This specification covers cored, annular, concentric-lay-stranded conductors made from round soft copper wires either uncoated or coated with tin for use as electrical conductors. The core may be of any materials and its size and surface firmness as a base for the overlaid wires shall be adequated to prevent forcing or dropping of any wire out of its layer position. No splice shall be made in the conductor as a whole, welds or brazes may be made in the finished individual wires. The materials shall conform to the required nominal conductor size, number of layers of wires, number, diameter, lay-up wires, approximate core diameter, and maximum conductor diameter. The mass per unit length and electrical resistance of a unit length of stranded conductor are a function of the length of lay and shall be calculated. The are of cross section of a conductor shall be considered to be the sum of the cross-sectional areas of its component wires at any section when measured perpendicularly to their individual axes.

1.1 This specification covers cored, annular, concentric-lay-stranded conductors made from round soft copper wires, either uncoated or coated with tin for use as electrical conductors (Explanatory Note 1 and Note 2).

1.2 The constructions prescribed herein are suitable for bare conductors, or for conductors to be covered with weather-resistant (weather-proof) material, or for conductors to be insulated with rubber, varnished cloth, or impregnated paper, except types such as “oil-filled” or “gas-filled” (Explanatory Note 3).

1.3 Cored, annular conductor constructions not included in this specification shall be specifically agreed upon between the manufacturer and the purchaser when placing the order.

1.4 These constructions are not recommended for use as electric furnace leads where great flexibility is required and special conductor designs are indicated in consideration of the particular service requirements.

1.5 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.