I have several spare 240 breakers in my panel box. I'm adding 8 outlets from 2 different rooms. Can I use half of the 240 breaker instead of replacing with a 120, or should I pull the 240 and replace with a 120? One of the spare 240's has wires coming out but are no longer in use (for old baseboard heat).

  • 1
    ?hat size breakers and 8 outlets for two rooms on one circuit?? What wire size?
    – JACK
    Commented Apr 3, 2020 at 0:19
  • What make and model are your existing breakers? Commented Apr 3, 2020 at 0:56
  • You may also want to research Multi Wire Branch Circuits (MWBC) which use "240v" breakers to make two 120v circuits. You get two safe circuits that share a neutral wire.
    – JPhi1618
    Commented Apr 3, 2020 at 16:51
  • Thanks all for quick responses. My existing single pole breakers are 20amp "D", type E. The 2 poles are "D" issue no. RT-1372. If that answers your question. Wire size: 12/2 (That's what I had)
    – Joel
    Commented Apr 4, 2020 at 1:50
  • Can you post photos of the existing breakers please? Commented Apr 4, 2020 at 3:27

2 Answers 2


You can use either or both halves as separate single pole circuits as long as the amperage rating is correct for the wire size and receptacle type.


Yes. The only issue you'll get into is if your nation's electrical code requires a higher grade of breaker. For instance most breakers in the USA or Canada need to be AFCI type. You'd be better off with single AFCIs rather than fooling around with a 2-pole AFCI.

In some cases, both AFCI and GFCI is required (or desirable) and in that case an AFCI+GFCI dual-mode breaker is cheaper than an AFCI breaker + GFCI recep(s).

If AFCI is required you cannot use an AFCI recep unless you run metal conduit.

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