ASTM B778 - 02(2012)

    Standard Specification for Shaped Wire Compact Concentric-Lay-Stranded Aluminum Conductors (AAC/TW)

    Active Standard ASTM B778 | Developed by Subcommittee: B01.07

    Book of Standards Volume: 02.03


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    ASTM B778

    Abstract

    This specification covers shaped wire compact concentric-lay-stranded aluminum conductor (AAC/TW) and its component wires for use as overhead electrical conductors. The trapezoidal aluminum wires shall meet the prescribed tensile strength and elongation requirements. Electric-butt welds, electric-butt cold-upset welds, or cold-pressure welds may be made in the individual aluminum wires during the stranding process. Requirements for the lay and construction of the conductor are detailed. The methods of determining the rated strength, breaking strength, mass, and electrical resistance are given. Tests for mechanical and electrical properties of aluminum wires shall be made before stranding. For the purpose of calculating mass per unit length, cross-sections, and the like, the density of aluminum to be taken is specified.

    This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

    1. Scope

    1.1 This specification covers shaped wire compact concentric-lay-stranded aluminum conductor (AAC/TW) and its component wires for use as overhead electrical conductors (Explanatory Note 1 and Note 2).

    1.2 The values stated in inch-pound units are to be regarded as the standard with the exception of temperature and resistivity. The SI equivalents of inch-pound units may be approximate.

    Note 1AAC/TW is designed to increase the aluminum area for a given diameter of conductor by the use of trapezoidally shaped wires (TW). The conductors consist of a central core of one round aluminum wire or a seven-strand compact round core surrounded by two or more layers of trapezoidal aluminum 1350-H19 wires. For the purposes of this specification, the sizes listed are tabulated on the basis of the finished conductor having an area equal to that of specific sizes of standard AAC (Table 1) or in fixed diameter increments (Table 2) so as to facilitate conductor selection.
    TABLE 1 Construction Requirements for Shaped Wire Compact Concentric-Lay-Stranded Aluminum Conductors Sized to Have Areas Equal to AAC Size

    Code WordA

    AAC/TW
    Conductor size

    Nominal Outside
    Diameter

    Number of
    Aluminum
    Wires

    Number
    of Layers

    Nominal Mass

    Rated Strength

    kcmil

    mm

    in.

    mm

    lb/1000ft

    kg/km

    1000 lbf

    kN

    Tulip/TW

    336.4

    170

    0.612

    15.5

    17

    2

    315.3

    469.4

    6.02

    26.8

    Canna/TW

    397.5

    201

    0.661

    16.8

    17

    2

    372.6

    554.7

    6.96

    31

    Cosmos/TW

    477.0

    242

    0.720

    18.3

    17

    2

    447.1

    665.6

    8.36

    37.2

    Zinnia/TW

    500.0

    253

    0.736

    18.7

    17

    2

    468.7

    697.7

    8.76

    39

    Mistletoe/TW

    556.5

    282

    0.775

    19.7

    17

    2

    521.6

    776.5

    9.75

    43.4

    Meadowsweet/TW

    600.0

    304

    0.803

    20.4

    17

    2

    562.4

    837.2

    10.52

    46.8

    Orchid/TW

    636.0

    322

    0.825

    21.0

    17

    2

    596.1

    887.4

    11.1

    49.4

    Verbena/TW

    700.0

    355

    0.864

    21.9

    17

    2

    656.1

    976.7

    12.3

    54.7

    Nasturtium/TW

    750.0

    380

    0.893

    22.7

    17

    2

    702.1

    1045

    13.1

    58.3

    Arbutus/TW

    795.0

    403

    0.919

    23.3

    17

    2

    745.1

    1109

    13.6

    60.5

    Cockscomb/TW

    900.0

    456

    0.990

    25.1

    31

    3

    843.6

    1256

    15.4

    68.5

    Magnolia/TW

    954.0

    483

    1.018

    25.9

    31

    3

    894.2

    1331

    16.4

    72.9

    Hawkweed/TW

    1000.0

    507

    1.041

    26.4

    31

    3

    937.3

    1395

    17.1

    76.1

    Bluebell/TW

    1033.5

    524

    1.057

    26.8

    31

    3

    968.7

    1442

    17.7

    78.7

    Marigold/TW

    1113.0

    564

    1.095

    27.8

    31

    3

    1043.2

    1553

    19.1

    85.0

    Hawthorn/TW

    1192.5

    604

    1.132

    28.8

    31

    3

    1117.7

    1664

    20.4

    90.7

    Narcissus/TW

    1272.0

    644

    1.168

    29.7

    31

    3

    1192.2

    1775

    21.8

    97.0

    Columbine/TW

    1351.5

    685

    1.202

    30.5

    31

    3

    1266.3

    1885

    23.2

    103

    Carnation/TW

    1431.0

    725

    1.236

    31.4

    31

    3

    1341.3

    1997

    24.0

    107

    Coreopsis/TW

    1590.0

    805

    1.315

    33.4

    49

    4

    1490.3

    2219

    27.0

    120

    Jessamine/TW

    1750.0

    887

    1.377

    35.0

    49

    4

    1640.3

    2442

    29.7

    132

    Cowslip/TW

    2000.0

    1013

    1.468

    37.3

    49

    4

    1893.0

    2818

    33.9

    151

    Lupine/TW

    2500.0

    1266

    1.648

    41.9

    71

    5

    2366.2

    3522

    41.9

    186

    Trillium/TW

    3000.0

    1520

    1.799

    45.7

    71

    5

    2839.5

    4227

    50.3

    224

    A Code words shown in this column are obtained from “Publication 50, Code Words for Overhead Aluminum Electrical Conductors,” by the Aluminum Association. They are provided for information only.
    TABLE 2 Construction Requirements for Shaped Wire Compact Concentric-Lay-Stranded Aluminum Conductors, in Fixed-Diameter Increments

    Code WordA

    AAC/TW
    Conductor Size

    Nominal Outside
    Diameter

    Number of
    Aluminum
    Wires

    Number
    of Layers

    Nominal Mass

    Rated Strength

    kcmil

    mm

    in.

    mm

    lb/1000 ft

    kg/km

    1000 lbf

    kN

    Logan/TW

    322.5

    163

    0.60

    15.2

    17

    2

    302.3

    450

    5.88

    26.2

     

    384.5

    195

    0.65

    16.5

    17

    2

    360.4

    536.5

    6.74

    30

    Wheeler/TW


    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

    B230/B230M Specification for Aluminum 1350-H19 Wire for Electrical Purposes

    B263 Test Method for Determination of Cross-Sectional Area of Stranded Conductors

    B354 Terminology Relating to Uninsulated Metallic Electrical Conductors

    E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications

    E527 Practice for Numbering Metals and Alloys in the Unified Numbering System (UNS)

    Other Documents

    AluminumAssociationP Code Words for Overhead Aluminum Electrical Conductors Available from Aluminum Association, Inc., 1525 Wilson Blvd., Suite 600, Arlington, VA 22209, http://www.aluminum.org.


    ICS Code

    ICS Number Code 29.240.20 (Power transmission and distribution lines)

    UNSPSC Code

    UNSPSC Code 26121500(Electrical wire)


    DOI: 10.1520/B0778-02R12

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