I currently have a 200amp service feeding house including a 20amp 2 pole pool pump and a 60amp 2 pole pool heater/cooler, these circuits are not GFCI protected. I would like to replace the pool circuits with GFCI breakers as well as add a 50amp RV plug.

All single pole circuits have already been changed to tandems and I am out of space in panel. I think a sub panel is best, is there another option? If I do a sub panel is this circuit correct?

  • 100amp breaker in main panel

  • #4/4 AWG 5 feet to sub panel, sub panel neutral and ground not bonded

  • 20 & 60amp GFCI breakers in sub panel feeding existing pool circuits moved to sub panel

  • #4/4 AWG 12 feet to RV 50amp plug with one leg also feeding a 120v receptacle

All circuits have no neutral or grounds connected to any other circuit except the sub panel bus bars. am I correct, and is there anything I'm missing to make this up to code and safe? Thank you!

  • 1
    #4/4 AWG 12 feet to RV 50amp plug with one leg also feeding a 110v plug - uhm, not without a 15 or 20 amp breaker you didn't mention, you don't. Connecting a 120V 15-20A receptacle to a 50A breaker is a definite no-no.
    – Ecnerwal
    Nov 1, 2020 at 15:06
  • Given it's all of 12 feet, just run a 20A breaker and 12 feet of 12/2 for your 120V receptacle.
    – Ecnerwal
    Nov 1, 2020 at 15:19

1 Answer 1


You cannot use any wire smaller than #3 CU 75°C wire feed a 100A subpanel.

You don't indicate wire type you are using for the 50A feed to the RV receptacle, UF cable would require #6 CU, using conduit and THWN would only require #8.

If you wan't to use one leg of the 240v branch circuit to the RV to feed a 120v receptacle you will need to provide overcurrent protection suitable for the receptacle. You can't just put a 15 or 20A receptacle on a 50A breaker. For the short distance you describe a separate #12 feed might be easier. Easiest would be to buy an RV pedestal already has the breakers and receptacles in place https://amzn.to/3oP1zRQ .

  • I get now how stupid that was on the 120v plug. Thanks for wire size and panel suggestion
    – Tno
    Nov 1, 2020 at 16:23

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.