I have one 15 amp (Square-D QO, non-AFCI/GFCI) which was originally installed for unfinished basement. now I have replaced it with 15 amp AFCI for a finished basement.

Now I have a 30' 14 gauge wire and one 15 Amp non AFCI/GFCI left. I know at least that I can't use the breaker in the finished area.

Can I still use it for an unfinished area or outdoor?

Similar I found online: https://www.homedepot.com/p/Square-D-QO-15-Amp-Single-Pole-Circuit-Breaker-QO115CP/100061177

  • 1
    Thanks @FreeMan for correcting me. updated. its non FCI.
    – PowerTech
    Sep 21, 2021 at 18:06
  • I think depending on what state you are in, you might be able to use it in a bedroom, but are you just trying to make use of a $10 item?
    – JPhi1618
    Sep 21, 2021 at 18:10
  • 3
    You can put the AFCI/GFCI protection on the outlets or some place downstream of the breaker; the breaker is not required to be an AFCI breaker itself.
    – TylerH
    Sep 21, 2021 at 18:27

2 Answers 2


Plain breakers are an option for fewer and fewer circuits of late.

However, here's something: if you have a 240V load that does not have a neutral (so we're talking water heater, air conditioner, EVSE etc.) you can take 2 singles and sandwich them into a 240V breaker, using a factory handle-tie. Again this does not work if the circuit is 240V with a neutral.

See, common trip (one side overloads, both sides guaranteed to trip) is provided by an internal mechanism in a 240V breaker - not by the handle tie. That's what makes 240V breakers different from 2 singles handle-tied. And if a load is 240V with neutral, it needs common trip. But if it's 240V without neutral, it does not need that. So sandwich away!

If a circuit requires AFCI, you can run metal conduit to the first metal junction box, and use an AFCI receptacle there. (the metal conduit provides superlative protection for the wires from breaker to recep, thus, acceptable.) NEC 210.12(A)(5). My standard ploy is to fit a 4-11/16" square deep box right next to the panel, and connect it with short EMT metal conduit to the panel (thus taking care of ground). The bigger box has ample space for dual GFCI or AFCI receptacles with their wiring.

But the single most important use of a spare breaker is as an empty hole filler.

We see lots and lots of panel photos with empty gaping holes, waiting for curious fingers. This is where the cover knockout has been removed, and there's no breaker there, and quite likely, the official plastic blank cover plate fell off because they're flimsy. Spare breaker? Problem solved.

  • I didn't know that about 240v breakers... I thought that overloading one side would cause them both to trip because of the handle tie. That's good to know!
    – JPhi1618
    Sep 21, 2021 at 18:53
  • 1
    @JPhi1618 Ah yes, the key there is a breaker's "Trip Free" function: it must trip even if being held (or locked) in the on position. So if the breaker doesn't have the "oomph" to throw the other 1-2 breakers, it just trips itself. Sep 21, 2021 at 19:01
  • 1
    Yep, makes sense. I remember seeing pictures of a breaker wired up so that it couldn't be turned off, and the consensus was that it would trip no mater what, but I didn't make that connection at the time.
    – JPhi1618
    Sep 21, 2021 at 19:08

In the 2020 edition of the NEC®, Section 210.12 requires that

for dwelling units, all 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets or devices installed in dwelling unit kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, laundry areas, or similar rooms or areas shall be protected by AFCIs.

So if you can find a place they're not required based on the above information, you can use it. You could also use it in a non dwelling unit like an office, retail store or factory.

  • If that's a direct quote from the NEC, please indicate it by using the quote formatting of > quoted text. Use the greater than sign > and a space ` `, then the quote. That will help distinguish between exact quotes and paraphrases.
    – FreeMan
    Sep 21, 2021 at 18:17
  • I think that's what you're after. ;) No worries, it'll come! BTW, if I missed a bit somewhere, please correct the edit!
    – FreeMan
    Sep 21, 2021 at 18:25
  • Welcome to StackExchange! Yeah, convention here is you can edit anytime you want, provided you don't turn it into a totally different answer after getting a bunch of upvotes. Also, if you write a comment and stick the word "edit" inside square brackets, it automagically turns it into a hot link... that only took me 3 years to figure out! Sep 21, 2021 at 18:32
  • Washrooms not on list. May be because GFCI receptacles are used.
    – user263983
    Sep 21, 2021 at 23:36

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.