ASTM B778-22

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

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.
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 1: AAC/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.
Note 2: The aluminum and temper designations conform to ANSI Standard H 35.1. Aluminum 1350 corresponds to Unified Numbering System (UNS) A91350 in accordance with Practice E527.    
1.3 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.

General Information

• Status: Published
• Publication Date: 30-Nov-2022
• ICS: 29.240.20 - Power transmission and distribution lines
• Technical Committee: B01 - Electrical Conductors
• Drafting Committee: B01.07 - Conductors of Light Metals

Standards Content (Sample)

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.
Designation: B778 −22
Standard Specification for
Shaped Wire Compact Concentric-Lay-Stranded Aluminum
1
Conductors (AAC/TW)
This standard is issued under the fixed designation B778; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope B230/B230M Specification for Aluminum 1350–H19 Wire
for Electrical Purposes
1.1 This specification covers shaped wire compact
B263/B263M Test Method for Determination of Cross-
concentric-lay-stranded aluminum conductor (AAC/TW) and
Sectional Area of Stranded Conductors
its component wires for use as overhead electrical conductors
B354 Terminology Relating to Uninsulated Metallic Electri-
(Explanatory Note 1 and Note 2).
cal Conductors
1.2 The values stated in inch-pound units are to be regarded
B1006 Specification for Electrical Overhead Conductor
as the standard with the exception of temperature and resistiv-
Code Word Names
ity. The SI equivalents of inch-pound units may be approxi-
E29 Practice for Using Significant Digits in Test Data to
mate.
Determine Conformance with Specifications
E527 Practice for Numbering Metals and Alloys in the
NOTE 1—AAC/TW is designed to increase the aluminum area for a
given diameter of conductor by the use of trapezoidally shaped wires Unified Numbering System (UNS)
(TW). The conductors consist of a central core of one round aluminum
2.3 Other Documents:
wire or a seven-strand compact round core surrounded by two or more
ANSI H35.1 American National StandardAlloy and Temper
layers of trapezoidal aluminum 1350-H19 wires. For the purposes of this
3
Designation Systems for Aluminum
specification, the sizes listed are tabulated on the basis of the finished
4
conductor having an area equal to that of specific sizes of standard AAC
NBS Handbook 100 — Copper Wire Tables
(Table 1) or in fixed diameter increments (Table 2) so as to facilitate
conductor selection.
3. Ordering Information
NOTE 2—The aluminum and temper designations conform to ANSI
Standard H 35.1. Aluminum 1350 corresponds to Unified Numbering 3.1 Orders for material under this specification shall include
System (UNS) A91350 in accordance with Practice E527.
the following information:
1.3 This international standard was developed in accor- 3.1.1 Quantity of each size,
dance with internationally recognized principles on standard-
3.1.2 Conductor size: kcmil area and diameter (Table 1 and
ization established in the Decision on Principles for the Table 2),
Development of International Standards, Guides and Recom-
3.1.3 Special tension test, if required (see 8.2),
mendations issued by the World Trade Organization Technical 3.1.4 Place of inspection (Section 15),
Barriers to Trade (TBT) Committee.
3.1.5 Package size and type (see 15.1),
3.1.6 Special package markings, if required (Section 15),
2. Referenced Documents
and
3.1.7 Heavy wood lagging, if required (see 15.3).
2.1 The following documents of the issue in effect on date
of material purchase form a part of this specification to the
4. Requirement for Wires
extent referenced herein.
2 4.1 Before stranding, the trapezoidal aluminum wires shall
2.2 ASTM Standards:
conform to the requirements of Specification B230/B230M
except for shape and diameter tolerance. The tensile strength
1 and elongation requirements of trapezoidal wires shall be the
This specification is under the jurisdiction of ASTM Committee B01 on
Electrical Conductors and is the direct responsibility of Subcommittee B01.07 on sameasforroundwiresofequalarea.Theareatolerancesshall
Conductors of Light Metals.
be such that the finished conductor conforms to Section 11.
Current edition approved Dec. 1, 2022. Published January 2023. Originally
approved in 1987. Last previous edition approved in 2019 as B778 – 19. DOI:
10.1520/B0778-22.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM 4th Floor, New York, NY 10036, http://www.ansi.org.
4
Standards volume information, refer to the standard’s Document Summary page on Available from National Institute of Standards and Technology (NIST), 100
the ASTM website. Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
B778
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: B778 − 19 B778 − 22
Standard Specification for
Shaped Wire Compact Concentric-Lay-Stranded Aluminum
1
Conductors (AAC/TW)
This standard is issued under the fixed designation B778; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
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 1—AAC/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.
NOTE 2—The aluminum and temper designations conform to ANSI Standard H 35.1. Aluminum 1350 corresponds to Unified Numbering System (UNS)
A91350 in accordance with Practice E527.
1.3 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.
2. Referenced Documents
2.1 The following documents of the issue in effect on date of material purchase form a part of this specification to the extent
referenced herein.
2
2.2 ASTM Standards:
B230/B230M Specification for Aluminum 1350–H19 Wire for Electrical Purposes
B263B263/B263M Test Method for Determination of Cross-Sectional Area of Stranded Conductors
B354 Terminology Relating to Uninsulated Metallic Electrical Conductors
B1006 Specification for Electrical Overhead Conductor Code Word Names
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)
1
This specification is under the jurisdiction of ASTM Committee B01 on Electrical Conductors and is the direct responsibility of Subcommittee B01.07 on Conductors
of Light Metals.
Current edition approved March 1, 2019Dec. 1, 2022. Published March 2019January 2023. Originally approved in 1987. Last previous edition approved in 20142019 as
B778 – 14.B778 – 19. DOI: 10.1520/B0778-19.10.1520/B0778-22.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
B778 − 22
TABLE 1 Construction Requirements for Shaped Wire Compact Concentric-Lay-Stranded Aluminum Conductors Sized to Have Areas
Equal to AAC Size
AAC/TW Nominal Outside
Number of
Nominal Mass Rated Strength
Number
A
Conductor size Diameter
Code Word Aluminum
of Layers
Wires
kcmil mm in. mm lb/1000 ft 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 7
...