I am replacing a single pole on/off light switch with a dimmer switch. The switch is on a 20 amp circuit. I have 14 gauge wire on hand. Can I use 14 gauge pigtails to connect the switch? Or do I need to use heavier gauge wire for this?

  • I wonder if there is an exception for pigtails inside switch boxes for switches that are rated for 15A or less switching capacity. Which is often the case for ordinary switches and especially the case for dimmers. Jul 14 at 3:37
  • I always think of the hypothetical 17A current that a slightly failed switch can produce. Too small to trip the 20A breaker, but big enough to burn through the theoretical capacity of the awg14 wire. (I know EEs will explain how awg14 wire can carry more than 15A, but you get the idea.) If there is an exception, I'll be glad to learn of it. Jul 14 at 3:43
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    Why do you need pigtails in the first place? Jul 14 at 4:00
  • No you can't. ........... And that's why I don't have 14 AWG wire on hand. If I'm going to own one wire size, it'll be #12. @ThreePhaseEel because the spec-grade switches that can take 2 #12 wires per screw are $2 more. Jul 14 at 18:31

1 Answer 1


All wire in the circuit and the breaker have to coordinate: 20A breaker, awg12 wire. 15A breaker, awg14 (or bigger) wire.

So, no awg14 on your 20A breaker.

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