This specification covers standard requirements for bare-concentric-lay stranded conductors made from round copper wires, either uncoated or coated with tin, lead, or lead alloy for general use for electrical purposes. These conductors shall be constructed with a central core surrounded by one or more layers of helically laid wires. The conductors shall be classified as follows: Class AA, Class A, Class B, Class C, and Class D. Sizes, number of wires, and diameter of wires in the various classes of concentric-lay-stranded conductors shall conform to the prescribed requirements. Welds and brazes may be made in rods or in wires prior to final drawing. The completed conductor of varying classes shall conform to the minimum distance required between the joints. Diameters, areas, and mass of concentric-lay-stranded copper conductors shall conform to the prescribed requirements. Physical and electrical tests of conductors stranded of hard-drawn or medium-hard-drawn wires shall be conducted before but not after stranding. The approximate mass and electrical resistance may be determined using the required increments. The material shall also conform to the temperature corrections factor for conductor resistance.

1.1 This specification covers bare concentric-lay-stranded conductors made from round copper wires, either uncoated or coated with tin, lead, or lead alloy for general use for electrical purposes. These conductors shall be constructed with a central core surrounded by one or more layers of helically laid wires.

Note 1—This specification also permits conductors for use as covered or insulated electrical conductors.

Note 2—Sealed conductors, that are intended to prevent longitudinal water propagation and are further covered/insulated, are also permitted within the guidelines of this specification.

1.2 For the purposes of this specification, conductors are classified as follows (Explanatory Note 1 and Note 2):

1.2.1 Class AA—For bare conductors usually used in overhead lines.

1.2.2 Class A—For conductors to be covered with weather-resistant (weather-proof), slow-burning materials, and for bare conductors where greater flexibility than is afforded by Class AA is required.

1.2.3 Class B—For conductors to be insulated with various materials such as rubber, paper, varnished cloth, and so forth, and for the conductors indicated under Class A where greater flexibility is required.

1.2.4 Class C and Class D—For conductors where greater flexibility is required than is provided by Class B conductors.

1.3 The SI values for density are regarded as the standard. For all other properties, the inch-pound values are to be regarded as standard and the SI units may be approximate.