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

The minimum size box is determined by calculating the volume needed for the conductors and clamps. Each 12 AWG conductor requires 2.25 cubic inches, and each clamp requires 1 conductor volume. Therefore, the total volume needed is (10 conductors + 4 grounding conductors + 4 clamps) * 2.25 = 40.5 cubic inches. A 4" square box with a depth of 2-1/8" provides 42 cubic inches, which is sufficient.

A Metal 4" Square Box Has Ten 12 AWG Conductors