Which wiring method requires a separate equipment grounding conductor to be run with the circuit conductors?

The correct answer indicates that when using Electrical Metallic Tubing (EMT) as a wiring method, it is necessary to install a separate equipment grounding conductor alongside the circuit conductors. While EMT provides some level of grounding through its metallic structure, the National Electrical Code (NEC) requires that a dedicated equipment grounding conductor be provided to ensure optimal safety and fault protection.

This additional grounding conductor is essential because it allows for a defined path back to the ground should there be a fault in the system, reducing the risk of electric shock and equipment damage. EMT itself, although grounded effectively through its connections to various fittings, is not considered sufficient on its own to meet the grounding requirements set by NEC when protecting against fault current.

In contrast, other wiring methods such as PVC, which does not have metallic properties, inherently cannot provide grounding through the conduit, thus requiring a separate grounding conductor as well. Although EMT requires a grounding conductor, there are scenarios where the conduit type—or the specific compliance with grounding standards—determines whether a separate grounding wire is needed. Understanding the nuances of each conduit type is crucial in ensuring compliance with safety standards during installations.