1、Designation: D3353 18Standard Test Methods forFibrous-Insulated Magnet Wire1This standard is issued under the fixed designation D3353; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parenthes
2、es indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 These test methods cover the testing of fibrous-insulatedelectrical conductors, commonly referred to as magnet wire,which are used in electrical apparatu
3、s. The test methods areintended primarily for evaluation of the electrical insulatingmaterials used. It is intended that these test methods be used,except where modified by individual specifications for particu-lar applications.1.1.1 These test methods apply to those magnet wires thatare fiber-cover
4、ed and in which the substrate is bare conductoror is coated with an underlying insulating film as covered byTest Methods D1676. Fiber-covered wires are produced byserving helically or wrapping fibers or fibrous-tape insulationuniformly around the wire in single and multiple layers. Theserved or wrap
5、ped materials are bonded or not bonded to theunderlying wire.1.2 The test methods appear in the following sections:Procedure SectionMeasurement of Dimensions 7Electrical Resistance of Conductors 5Elongation 4Adhesion and Flexibility 8Fibrous Coverage 6Dielectric Breakdown Voltage 91.3 This standard
6、and IEC 60851 are similar if not equiva-lent in technical content.1.4 This standard and NEMA MW 1000 are similar if notequivalent in technical content.1.5 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that
7、 are provided for information onlyand are not considered standard.1.6 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 establish appro-priate safety, health, and environmental practices and d
8、eter-mine the applicability of regulatory limitations prior to use.See 8.4.1 and 9.4.1 for specific caution statements.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopm
9、ent of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2B193 Test Method for Resistivity of Electrical ConductorMaterialsD149 Test Method for Dielectric Breakdown Voltage
10、andDielectric Strength of Solid Electrical Insulating Materialsat Commercial Power FrequenciesD1676 Test Methods for Film-Insulated Magnet WireD1711 Terminology Relating to Electrical InsulationD5423 Specification for Forced-Convection Laboratory Ov-ens for Evaluation of Electrical InsulationE8 Test
11、 Methods for Tension Testing of Metallic Materials2.2 Other Standards:IEC 60851 Methods of Test for Winding Wires3NEMA Standards Publication No. MW 1000 on MagnetWire43. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method, referto Terminology D1711.3.1.2 Definition of
12、Term(s) Specific to this Standard:3.1.2.1 servinga uniform wrapping of fibrous insulationaround a magnet wire of bare conductor.3.1.2.2 fibrous coverage, of served-magnet wirethat char-acteristic which allows a fibrous served magnet wire to be1These test methods are under the jurisdiction of ASTM Co
13、mmittee D09 onElectrical and Electronic Insulating Materials and are the direct responsibility ofSubcommittee D09.12 on Electrical Tests.Current edition approved March 15, 2018. Published March 2018. Originallyapproved in 1974. Last previous edition approved in 2010 as D3353 10. DOI:10.1520/D3353-18
14、.2For referenced ASTM standards, 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 International Engineering Consortium, 549 We
15、st RandolphStreet, Suite 600, Chicago IL 606612208.4Available from National Electrical Manufacturers Association (NEMA), 1300N. 17th St., Suite 1752, Rosslyn, VA 22209, http:/www.nema.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor D
16、rive, 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 Standards, Guides and Recommendations
17、issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1wound around mandrels in a prescribed manner withoutcausing observable openings in the fibrous coverage.4. Elongation4.1 ScopeThis test method covers the determination of theelongation of fibrous insulated magnet wir
18、e that results in afracture of the conductor.4.2 Significance and UseThe elongation determined bythis test method provides a general measure of the ductility ofthe conductor and the effect of the processing to which it hasbeen subjected during the insulating operation.4.3 ApparatusThe equipment shal
19、l have a minimum sepa-ration sufficient to attach and measure the length of the testspecimen between grips, and be capable of elongating thespecimen to its breaking point, at a constant rate. The equip-ment shall be such that the error of the length measurement willbe 1 % or less. Suitable, non-slip
20、 grips are required that willnot damage the specimen in the region of elongation. Drum orcapstan type grips have been found to be unsatisfactory.NOTE 1See Test Methods E8 for a discussion of machines, grippingdevices, and rates of stressing.4.4 Procedure:4.4.1 Remove the fibrous insulation without d
21、istorting theconductor for wire sizes 0.0253 in. (0.6426 mm) (AWG 22)and finer. Do not remove the fibrous insulation from sizeslarger than 0.0253 in (0.6426 mm) (AWG 22).4.4.2 Standard Method: Insert the test specimen into thegrips resulting in an original length of 10 6 0.1 in. (254 6 2.5mm) to be
22、stretched. Elongate the wire at a constant rate of 126 1 in./min (305 6 25 mm/min) until the conductor breaks.Determine the length at break by measuring the final distancebetween the grips. Discard the results for any specimens thatbreak within14 in. (6 mm) of the grips. When breaks occurfrequently
23、in this manner, a need for modification of theequipment or technique is indicated.4.4.3 Bench Mark Method: Rectangular, square, or roundwire larger than 0.0651 in. (1.654 mm) in diameter is allowedto be tested using bench marks. Measure the original lengthbetween bench marks to ensure the distance b
24、etween the benchmarks is 10 6 0.1 in. (254 6 2.5 mm). Insert the wire specimeninto the grips and locate the bench marks centrally and notmore than12 in. (12.7 mm) from either grip. Elongate the wirespecimen at a constant rate of 12 6 1 in./min (305 6 25mm/min) until the conductor breaks. Match the b
25、roken ends ofthe specimen, place together, and measure the final length tothe nearest 0.1 in. at break between the bench marks. In orderto minimize the effect of local variations in the wire under test,test three specimens of the sample. Discard the results for anyspecimens that break within14 in. (
26、6 mm) of the grips or thebench marks. When breaks occur frequently in this manner, aneed for modification of the equipment or technique is indi-cated.4.5 CalculationCalculate the elongation as follows:Elongation, % 5 A 2 B!/B# 3100 (1)where:A = length at break, andB = original length4.6 Report the F
27、ollowing Information:4.6.1 Bare conductor dimensions,4.6.2 Bare conductor material,4.6.3 Type and build of film insulation,4.6.4 Type of fibrous-insulation,4.6.5 Number of servings,4.6.6 Direction of servings,4.6.7 Type of varnish,4.6.8 Whether or not bench marks are used, and4.6.9 Individual and av
28、erage elongation.4.7 Precision and Bias:4.7.1 This test method has been in use for many years, butno statement of precision has been made and no activity isplanned to develop such a statement.4.7.2 No information is presented on the bias of thisprocedure in Section 4, for measuring the percent elong
29、ation,as no material having an accepted reference value is available.5. Electrical Resistance of Conductors5.1 ScopeThis test method covers the determination of theelectrical resistance of fibrous insulated magnet wire conduc-tors.5.2 Significance and UseAccurate control of resistance isnecessary to
30、 meet apparatus design parameters. Resistance isexpressed in terms of ohms per unit length corrected to 20C(68F) and is a function of conductor dimensions, resistivity,and temperature. Resistance is affected by the processingoperation.5.3 ApparatusThe types of apparatus utilized for measur-ing resis
31、tance and length are specified in Test Method B193.5.4 ProcedureRemove the insulation on both ends of thetest specimen for electrical contact. The cleaning operationmust not affect the conductor dimensions. Determine theelectrical resistance of the test specimen.NOTE 2While balancing the bridge, car
32、e must be taken to preventexcessive heating of the specimen as a result of prolonged current, and toavoid changes in temperature due to air drafts or to variations in ambientconditions.5.5 Report the Following Information:5.5.1 Bare conductor dimensions,5.5.2 Bare conductor material,5.5.3 Type and b
33、uild of film insulation,5.5.4 Type of fibrous-insulation,5.5.5 Number of servings,5.5.6 Direction of servings,5.5.7 Type of varnish,5.5.8 Test temperature,5.5.9 Specimen length,5.5.10 Apparatus used,5.5.11 Resistance reading, and5.5.12 Resistance ohms per unit length corrected to 20C(68F).5.6 Precis
34、ion and Bias:D3353 1825.6.1 This test method has been in use for many years, butno statement of precision has been made and no activity isplanned to develop such a statement.5.6.2 No information is presented on the bias of thisprocedure in Section 5, for measuring the electrical resistanceof the con
35、ductor, as no material having an accepted referencevalue is available.6. Fibrous Coverage6.1 ScopeThis test method covers the determination of thequality of fibrous servings on round magnet wire or bareconductor.6.2 Significance and UseThe results of this test areindicative of the quality of the fib
36、rous servings applied to thewire. High quality serving is required since it will permit thewire to be stressed by bending without exposing the conductoror underlying film.6.3 Apparatus:6.3.1 Means for chucking and rotating mandrels whilemaintaining suitable wire tension.6.3.2 Mandrels, to be specifi
37、ed.6.4 Procedure:6.4.1 Wind the wire, with only sufficient tension to form itaround a mandrel of a diameter to be specified, withouttwisting or stretching and at a speed not to exceed 40 rpm. Tenturns closely spaced along the mandrel shall constitute a testspecimen.NOTE 3Commercially, it is normally
38、 specified that the bare conductoror underlying film is not exposed when the specimen is wound around amandrel having a diameter ten times the diameter of the bare conductor.6.4.2 Examine the test specimen for exposed bare conductoror underlying film with normal vision.6.5 Report the Following Infor
39、mation:6.5.1 Bare conductor dimensions,6.5.2 Bare conductor material,6.5.3 Type and build of film insulation,6.5.4 Type of fibrous-insulation,6.5.5 Number of servings,6.5.6 Direction of servings, and6.5.7 List the smallest mandrel diameter that does notexpose the bare conductor or underlying film.6.
40、6 Precision and Bias:6.6.1 No information is presented about either the precisionor bias of Section 6 for evaluating fibrous coverage since thetest result is nonquantitative.7. Measurement of Dimensions7.1 Scope:7.1.1 These test methods determine the dimensions of thebare or film insulated conductor
41、 and the fibrousinsulatedmagnet wire.7.1.1.1 The micrometer technique is applicable to wireswhere compressibility of the conductor or insulation is not afactor.7.1.1.2 The tapered mandrel technique is suitable for mea-suring the diameter of wires where compressibility is a factoras in stranded or li
42、tz wire, or where the insulating material isreadily distorted as in the case of some organic fibers.7.2 Significance and UseKnowledge of the dimensions ofthe bare conductor, overall dimensions of fibrousinsulatedmagnet wire, and average insulation addition to the dimensionsare necessary for specific
43、ation and use purposes. Bare conduc-tor dimensions are one of the basic parameters used in thedesign of electrical machinery and the breakdown voltage isrelated to the thickness of the insulation.7.3 Apparatus:7.3.1 Micrometer, apparatus for measuring the dimensionsof bare conductor and fibrousinsul
44、ated wire shall consist ofaccurate hand or bench micrometers. The micrometer spindleloading shall not be greater than 8 oz/14-in. diameter anvil (225g/6.36-mm diameter anvil) for 0.0651 in. (1.654 mm) (AWG14) and finer. For all round wire sizes larger than 0.0651 in.(1.654 mm) and for all rectangula
45、r and square wire sizes, themicrometer spindle loading shall be 3 lb 6 1 oz/14-in. diameteranvil (1360 6 28 g/6.36-mm diameter anvil).NOTE 4Other instruments such as electronic micrometers or lightwave micrometers have been found suitable for measuring the bare or filminsulated conductor diameter.NO
46、TE 5Spindle pressures specified above have been established basedon experience with copper.7.3.2 Mandrel, tapered (Fig. 1).7.3.3 Weights, suitable (Table 1).7.3.4 Calipers, precision, with vernier reading to 0.001 in.(0.025 mm).7.4 Specimens:7.4.1 When using the micrometer technique, the test speci-
47、mens shall consist of at least 3 in. (76 mm) straight lengths ofwire free of kinks or obvious defects. Carefully remove thespecimens from the spool or container at 1 ft (0.3 m) intervalswithout more than 1 % stretch for straightening.7.4.2 When measuring the diameter using the tapered man-drel techn
48、ique, the specimen shall be of sufficient length towind a minimum of 25 turns on the tapered mandrel and shallbe free of kinks or other obvious defects. Carefully remove thespecimens from the spool to avoid damaging or stretching.7.5 Procedure:7.5.1 For round wire, using a micrometer, measure theove
49、rall diameter at four places approximately 45 apart aroundthe specimen. The average of the high and low values isconsidered the overall specimen diameter.7.5.2 For round wire, using the tapered mandrel technique,attach one end of the specimen to the small end of the mandrel,pass the wire over a pulley as indicated in Fig. 2 and attach thefree end of the wire to the load specified in Table 1. Closelywind a minimum of 25 turns onto the tapered mandrel at therate of approximately 12 rpm. Measure the length of thewinding along the mandrel with a vernie
