According to NEC® Section 250.118, what can be utilized as an equipment grounding conductor?

The option referencing the armor of Type AC cable as an acceptable equipment grounding conductor aligns with the requirements set forth in NEC® Section 250.118. This section specifies the types of conductors and systems that can function as effective equipment grounding conductors. Type AC cable, which is typically armored with metal, provides a reliable path for fault current back to the source, thereby ensuring safety by reducing the risk of electric shock or fire due to fault conditions.

The armor of Type AC cable is continuous and can be effectively connected to the grounding system, making it an appropriate choice for grounding. The integrity of the grounding path is essential for the proper operation of overcurrent protection devices and to ensure that any potential fault current is safely conducted.

In contrast, options like plastic conduit and Type NM cable do not provide a conductive pathway necessary for grounding; plastic conduit is non-metallic and does not conduct electricity, while Type NM cable typically lacks a grounding conductor unless specifically configured. Ground grid systems, while important for grounding in certain applications, are not utilized as equipment grounding conductors in the same capacity as the armor of AC cable. Thus, the choice of the armor of Type AC cable is justified within NEC guidelines as an effective means for equipment grounding.