1、Designation: D3353 10Standard 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 and health practices and determine the app
8、lica-bility of regulatory limitations prior to use.See 8.4.1 and 9.4.1for specific caution statements.2. Referenced Documents2.1 ASTM Standards:2B193 Test Method for Resistivity of Electrical ConductorMaterialsD149 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electric
9、al 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 Methods for Tension Testing of Metallic
10、 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 Term(s) Specific to this Standard:3.1.2.
11、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 bewound around mandrels in a prescribed manner withoutcausing observable openings in the fibrous co
12、verage.4. Elongation4.1 ScopeThis test method covers the determination of theelongation of fibrous insulated magnet wire that results in afracture of the conductor.1These test methods are under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and are the direct
13、 responsibility ofSubcommittee D09.12 on Electrical Tests.Current edition approved Jan. 1, 2010. Published February 2010. Originallyapproved in 1974. Last previous edition approved in 2004 as D335304. DOI:10.1520/D3353-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontac
14、t 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 West RandolphStreet, Suite 600, Chicago IL 606612208.4Available from National Ele
15、ctrical 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 Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis internat
16、ional 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 issued by the World Trade Organization Technical Barriers to Trade (TBT) Commit
17、tee.14.2 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 shall have a minimum sepa-ration sufficient
18、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 grips are required that willnot damage
19、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 distorting theconductor for wire sizes 0.
20、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 stretched. Elongate the wire at a consta
21、nt 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 in this manner, a need for modification
22、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 can betested using bench marks. Measure the original length betweenbench marks to ensure the distance between the bench marks is10 6 0.1 in. (254 6 2.5 m
23、m). Insert the wire specimen into thegrips and locate the bench marks centrally and not more than12 in. (12.7 mm) from either grip. Elongate the wire specimenat a constant rate of 12 6 1 in./min (305 6 25 mm/min) untilthe conductor breaks. Match the broken ends of the specimen,place together, and me
24、asure the final length to the nearest 0.1in. at break between the bench marks. In order to minimize theeffect of local variations in the wire under test, test threespecimens of the sample. Discard the results for any specimensthat break within14 in. (6 mm) of the grips or the bench marks.When breaks
25、 occur frequently in this manner, a need formodification of the equipment or technique is indicated.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 Following Information:4.6.1 Bare conductor dimensio
26、ns,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 average elongation.4.7 Precision and Bias:4.7.1 This
27、 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 can be presented on the bias of thisprocedure in Section 4, for measuring the percent elongation,as no material having an accepted refere
28、nce 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 meet apparatus design parameters. Resistance
29、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 resistance and length are specified in Test Method
30、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, care must be taken to preventexcessive heating of
31、 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 build of film insulation,5.5.4 Type of fibrous-
32、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 Precision and Bias:5.6.1 This test method has been i
33、n 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 can be presented on the bias of thisprocedure in Section 5, for measuring the electrical resistanceof the conductor, as no material having an accepted reference
34、value is available.D3353 1026. 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 fibrous servings applied to thewire. High qua
35、lity 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 specified.6.4 Procedure:6.4.1 Wind the wire, with
36、 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 specified that the bare conductoror under
37、lying 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 Information:6.5.1 Bare conductor dimensions,6.5
38、.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.6.6 Precision and Bias:6.6.1 No information
39、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 and the fibrousinsulatedmagnet wire.7.1.1
40、.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 litz wire, or where the insulating material
41、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 specification and use purposes. Bare conduc-tor di
42、mensions 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 fibrousinsulated wire shall consist ofaccurate hand or
43、 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 rectangular and square wire sizes, themicrometer spi
44、ndle 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.NOTE 5Spindle pressures specified above have
45、 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).FIG. 1 Tapered MandrelD3353 1037.4 Specimens:7.4.1 When using the micrometer technique, the test speci-mens shall
46、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 technique, the s
47、pecimen 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 theoverall diamet
48、er 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 indic
49、ated 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 vernier caliper and dividethis distance by the number of turns along the mandrel. Thequotient is the average overall diameter of the wire.7.5.3 For rectangular wire, measure the overall thicknessand width for each of three specimens. On square wire, markone side to insure that the measurement will be taken on thesa
