ASTM B786/B786M-08(2013)e1

Standard Specification for 19 Wire Combination Unilay-Stranded Aluminum Conductors for Subsequent Insulation

SCOPE
1.1 This specification covers bare combination unilay-stranded conductors made from round wires of aluminum 1350 and 8000 series of aluminum alloys, for insulated conductors for electrical purposes. Aluminum 1350 wires in tempers -H19 (extra hard), -H16 or -H26 (3/4 hard), -H14 or -H24 (1/2 hard), and -H142 or -H242 (1/2 hard) and 8000 series aluminum alloys wires in tempers “0” and H1X or H2X are permitted. 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 conductors. 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).
1.1.1 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 (Note 2 and Note 3).Note 2—Prior to 1975, aluminum 1350 was designated as EC aluminum.Note 3—The aluminum and temper designations conform to ANSI Standard H35.1. Aluminum 1350 corresponds to Unified Numbering System A91350 in accordance with Practice E527. Unified Numbering System alloy designations for 8000 Series aluminum alloys in accordance with Practice E527 are listed in Table number 1 of Specification B800.  
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

General Information

• Status: Historical
• Publication Date: 31-Mar-2013
• ICS: 29.060.20 - Cables
• Technical Committee: B01 - Electrical Conductors
• Drafting Committee: B01.07 - Conductors of Light Metals

Relations

• Replaces: ASTM B786-08(2013) - Standard Specification for 19 Wire Combination Unilay-Stranded Aluminum Conductors for Subsequent Insulation
• Effective Date: 01-Apr-2013
• Replaced By: ASTM B786/B786M-08(2018) - Standard Specification for 19 Wire Combination Unilay-Stranded Aluminum Conductors for Subsequent Insulation
• Effective Date: 01-Mar-2018

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
´1
Designation:B786/B786M −08 (Reapproved 2013)
Standard Specification for
19 Wire Combination Unilay-Stranded Aluminum
Conductors for Subsequent Insulation
This standard is issued under the fixed designation B786/B786M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—Designation was corrected editorially in October 2013.
1. Scope system shall be used independently of the other. Combining
values from the two systems may result in non-conformance
1.1 This specification covers bare combination unilay-
with the standard.
strandedconductorsmadefromroundwiresofaluminum1350
and 8000 series of aluminum alloys, for insulated conductors
2. Referenced Documents
for electrical purposes.Aluminum 1350 wires in tempers -H19
3 1
(extra hard), -H16 or -H26 ( ⁄4 hard), -H14 or -H24 ( ⁄2 hard),
2.1 The following documents of the issue in effect on date
and-H142or-H242( ⁄2hard)and8000seriesaluminumalloys
of material purchase form a part of this specification to the
wires in tempers “0” and H1X or H2X are permitted. These
extent referenced herein.
conductors shall be constructed with a central core wire
2.2 ASTM Standards:
surroundedbytwolayersofhelicallylaidwires,resultinginan
B193Test Method for Resistivity of Electrical Conductor
outer diameter equal to the compressed-stranded equivalent
conductors.
Materials
B230/B230MSpecification for Aluminum 1350–H19 Wire
NOTE 1—For the purpose of this specification, combination unilay
for Electrical Purposes
conductor is defined as follows: a central core wire surrounded by a layer
B263Test Method for Determination of Cross-Sectional
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
Area of Stranded Conductors
six wires of the same diameter as the wires in the layer underneath. Both
B609/B609M Specification for Aluminum 1350 Round
layers have a common length and direction of lay (see Fig. 1).
Wire, Annealed and Intermediate Tempers, for Electrical
1.1.1 Forthepurposeofthisspecification,normalconductor
Purposes
classification (Class AA, A, B, C) is not applicable, as these
B800Specification for 8000 Series Aluminum Alloy Wire
conductorsareintendedforsubsequentinsulation.Thedescrip-
forElectricalPurposes—AnnealedandIntermediateTem-
tivetermcombinationunilay-strandedshallbeusedinplaceof
pers
conductor classification (Note 2 and Note 3).
B801SpecificationforConcentric-Lay-StrandedConductors
of 8000 SeriesAluminumAlloy for Subsequent Covering
NOTE 2—Prior to 1975, aluminum 1350 was designated as EC
aluminum. or Insulation
NOTE 3—The aluminum and temper designations conform to ANSI
E29Practice for Using Significant Digits in Test Data to
Standard H35.1. Aluminum 1350 corresponds to Unified Numbering
Determine Conformance with Specifications
System A91350 in accordance with Practice E527. Unified Numbering
E527Practice for Numbering Metals and Alloys in the
System alloy designations for 8000 Series aluminum alloys in accordance
Unified Numbering System (UNS)
with Practice E527 are listed in Table number 1 of Specification B800.
2.3 ANSI Standard:
1.2 The values stated in either SI units or inch-pound units
ANSI H35.1/H35.1(M)Alloy and Temper Designation Sys-
are to be regarded separately as standard. The values stated in
each system may not be exact equivalents; therefore, each tems for Aluminum
1 2
This specification is under the jurisdiction of ASTM Committee B01 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Electrical Conductors and is the direct responsibility of Subcommittee B01.07 on contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Conductors of Light Metals. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved April 1, 2013. Published April 2013. Originally the ASTM website.
approved in 1988. Last previous edition approved in 2008 as B786–08. DOI: Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
10.1520/B0786_B0786M-08R13E01. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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B786/B786M−08 (2013)
3.1.7 Whenphysicaltestsshallbemade(seeSections7and
8),
3.1.8 Package size (see 16.1),
3.1.9 Heavy wood lagging, if required (see 17.2),
3.1.10 Special package marking, if required (Section 17),
and
3.1.11 Place of inspection (Section 15).
4. Joints
FIG. 1 Cross Section of Conductor
4.1 Electric-butt welds, cold pressure welds, or electric-butt
TABLE 1 Construction Requirements for 19-Wire Combination
cold-upset welds may be made in the finished individual wires
Unilay Stranded Aluminum Conductors
composing the conductor but shall not be closer together than
A B
Wire D Wire D
Area of Size, American (or
1 2
1 ft (Explanatory Note 2).
Diameter Diameter
Cross-Section, Brown and Sharpe)
cmil Wire Gage
mils mm mils mm
5. Lay
556 500 185.3 4.71 135.6 3.44
500 000 175.6 4.46 128.5 3.26 5.1 For combination unilay conductors the lay of a layer of
477 000 171.5 4.36 125.5 3.19
wires shall be not less than 8 nor more than 16 times the
450 000 166.6 4.23 121.9 3.10
outside diameter of the outer layer.
397 500 156.6 3.98 114.6 2.91
350 000 146.9 3.73 107.5 2.73
5.2 Other lays for special purposes shall be furnished by
336 400 144.0 3.66 105.4 2.68
specialagreementbetweenthemanufacturerandthepurchaser.
300 000 136.0 3.45 99.6 2.53
266 800 128.3 3.26 93.9 2.38
NOTE4—Certaintypesofinsulationconductorsmayrequireshorterlay
250 000 124.2 3.15 90.9 2.31
than other conductors. It is expected that special requirements regarding
211 600 0000 114.2 2.90 83.6 2.12
length of lay will be specified by the purchaser in such instances.
167 800 000 101.7 2.58 74.5 1.89
133 100 00 90.6 2.30 66.3 1.68
5.3 The direction of lay shall be left-hand unless the
105 600 0 80.7 2.05 59.1 1.50
83 690 1 71.8 1.82 52.6 1.34 direction of lay is specified otherwise by the purchaser.
66 360 2 64.0 1.63 46.8 1.19
52 620 3 57.0 1.45 41.7 1.06
6. Construction (Explanatory Note 1)
41 740 4 50.7 1.29 37.1 0.94
33 090 5 45.2 1.15 33.1 0.84 6.1 The areas of cross section, numbers, and diameters of
26 240 6 40.2 1.02 29.4 0.75
wires in the various conductors shall conform to the require-
20 820 7 35.8 0.91 26.2 0.67
ments prescribed in Table 1 (Note 3) (see Fig. 1).
16 510 8 31.9 0.81 23.4 0.59
13 090 9 28.4 0.72 20.8 0.53
6.2 ThediametersofthewireslistedinTable2arenominal.
10 380 10 25.3 0.64 18.5 0.47
In order to produce an essentially round 19-wire construction,
6 530 12 20.1 0.51 14.7 0.37
A the outer 12-wire layer in the combination unilay product is
Equation to calculate D :
comprised of 6 wires of the same diameter as the wires in the
Cross2Sectional Area
D 5
Π7-wire core, and 6 wires approximately 25% smaller. The
16.2149
2-wire sizes are alternated around the 7-wire core.
B
Equation to calculate D :
D 5 D 30.732.
7. Mechanical and Electrical Tests of Conductors not
2 1
Annealed after Stranding
7.1 Wires composing the conductors shall be tested prior to
stranding in accordance with the applicable specification (see
2.4 NIST Standard:
11.1.2), and tests on the completed conductor are not required.
NBS Handbook 100
However, when requested by the purchaser and agreed to by
the manufacturer at time of ordering, the tension tests of wires
3. Ordering Information
before stranding may be waived and the completed conductor
3.1 Orders for materials under this specification shall in-
tested in accordance with 7.2, or wires removed from the
clude the following information:
completed conductor tested in accordance with 7.5.
3.1.1 Conductor alloy,
7.2 When the completed conductor is tested as a unit, the
3.1.2 Quantity of each size,
breaking strength shall be not less than the rated strength of
3.1.3 Conductor size: Circular-mil area or American Wire
1350-H19 conductors or the minimum rated strength of 1350-
Gage, AWG (Section 6 and Table 1),
H16, -H26, -H14, -H24, -H142, and -H242 conductors if
3.1.4 Stranding (see Explanatory Note 1),
failure occurs in the free length at least 1 in. [25 mm] beyond
3.1.5 Temper (see Section 11),
theendofeithergrippingdevice.Thestrengthshallbenotless
3.1.6 Details of special-purpose lays, if required (see 5.2),
than 95% of the rated or minimum rated strength if failure
occurs inside, or within 1 in. of the end of either gripping
device.Thebreakingstrengthof1350-H16,-H26,-H14,-H24,
Available from National Institute of Standards and Technology (NIST), 100
Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov. -H142, and -H242 conductors shall be not greater than their
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B786/B786M−08 (2013)
A
TABLE 2 Diameters, Areas and Mass of 19-Wire Combination Unilay Stranded Aluminum Conductor
Size of
Nominal Conductor Direct Current Resistance
Nominal Area Mass
B
Conductor,
Diameter at 20°C
cmil or
2 2
in. mm in. mm lb/1000 ft kg/km Ω/1000 ft Ω/km
AWG
556 500 0.827 21.0 0.4371 282 521 775 0.0312 0.1024
500 000 0.784 19.9 0.3927 253 468 697 0.0347 0.1139
477 000 0.766 19.5 0.3746 242 447 665 0.0364 0.1194
450 000 0.744 18.9 0.3534 228 421 627 0.0385 0.1263
397 500 0.699 17.8 0.3122 201 372 554 0.0436 0.1431
350 000 0.656 16.7 0.2749 177 328 488 0.0495 0.1624
336 400 0.643 16.3 0.2642 170 315 469 0.0516 0.1693
300 000 0.607 15.4 0.2356 152 281 418 0.0578 0.1896
266 800 0.573 14.6 0.2095 135 250 372 0.0650 0.2133
250 000 0.554 14.1 0.1963 127 234 348 0.0694 0.2277
0000 0.510 13.0 0.1662 107 198 295 0.0820 0.2690
000 0.454 11.5 0.1318 85.0 157 234 0.103 0.3389
00 0.404 10.3 0.1045 67.4 125 185 0.130 0.4275
0 0.360 9.14 0.08291 53.5 98.9 147 0.164 0.5387
1 0.321 8.15 0.06573 42.4 78.4 117 0.207 0.6798
2 0.286 7.26 0.05212 33.6 62.1 92.4 0.261 0.8573
3 0.254 6.45 0.04133 26.7 49.3 73.4 0.330 1.0814
4 0.226 5.74 0.03278 21.1 39.1 58.2 0.416 1.3633
5 0.202 5.13 0.02599 16.8 31.0 46.1 0.523 1.72
6 0.179 4.55 0.02061 13.3 24.6 36.6 0.661 2.1684
7 0.160 4.06 0.01635 10.5 19.5 29.0 0.834 2.7362
8 0.143 3.63 0.01297 8.37 15.5 23.1 1.05 3.4464
9 0.127 3.23 0.01028 6.63 12.3 18.3 1.32 4.3307
10 0.113 2.87 0.00816 5.26 9.73 14.5 1.67 5.4790
12 0.090 2.29 0.00513 3.31 6.12 9.11 2.67 8.7598
A
Mass and electrical resistance are based on aluminum 1350.
B
To calculate the diameter, multiply the large wire diameter in Table 1 times 3 and add two times the small wire diameter.
Example: AWG 4/0 diameter = [3(114.2) + 2(83.6)] = 509.8
maximumratedstrengths.Thefreelengthbetweengripsofthe 105% of the maximum tensile strength prescribed in Specifi-
test specimen shall be not less than 24 in. (600 mm) and care cation B609/B609M, as applicable (Explanatory Note 4).
shall be taken to ensure that the wires in the conductor are
7.6 All wires composing the conductors shall be capable of
evenly gripped during the test (Explanatory Note 3).
meeting the bending properties stated in Specification B230/
7.3 The rated strength of 1350-H19 conductors and the
B230Mafterstranding.Routineproductiontestingafterstrand-
minimum rated strength of 1350-H16, -H26, -H14, -H24,
ing is not required.
-H142, and -H242 conductors shall be taken as 93% of the
7.7 Mechanical and electrical tests of conductors in 8000
sum of the specified minimum average tensile strengths of the
series aluminum alloys in “0” temper, H1X or H2X wire and
component wires for 1350-H19 conductors, as prescribed in
not annealed after stranding shall be in accordance with
Table 1, Tensile Requirements, of Specification B230/B230M,
Section 9 of Specification B801.
and of the sum of the specified minimum tensile strengths of
the component wires for 1350-H16, -H26, -H14, -H24, -H142,
8. Mechanical and Electrical Tests of Conductors
and -H242 conductors, as prescribed in Specification B609/
Annealed after Stranding
B609M, as applicable. The maximum rated strength of the
1350-H16, -H26, -H14, -H24, -H142 and -H242 conductors
8.1 Tensile properties and electrical resistivity shall be
shall be taken as the sum of the specified maximum strengths
determinedonsamplestakenfrom10%ofthereelsorcoilsof
of the component wires, as prescribed in Specification B609/
conductor, but from not less than five (or all if the lot is less
B609M, as applicable. The rated strengths shall be calculated
than five) reels or coils. Resistivity shall be determined as
using specified nominal wire diameters.
prescribed in the Resistivity section of Specification B230/
B230M on one wire from each conductor sample except this
7.4 Rated strength and breaking strength values shall be
test is not required if performed previously on the 1350-H19
rounded to three significant figures, in the final value only, in
wire.At the manufacturer’s option, tension tests shall be made
accordance with the rounding method in Practice E29.
either on one of the inner seven wires and one wire from each
7.5 When wires are removed from the completed conductor
additional layer of each conductor sample to determine con-
and tested, 1350-H19 wires shall have minimum tensile
formance with 8.2 or on the conductor as a unit to determine
strengths not less than 95% of the tensile strengths prescribed
conformation with 8.3.
for individual tests in Table 1, Tensile Requirements, of
Specification B230/B230M. 1350-H16, -H26, -H14, -H24, 8.2 When wires removed from the completed conductor are
-H142, and -H242 wires shall have tensile strengths not less tested, 1350-H26, -H24, and -H242 wires shall have tensile
than 95% of the minimum tensile strength nor more than strengths not less than 95% of the minimum tensile strength
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B786/B786M−08 (2013)
nor more than 105% of the maximum tensile strength pre- 11. Requirements for Wires
scribed in Specification B609/B609M, as applicable (Explana-
11.1 Thepurchasershalldesignatethetemperofwirestobe
tory Note 4).
used in the conductor.
8.3 When the completed conductor is tested as a unit, the 11.1.1 Forconductorsofaluminum1350withtempersother
breaking strengths of 1350-H26, -H24, and -H242 conductors than 1350-H19, the manufacturer shall have the following
shall conform with 7.2, 7.3, and 7.4. options on manufacturing method:
11.1.1.1 Strand the conductor from wires drawn to final
8.4 All wires composing the conductors shall be capable of
temper,
meeting the bending properties stated in Specification B230/
11.1.1.2 Strand the conductor from wires drawn to H19
B230Mafterstranding.Routineproductiontestingafterstrand-
te
...