1、Designation: B 786 02aStandard Specification for19 Wire Combination Unilay-Stranded AluminumConductors for Subsequent Insulation1This standard is issued under the fixed designation B 786; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers bare combination unilay-stranded conductors made from round wires of alumi
3、num 1350and 8000 series of aluminum alloys, for insulated conductorsfor electrical purposes. Aluminum 1350 wires in tempers -H19(extra hard), -H16 or -H26 (34 hard), -H14 or -H24 (12 hard),and -H142 or -H242 (12 hard) and 8000 series aluminum alloyswires in tempers “0” and H1X or H2X are permitted.
4、Theseconductors shall be constructed with a central core wiresurrounded by two layers of helically laid wires, resulting in anouter diameter equal to the compressed-stranded equivalentconductors.NOTE 1For the purpose of this specification, combination unilayconductor is defined as follows: a central
5、 core wire surrounded by a layerof six helically laid wires of the same diameter as the core wire with ahelically laid outer layer containing six smaller wires alternated betweensix wires of the same diameter as the wires in the layer underneath. Bothlayers have a common length and direction of lay
6、(see Fig. 1).1.1.1 For the purpose of this specification, normal conductorclassification (Class AA, A, B, C) is not applicable, as theseconductors are intended for subsequent insulation. The descrip-tive term combination unilay-stranded shall be used in place ofconductor classification (Note 2 and N
7、ote 3).NOTE 2Prior to 1975, aluminum 1350 was designated as EC alumi-num.NOTE 3The aluminum and temper designations conform to ANSIStandard H35.1. Aluminum 1350 corresponds to Unified NumberingSystem A91350 in accordance with Practice E 527. Unified NumberingSystem alloy designations for 8000 Series
8、 aluminum alloys in accordancewith Practice E 527 are listed in Table number 1 of Specification B 800.1.2 The values stated in inch-pound or SI units are to beregarded separately as standard. The values in each system arenot exact equivalents; therefore, each system shall be usedindependently of the
9、 other. Combining values from the twosystems may result in nonconformance with the specification.1.2.1 For density, resistivity and temperature, the valuesstated in SI units are to be regarded as standard.2. Referenced Documents2.1 The following documents of the issue in effect on dateof material pu
10、rchase form a part of this specification to theextent referenced herein.2.2 ASTM Standards:B 193 Test Method for Resistivity of Electrical ConductorMaterials2B 230 Specification for Aluminum 1350-H19 Wire for Elec-trical Purposes2B 263 Test Method for Determination of Cross-SectionalArea of Stranded
11、 Conductors2B 609 Specification for Aluminum 1350 Round Wire, An-nealed and Intermediate Tempers, for Electrical Purposes2B 800 Specification for 8000 Series Aluminum Alloy Wirefor Electrical PurposesAnnealed and Intermediate Tem-pers2B 801 Specification for Concentric-Lay-Stranded Conduc-tors of 80
12、00 Series Aluminum Alloy for SubsequentCovering or Insulation2E 29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications3E 527 Practice for Numbering Metals and Alloys (UNS)42.3 ANSI Standard:ANSI H35.1 Alloy and Temper Designation Systems forAluminum52.4 NIS
13、T Standard:NBS Handbook 10063. Ordering Information3.1 Orders for materials under this specification shall in-clude the following information:3.1.1 Conductor alloy,3.1.2 Quantity of each size,3.1.3 Conductor size: Circular-mil area or American WireGage, AWG (Section 6 and Table 1),3.1.4 Stranding (s
14、ee Explanatory Note 1),1This specification is under the jurisdiction of ASTM Committee B01 onElectrical Conductors and is the direct responsibility of Subcommittee B01.07 onConductors of Light Metals.Current edition approved Oct. 10, 2002. Published Decemeber 2002. Originallyapproved in 1988. Last p
15、revious edition approved in 2002 as B 786 02.2Annual Book of ASTM Standards, Vol 02.03.3Annual Book of ASTM Standards, Vol 14.02.4Annual Book of ASTM Standards, Vol 01.01.5Available from American National Standards Institute, 25 W. 43rd St., 4thFloor, New York, NY 10036.6Available from the National
16、Institute of Standards and Technology, (NIST), 100Bureau Drive, Stop 3460, Gaithersburg, MD 20899-3460.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.5 Temper (see Section 11),3.1.6 Details of special-purpose lays, if required (
17、see 5.2),3.1.7 When physical tests shall be made (see Sections 7 and8),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),and3.1.11 Place of inspection (Section 15).4. Joints4.1 Electric-butt welds, cold pressure we
18、lds, or electric-buttcold-upset welds may be made in the finished individual wirescomposing the conductor but shall not be closer together than1 ft (Explanatory Note 2).5. Lay5.1 For combination unilay conductors the lay of a layer ofwires shall be not less than 8 nor more than 16 times theoutside d
19、iameter of the outer layer.5.2 Other lays for special purposes shall be furnished byspecial agreement between the manufacturer and the purchaser.NOTE 4Certain types of insulation conductors may require shorter laythan other conductors. It is expected that special requirements regardinglength of lay
20、will be specified by the purchaser in such instances.5.3 The direction of lay shall be left-hand unless thedirection of lay is specified otherwise by the purchaser.6. Construction (Explanatory Note 1)6.1 The areas of cross section, numbers, and diameters ofwires in the various conductors shall confo
21、rm to the require-ments prescribed in Table 1 (Note 3) (see Fig. 1).6.2 The diameters of the wires listed in Table 2 are nominal.In order to produce an essentially round 19-wire construction,the outer 12-wire layer in the combination unilay product iscomprised of 6 wires of the same diameter as the
22、wires in the7-wire core, and 6 wires approximately 25 % smaller. The2-wire sizes are alternated around the 7-wire core.7. Mechanical and Electrical Tests of Conductors notAnnealed after Stranding7.1 Wires composing the conductors shall be tested prior tostranding in accordance with the applicable sp
23、ecification (see11.1.2), and tests on the completed conductor are not required.However, when requested by the purchaser and agreed to bythe manufacturer at time of ordering, the tension tests of wiresbefore stranding may be waived and the completed conductortested in accordance with 7.2, or wires re
24、moved from thecompleted conductor tested in accordance with 7.5.7.2 When the completed conductor is tested as a unit, thebreaking strength shall be not less than the rated strength of1350-H19 conductors or the minimum rated strength of 1350-H16, -H26, -H14, -H24, -H142, and -H242 conductors iffailur
25、e occurs in the free length at least 1 in. (25 mm) beyondthe end of either gripping device. The strength shall be not lessthan 95 % of the rated or minimum rated strength if failureoccurs inside, or within 1 in. of the end of either grippingdevice. The breaking strength of 1350-H16, -H26, -H14, -H24
26、,-H142, and -H242 conductors shall be not greater than theirmaximum rated strengths. The free length between grips of thetest specimen shall be not less than 24 in. (600 mm) and careshall be taken to ensure that the wires in the conductor areevenly gripped during the test (Explanatory Note 3).7.3 Th
27、e rated strength of 1350-H19 conductors and theminimum rated strength of 1350-H16, -H26, -H14, -H24,-H142, and -H242 conductors shall be taken as 93 % of thesum of the specified minimum average tensile strengths of thecomponent wires for 1350-H19 conductors, as prescribed inTable 1, Tensile Requirem
28、ents, of Specification B 230, and ofthe sum of the specified minimum tensile strengths of thecomponent wires for 1350-H16, -H26, -H14, -H24, -H142, and-H242 conductors, as prescribed in Specification B 609, asapplicable. The maximum rated strength of the 1350-H16,-H26, -H14, -H24, -H142 and -H242 co
29、nductors shall be takenas the sum of the specified maximum strengths of the compo-nent wires, as prescribed in Specification B 609, as applicable.The rated strengths shall be calculated using specified nominalwire diameters.7.4 Rated strength and breaking strength values shall beFIG. 1 Cross Section
30、 of ConductorTABLE 1 Construction Requirements for 19-Wire CombinationUnilay Stranded Aluminum ConductorsArea ofCross-Section,cmilSize, American (orBrown and Sharpe)Wire GageWire D1ADiameterWire D2BDiametermils mm mils mm556 500 185.3 4.71 135.6 3.44500 000 175.6 4.46 128.5 3.26477 000 171.5 4.36 12
31、5.5 3.19450 000 166.6 4.23 121.9 3.10397 500 156.6 3.99 114.6 2.91350 000 146.9 3.98 107.5 2.73336 400 144.0 3.73 105.4 2.68300 000 136.0 3.66 99.6 2.53266 800 128.3 3.45 93.9 2.38250 000 124.2 3.26 90.9 2.31211 600 0000 114.2 3.15 83.6 2.12167 800 000 101.7 2.90 74.5 1.89133 100 00 90.6 2.58 66.3 1
32、.68105 600 0 80.7 2.30 59.1 1.5083 690 1 71.8 2.05 52.6 1.3466 360 2 64.0 1.82 46.8 1.1952 620 3 57.0 1.62 41.7 1.0641 740 4 50.7 1.45 37.1 0.9433 090 5 45.2 1.29 33.1 0.8426 240 6 40.2 1.15 29.4 0.7520 820 7 35.8 1.02 26.2 0.6716 510 8 31.9 0.81 23.4 0.5913 090 9 28.4 0.72 20.8 0.5310 380 10 25.3 0
33、.64 18.5 0.476 530 12 20.1 0.51 14.7 0.37AEquation to calculate D1:D15Cross2Sectional Area16.2149BEquation to calculate D2:D25 D13 0.732.B 786 02a2rounded to three significant figures, in the final value only, inaccordance with the rounding method in Practice E 29.7.5 When wires are removed from the
34、 completed conductorand tested, 1350-H19 wires shall have minimum tensilestrengths not less than 95 % of the tensile strengths prescribedfor individual tests in Table 1, Tensile Requirements, ofSpecification B 230. 1350-H16, -H26, -H14, -H24, -H142, and-H242 wires shall have tensile strengths not le
35、ss than 95 % ofthe minimum tensile strength nor more than 105 % of themaximum tensile strength prescribed in Specification B 609, asapplicable (Explanatory Note 4).7.6 All wires composing the conductors shall be capable ofmeeting the bending properties stated in Specification B 230after stranding. R
36、outine production testing after stranding isnot required.7.7 Mechanical and electrical tests of conductors in 8000series aluminum alloys in “0” temper, H1X or H2X wire andnot annealed after stranding shall be in accordance withSection 9 of Specification B 801.8. Mechanical and Electrical Tests of Co
37、nductorsAnnealed after Stranding8.1 Tensile properties and electrical resistivity shall bedetermined on samples taken from 10 % of the reels or coils ofconductor, but from not less than five (or all if the lot is lessthan five) reels or coils. Resistivity shall be determined asprescribed in the Resi
38、stivity section of Specification B 230 onone wire from each conductor sample except this test is notrequired if performed previously on the 1350-H19 wire. At themanufacturers option, tension tests shall be made either onone of the inner seven wires and one wire from each additionallayer of each cond
39、uctor sample to determine conformance with8.2 or on the conductor as a unit to determine conformationwith 8.3.8.2 When wires removed from the completed conductor aretested, 1350-H26, -H24, and -H242 wires shall have tensilestrengths not less than 95 % of the minimum tensile strengthnor more than 105
40、 % of the maximum tensile strength pre-scribed in Specification B 609, as applicable (Explanatory Note4).8.3 When the completed conductor is tested as a unit, thebreaking strengths of 1350-H26, -H24, and -H242 conductorsshall conform with 7.2, 7.3, and 7.4.8.4 All wires composing the conductors shal
41、l be capable ofmeeting the bending properties stated in Specification B 230after stranding. Routine production testing after stranding isnot required.8.5 Mechanical and electrical tests of conductors of 8000series aluminum alloys fabricated from wires other than H2Xand annealed after stranding to me
42、et “0” temper or H2Xrequirements shall be in accordance with Section 10 ofSpecification B 801.9. Mass and Resistance9.1 The mass and electrical resistance of a unit length ofstranded conductor are a function of the length of lay. Theapproximate mass and electrical resistance may be determinedusing t
43、he standard increment of 2 %. When greater accuracy isdesired, the increment based on the specific lay of the conduc-tor may be calculated (Explanatory Note 1).9.2 The maximum electrical resistance of a unit length ofstranded conductor shall not exceed 2 % over the nominal d-cresistance shown in Tab
44、le 2 (Explanatory Note 6). When thed-c resistance is measured at other than 20C, it is to beTABLE 2 Diameters, Areas and Mass of 19-Wire Combination Unilay Stranded Aluminum ConductorASize ofConductor,cmil orAWGNominal ConductorDiameterBNominal Area MassDirect Current Resistanceat 20Cin. mm in.2mm2l
45、b/1000 ft kg/km V/1000 ft V/km556 500 0.827 21.0 0.4371 282 521 775 0.0312 0.1024500 000 0.784 19.9 0.3927 253 468 697 0.0347 0.1139477 000 0.766 19.5 0.3746 242 447 665 0.0364 0.1194450 000 0.744 18.9 0.3534 228 421 627 0.0385 0.1263397 500 0.699 17.8 0.3122 201 372 554 0.0436 0.1431350 000 0.656 1
46、6.7 0.2749 177 328 488 0.0495 0.1624336 400 0.643 16.3 0.2642 170 315 469 0.0516 0.1693300 000 0.607 15.4 0.2356 152 281 418 0.0578 0.1896266 800 0.573 14.6 0.2095 135 250 372 0.0650 0.2133250 000 0.554 14.1 0.1963 127 234 348 0.0694 0.22770000 0.510 13.0 0.1662 107 198 295 0.0820 0.2690000 0.454 11
47、.5 0.1318 85.0 157 234 0.103 0.338900 0.404 10.3 0.1045 67.4 125 185 0.130 0.42750 0.360 9.14 0.08291 53.5 98.9 147 0.164 0.53871 0.321 8.15 0.06573 42.4 78.4 117 0.207 0.67982 0.286 7.26 0.05212 33.6 62.1 92.4 0.261 0.85733 0.254 6.45 0.04133 26.7 49.3 73.4 0.330 1.08144 0.226 5.74 0.03278 21.1 39.
48、1 58.2 0.416 1.36335 0.202 5.13 0.02599 16.8 31.0 46.1 0.523 1.726 0.179 4.55 0.02061 13.3 24.6 36.6 0.661 2.16847 0.160 4.06 0.01635 10.5 19.5 29.0 0.834 2.73628 0.143 3.63 0.01297 8.37 15.5 23.1 1.05 3.44649 0.127 3.23 0.01028 6.63 12.3 18.3 1.32 4.330710 0.113 2.87 0.00816 5.26 9.73 14.5 1.67 5.4
49、79012 0.090 2.29 0.00513 3.31 6.12 9.11 2.67 8.7598AMass and electrical resistance are based on aluminum 1350.BTo 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) = 509.8B 786 02a3corrected by using the multiplying factor given in Table 3.9.3 For conductors to be used in covered or insulated wiresor cables, d-c resistance measurement may be used instead ofthe method outlined in Section 14, to determine compliancewith this specification; however, the refere
