A box contains six 12 AWG conductors, one internal cable clamp and one duplex receptacle, all 12 AWG. What minimum box volume is required?

Explanation

Count six conductors, one allowance for all internal clamps and two allowances for the device yoke, giving 9 volume allowances. Each 12 AWG allowance is 2.25 cubic inches, so 9 x 2.25 = 20.25 cubic inches. Counting only the conductors gives 13.5 cubic inches, and forgetting that a yoke counts as two conductors gives 18.0 cubic inches.