:slaphead:
Oops.
Still significant enough reduction there is only room for three 14-2 in that 2 gang box.
A 27.5cu in 2 gang box w/internal clamps, 2 devices, and all 14ga wire:
2 cu in deduction for all clamps
8 cu in taken by devices
that's 10 cu in, leaving 17.5cu in left. That's 8 conductors, 7 + all grounds, gives 3 14/2 as you say, or two 14/2 and a 14/3, remainder 1.5 cu in. However, isnt one allowed rounding up here, or no?
27.5cu in for a 2 gang is pretty small; many are 34-38cu in.
Back to the original question, I've no problem running a single 12 or 14/2 to a pancake box regardless of its marked capacity. The 314.16(B)(1) exception is what I was thinking as well for omitting the ground.
I too hate pancake boxes but sometimes you have to put a box right on a stud or joist, like sconce lights in bathrooms. If possible, i'll use something like an arlington box that has box capacity on the side of the lumber
ETA: I do not consider those heavy duty plastic tabs in carlon boxes as internal clamps. Now, a butterfly clamp in a metal box one screws down on top of NM, yes.
