ASTM B786-08(2013)

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Designation:B786 −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; 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.
1. Scope 2. Referenced Documents
1.1 This specification covers bare combination unilay- 2.1 The following documents of the issue in effect on date
strandedconductorsmadefromroundwiresofaluminum1350 of material purchase form a part of this specification to the
and 8000 series of aluminum alloys, for insulated conductors extent referenced herein.
for electrical purposes.Aluminum 1350 wires in tempers -H19 2
2.2 ASTM Standards:
3 1
(extra hard), -H16 or -H26 ( ⁄4 hard), -H14 or -H24 ( ⁄2 hard),
B193Test Method for Resistivity of Electrical Conductor
and-H142or-H242( ⁄2hard)and8000seriesaluminumalloys
Materials
wires in tempers “0” and H1X or H2X are permitted. These
B230/B230MSpecification for Aluminum 1350–H19 Wire
conductors shall be constructed with a central core wire
for Electrical Purposes
surroundedbytwolayersofhelicallylaidwires,resultinginan
B263Test Method for Determination of Cross-Sectional
outer diameter equal to the compressed-stranded equivalent
Area of Stranded Conductors
conductors.
B609/B609M Specification for Aluminum 1350 Round
Wire, Annealed and Intermediate Tempers, for Electrical
NOTE 1—For the purpose of this specification, combination unilay
conductor is defined as follows: a central core wire surrounded by a layer
Purposes
of six helically laid wires of the same diameter as the core wire with a
B800Specification for 8000 Series Aluminum Alloy Wire
helically laid outer layer containing six smaller wires alternated between
forElectricalPurposes—AnnealedandIntermediateTem-
six wires of the same diameter as the wires in the layer underneath. Both
pers
layers have a common length and direction of lay (see Fig. 1).
B801SpecificationforConcentric-Lay-StrandedConductors
1.1.1 Forthepurposeofthisspecification,normalconductor
of 8000 SeriesAluminumAlloy for Subsequent Covering
classification (Class AA, A, B, C) is not applicable, as these
or Insulation
conductorsareintendedforsubsequentinsulation.Thedescrip-
E29Practice for Using Significant Digits in Test Data to
tivetermcombinationunilay-strandedshallbeusedinplaceof
Determine Conformance with Specifications
conductor classification (Note 2 and Note 3).
E527Practice for Numbering Metals and Alloys in the
NOTE 2—Prior to 1975, aluminum 1350 was designated as EC
Unified Numbering System (UNS)
aluminum.
2.3 ANSI Standard:
NOTE 3—The aluminum and temper designations conform to ANSI
ANSI H35.1/H35.1(M)Alloy and Temper Designation Sys-
Standard H35.1. Aluminum 1350 corresponds to Unified Numbering
tems for Aluminum
System A91350 in accordance with Practice E527. Unified Numbering
System alloy designations for 8000 Series aluminum alloys in accordance
2.4 NIST Standard:
with Practice E527 are listed in Table number 1 of Specification B800.
NBS Handbook 100
1.2 The values stated in either SI units or inch-pound units
3. Ordering Information
are to be regarded separately as standard. The values stated in
each system may not be exact equivalents; therefore, each
3.1 Orders for materials under this specification shall in-
system shall be used independently of the other. Combining
clude the following information:
values from the two systems may result in non-conformance
3.1.1 Conductor alloy,
with the standard.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
This specification is under the jurisdiction of ASTM Committee B01 on Standards volume information, refer to the standard’s Document Summary page on
Electrical Conductors and is the direct responsibility of Subcommittee B01.07 on the ASTM website.
Conductors of Light Metals. Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
Current edition approved April 1, 2013. Published April 2013. Originally 4th Floor, New York, NY 10036, http://www.ansi.org.
approved in 1988. Last previous edition approved in 2008 as B786–08. DOI: Available from National Institute of Standards and Technology (NIST), 100
10.1520/B0786-08R13. 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
B786−08 (2013)
composing the conductor but shall not be closer together than
1 ft (Explanatory Note 2).
5. Lay
5.1 For combination unilay conductors the lay of a layer of
wires shall be not less than 8 nor more than 16 times the
outside diameter of the outer layer.
5.2 Other lays for special purposes shall be furnished by
FIG. 1 Cross Section of Conductor
specialagreementbetweenthemanufacturerandthepurchaser.
NOTE4—Certaintypesofinsulationconductorsmayrequireshorterlay
3.1.2 Quantity of each size,
than other conductors. It is expected that special requirements regarding
3.1.3 Conductor size: Circular-mil area or American Wire
length of lay will be specified by the purchaser in such instances.
Gage, AWG (Section 6 and Table 1),
5.3 The direction of lay shall be left-hand unless the
3.1.4 Stranding (see Explanatory Note 1),
direction of lay is specified otherwise by the purchaser.
3.1.5 Temper (see Section 11),
3.1.6 Details of special-purpose lays, if required (see 5.2),
6. Construction (Explanatory Note 1)
3.1.7 Whenphysicaltestsshallbemade(seeSections7and
6.1 The areas of cross section, numbers, and diameters of
8),
wires in the various conductors shall conform to the require-
3.1.8 Package size (see 16.1),
ments prescribed in Table 1 (Note 3) (see Fig. 1).
3.1.9 Heavy wood lagging, if required (see 17.2),
6.2 ThediametersofthewireslistedinTable2arenominal.
3.1.10 Special package marking, if required (Section 17),
In order to produce an essentially round 19-wire construction,
and
the outer 12-wire layer in the combination unilay product is
3.1.11 Place of inspection (Section 15).
comprised of 6 wires of the same diameter as the wires in the
4. Joints 7-wire core, and 6 wires approximately 25% smaller. The
2-wire sizes are alternated around the 7-wire core.
4.1 Electric-butt welds, cold pressure welds, or electric-butt
cold-upset welds may be made in the finished individual wires
7. Mechanical and Electrical Tests of Conductors not
Annealed after Stranding
TABLE 1 Construction Requirements for 19-Wire Combination
7.1 Wires composing the conductors shall be tested prior to
Unilay Stranded Aluminum Conductors
stranding in accordance with the applicable specification (see
A B
Wire D Wire D
Area of Size, American (or 1 2
11.1.2), and tests on the completed conductor are not required.
Diameter Diameter
Cross-Section, Brown and Sharpe)
However, when requested by the purchaser and agreed to by
cmil Wire Gage mils mm mils mm
the manufacturer at time of ordering, the tension tests of wires
556 500 185.3 4.71 135.6 3.44
before stranding may be waived and the completed conductor
500 000 175.6 4.46 128.5 3.26
477 000 171.5 4.36 125.5 3.19
tested in accordance with 7.2, or wires removed from the
450 000 166.6 4.23 121.9 3.10
completed conductor tested in accordance with 7.5.
397 500 156.6 3.98 114.6 2.91
350 000 146.9 3.73 107.5 2.73
7.2 When the completed conductor is tested as a unit, the
336 400 144.0 3.66 105.4 2.68
breaking strength shall be not less than the rated strength of
300 000 136.0 3.45 99.6 2.53
266 800 128.3 3.26 93.9 2.38 1350-H19 conductors or the minimum rated strength of 1350-
250 000 124.2 3.15 90.9 2.31
H16, -H26, -H14, -H24, -H142, and -H242 conductors if
211 600 0000 114.2 2.90 83.6 2.12
failure occurs in the free length at least 1 in. (25 mm) beyond
167 800 000 101.7 2.58 74.5 1.89
133 100 00 90.6 2.30 66.3 1.68 theendofeithergrippingdevice.Thestrengthshallbenotless
105 600 0 80.7 2.05 59.1 1.50
than 95% of the rated or minimum rated strength if failure
83 690 1 71.8 1.82 52.6 1.34
occurs inside, or within 1 in. of the end of either gripping
66 360 2 64.0 1.63 46.8 1.19
52 620 3 57.0 1.45 41.7 1.06 device.Thebreakingstrengthof1350-H16,-H26,-H14,-H24,
41 740 4 50.7 1.29 37.1 0.94
-H142, and -H242 conductors shall be not greater than their
33 090 5 45.2 1.15 33.1 0.84
maximumratedstrengths.Thefreelengthbetweengripsofthe
26 240 6 40.2 1.02 29.4 0.75
20 820 7 35.8 0.91 26.2 0.67
test specimen shall be not less than 24 in. (600 mm) and care
16 510 8 31.9 0.81 23.4 0.59
shall be taken to ensure that the wires in the conductor are
13 090 9 28.4 0.72 20.8 0.53
evenly gripped during the test (Explanatory Note 3).
10 380 10 25.3 0.64 18.5 0.47
6 530 12 20.1 0.51 14.7 0.37
7.3 The rated strength of 1350-H19 conductors and the
A
Equation to calculate D :
minimum rated strength of 1350-H16, -H26, -H14, -H24,
Cross2Sectional Area
-H142, and -H242 conductors shall be taken as 93% of the
D 5
Œ
16.2149
sum of the specified minimum average tensile strengths of the
B
component wires for 1350-H19 conductors, as prescribed in
Equation to calculate D :
Table 1, Tensile Requirements, of Specification B230/B230M,
D 5 D 30.732.
2 1
and of the sum of the specified minimum tensile strengths of
B786−08 (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
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
8.1 Tensile properties and electrical resistivity shall be
1350-H16, -H26, -H14, -H24, -H142 and -H242 conductors
determinedonsamplestakenfrom10%ofthereelsorcoilsof
shall be taken as the sum of the specified maximum strengths
conductor, but from not less than five (or all if the lot is less
of the component wires, as prescribed in Specification B609/
than five) reels or coils. Resistivity shall be determined as
B609M, as applicable. The rated strengths shall be calculated
prescribed in the Resistivity section of Specification B230/
using specified nominal wire diameters.
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
8.2 When wires removed from the completed conductor are
Specification B230/B230M. 1350-H16, -H26, -H14, -H24,
tested, 1350-H26, -H24, and -H242 wires shall have tensile
-H142, and -H242 wires shall have tensile strengths not less
strengths not less than 95% of the minimum tensile strength
than 95% of the minimum tensile strength nor more than
nor more than 105% of the maximum tensile strength pre-
105% of the maximum tensile strength prescribed in Specifi-
scribed in Specification B609/B609M, as applicable (Explana-
cation B609/B609M, as applicable (Explanatory Note 4).
tory Note 4).
7.6 All wires composing the conductors shall be capable of
8.3 When the completed conductor is tested as a unit, the
meeting the bending properties stated in Specification B230/
breaking strengths of 1350-H26, -H24, and -H242 conductors
B230Mafterstranding.Routineproductiontestingafterstrand-
shall conform with 7.2, 7.3, and 7.4.
ing is not required.
8.4 All wires composing the conductors shall be capable of
7.7 Mechanical and electrical tests of conductors in 8000
series aluminum alloys in “0” temper, H1X or H2X wire and meeting the bending properties stated in Specification B230/
B230Mafterstranding.Routineproductiontestingafterstrand-
not annealed after stranding shall be in accordance with
Section 9 of Specification B801. ing is not required.
B786−08 (2013)
8.5 Mechanical and electrical tests of conductors of 8000 11.1.1.3 Strand the conductor from 1350-H19 wires and
series aluminum alloys fabricated from wires other than H2X anneal the stranded conductor to final temper.
and annealed after stranding to meet “0” temper or H2X 11.1.2 Before stranding, the aluminum wire used shall meet
requirements shall be in accordance with Section 10 of all of the requirements of Specification B230/B230M or
Specification B801.
...