I have a sub panel that was from when the previous owners had a hot tub.

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I'm currently needing a 30 amp circuit for a mini split system and was wondering if I could just swap this 50 amp breaker and then run my 10/2 ** ( correction 10 gauge wire) ** in place of the 6 gauge wire that's currently in place?

I know I could run a sub panel from this panel or replace this with a small panel and have the advantage of expanding things in the future. However I can't see any scenario where I would ever need that.

** Update For Clarification ** The conduit and 6 gauge wire that was feeding the hot tub would remain in place just be capped and disconnected in the box. I would punch a new hole and run the new conduit and 10 gauge wire about 10 feet from here to the outside condenser.

  • How many wires are in the existing conduit, and what size and type (LFMC or LFNC) is it? Commented Jun 22, 2020 at 1:07
  • Also, why do you want to run 10/2 (a cable) inside the flex whip? Commented Jun 22, 2020 at 1:17
  • I updated the original post to add some clarification. My brain just automatically typed 10/2, you are correct I would not be running that through the conduit. 3 wires in the current 1 inch LFMC Conduit. However, I do not plan to reuse the the wires or that conduit.
    – Cwarbucks
    Commented Jun 22, 2020 at 1:52
  • How do you plan to run the cable connecting the indoor and outdoor units BTW? Commented Jun 22, 2020 at 2:37
  • through LFMC Conduit from the Condenser going straight up the house into an attic section.
    – Cwarbucks
    Commented Jun 22, 2020 at 3:04

2 Answers 2


You can do that. You will have to pigtail a piece of #10 cu to the #6 because the #6 won't fit into a 30 Amp breaker. I would replace the breaker in your main panel and do the pigtailing in there. Then replace this breaker box with a 30 Amp disconnect switch with separate neutral and grounding bars. This breaker is an old Challenger breaker and they have been known to be fire starters. I think it's a stabloc but I'm not sure. Hoping one of the big three will chime in if I'm wrong.

Ok we've got confirmation it's not a Stab-Loc. I'd still replace it with a disconnect.

  • Nooope, it's not a Stab-Lok Commented Jun 22, 2020 at 1:03
  • Also, they may have to replace the wiring in the flex whip due to needing space to route the control wiring between the two halves of the minisplit Commented Jun 22, 2020 at 1:07
  • They could simply replace it with a BR230... Commented Jun 22, 2020 at 1:14
  • I have space/capacity on my inside pane to add a 220/30 amp circuit and wire a disconnect for the condenser. I was just trying to see if I could use what was already in place instead of doing another run.
    – Cwarbucks
    Commented Jun 22, 2020 at 2:05
  • You should have a 50 Amp breaker in your main panel for this circuit anyway. Just replace it with a 30 Amp breaker and use your #6 run from the panel to the disconnect.
    – JACK
    Commented Jun 22, 2020 at 2:15

You can reuse all the #6 wire and old conduit that you please to use.

There is no reason to rip out or change any wires (and some reason not to: future expansion.

ONE of the breakers needs to be 30A.

You need to change either the main-panel breaker to 30A, or the breaker in this mini-panel/disconnect switch. No need to change both. If you change the mini-panel breaker, then the run to the main panel needs to continue to be #6/8/whatever it is now.

That Challenger breaker must go. The panel is a keeper.

Challenger had the same kind of "faulty breaker" problem that Federal Pacific did. However unlike FPE, this panel bus design is tip-top, and in fact lives on today in the very popular Eaton BR line. Technically this busing requires a Type C breaker, but if you look at any BR breaker on the market, they are dual-listed Type BR Type C.

If your main panel is also a Challenger, same deal. The old breakers must go; Eaton BR is a listed substitute.

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