What is the maximum number of 12 AWG conductors allowed in a 3 in. x 2 in. x 3 1/2 in. device box?

The maximum number of 12 AWG conductors that can be placed in a device box is determined by the volume of the box and the space required for each conductor. The National Electrical Code (NEC) specifies that each 12 AWG conductor requires a certain volume allowance, typically 2.0 cubic inches per conductor.

In this case, the internal volume of the device box must first be calculated. A box that measures 3 inches by 2 inches by 3 1/2 inches has a total internal volume of 21 cubic inches (3 in. x 2 in. x 3.5 in. = 21 in³).

Dividing the total volume of the box by the volume required per conductor gives an idea of how many 12 AWG conductors can fit in the box. Since each 12 AWG conductor takes up 2 cubic inches, dividing the total volume (21 cubic inches) by the volume per conductor (2 cubic inches) results in 10.5. However, it's important to only count whole conductors, meaning only 10 12 AWG conductors can be accommodated.

Therefore, the maximum number of 12 AWG conductors allowed in the specified box is