I've purchased a Lutron dimmer switch (DVWCL-153PH-WH) to install for ceiling mounted LED lighting. The wires for the current switch are 12 gauge with a 20A circuit breaker while the dimmer switch wires are 16-18 gauge (didn't measure precisely, but significantly thinner).

Is it safe to join these different gauge wires together with wire nuts? Haven't installed a dimmer switch before so not sure if this is standard.


1 Answer 1


The wire that comes on the switch / dimmer is UL listed for use on 15 & 20 amp circuits. They have a wattage limit many around 600W for incandescent / halogen type lights and 150W for the led type this is the limiting factor with dimmers put two many lights on the dimmer and they get hot and usually will shutdown if they don't have thermal limiterss the electronics in the switch fail before the wire is damaged so you are ok in this case joining the smaller factory installed wires from the switch to your 12 AWG wire.

  • 1
    Ed has the answer, it is because UL approved it that way, because appliance design rules permit this. It is, after all, entirely contained inside a junction box. Commented Sep 25, 2018 at 21:45

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.