1、Designation: D 3353 04An American National StandardStandard Test Methods forFibrous-Insulated Magnet Wire1This standard is issued under the fixed designation D 3353; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover the testing of fibrous-insulatedelectrical conductors, commonly referred to as magnet wire,which
3、are used in electrical apparatus. 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 m
4、agnet wires thatare fiber-covered and in which the substrate is bare conductoror is coated with an underlying insulating film as covered byTest Methods D 1676. Fiber-covered wires are produced byserving helically or wrapping fibers or fibrous-tape insulationuniformly around the wire in single and mu
5、ltiple layers. Theserved or wrapped materials are bonded or not bonded to theunderlying wire.1.2 The values stated in inch-pound units are the standard.The SI equivalents of inch-pound units are provided forreference.1.3 The test methods appear in the following sections:Procedure SectionMeasurement
6、of Dimensions 7Electrical Resistance of Conductors 5Elongation 4Adhesion and Flexibility 8Fibrous Coverage 6Dielectric Breakdown Voltage 91.4 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
7、establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.See 8.4.1 and 9.4.1for specific caution statements.1.5 This standard and IEC 60851 are similar if not equiva-lent in technical content.1.6 This standard and NEMA, MW 1000 are si
8、milar if notequivalent in technical content.2. Referenced Documents2.1 ASTM Standards:2B 193 Test Method for Resistivity of Electrical ConductorMaterialsD 149 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating Materialsat Commercial Power FrequenciesD
9、1676 Test Methods for Film-Insulated Magnet WireD 1711 Terminology Relating to Electrical InsulationD 5423 Specification for ForcedConvection LaboratoryOvens for Evaluation of Electrical InsulationE 8 Test Methods for Tension Testing of Metallic Materials2.2 Other Standards:IEC 60851 Methods of Test
10、 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 D 1711.3.1.2 Definition of Term(s) Specific to this Standard:3.1.2.1 servinga uniform wrapping of fibrous insulationaroun
11、d 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 coverage.4. Elongation4.1 ScopeThis test method covers t
12、he determination ofthe elongation of fibrous insulated magnet wire that results ina fracture of the conductor.1These test methods are under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and are the direct responsibility ofSubcommittee D09.10 on Magnet Wire I
13、nsulation.Current edition approved April 1, 2004. Published May 2004. Originallyapproved in 1974. Last previous edition approved in 1998 as D 3353 98.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStand
14、ards 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 Electrical Manufacturers Association (NEMA), 1300N. 17th St., Suite 1847, R
15、osslyn, VA 22209.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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 whi
16、ch it hasbeen subjected during the insulating operation.4.3 ApparatusThe equipment shall 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
17、be such that the error of the length measurement willbe 1 % or less. Suitable, non-slip 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 E 8 for a discussion of machines, grippingdev
18、ices, and rates of stressing.4.4 Procedure:4.4.1 Remove the fibrous insulation without distorting theconductor for wire sizes 0.0253 in. (0.6426 mm) (AWG 22)and finer. The insulation need not be removed from sizes largerthan 0.0253 in.4.4.2 Standard Method: Insert the test specimen into thegrips res
19、ulting in an original length of 10 6 0.1 in. (254 6 2.5mm) being 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 thatbre
20、ak within14 in. (6 mm) of the grips. When breaks occurfrequently in this manner, a need for modification of theequipment or technique is indicated.4.4.3 Bench Mark Method: Rectangular, square, and roundwire larger than 0.0651 in. (1.654 mm) in diameter can betested using bench marks. Measure the ori
21、ginal length betweenbench marks to ensure the distance between the bench marks is10 6 0.1 in. (254 6 2.5 mm). 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
22、 (305 6 25 mm/min) untilthe conductor breaks. Match the broken ends of the specimen,place together, and measure 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. Disca
23、rd the results for any specimensthat break within14 in. (6 mm) of the grips or the bench marks.When breaks 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 3 100 (1)where:A =
24、 length at break, andB = original length4.6 Report the following 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
25、 or not bench marks are used, and4.6.9 Individual and average 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 can be presented on the bias of
26、 thisprocedure in Section 4, for measuring the percent elongation,as no material having an accepted reference value is available.5. Electrical Resistance of Conductors5.1 ScopeThis test method covers the determination ofthe electrical resistance of fibrous insulated magnet wireconductors.5.2 Signifi
27、cance and UseAccurate control of resistance isnecessary to 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 App
28、aratusThe types of apparatus utilized for measur-ing resistance and length are specified in Test Method B 193.5.4 ProcedureRemove the insulation on both ends of thetest specimen for electrical contact. The cleaning operationmust not affect the conductor dimensions. Determine theelectrical resistance
29、 of the test specimen.NOTE 2While balancing the bridge, care 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 conducto
30、r dimensions,5.5.2 Bare conductor material,5.5.3 Type and build 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 Resis
31、tance ohms per unit length corrected to 20C(68F).5.6 Precision and Bias5.6.1 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 can be presented on the bias of thisprocedure in Section
32、 5, for measuring the electrical resistanceof the conductor, as no material having an accepted referencevalue is available.6. Fibrous Coverage6.1 ScopeThis test method covers the determination ofthe quality of fibrous servings on round magnet wire or bareconductor.6.2 Significance and UseThe results
33、 of this test areindicative of the quality of the fibrous servings applied to theD3353042wire. 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 whilema
34、intaining suitable wire tension.6.3.2 Mandrels, to be specified.NOTE 3Commercially, it is normally 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 Procedure:6.4.1 Wind the
35、 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.6.4.2 Examine the test specimen for exposed bare conductoror unde
36、rlying film with normal vision.6.5 Report the following information: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
37、 that does notexpose the bare conductor or underlying film.6.6 Precision and Bias6.6.1 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 det
38、ermine the dimensions of thebare or film insulated conductor 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
39、 wires where compressibility is a factoras in stranded or litz 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 ins
40、ulation addition to the dimensionsare necessary for specification 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 fo
41、r measuring the dimensionsof bare conductor and fibrousinsulated 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 s
42、izes larger than 0.0651 in.(1.654 mm) and for all rectangular 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 f
43、or measuring the bare or filminsulated conductor diameter.NOTE 5Spindle pressures specified above have been establishedbased on 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 Specimen
44、s:7.4.1 When using the micrometer technique, the test speci-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
45、When measuring the diameter using the tapered man-drel technique, the specimen shall be of sufficient length towind a minimum of 25 turns on the tapered mandrel and shallFIG. 1 Tapered MandrelD3353043be free of kinks or other obvious defects. Carefully remove thespecimens from the spool to avoid dam
46、aging or stretching.7.5 Procedure:7.5.1 For round wire, using a micrometer, measure theoverall 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 techniqu
47、e,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 o
48、f 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
49、 to insure that the measurement will be taken on thesame sides on both the insulated wire and bare conductor. Theaverage of the three thicknesses and width measurements shallbe the overall thickness or width, or both.7.5.4 Remove the fibrous insulation without distorting theconductor and measure the diameter or thickness and width asin 7.5.1 or 7.5.3. In the case of stranded or litz wire it isdesirable to measure the conductor diameter as described in7.5.2.7.5.5 When an insulating film underlies the fibrous insula-tion, remove it by chemical mean
