When ganging two single-gang switch boxes together, what is the smallest box you can use without violating NEC®?

When ganging two single-gang switch boxes together, the National Electrical Code (NEC) provides guidelines for the minimum size of the box to ensure safe and adequate space for the wiring and devices. The correct choice, which is 3 x 2 x 3.5 inches, meets the minimum cubic inch requirements for the conductor fill and offers enough room for the installation of the switches.

In the NEC, there are specific calculations to determine the required volume for a box based on the number of conductors, devices, and any additional space required for fittings. When ganging two single-gang boxes, it is essential that the chosen box can accommodate the wiring for both switches without exceeding the allowable fill capacity.

The 3 x 2 x 3.5-inch box provides sufficient volume to comply with NEC volume calculations, which consider not only the size and number of devices but also the conductors that will be terminating in the box. This size allows for the safe and compliant installation of electrical devices without risking overcrowding, which can lead to overheating and other safety hazards.

In contrast, the other options either do not meet the volume requirements or do not provide enough room for conductors and devices. Utilizing a box that does not meet these standards