I’m replacing an outlet on a 20 amp circuit with a GFCI, and I noticed the wiring is 14 gauge. This is in a house built in 1964. I know this generally isn’t safe and have read a few other questions on the topic (e.g., 14g wire on 20amp circuits all over home My 20 amp circuit has some 14 gauge wire in it. Is that OK?). But I still have a couple questions.

One, in of those threads, a commenter mentioned “it would take more than 15 amps plugged into the duplex outlet at the end of the circuit to overload the wire” — does that mean I can address the issue by putting in a 15A receptacle instead of 20A? (FWIW, the old receptacle was 15A.)

Two, in this random forum thread I found, someone commented “It could be permissible to have conductors with a lower ampacity than the OCPD if the circuit were feeding AC units or motor loads.” Could someone unpack that for me? There’s a washer and dryer on this same circuit — since those have motors, are they “motor loads” and is it OK for them to be on a 20A circuit with 14 gauge wiring?

  • 3
    No. You seem to be indulging in wishful thinking. Stop it and put the 15A breaker in there where it needs to be. The exception in the Article 430 motor rules applies to a dedicated circuit to ONE SPECIFIC motor which has overload protection ON THE MOTOR. Thus the breaker doesn't need to be involved in overload protection, only short-circuit protection. Doesn't work for 2 motors. The other quote is either wrong or you lifted it out of context. Jan 23, 2023 at 4:00
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    15 amp receptacles are made to take 20 amps, but 14 gauge wire is not made to take 20 amps. This only works for 15 amp receptacles, no other sizes. Receptacles do not limit how much power/amps go though them, that is the breakers job.
    – crip659
    Jan 23, 2023 at 11:14
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    Changing the breaker to 15A is the solution, unless you replace all the 14 Ga wire with 12 Ga. You can find all sorts of wrong answers on the internet to quote - they are still wrong.
    – Ecnerwal
    Jan 23, 2023 at 14:36
  • Is there anything I should think about or check before changing to a 15A breaker? There aren’t any 20A receptacles on the circuit, but is there any other reason that the circuit might require a 20A breaker (in which case I’d have to have the wiring changed to 12 Ga)?
    – zephryl
    Jan 23, 2023 at 21:18


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