1、Designation: B784 01 (Reapproved 2012)Standard 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 o
2、r, 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.1. Scope1.1 This specification covers bare modified concentric-lay-stranded conductors mad
3、e 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, surrounded by one or more layers of helically laid wires.1.2 For the pur
4、poses 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 Modified and Class D ModifiedConductorswhere greater flexibility is
5、 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 twosystems may result in non- conformance with the specification.For c
6、onductor 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 unitshave been numerically converted from corresponding valuesstated or
7、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, resitivity and temperature, the valuesstated in SI units are to be regarded as standard.NOTE 1The significant differences in this specification from Speci
8、fi-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 stranded assemblies of 19 or more wires.2. Referenced Documents2.1 T
9、he 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 WireB8 Specification for Concentric-Lay-Stranded Copper Con-ductors, Hard, Medium-Hard, or S
10、oftB33 Specification for Tin-Coated Soft or Annealed CopperWire for Electrical PurposesB189 Specification for Lead-Coated and Lead-Alloy-Coated Soft Copper Wire for Electrical PurposesB263 Test Method for Determination of Cross-SectionalArea of Stranded ConductorsB354 Terminology Relating to Uninsul
11、ated Metallic Elec-trical 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 and class,3.1.2 Conductor size: circular-mil area or American WireGage (AWG) (Section 6),
12、3.1.3 Class (see 1.2 and Table 1),3.1.4 Temper (see 10.2),3.1.5 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),1This specification is under the jurisdiction of ASTM Committee B01 onElectrical Conductors
13、 and is the direct responsibility of Subcommittee B01.04 onConductors of Copper and Copper Alloys.Current edition approved April 1, 2012. Published August 2012. Originallyapproved in 1988. Last previous edition approved in 2006 as B784 01 (2006).DOI: 10.1520/B0784-01R12.2For referenced ASTM standard
14、s, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from National Technical Information Service (NTIS), 5285 PortRoyal Rd., Springf
15、ield, VA 22161, http:/www.ntis.gov.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.7 Lagging, if required (see 14.2),3.1.8 Special package marking, if required (Section 13),3.1.9 Place of inspection (Section 12), and4. Joints4.1
16、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 together than prescribed in Table 2.5. Lay5.1 The lay of a layer of wires shall be not less than eightnor more than six
17、teen 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 other than the two outer layers shall be at the optionof the manufacturer, unless otherwise agreed upon.5.2 Other lays
18、 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-handunless the direction of lay is specified otherwise by thepurchaser.5.4 The direction of lay shall be reversed in s
19、uccessivelayers, 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-stranded conduc-tors shall conform to the requirements prescribed in Table 1.6.2 The diameters of the wires listed in Ta
20、ble 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 of 6 5 %, provided that the area of crosssection after stranding is in a
21、ccordance with Section 11.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 ofWiresDiameterNumber ofWiresDiameterNumber ofWiresDiameter(mils) (
22、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 000A169 133.2 3.38 217 117.6 2.99 271 105.2 2.672 5
23、00 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 2.59 217 89.8 2.281 700 000 127 115.7 2.94 169 100.3 2.
24、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 99.2 2.52 169 86.0 2.181 200 000 91 114.8 2.92 1
25、27 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 90.8 2.31 127 76.8 1.95700 000A61 107.1 2.72 91 87.
26、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 1.79400 000A37 104.0 2.64 61 81.0 2.06 91 66.3 1
27、.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 000A00 19 83.7 2.13 37 60.0 1.52 61 46.7 1.19105 000A
28、0 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 simply asa matter of reference and it is suggested that their
29、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 thecompleted conductor.B784 01 (2012)26.3 Where compressed
30、 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 reducing the outside diameter ofthe conductor by not more than 3 %, provided that the area ofcross section after stranding
31、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 soft or annealed copper wire, bare orcoated, shall be made before stranding.7.2 Tests for the physical properties of sof
32、t 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 shallbe taken to avoid mechanical injury to wire removed from theconductor for the purpose of testing.7.3 The physical
33、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 shall be permitted to vary fromthe applicable requirements of 10.2 by the following amounts(Explanatory Note 4):7.4.1
34、 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 the wire before stranding.7.4.2 Results Obtained on Individual WiresThe elonga-tion of individual wires shall be reduc
35、ed in numerical value 15from the 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 less than 5 %.7.5 In the event that the requirements prescribed in 7.4.2 aremet but those prescribed in 7.4.1 are no
36、t 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 compliance shall not bemade on the conductor as a unit (Explanatory Note 6).7.7 If a tinning, lead-coating, or lead-alloy
37、-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 copper shall be taken as0.32117 lb/in.3or 8.89 g/cm3at 20C (Note 2 and ExplanatoryNote 7).NOTE 2The term “mass” is bei
38、ng 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 conductor are a function of the length of lay. Theapproximate mass and electrical resistance may be determinedusing t
39、he 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 for Wires10.1 The purchaser shall designate the type of wire and thekind of coating, if any, to be used in the con
40、ductor.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 be made of wire of the same typeand temper as the concentric layers, unless otherwise specified.11. Variation in Ar
41、ea11.1 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, themanufacturer may have the option of determining the cross-sectional area by either of the following methods; except that
42、in 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 measurements, ex-pressed to four decimal places, of its component wires at anypoint when measured perpendicularly to their
43、 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 value specified in 9.1 or may be calculated from themeasured component dimensions of the sample under test. Incase
44、 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, the manufacturer shall be responsible for the perfor-mance of all inspection and test requirements specified.12.2 Al
45、l 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 afford the inspector represent-ing the purchaser all reasonable manufacturers facilities tosatisfy that the material
46、is being furnished in accordance withthis specification.13. 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
47、 on a tagattached to the end of the conductor inside of the package. Thesame information, together with the manufacturers serialTABLE 3 Standard Increments Due to StrandingType of ConductorIncrement of Resistanceand Mass, %Classes B Modified, C Modified, and DModified, 2 000 000 cmil and under2Over
48、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 (2012)3number (if any) and all shipping marks required by thepurchaser, shall appear on the outside of each package.14. Packaging and Package Marking14.1 Package sizes for conductors shall be agr
49、eed upon bythe manufacturer and the purchaser in the placing of individualorders (Explanatory Note 9).14.2 The conductors shall be protected against damage inordinary handling and shipping. If heavy wood lagging isrequired, it shall be specified by the purchaser at the time ofpurchase.15. Keywords15.1 copper conductors for insulated wires; copper modifiedconcentric-lay-stranded; electrical copper conductorsTABLE 4 Diameter, Area, and Mass of Modified Concentric-Lay-Stranded Copper ConductorsSize ofConductorcmil or AWGNumberNominal ConductorDiameterClass B ModifiedAAre
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