Argthtjtr

I'm building an outdoor bbq and have a 20A circuit with 2 runs - 1 for outlets and 1 for lights. The outlets are done with 20A receptacles and 12 ga wire inside 1/2" emc.

The lights will be hanging pull lights (16 ga wire in the cord) and because it's a little cheaper and easier, I wanted to get power to the fixtures by 14 ga wire, also in 1/2" emc.

Is this a no-no? The only thing on this run would be 5 lights, so very low load.

You can't do this unless you change the breaker to 15A. The 16 AWG wire as part of the lamps is allowed because the lamps, by design, will never have more power going through them. But the wires you put in could, someday, have additional power - perhaps another owner decides to put more lights or convert one to a receptacle for outdoor power tools. You can't control all of that (as much as you think you can) so you have to stick to the rules. 12 AWG for 20 A. 14 AWG for 15 A. You can have a mix of 12 & 14 on a 15 A circuit, but can't do that on a 20 A circuit because the circuit breaker has to be small enough to protect all the wires connected to it.

You could do it if you switched to 15A breakers, but you can't wire the 20A circuit with 14 gauge wire.

In EMT, it will be almost no difference in time or money to do this with 12 gauge wire.

The lamps have been UL listed to allow the smaller wire, and that wire will go no farther than a junction box. And the lamp is in the jurisdiction of UL's rules and the product safety laws, not NEC.

In conduit, you are running single wires called THHN (or THWN-2, or the more deluxe XHHW) unless you are a masochist. The cost between #12 and #14 is fairly minor; I have 10 colors of THHN and I don't even bother owning any #14, just do it all in #12.

If your concern is that #12 wire is stiffer, than definitely use stranded #12 THHN. The stuff is a total pleasure to work with, though it can take a knack to twisting it tightly enough to put it on receptacle screws. Just get the $3 Leviton screw-to-clamp type receptacles and switches, that solves that.

If your concern is #12 won't fit in backstabs, that is correct, but backstabs are a reliability disaster and cause a tremendous number of arcing and unreliable connection complaints, so I would use the screws or screw-to-clamp.