Forum Discussion

rickfraza's avatar
rickfraza
Explorer
Jul 14, 2019

Add second air conditioner to 30 amp RV

I'm looking for advice from either a Master Electrician or Electrical Engineer on this question. I've seen a video showing how to add a second air conditioner to a 30 amp RV. The video shows wiring a 13.5 BTU unit to an outside 15 amp plug and then connecting to the 20 amp outlet on the RV pedestal with a short (25') 10 awg extension cord. That would leave the RV on the 30 amp service, while powering the air conditioner using the 20 amp outlet. Power consumption for the air conditioner is stated as 1670 watts which should be between 13.9-14.6 amps. The 20 amp breaker should handle 16 amps continuously. I know when air conditioners first start that they pull more amps (~16A) very briefly before they drop to their "run" amperage. Would it be smarter to use the 50 amp service with one of those 50A pigtails that provides 2 x 30 amp outlets? The RV would be plugged into one of the 30 amp outlets with a surge protector and the other outlet would be plugged into the second air conditioner using a 30->20 amp dog bone adapter. Or would it be better to plug the 30A service in as always, and only plug the air conditioner into one of the 30A outlets with that 30-20 adapter? Or should I just plug the A/C in directly to the 20A outlet and the RV into the 30A outlet? If this doesn't work, I'm afraid my wife will insist on either only using the RV when it's cold, or getting rid of it altogether.

22 Replies

Show More
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jul 14, 2019
    Always smarter to use 50 amp if you got it (My opinion)

    BUt I have a 50 amp rig. I "Broke out" (Technical term) the bedroom A/C so that when I'm on a 30 amp site I open a door pull a plug and now the Rear A/C is independent of the RV. I use a 12ga cord to the park's 20 amp breaker

    Suggest the following hookup for the added A/C also suggest you go 15000 BTU I mean for a few dollars more you get more cooling and as the world warms. YOU WILL NEED IT.

    A/C----Single breaker box, 20 amps----- 20 amp (Twist lock) Inlet

    20 amp (Twist lock) 12ga cord----------- Park 20 amp outlet .


    ON a 50 amp site you have choices

    1: will need to buy or build a "Break out" box 50 amp male plug. Two breakers (1-20 1-30) TT-30 outlet and a 15/20 Duplex receptacle

    I'd add a few neon Lamp indicators to show things like good safety ground and such but hey that's technical stuff.

    The other.. Use the park's 20 amp outlet for the A/c
    Feed the RV by either using a 30-50 Dogbone or off the park's TT-30

    You won't overload the circuit using any of those methods.

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,315 PostsLatest Activity: Sep 09, 2025