I'm running out of slots in my old electrical panel. All of my breakers have a single wire plugged in. Can I free one up by feeding my doorbell low voltage converter into the same circuit breaker that I use for my ceiling lights?

  • 2
    The short answer is yes, if you have breakers that accept two wires, or if you pigtail them in the panel and connect a jumper to the breaker.
    – isherwood
    Commented Nov 27, 2018 at 16:21
  • But what else is on the same circuit as the "door bell low voltage converter"? Commented Nov 27, 2018 at 16:53
  • @isherwood this should be an answer. Having the doorbell on the lighting circuit is fine as long as the wires to the transformer are of proper size. 14 awg wire on 15 amp breaker 12 awg wire on 20 amp. If the lighting circuit and the transformer wires are the same gauge it will be fine.
    – Ed Beal
    Commented Nov 27, 2018 at 17:29
  • I voted to close as duplicate. No answer is warranted.
    – isherwood
    Commented Nov 27, 2018 at 17:41
  • 1
    @isherwood - while this is technically a duplicate of that other question, I'm not sure it's immediately obvious to the layman that it's a dupe since the title of that question is not clear, so if this question is closed, it will likely come up again. Few people wondering how to hook up two circuits to one breaker will see the title "What is electrical code for number of wires in a breaker" and know that it's a dupe. Maybe that one can be re-titled to make it more obvious.
    – Johnny
    Commented Nov 27, 2018 at 21:16

1 Answer 1


Yes, it's fine to combine circuits onto one breaker, at which point they become one circuit. Provided, of course, that there is not a Code prohibition on that due to certain particular circuits needing to be dedicated, i.e. You can't add anything to a furnace circuit, and cannot add non-bathroom loads to a bathroom receptacle circuit.

Mechanically, you must use breakers listed for your panel by UL. Your breakers might allow 2 wires on a terminal, if not just pigtail them. Wire nuts are allowed in panels.

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