EC&M Tech Talk Video — NEC Art. 330 and MC Cable

In this episode of “EC&M Tech Talks,” Randy Barnett, a journeyman electrician, inspector, author, trainer, and electrical safety expert, discusses one of the most common wiring methods found in the National Electrical Code (NEC) — metal-clad (MC) cable.  Ampacity determinations, conductor insulation, conductor sizes, fittings, securing, and support requirements are all covered in Art. 330 for metal-clad cable and are explained in this EC&M Tech Talk.

Article 330 of the NEC is titled “Metal-Clad Cable, Type MC.” Section 330.1 tells users that the Article covers the use, application, and construction specifications of MC cable. Randy begins with Part III, explaining construction specifications. Although the interlocking metal tape type of MC cable is the most commonly used, two other types are also discussed. Randy also dives into construction specifications beyond NEC Part III. 

MC cable, normally suitable only for use in dry locations, can also be constructed for use in damp and wet locations. In fact, MC cable can also be constructed and applied in hazardous (Classified) locations. Some MC cables may be color-coded on the outer sheath. While not required by the NEC, industry standards have evolved and are discussed in the video. For example, a green outer sheath is assumed to be for use in health care facilities.