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.
RIGID CONDUIT AND KNOCKOUT SIZES. Conduit is used to protect and support electrical wires. Both rigid conduit and intermediate metallic conduit are threaded and accept couplings, nuts, and bushings et cetera directly. (1) UL Table NAE.3.