Classes A, B, C, D, G, and M. 1  Classes A â C permit operation of motor vehicles based on GVW rating and must be renewed every 5 years. 2  Classes D and G are valid for operation of a single motor vehicle with a GVW rating of 26,000 lbs. or less.
Electrical Metallic Tubing (EMT) Electrical metallic tubing (EMT), also commonly called thin-wall, is a listed steel raceway of circular cross section, which is unthreaded, and nominally 10â² long. 20â² lengths are also available. Covered by Article 358 of the NEC, EMT is available in trade sizes 1/2 through 4.
Electrical Fittings. Conduit fittings are used to connect runs of conduit together or to connect conduit to electrical devices. The types of fittings you use will depend on whether youâre using metallic or non-metallic conduit, and the types of connections you need to make. In addition, electrical fittings are sized to fit the different diameters of conduit.