ASTM-B857 Standard Specification for Shaped Wire Compact Concentric-Lay-Stranded Aluminum Conductors, Coated-Steel Supported (ACSS/TW)

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This specification covers shaped wire compact concentric-lay-stranded aluminum conductors, steel supported (ACSS/TW) for use as overhead electrical conductors. Electric-butt welds, cold-pressure welds, and electric-butt, cold upsed welds in the finished individual aluminum wires composing the conductor may be made during the stranding process. The electrical resistivity of the material shall meet the minimum resistivity specified. The rated strength of the completed conductor may be determined by mechanical tests. Mass and density of the conductors shall be determined.




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1.1 This specification covers shaped wire compact concentric-lay-stranded aluminum conductors, steel supported (ACSS/TW) for use as overhead electrical conductors (see Explanatory Note 1).

1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.2.1 Exceptions—For conductor sizes designated by AWG or kcmil sizes, the requirements in SI units are numerically converted from the corresponding requirements in inch-pound units. For conductor sizes designated by SI units only, the requirements are stated or derived in SI units. For density, resistivity, and temperature, the values stated in SI units are to be regarded as standard.

1.3 ACSS/TW is designed to increase the aluminum area for a given diameter of conductor by the use of trapezoidal shaped wires (TW), or to reduce the diameter for a given area of aluminum. The conductors consist of a central core of round steel wire(s) surrounded by two or more layers of trapezoidal aluminum 1350-0 wires. Different strandings of the same size of conductor are identified by type, which is the approximate ratio of steel area to aluminum area expressed in percent (see Table 1, Table 2 and Table 3). For the purpose of this specification, the sizes listed in Table 1 and Table 2 are tabulated on the basis of the finished conductor having an area or outside diameter equal to that of specified sizes of standard ACSR, ACSS, and ACSR/TW so as to facilitate conductor selection.

1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.


aluminum conductors; concentric-lay stranded aluminum conductors; electrical conductors; electrical conductors, aluminum; steel-reinforced conductors; steel-supported aluminum conductors; stranded aluminum conductors;; ICS Number Code 29.060.10 (Wires)

To find similar documents by ASTM Volume:

02.03 (Electrical Conductors)

To find similar documents by classification:

29.060.10 (Wires Including electric rods, busbars, etc.)

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Publication Date

March 1, 2018

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8 pages

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