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Tuckerman52's avatar
Tuckerman52
Explorer
Jul 04, 2022

Breaker issues

Good evening I am new to this I have a 1999 35 ft newmar Dutch star with a Ford Triton V8 have twin AC roof mount and my problem is I purchased a standalone portable air conditioner that pulls only 10 amps according to the label and as a regular three prong plug-in and every time I plug it in to the motorhome when I am on shore power now that is I have only access right now to a regular outlet in my carport regular 110 and when I plug the portable AC into the motorhome anywhere in it it then throws the breaker in my panel now I have 2 50amp main breakers and three sets of 20 amp 15 amp breakers besides that. I have made sure nothing else is running it's a 12,000 BTU portable AC and like I said it says it only pulls 10 amps if I plug it directly into the house and not into a socket in the RV then it will run fine I'm wondering if I possibly have two smaller cord running from the house to the motorhome but besides that I plugged my motorhome into itself fired up the generator which is an Onan 5500 and put one of the rooftop ACs on and as soon as I plugged in and turned on the portable AC it killed the generator which doesn't make any sense just looking for some help I'm going to talk to an electrician friend if I can tomorrow anybody have any ideas thank you and it much in advance for help
Class A
  • enblethen's avatar
    enblethen
    Nomad
    Jul 05, 2022
    The breaker in your panel, is in the house or the rig?
    If in the rig, start by checking your shore power cord adapter.
  • MountainAir05's avatar
    MountainAir05
    Explorer II
    Jul 05, 2022
    Just run a 120 volt extension cord from house to Rv. Now plug the one AC into it and if it blows the breaker you know that the AC has an issue. Keep it simple Unplug all other cords.
  • CA_Traveler's avatar
    CA_Traveler
    Explorer III
    Jul 05, 2022
    Extension cord needs to be as short as possible, 10 gauge wire and plugged into a dedicated 20A garage plug, not into a common multidrop regular plug.

    Are you sure everything is off - hot water, refer, charger, etc?

    Best to install at least a 30A RV plug if not a 50A RV plug.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jul 05, 2022
    First the 10 amps is running. might be much higher starting but... The breaker should allow that (Short time delay).

    Second if you plug the A/C into the RV's outlet and plug the R/V into the carport.. there are other thigns in the RV.. a Progressive Dynamics 9180 with wizard can easily suck 10 (or more) amps if the batteries are Hungry. The Fridge may also be auto switching to A/C (about 3 amps) .
  • JRscooby's avatar
    JRscooby
    Explorer II
    Jul 05, 2022
    OP, RU2 home? If so, first step is plug the AC N2 house. If that does not trip house breaker, look at RV.
  • dodge_guy's avatar
    dodge_guy
    Explorer II
    Jul 05, 2022
    JRscooby wrote:
    OP, RU2 home? If so, first step is plug the AC N2 house. If that does not trip house breaker, look at RV.


    What? I can not even follow that!
  • CA_Traveler's avatar
    CA_Traveler
    Explorer III
    Jul 05, 2022
    dodge guy wrote:
    JRscooby wrote:
    OP, RU2 home? If so, first step is plug the AC N2 house. If that does not trip house breaker, look at RV.

    /
    What? I can not even follow that!
    As stated in his post it's a portable A/C that is OK in the house.

    Other loads in the RV and excessibe voltage drop due to the extension cord and possible garage circuit.
  • CA_Traveler's avatar
    CA_Traveler
    Explorer III
    Jul 05, 2022
    OP With a 30A RV plug and 30A extensions you might be able to run the portable A/C.

    HOWEVER, Consider installing a 50A plug.
  • JRscooby's avatar
    JRscooby
    Explorer II
    Jul 05, 2022
    CA Traveler wrote:
    dodge guy wrote:
    JRscooby wrote:
    OP, RU2 home? If so, first step is plug the AC N2 house. If that does not trip house breaker, look at RV.

    /
    What? I can not even follow that!
    As stated in his post it's a portable A/C that is OK in the house.

    Other loads in the RV and excessibe voltage drop due to the extension cord and possible garage circuit.


    Sorry, I gave up following the OP, thought maybe I would throw another code in there.

    If AC works when plugged into home outlet, but trips a breaker in RV, look at what else looses power at trip. Add the loads to AC, compare to size of breaker.
  • CA_Traveler's avatar
    CA_Traveler
    Explorer III
    Jul 05, 2022
    Hopefull the OP will provide more info.

    I'm not even sure a portable A/C is practical unless it's vented outside.

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