1、Designation: B228 11a (Reapproved 2016)Standard 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 yea
2、r 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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This specification covers b
3、are concentric-lay-strandedconductors 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, Grade 30EHS, Grade 40 DSA, and Grade 30 DSA.The grades covered by this s
4、pecification correspond to thefollowing commercial designations:Grade 40 HS, High Strength, 40% Conductivity, Hard DrawnGrade 30 HS, High Strength, 30% Conductivity, Hard DrawnGrade 30 EHS, Extra High Strength, 30% Conductivity, Hard DrawnGrade 40 DSA, 40% Conductivity, Dead Soft AnnealedGrade 30 DS
5、A, 30% Conductivity, Dead Soft Annealed1.3 The values stated in inch-pound units are to be regardedas standard. The values 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
6、all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish 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 iss
7、ue in effect on thedate of material purchase form a part of this specification to theextent referenced herein:2.2 ASTM Standards:2B227 Specification for Hard-Drawn Copper-Clad Steel WireB354 Terminology Relating to Uninsulated Metallic Electri-cal ConductorsE29 Practice for Using Significant Digits
8、in Test Data toDetermine Conformance with SpecificationsB910/B910M Specification for Annealed Copper-Clad SteelWire2.3 ANSI Standards:C42Definitions of Electrical Terms32.4 National Institute of Standards and Technology:NBS Handbook 100Copper Wire Tables43. Ordering Information3.1 Orders for materia
9、l 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);3.1.4 Direction of lay of out
10、er 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, Supplementary Requireme
11、nts 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 Before stranding, the copper
12、-clad steel wire shall meetall the requirements of Specification B227 for Grade 40 HS,Grade 30 HS and Grade 30 EHS and the requirements ofSpecification B910/B910M for Grade 40 DSA and Grade 30DSA.1This specification is under the jurisdiction of ASTM Committee B01 onElectrical Conductors and is the d
13、irect responsibility of Subcommittee B01.06 onBi-Metallic Conductors.Current edition approved April 1, 2016. Published April 2016. Originallyapproved in 1948. Last previous edition approved in 2011 as B228 11a. DOI:10.1520/B0228-11AR16.2For referenced ASTM standards, visit the ASTM website, www.astm
14、.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, NY 10036, http:/www.ansi.or
15、g.4Available from National Institute of Standards and Technology (NIST), 100Bureau 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 States14.3 All wires in the conductor shall be
16、 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, using more than three wires provided that suchjoints or splices have a protection equivalent to that of the wireitself and that they
17、 do not decrease the strength of the finishedstranded conductor below the minimum breaking strengthshown in Table 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
18、 in theirfinished size are made by electrical butt welding. Two types of joints areused and are described as 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
19、one of two approaches:1. A snug fitting seamless copper sleeve which extends at least38 in.(9.5 mm) on each side of the weld and which is thoroughly sealed to thewire with solder. The wall thickness of the sleeve is at least 10 % of theradius of the wire.2. Protect the weld from corrosion and ensure
20、 acceptable conductivitythrough the use of a silver solder that extends at least 3/8 in. (9.5 mm) oneach side of the weld.This type of joint is applicable for 7, 12, and 19 wire strandedconfigurations. When joints made on annealed individual wires, thecompleted stranded conductor is required to have
21、 the full rated strength.For hard drawn material, this joint has a tensile strength of approximately60 000 psi (415 MPa). This is less than the strength of the individualwires, but an allowance is made for this in the rated strength of theconductor as a whole. The completed conductor when containing
22、 suchjoints is required to have the full rated strength. Other protection methodsmay also be used as agreed upon between the purchaser and manufacturer.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 Join
23、tsCompression-weld joints 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 a
24、s to completely seal the 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. ThisTABLE 1 Construction Requirements and Breaking Strength
25、 of Concentric-Lay-Stranded Copper-Clad Steel ConductorsNOTE 1Metric EquivalentsFor diameter, 1 in. = 25.40 mm (round to four significant figures); for breaking strength, 1 lb = 0.45359 kg (round tofour significant figures).Size DesignationConductorDiameter,in.ARated Breaking Strength, min, lbBInchC
26、AWGDGrade 40HSGrade 30HSGrade 30EHSGrade 40DSAGrade 30DSA78 19 No. 5 0.910 48 740 53 910 64 910 17 250 19 4101316 19 No. 6 0.810 40 370 44 470 53 880 13 680 15 3902332 19 No. 7 0.721 33 360 36 610 44 480 10 850 12 2002132 19 No. 8 0.642 27 550 30 140 36 590 8610 9686916 19 No. 9 0.572 22 690 24 730
27、29 700 6823 767658 7 No. 4 0.613 21 630 24 040 28 540 8012 9014916 7 No. 5 0.546 17 960 19 860 23 910 6356 715012 7 No. 6 0.486 14 870 16 390 19 850 5041 5672716 7 No. 7 0.433 12 290 13 490 16 390 3996 449638 7 No. 8 0.385 10 150 11 100 13 480 3172 35691132 7 No. 9 0.343 8359 9113 10 940 2514 282851
28、6 7 No. 10 0.306 6913 7531 8928 1995 2244. . . 3 No. 5 0.392 8122 8985 10 820 2875 3235. . . 3 No. 6 0.349 6728 7412 8980 2281 2566. . . 3 No. 7 0.311 5559 6102 7413 1808 2034. . . 3 No. 8 0.277 4592 5023 6099 1435 1614. . . 3 No. 9 0.247 3781 4122 4950 1137 1279. . . 3 No. 10 0.220 3127 3407 4039 9
29、03 1015. . . 3 No. 12 0.174 1647 1719 2564 573 645ADiameter 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 of t
30、he 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 wires e
31、ach 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 11a (2016)2joint develops th
32、e full strength of the wire.6. Lay6.1 For 3-wire conductors the 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 sh
33、all not be lessthan 10 nor more than 16 times this diameter.6.3 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 natura
34、lly in their truepositions in the completed conductor. They shall 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.7. Construction7.1 The numbers and diameters of the wires in theconcentric-
35、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 Electrical Tests8.1 Tests for physical and electrical pr
36、operties 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 may be tested as a unit. The breaking strength of the
37、conductors 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 (4540 kg) or less, two samples shall be taken from sepa
38、ratereels 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 minimumnumber of samples shall be three.8.4 Specimens of
39、 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 obviously caused by impropersocketing of the specimen,
40、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, and so forth, the density of thecopper-clad steel wire
41、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 been found to be in accordance with usual values enco
42、unteredin 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 electrical resistance may be determinedusing the standard
43、 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 (k) in percent isk 5 100m 2 1!where m is the strandin
44、g 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 parallel to the conductor axis.The stranding factor
45、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) for any given wire ina concentric-lay-stranded cond
46、uctor ismind5 =119.8696/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 97 % of the area specified. The area ofcross section o
47、f 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). For the purpose of determining conformance to thisstandard, a measured or calculated value for cross sectionalarea shall be
48、 rounded to four significant figures in accordancewith the rounding method of Practice E29.NOTE 6For the convenience of the users of this specification, Table 4has been prepared giving areas, resistances per 1000 ft, and mass per 1000ft, and per mile, of the various constructions referred to in Tabl
49、e 1.12. 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.TABLE 3 Standard Increments Due to StrandingType of ConductorIncrement (Increase) of Resistanceand Mass, %3 Wire 0.87 Wire 1.019 Wire 1.4B228 11a (2016)312.2 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
