to be worse than other loads. This generator claims to handle starting load twice that of full load amps. I hoped that meant a struggle to start, it'd take a second to get up to speed. It seems with more experimenting to sometimes manage to start the load. I'm leaning toward installing the soft start.
  • KD4UPL's avatar
    KD4UPL
    Explorer
    Jun 26, 2023
    Your generator is likeky rated at sea level. Higher elevation reduces power output.
  • CA_Traveler's avatar
    CA_Traveler
    Explorer III
    Jun 26, 2023
    Motors and especially heavier duty motors can draw substantial amps during startup. I just bought a 3,200 watt rated inverter gen with a 4,000 watt peak. I would not expect a problem with one A/C starting, 2 at the same time could be a problem. Will do some testing with the RV A/Cs because I want to know. I don't expect any issue with it's intended application of 2 household refers.
  • Mike134's avatar
    Mike134
    Explorer
    Jun 26, 2023
    AC units (any motor) will need to draw 6X running current for just an instant at startup. When plugged in at home or a campsite that is no problem getting that from the utility.
    Problem comes in trying to do it from a generator.
    Solution is the Mico air soft start. Don't waste $15 on a "hard start capacitor" those only help when connected to the utility power.

    https://www.micro-air.com/products_groups_easystart_soft_starters_microair.cfm
  • Willie_Jim's avatar
    Willie_Jim
    Explorer
    Jun 26, 2023
    I'll try disconnecting battery. I see no circuit labeled battery charger in the breaker panel, guess it is powered through the main breaker.
  • TenOC's avatar
    TenOC
    Nomad
    Jun 26, 2023
    Make sure the house battery is fully charged or disconnect the battery. If the battery is drawing a charge from the generator this may "rob" power from starting the A/C.

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