The minimum depth of a "4 square" box according to NEC® should be what measurement to avoid violation?

The minimum depth of a "4 square" box is specified by the National Electrical Code® (NEC) to ensure proper installation and safe electrical practices. According to NEC guidelines, a "4 square" box must have a minimum depth of 1.5 inches. This depth is critical for accommodating conductors, connectors, and devices that may be housed within the box while also allowing for adequate space for the wiring and any associated devices that will be installed. Sufficient depth helps prevent overcrowding, which can lead to overheating and potential fire hazards.

Hence, the correct answer confirms the NEC requirement of having a minimum depth of 1.5 inches for "4 square" boxes, ensuring compliance with safety standards and promoting optimal functionality.