A metal 4" square box has ten 12 AWG conductors, four 12 AWG grounding conductors, and four external clamps. What is the minimum size 4" square box you could use?

Question

Quizplus · Accepted Answer

According to NEC 314.16(A)(1), the minimum size of a square box containing more than eight 12 AWG conductors is 24.5 cubic inches. Adding the external clamps, the total box fill is 24.5 + (4 x 2.25) = 33.5 cubic inches. The closest box size meeting this requirement is a 4" square with a depth of 2 1/8", which has a volume of 34.56 cubic inches. Therefore, the minimum size 4" square box that could be used is C) 4 * 2 1/8.

A Metal 4" Square Box Has Ten 12 AWG Conductors