When burying rigid metal conduit (RMC) in the ground and covered with 2 inches of concrete, how deep must the RMC be buried underground?

The requirement for the burial depth of rigid metal conduit (RMC) when it is covered with 2 inches of concrete is specified in the National Electrical Code (NEC). According to the NEC guidelines, when RMC is installed underground and covered with concrete, it must be buried to a minimum depth of 6 inches.

This requirement ensures that the conduit is adequately protected from physical damage and provides sufficient coverage to safeguard the conduit from potential disturbances or excavation activities that may occur in the area. When concrete is poured over the conduit, it gives additional support and rigidity, but the base depth still needs to be at least 6 inches to account for any potential settlement and to comply with safety protocols.

Given this context, the correct answer correctly reflects the NEC's standards for underground installations of RMC when encased in concrete.