1、Designation: B784 01 (Reapproved 2017)1Standard Specification forModified Concentric-Lay-Stranded Copper Conductors forUse in Insulated Electrical Cables1This standard is issued under the fixed designation B784; the number immediately following the designation indicates the year oforiginal adoption
2、or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTETypos in Section 1 were corrected editorially in April 2017.1. Scope1.1 This specifi
3、cation covers bare modified concentric-lay-stranded conductors made from round copper wires, eitheruncoated or coated with tin, lead, or lead alloy for general usein insulated electrical cables. These conductors shall be con-structed with a central core consisting of not more than sevenwires, surrou
4、nded by one or more layers of helically laid wires.1.2 For the purposes of this specification, conductors areclassified as follows (Explanatory Note 1 and Note 2):1.2.1 Class B ModifiedConductors to be insulated withvarious materials such as rubber, paper, and crosslink polyeth-ylene.1.2.2 Class C M
5、odified and Class D ModifiedConductorswhere greater flexibility is required than is provided by ClassB Modified conductors.1.3 The values stated in inch-pound or SI units are to beregarded separately as standard. Each system shall be usedindependently of the other. Combining the values from the twos
6、ystems may result in non- conformance with the specification.For conductor sizes designated by AWG or kcmil sizes, therequirements in SI units are numerically converted from thecorresponding requirements in inch-pound units. For conductorsizes designated byAWG or kcmil, the requirements in SI unitsh
7、ave been numerically converted from corresponding valuesstated or derived in inch-pound units. For conductor sizesdesignated by SI units only, the requirements are stated orderived in SI units.1.3.1 For density, resistivity and temperature, the valuesstated in SI units are to be regarded as standard
8、.NOTE 1The significant differences in this specification from Specifi-cation B8 are as follows: (1) The central core is permitted to contain up toseven wires drawn into the assembly with an infinite length of lay whileSpecification B8 permits only one, and (2) The construction is applicableonly to s
9、tranded assemblies of 19 or more wires.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World
10、Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 The following documents of the issue in effect at thedate of material purchase form a part of this specification to theextent referenced herein.2.2 ASTM Standards:2B3 Specification for Soft or Annealed Copper Wi
11、reB8 Specification for Concentric-Lay-Stranded CopperConductors, Hard, Medium-Hard, or SoftB33 Specification for Tin-Coated Soft or Annealed CopperWire for Electrical PurposesB189 Specification for Lead-Coated and Lead-Alloy-CoatedSoft Copper Wire for Electrical PurposesB263 Test Method for Determin
12、ation of Cross-SectionalArea of Stranded ConductorsB354 Terminology Relating to Uninsulated Metallic Electri-cal Conductors2.3 Other Standard:NBS Handbook 10033. Ordering Information3.1 Orders for material under this specification shall includethe following information:3.1.1 Quantity of each size an
13、d class,3.1.2 Conductor size: circular-mil area or American WireGage (AWG) (Section 6),3.1.3 Class (see 1.2 and Table 1),3.1.4 Temper (see 10.2),1This specification is under the jurisdiction of ASTM Committee B01 onElectrical Conductors and is the direct responsibility of Subcommittee B01.04 onCondu
14、ctors of Copper and Copper Alloys.Current edition approved April 1, 2017. Published April 2017. Originallyapproved in 1988. Last previous edition approved in 2012 as B784 01 (2012).DOI: 10.1520/B0784-01R17E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Custom
15、er Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Available from National Technical Information Service (NTIS),5301 Shawnee Rd., Alexandria, VA 22312, http:/www.ntis.gov.Copyright ASTM I
16、nternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standar
17、ds, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.1.5 Whether coated or uncoated; if coated, designate typeof coating (see 10.1 and 10.2),3.1.6 Details of special-purpose lays, if required (see 5.2),3.1.7 Lagging, if required (see 14
18、.2),3.1.8 Special package marking, if required (Section 13),3.1.9 Place of inspection (Section 12), and4. Joints4.1 Welds and brazes may be made in rods or in wires priorto final drawing. Welds and brazes may be made in the finishedindividual wires composing the conductor, but shall not becloser tog
19、ether than prescribed in Table 2.5. Lay5.1 The lay of a layer of wires shall be not less than eightnor more than sixteen times the outside diameter of that layer,except that for conductors composed of 37 wires or more, thisrequirement shall apply only to the two outer layers. The lay ofthe layers ot
20、her than the two outer layers shall be at the optionof the manufacturer, unless otherwise agreed upon.5.2 Other lays for special purposes shall be furnished byspecial agreement between the manufacturer and the purchaser(Explanatory Note 3).5.3 The direction of lay of the outer layer shall be left-ha
21、ndunless the direction of lay is specified otherwise by thepurchaser.5.4 The direction of lay shall be reversed in successivelayers, unless otherwise specified by the purchaser.6. Construction6.1 The areas of cross section, numbers, and diameters ofwires in the various classes of concentric-lay-stra
22、nded conduc-tors shall conform to the requirements prescribed in Table 1.TABLE 1 Construction Requirements of Modified Concentric-Lay-Stranded Copper ConductorsNOTE 1See Explanatory Note 5.Circular MilsSizeAmericanWire GageClass B Modified Class C Modified Class D ModifiedNumber ofWiresDiameter Numb
23、er ofWiresDiameter Number ofWiresDiameter(mils) (mm) (mils) (mm) (mils) (mm)5 000 000A217 151.8 3.86 271 135.8 3.45 271 135.8 3.454 000 000 217 144.0 3.66 271 128.9 3.27 271 128.9 3.274 000 000 217 135.8 3.45 271 121.5 3.09 271 121.5 3.093 500 000 169 143.9 3.66 217 127.0 3.23 271 113.6 2.893 000 00
24、0A169 133.2 3.38 217 117.6 2.99 271 105.2 2.672 500 000A127 140.3 3.56 169 121.6 3.09 217 107.3 2.732 000 000A127 125.5 3.19 169 108.8 2.76 217 96.0 2.441 900 000 127 122.3 3.11 169 106.0 2.69 217 93.6 2.381 800 000 127 119.1 3.03 169 103.2 2.62 217 91.1 2.311 750 000A127 117.4 2.98 169 101.8 2.59 2
25、17 89.8 2.281 700 000 127 115.7 2.94 169 100.3 2.55 217 88.5 2.251 600 000 127 112.2 2.85 169 97.3 2.47 217 85.9 2.181 500 000A91 128.4 3.26 127 108.7 2.76 169 94.2 2.391 400 000 91 124.0 3.15 127 105.0 2.67 169 91.0 2.311 300 000 91 119.5 3.04 127 101.2 2.57 169 87.7 2.231 250 000 91 117.2 2.98 127
26、 99.2 2.52 169 86.0 2.181 200 000 91 114.8 2.92 127 97.2 2.47 169 84.3 2.141 100 000 91 109.9 2.79 127 93.1 2.36 169 80.7 2.051 000 000A61 128.0 3.25 91 104.8 2.66 127 88.7 2.25900 000 61 121.5 3.09 91 99.4 2.52 127 84.2 2.14800 000A61 114.5 2.91 91 93.8 2.38 127 79.4 2.02750 000A61 110.9 2.82 91 90
27、.8 2.31 127 76.8 1.95700 000A61 107.1 2.72 91 87.7 2.23 127 74.2 1.88650 000 61 103.2 2.62 91 84.5 2.15 127 71.5 1.82600 000A61 99.2 2.52 91 81.2 2.06 127 66.7 1.69550 000 61 95.0 2.41 91 77.7 1.97 127 65.8 1.67500 000A37 116.2 2.95 61 90.5 2.30 91 74.1 1.88450 000 37 110.3 2.80 61 85.9 2.18 91 70.3
28、 1.79400 000A37 104.0 2.64 61 81.0 2.06 91 66.3 1.68350 000A37 97.3 2.47 61 75.7 1.92 91 62.0 1.57300 000A37 90.0 2.29 61 70.1 1.78 91 57.4 1.46250 000A37 82.2 2.09 61 64.0 1.63 91 52.4 1.33211 000A0000 19 105.5 2.68 37 75.6 1.92 61 58.9 1.50167 000A000 19 94.0 2.39 37 67.3 1.71 61 52.4 1.33133 000A
29、00 19 83.7 2.13 37 60.0 1.52 61 46.7 1.19105 000A0 19 74.5 1.89 37 53.4 1.36 61 41.6 1.0683 000A1 19 66.4 1.69 37 47.6 1.21 61 37.0 0.94AThese sizes of conductors provide for one or more schedules of preferred series and commonly are used in the industry. The sizes not marked are given simplyasamatt
30、er of reference and it is suggested that their use be discouraged.TABLE 2 Minimum Distance Between Joints in the CompletedConductorNumber of Wires in Conductor Soft All Classes19 1 ft20 and over 1 ft in a layerAAExcept as indicated, the limitations apply to closeness of joints throughout thecomplete
31、d conductor.B784 01 (2017)126.2 The diameters of the wires listed in Table 1 are nominal.Where “combination strand” is required in order to insulate theconductor properly (strands in the outer layer having a largerdiameter than those in the inner layers) the diameters shall besubject to a tolerance
32、of 65 %, provided that the area of crosssection after stranding is in accordance with Section 11.6.3 Where compressed stranding is required in order toinsulate the conductor properly, one or more layers of anystranded conductor consisting of 19 wires or more may beslightly compressed, thereby reduci
33、ng the outside diameter ofthe conductor by not more than 3 %, provided that the area ofcross section after stranding is in accordance with Section 11.7. Physical and Electrical Tests of Stranded Conductorsof Soft Wires7.1 Tests for the electrical properties of wires composingconductors made from sof
34、t or annealed copper wire, bare orcoated, shall be made before stranding.7.2 Tests for the physical properties of soft or annealedcopper wire, bare or coated, may be made upon the wiresbefore stranding or upon wires removed from the completestranded conductor, but need not be made upon both. Care sh
35、allbe taken to avoid mechanical injury to wire removed from theconductor for the purpose of testing.7.3 The physical properties of wires when tested beforestranding shall conform to the applicable requirements of 10.2.7.4 The physical properties of wires removed from thecompleted stranded conductor
36、shall be permitted to vary fromthe applicable requirements of 10.2 by the following amounts(Explanatory Note 4):7.4.1 Average of Results Obtained on All Wires TestedTheminimum elongation required shall be reduced in numericalvalue 5 (for example, from 30 to 25 %) from the numericalrequirements for t
37、he wire before stranding.7.4.2 Results Obtained on Individual WiresThe elongationof individual wires shall be reduced in numerical value 15 fromthe minimum requirements before stranding (that is, 10 inaddition to the 5 allowed in 7.4.1), but in no case shall theelongation of any individual wire be l
38、ess than 5 %.7.5 In the event that the requirements prescribed in 7.4.2 aremet but those prescribed in 7.4.1 are not met, a retest shall bepermitted wherein all wires of the conductor shall be tested forthe purpose of final determination of conformance to 7.4.7.6 Elongation tests to determine compli
39、ance shall not bemade on the conductor as a unit (Explanatory Note 6).7.7 If a tinning, lead-coating, or lead-alloy-coating test isrequired, it shall be made on the wires prior to stranding.8. Density8.1 For the purpose of calculating mass per unit length,cross sections, etc., the density of the cop
40、per shall be taken as0.32117 lb/in.3or 8.89 g/cm3at 20C (Note 2 and ExplanatoryNote 7).NOTE 2The term “mass” is being used in this specification as beingmore technically correct. It replaces the term “weight.”9. Mass and Resistance9.1 The mass and electrical resistance of a unit length ofstranded co
41、nductor are a function of the length of lay. Theapproximate mass and electrical resistance may be determinedusing the standard increments shown in Table 3. When greateraccuracy is desired, the increment based on the specific lay ofthe conductor may be calculated (Explanatory Note 8).10. Requirements
42、 for Wires10.1 The purchaser shall designate the type of wire and thekind of coating, if any, to be used in the conductor.10.2 Before stranding, the copper wire used shall meet all ofthe requirements of ASTM Specifications B3, B33, and B189that are applicable to its type.10.3 The central core shall
43、be made of wire of the same typeand temper as the concentric layers, unless otherwise specified.11. Variation in Area11.1 The area of cross section of the completed conductorshall be not less than 98 % of the area indicated in Column 1of Table 1. Unless otherwise specified by the purchaser, themanuf
44、acturer may have the option of determining the cross-sectional area by either of the following methods; except thatin case of a question regarding area compliance, the method of11.1.2 shall be used.11.1.1 The area of cross section of a conductor may bedetermined by calculations from diameter measure
45、ments, ex-pressed to four decimal places, of its component wires at anypoint when measured perpendicularly to their axes.11.1.2 The area of cross section of a conductor may bedetermined by Test Method B263. In applying that method, theincrement in mass resulting from stranding may be the appli-cable
46、 value specified in 9.1 or may be calculated from themeasured component dimensions of the sample under test. Incase of a question regarding area compliance, the actual massincrement due to stranding shall be calculated.12. Inspection12.1 Unless otherwise specified in the contract or purchaseorder, t
47、he manufacturer shall be responsible for the perfor-mance of all inspection and test requirements specified.12.2 All inspections and tests shall be made at the place ofmanufacture unless otherwise agreed upon by the manufacturerand the purchaser at the time of purchase.12.3 The manufacturer shall af
48、ford the inspector represent-ing the purchaser all reasonable manufacturers facilities tosatisfy that the material is being furnished in accordance withthis specification.TABLE 3 Standard Increments Due to StrandingType of ConductorIncrement of Resistanceand Mass, %Classes B Modified, C Modified, an
49、d DModified, 2 000 000 cmil and under2Over 2 000 000 to 3 000 000 cmil 3Over 3 000 000 to 4 000 000 cmil 4Over 4 000 000 to 5 000 000 cmil 5B784 01 (2017)1313. Product Marking13.1 The net mass, length (or lengths and number oflengths, if more than one length is included in the package),size, kind of conductor, purchase order number, and any othermarks required by the purchase order shall be marked on a tagattached to the end of the conductor inside of the package. Thesame information, together with the manufacturers serialnumber (if any) and all shipping marks requ
