In a noncombustible ceiling, the front edge of an outlet box may be set back from the surface by how much?

In a noncombustible ceiling, the front edge of an outlet box may be set back from the surface by a maximum distance of 1/4 inch. This requirement is established to ensure that the outlet box is properly recessed while still maintaining accessibility and safety standards. Having the outlet box set back correctly helps to prevent potential hazards, such as accidental damage to the box or wires, and ensures that devices can be easily installed or replaced without obstruction.

This specific measurement is crucial in ensuring compliance with electrical codes and building standards that govern electrical installations in noncombustible materials. Proper installation practices not only enhance the functionality of electrical systems but also promote fire safety in structures where such guidelines are mandated.