1、Designation: B228 11Standard Specification forConcentric-Lay-Stranded Copper-Clad Steel Conductors1This standard is issued under the fixed designation B228; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This specification covers bare concentric-lay-stran
3、dedconductors made from bare round copper-clad steel wires forgeneral use for electrical purposes.1.2 For the purpose of this specification, conductors areclassified as follows: Grade 40 HS, Grade 30 HS, and Grade 30EHS.1.3 The values stated in inch-pound units are to be regardedas standard. The val
4、ues given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to est
5、ablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 The following documents of the issue in effect on thedate of material purchase form a part of this specification to theextent referenced herein:2.2 ASTM
6、Standards:2B227 Specification for Hard-Drawn Copper-Clad SteelWireB354 Terminology Relating to Uninsulated Metallic Elec-trical Conductors2.3 ANSI Standards:C 42 Definitions of Electrical Terms32.4 National Institute of Standards and Technology:NBS Handbook 100Copper Wire Tables43. Ordering Informat
7、ion3.1 Orders for material under this specification shall includethe following information:3.1.1 Quantity of each size and grade;3.1.2 Conductor size: approximate diameter in fractions ofan inch, or number and AWG size of individual wires (Section7 and Table 1);3.1.3 Grade (see 1.2 and Table 1);3.1.
8、4 Direction of lay of outer layer, if other than left-hand(see 6.3);3.1.5 When physical tests shall be made (see 8.2);3.1.6 Package size (see 13.1);3.1.7 Special package marking, if required (Section 12);3.1.8 Lagging, if required (see 13.2); and3.1.9 Place of inspection (Section 14).3.2 In addition
9、, Supplementary Requirements shall applyonly when specified by the purchaser in the inquiry, contract, orpurchase order for direct procurement by agencies of the U. S.Government (S1, S2, and S3).4. Material for Wires4.1 The purchaser shall specify the grade of wire to be usedin the conductor.4.2 Bef
10、ore stranding, the copper-clad steel wire shall meetall the requirements of Specification B227.4.3 All wires in the conductor shall be of the same grade andquality.5. Joints5.1 Joints or splices may be made in the finished individualcopper-clad steel wires composing concentric-lay-strandedconductors
11、, using more than three wires provided that suchjoints or splices have a protection equivalent to that of the wireitself and that they do not decrease the strength of the finishedstranded conductor below the minimum breaking strength1This specification is under the jurisdiction of ASTM Committee B01
12、 onElectrical Conductors and is the direct responsibility of Subcommittee B01.06 onComposite Conductors.Current edition approved April 1, 2011. Published May 2011. Originallyapproved in 1948. Last previous edition approved in 2004 as B228 04. DOI:10.1520/B0228-11.2For referenced ASTM standards, visi
13、t 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 American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York,
14、 NY 10036, http:/www.ansi.org.4Available from National Institute of Standards and Technology (NIST), 100Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.shown in T
15、able 1. Such joints or splices shall be not closer than50 ft (15 m) to any other joint in the same layer in theconductor (Note 1).NOTE 1Joints or splices in individual copper-clad steel wires in theirfinished size are made by electrical butt welding. Two types of joints areused and are described as
16、follows:(a) Weld-Annealed JointsAfter butt welding, the wire is annealed fora distance of approximately 5 in. (127 mm) on each side of the weld. Theweld is then protected from corrosion with a snug fitting seamless coppersleeve which extends at least38 in. (9.5 mm) on each side of the weld andwhich
17、is thoroughly sealed to the wire with solder. The wall thickness ofthe sleeve is at least 10 % of the radius of the wire.This joint has a tensile strength of approximately 60 000 psi (415 MPa).This is less than the strength of the individual wires, but an allowance ismade for this in the rated stren
18、gth of the conductor as a whole. Thecompleted conductor when containing such joints is required to have thefull rated strength.This type of joint is but slightly larger than the wire itself and isapplicable for 7, 12, and 19-wire stranded conductors.(b) Compression-Weld JointsCompression-weld joints
19、 differ fromweld-annealed joints in that the wire is not annealed after the butt-weldingoperation but is reinforced with a hard-drawn, seamless, silicon-tin bronzesleeve which is applied by means of a hydraulic compressor over the weld.This sleeve is covered with solder so as to completely seal the
20、ends. Thesesleeves have a wall thickness of 25 to 50 % of the radius of the wire,depending on the wire size. Their use is usually limited to 3-wireconductors where the relatively large diameter is not objectionable. Thisjoint develops the full strength of the wire.6. Lay6.1 For 3-wire conductors the
21、 preferred lay is 1612 times theoutside diameter, but the lay shall not be less than 14 times normore than 20 times this diameter.6.2 For 7- and 19-wire conductors the preferred lay is 1312times the diameter of that layer, but the lay shall not be lessthan 10 nor more than 16 times this diameter.6.3
22、 The direction of lay of the outer layer shall be left-handunless the direction of lay is specified otherwise by thepurchaser.6.4 The direction of lay shall be reversed in consecutivelayers.6.5 All wires in the conductor shall lie naturally in their truepositions in the completed conductor. They sha
23、ll tend to remainin position when the conductor is cut at any point and shallpermit restranding by hand after being forcibly unraveled at theend of the conductor.TABLE 1 Construction Requirements and Breaking Strength of Concentric-Lay-Stranded Copper-Clad Steel ConductorsNOTE 1Metric EquivalentsFor
24、 diameter, 1 in. = 25.40 mm (round to four significant figures); for breaking strength, 1 lb = 0.45359 kg (round tofour significant figures).Size DesignationConductor Diameter, in.ARated Breaking Strength, min, lbBInchCAWGDGrade 40 HS Grade 30 HS Grade 30 EHS78 19 No. 5 0.910 48 740 53 910 64 910131
25、6 19 No. 6 0.810 40 370 44 470 53 8802332 19 No. 7 0.721 33 360 36 610 44 4802132 19 No. 8 0.642 27 550 30 140 36 590916 19 No. 9 0.572 22 690 24 730 29 70058 7 No. 4 0.613 21 630 24 040 28 540916 7 No. 5 0.546 17 960 19 860 23 91012 7 No. 6 0.486 14 870 16 390 19 850716 7 No. 7 0.433 12 290 13 490
26、16 39038 7 No. 8 0.385 10 150 11 100 13 4801132 7 No. 9 0.343 8359 9113 10 940516 7 No. 10 0.306 6913 7531 8928. . . 3 No. 5 0.392 8122 8985 10 820. . . 3 No. 6 0.349 6728 7412 8980. . . 3 No. 7 0.311 5559 6102 7413. . . 3 No. 8 0.277 4592 5023 6099. . . 3 No. 9 0.247 3781 4122 4950. . . 3 No. 10 0.
27、220 3127 3407 4039. . . 3 No. 12 0.174 1647 1719 2564ADiameter of circumscribing circle.BMinimum breaking strength is calculated using the minimum diameter of the individual wire and the minimum tensile strength from B227. Breaking loads of 7-wire and19-wire conductors are taken as 90 % of the sum o
28、f the breaking loads of the individual wires; breaking load of 3-wire conductors is taken as 95 % of the sum of thebreaking loads of the individual wires.CThe designation “Inch” is the approximate diameter in proper fraction of an inch.DThe designation of “AWG” is a combination of the number of wire
29、s each of the American Wire Gage size indicated by “No.”TABLE 2 Density of Copper-Clad SteelUnits Grade 40 Density at 20C Grade 30 Density at 20CGrams per cubic centimetre 8.24 8.15Pounds per cubic inch 0.2975 0.2944Pounds per circular mil-foot 0.0000028039 0.0000027750B228 1127. Construction7.1 The
30、 numbers and diameters of the wires in theconcentric-lay-stranded conductors shall conform to the re-quirements prescribed in Table 1 (Note 2).NOTE 2For definitions of terms relating to conductors, referenceshould be made to (1) ANSI C42.35-latest revision and (2) TerminologyB354.8. Physical and Ele
31、ctrical Tests8.1 Tests for physical and electrical properties of wirescomposing concentric-lay-stranded conductors made fromcopper-clad steel wire shall be made before stranding.8.2 At the option of the purchaser, tension and elongationtests before stranding may be waived and the completeconductors
32、may be tested as a unit. The breaking strength of theconductors so tested shall be not less than that required in Table1.8.3 Where breaking strength tests are required on thefinished conductor, they shall be made on representativesamples not less than 4 ft (1.22 m) in length. For lots of 10 000lb (4
33、540 kg) or less, two samples shall be taken from separatereels or coils in the lot except that but one sample shall berequired where the total amount of conductor is 5000 ft (1525m) or less. For quantities over 10 000 lb, one sample for each10 000 lb, or fraction thereof, shall be taken, but the min
34、imumnumber of samples shall be three.8.4 Specimens of the completed conductor shall be tested ina tensile testing machine equipped with jaws suitable forgripping of the conductor or equipped for holding properlysocketed specimens. Any test in which the result is below thestated value and which is ob
35、viously caused by impropersocketing of the specimen, or due to the break occurring in orat the gripping jaws of the machine, shall be disregarded andanother sample from the same coil or reel shall be tested.9. Density9.1 For the purpose of calculating mass per unit length(Note 3), cross sections, an
36、d so forth, the density of thecopper-clad steel wire shall be taken as shown in Table 2 (Note4).NOTE 3The term mass per unit length is used in this specification asbeing more technically correct replaces the term “weights.”NOTE 4The value of density of copper-clad steel is an average valuewhich has
37、been found to be in accordance with usual values encounteredin practice. Equivalent expressions of density at 20C are given in Table2.10. Mass and Resistance10.1 The mass and electrical resistance of a unit length ofstranded conductor are a function of the length of lay. Theapproximate mass and elec
38、trical 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 (Note 5).NOTE 5The increment of mass or electrical resistance of a completedconcentric-lay-stranded conductor
39、(k) in percent isk 5 100m 2 1!where m is the stranding factor, and is also the ratio of the mass orelectrical resistance of a unit length of stranded conductor to that of a solidconductor of the same cross-sectional area or of a stranded conductor withinfinite length of stranding, that is, all wires
40、 parallel to the conductor axis.The stranding factor m for the completed stranded conductor is thenumerical average of the stranding factors for each of the individual wiresin the conductor, including the straight core wire, if any (for which thestranding factor is unity). The stranding factor (mind
41、) for any given wire ina concentric-lay-stranded conductor ismind5 =1 1 9.8696/n2!where n = length of lay/diameter of helical path of the wire. Thederivation of the above is given in NBS Handbook 100.11. Variation in Area11.1 The area of cross section of the completed conductorshall be not less than
42、 98 % of the area specified. The area ofcross section of a conductor shall be considered to be the sumof the cross-sectional areas of its component wires at anysection when measured perpendicularly to their individual axes(Note 6).NOTE 6For the convenience of the users of this specification, Table 4
43、has been prepared giving areas, resistances per 1000 ft, and mass per 1000ft, and per mile, of the various constructions referred to in Table 1.12. Inspection12.1 Unless otherwise specified in the contract or purchaseorder, the manufacturer shall be responsible for the perfor-mance of all inspection
44、 and test requirements specified.12.2 All inspections and tests shall be made at the place ofmanufacture unless otherwise especially agreed to between themanufacturer and the purchaser at the time of the purchase.12.3 The manufacturer shall afford the inspector represent-ing the purchaser all reason
45、able manufacturers facilities nec-essary to ensure that the material is being furnished inaccordance with this specification.13. Packaging and Package Marking13.1 Package sizes for conductors shall be agreed upon bythe manufacturer and the purchaser in the placing of individualorders.13.2 The conduc
46、tors shall be protected against damage inordinary handling and shipping. If heavy wood lagging isrequired, it shall be specified by the purchaser at the time of thepurchase.13.3 The net mass, length (or lengths, and number oflengths, if more than one length is included in the package),size, grade of
47、 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 required by thepurchaser shall app
48、ear on the outside of each package.TABLE 3 Standard Increments Due to StrandingType of ConductorIncrement (Increase) of Resistanceand Mass, %3 Wire 0.87 Wire 1.019 Wire 1.4B228 11314. Keywords14.1 clad steel electrical conductor; concentric-lay-strandedcopper-clad steel electrical conductor; copper-
49、clad steel elec-trical conductor; copper electrical conductorcopper-cladsteel; copper electrical conductorstranded; electricalconductorASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical co
