1. Scope
1.1 This specification covers bare combination unilay-stranded conductors made from round copper wires, either uncoated or coated with tin or lead alloy for insulated conductors for electrical purposes. These conductors shall be constructed with a central core wire surrounded by two layers of helically laid wires, resulting in an outer diameter equal to the compressed-stranded equivalent conductor. (See Explanatory Note 1 and Note 2).
Note 1—For the purpose of this specification, combination unilay conductor is defined as follows: a central core wire surrounded by a layer of six helically laid wires of the same diameter as the core wire with a helically laid outer layer containing six smaller wires alternated between six wires of the same diameter as the wires in the layer underneath. Both layers have a common length and direction of lay (see Fig 1).
<>1.2 For the purpose of this specification, normal conductor classification (Class AA, A, B, C) is not applicable as these conductors are intended for subsequent insulation. The descriptive term combination unilay-stranded shall be used in place of conductor classification.
1.3 The values stated in inch-pound or SI units are to be regarded separately as standard. Each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. For conductor sizes designated by AWG or kcmil, the requirements in SI units have been numerically converted from corresponding values, stated or derived, in inch-pound units. For conductor sizes designated by SI units only, the requirements are stated or derived in SI units.
1.3.1 For density, resistivity, and temperature, the values stated in SI units are to be regarded as standard.
2. Referenced Documents (purchase separately) 
The documents listed below are referenced within the subject standard but are not provided as part of the standard.
ASTM Standards
B1 Specification for Hard-Drawn Copper Wire
B2 Specification for Medium-Hard-Drawn Copper Wire
B3 Specification for Soft or Annealed Copper Wire
B33 Specification for Tinned Soft or Annealed Copper Wire for Electrical Purposes
B189 Specification for Lead-Coated and Lead-Alloy-Coated Soft Copper Wire for Electrical Purposes
B246 Specification for Tinned Hard-Drawn and Medium-Hard-Drawn Copper Wire for Electrical Purposes
B263 Test Method for Determination of Cross-Sectional Area of Stranded Conductors
B354 Terminology Relating to Uninsulated Metallic Electrical Conductors
Keywords
Electrical power systems--specifications; Insulated wire and cable--specifications; Mechanical analysis/testing; Rated strength (electrical conductor wire); Stranded copper electrical conductors--specifications; Strength--insulation applications; Unilay-stranded copper electrical conductors;
ICS Code
ICS Number Code 29.060.20 (Cables)
DOI: 10.1520/B0787_B0787M-01
ASTM International is a member of CrossRef.
Citing ASTM Standards
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