In this episode of “EC&M Tech Talks,” Randy Barnett, a journeyman electrician, inspector, author, trainer, and electrical safety expert, clears up some of the confusion regarding grounded conductors, grounding electrode conductors, neutrals, and equipment grounding conductors.
Article 100 Definitions of the NEC provides the terminology. Using slang terminology does not work when it comes to using and interpreting the NEC. Grounding and bonding are good examples where use of the wrong terms creates confusion. For example, equipment grounding conductors are just that — not grounding wires.
Once terminology issues and solutions are identified, Randy explains the operation of a typical 100A service. Grounded conductors must be identified using the rules of Art. 200. Sections 250.118 and 250.119 lists the types of equipment grounding conductors permitted and how they must be identified. Sizing of the various conductors and bonding jumpers connected to ground are covered in three separate tables. Table 250.66 sizes the grounding electrode conductors. Table 250.102(C)(1) sizes the grounded conductor and the main, system, and supply-side bonding jumpers in AC systems. Table 250.122 sizes the equipment grounding conductors. Finally, if the system is separately derived, the rules of Sec. 250.30 also apply and are discussed briefly.
