UL 758-2019 pdf download – Appliance Wiring Material.
4 Materials 4.1 Each material used in AWM shall be compatible with all of the other materials used in the wire or cable. 4.2 Due to possible incompatibility, TPE materials of the styrenic type may not be suitable for use in cords whereby direct contact with PVC may occur. A separator is one acceptable means of avoiding direct contact. Other combinations of materials which could be incompatible, if any, are as yet undetected. 4.3 Due to possible incompatibility, uncoated copper, copper alloy, copper-clad aluminum, copper-clad steel, or other components with uncoated copper on the outer surface shall not be used in wire or cable whereby direct contact with aluminum may occur. A separator is one acceptable means of avoiding direct contact, or the copper components shall be metal-coated.
5 Conductor 5.1 General 5.1.1 A conductor consisting of a single wire is designated as a solid conductor, while one consisting of a number of individual wires is designated as a stranded conductor. The American Wire Gauge (AWG) numbers, the kcmil (thousands of circular mils) sizes, and the square-millimeter sizes each signify a definite nominal total cross-sectional area (see Table 5.1 or Table 5.2) independent of the conductor material. The individual wires used in making up a stranded conductor are not required to correspond to any particular AWG or other standard gauge size. A tinsel conductor consists of a number of strands, twisted together, a portion of, or all strands being composed of one or more flattened wires of copper or copper alloy, helically wound on a fibrous polymeric thread. A conductor with a tubular cross-section and uniform wall thickness shall be of copper, and may be metal coated. A bus bar conductor consists of a single bar, or two or more bars stacked to form two or more layers, with each bar of solid rectangular cross-section with two plane, parallel surfaces and round or other simple regularly shaped edges. Fibrous yarns impregnated or coated with metal or other conductive materials may be used as a conductor, or may be assembled with other types of conductor strands to form a conductor. A carbon fiber filament conductor consists of a number of carbon fibers twisted together to form the conductor and the carbon fibers may be metal coated. A resistance wire is a conductor material used in products primarily as the source of heat based on a designed resistance per finished unit length.