Forum Discussion

etrippe's avatar
etrippe
Explorer
Jul 21, 2019

Running 1 ac unit on 20 amp shore power,

I have a dedicated 20 amp circuit next to where I park my MH when loading and unloading for trips. If only some 12 volt lights, but no frig or water heater on electric were running in the mh, could I run 1 of the roof top ac’ units? Both units are on single 20 amp breakers in the MH and one is 15,000 btu and one is 13,500 btu
.
Thanks in advance

Additional info

I have a 30 amp extension cord with an adapter to 20 amp that I could use.
  • road-runner's avatar
    road-runner
    Explorer III
    Jul 22, 2019
    2oldman wrote:
    GFI circuits don't work well.
    Mine do. Not a single trip in 15 years of plugging the RV into a GFCI circuit, with or without air conditioner running.
  • Dave_H_M's avatar
    Dave_H_M
    Explorer II
    Jul 22, 2019
    I been doing it for years with the 13,500 in the fifth wheel.
  • valhalla360's avatar
    valhalla360
    Navigator
    Jul 22, 2019
    Your average roof air/con will pull 10-12amps continuous (much more for a second on startup).

    As long as the breaker doesn't trip and you keep the other loads negligible, it should be fine if the connections are all clean and good condition.

    Use the biggest shortest extension cord you can to minimize voltage drop.
  • etrippe's avatar
    etrippe
    Explorer
    Jul 22, 2019
    pianotuna wrote:
    Have a way to monitor voltage. My comfort zone is 107 and above.


    Forgot to mention, I have a Progressive Industries EMS and it shows the voltage draw and I will monitor it. It also shuts down at 104 and below aotomatically.
  • TurnThePage's avatar
    TurnThePage
    Explorer
    Jul 22, 2019
    road-runner wrote:
    MitchF150 wrote:
    Best to check your voltage when plugged into whatever configuration you have and go from there...

    If you plug in and then turn on the AC get a volt meter and plug into any other 120v outlet in the rig and read it's voltage output..

    If it's much below 108v, then you might need to consider some other power source, but for a short time, and if it does not trip the 20a breaker then you are probably "ok"...

    No way to say for sure one way or the other, but you can also feel the cords and if they are really warm to the touch, then maybe you are drawing too much...

    Good luck!

    Mitch

    This answer gets my vote as the best. I check the voltage inside the rig, and it works out ok for me.
    x2 I did this for years, and on hot days the voltage would sag down to 103 or so before I would notice and shut it down. A Kill-a-watt is a super simple, and relatively cheap way to monitor your voltage.
  • etrippe's avatar
    etrippe
    Explorer
    Jul 22, 2019
    valhalla360 wrote:
    Your average roof air/con will pull 10-12amps continuous (much more for a second on startup).

    As long as the breaker doesn't trip and you keep the other loads negligible, it should be fine if the connections are all clean and good condition.

    Use the biggest shortest extension cord you can to minimize voltage drop.


    Thanks
  • etrippe's avatar
    etrippe
    Explorer
    Jul 22, 2019
    Thanks everybody. The plan is to use the ac only will parked in the driveway when getting ready to go or while unpacking, and only if it’s really hot out. I’ve run the generator in the past but if l’d rather use the house electric if possible. Again thanks for the responses, this forum is great
  • ford_truck_guy's avatar
    ford_truck_guy
    Nomad
    Jul 22, 2019
    Not to brag, but I will :B

    We are leaving for a 2-1/2 week trip on Wednesday and I have had ALL 3 of my 15K AC's running, set to 75 since last week while we pack it up.

    I got tired of being worried what would and would not work so I ran a dedicated 50amp outlet to the RV..
  • Cummins12V98's avatar
    Cummins12V98
    Explorer III
    Jul 22, 2019
    ford truck guy wrote:
    Not to brag, but I will :B

    We are leaving for a 2-1/2 week trip on Wednesday and I have had ALL 3 of my 15K AC's running, set to 75 since last week while we pack it up.

    I got tired of being worried what would and would not work so I ran a dedicated 50amp outlet to the RV..


    SMART MAN!!!

    Nothing better than 3 AC's at 113 degrees! Been there done that.

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