1、Designation: D4880 14D4880 18Standard Test Method forSalt Water Proofness of Insulating Varnishes OverEnamelled Magnet Wire1This standard is issued under the fixed designation D4880; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、the year 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.1. Scope*1.1 This test method covers the electrical performance in a specified water solution of an insulating varnish
3、 applied overenamelled magnet wire.1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversionsto inch-pound units that are provided for information only and are not considered standard.1.3 This standard does not purport to address al
4、l of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use. Specific precautionary statements a
5、re given in Section 6.NOTE 1There is no IEC method equivalent to this standard.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and
6、 Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1676 Test Methods for Film-Insulated Magnet WireD1711 Terminology Relating to Electrical Insulation3. Terminology3.1 Definitions:3.1.1 For definitions of ter
7、ms used in this test method refer to Terminology D1711.3.1.2 varnish, electrical insulating, n a liquid resin system that is applied to and cured on electrical components providingelectrical, mechanical, and environmental protection.3.1.2.1 DiscussionThere are two types of electrical insulating varn
8、ish solventcontaining and solventless. The solvent-containing varnish issolution, dispersion, or emulsion of a polymer or a mixture of polymers in a volatile, nonreactable liquid. The solventless type isa liquid resin system free of volatile, nonreactable solvents.3.1.3 varnished, adjreferring to an
9、y item on to which varnish has been applied and cured.4. Significance and Use4.1 This test method is useful in determining the performance of varnishes over enamelled magnet wire when subjected to thespecified sodium chloride solution. It is useful in evaluating the resistance of varnished magnet wi
10、re to a diluted sodium chloridesolution under applied voltage.1 This test method is under the jurisdiction of ASTM Committee D09 on Electrical and Electronic Insulating Materials and is the direct responsibility of SubcommitteeD09.01 on Electrical Insulating Varnishes, Powders and Encapsulating Comp
11、oundsProducts.Current edition approved May 15, 2014Nov. 1, 2018. Published May 2014November 2018. Originally approved in 1988. Last previous edition approved in 20082014 asD4880 08.D4880 14. DOI: 10.1520/D4880-14.10.1520/D4880-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, o
12、r contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes ha
13、ve been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official do
14、cument.*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 States15. Apparatus5.1 Description of Electrical Apparatus :5.1.1 The apparatus shall contain devices for limiting or int
15、errupting the current to each specimen whenever a failure occurs.In particular, 7.5 W light bulbs or 110 A fuses have been used. Lighting of the bulb or “blowing” of the fuse indicates failure.5.1.2 The power supply shall provide a source of filtered 120 6 2 V dc which drops by less than 2 V when a
16、current of 0.5A is drawn.5.1.3 A positive polarity of 120 V dc is applied to the specimens. The surrounding sodium chloride solution is at groundpotential. The ground connection, using an immersed electrode, is made using Nichrome, stainless steel, or other non-corrosivewire. Do not use iron, carbon
17、 steel, copper, or brass (see Fig. 1Figs. 1 and 2).5.2 An appropriate container shall be selected for the sodium chloride solution. Fit it with a cover to prevent evaporation of thesolution.6. Safety Precautions6.1 Do not use varnish at temperatures above the flash point when inadequate ventilation,
18、 and possibility of flames or sparksexist. Store varnish in sealed containers. These precautions shall also apply to the handling of the reagents and solvents called forin this test method.6.2 WarningLethal voltages are a potential hazard during the performance of this test. It is essential that the
19、 test apparatus,and all associated equipment electrically connected to it, be properly designed and installed for safe operation. Solidly ground allelectrically conductive parts which it is possible for a person to contact during the test. Provide means for use at the completionof any test to ground
20、 any parts which were at high voltage during the test or have the potential for acquiring an induced chargeduring the test or retaining a charge even after disconnection of the voltage source. Thoroughly instruct all operators as to thecorrect procedures for performing tests safely. When making high
21、 voltage tests, particularly in compressed gas or in oil, it ispossible for the energy released at breakdown to be sufficient to result in fire, explosion, or rupture of the test chamber. Designtest equipment, test chambers, and test specimens so as to minimize the possibility of such occurrences an
22、d to eliminate thepossibility of personal injury. If the potential for fire exists, have fire suppression equipment available.7. Test Specimens Preparation7.1 Selection of Enamelled Magnet Wire The type of enamelled magnet wire used for this test shall be agreed upon betweeninterested parties. Seven
23、 When tested in accordance with Section 8, seven of the nine unvarnished test specimens shall fail withinthe specified test time.7.2 Twist a section of 1.02-mm (0.0403-in.) (18-AWG) enamelled magnet wire with the appropriate number of twists andtension as described in Test Methods D1676 (see Fig. 23
24、). Note however, that one end of the specimen is a continuous loop insteadof two loose ends.7.3 Prepare 18 specimens in the manner described in 7.2.7.4 Dipping:7.4.1 Adjust the consistency of the solvent-containing varnish to give a 0.025 6 0.005-mm (0.0010 6 0.0002-in.) cured filmon each side of a
25、0.13-mm (.005-in.) copper strip withdrawn at a rate of approximately 100 mm/min (4 in./min). Use solventlessvarnish as received.FIG. 1 Typical Test ApparatusD4880 1827.4.2 Dip nine twisted specimens in the varnish to be tested. After the specimens are submerged in the varnish, withdraw themat a rate
26、 of approximately 100 mm/min (4 in./min). Drain the specimens for a minimum of 10 min. Cure according to themanufacturers specifications. Dip the specimens again in the reverse direction if a solvent-containing varnish was used. Whentesting solventless varnishes, dip test specimens only once.8. Proc
27、edure8.1 Perform the following for nine unvarnished specimens and nine varnished specimens.8.2 Remove the enamel from the loose ends of the twisted specimens. Use these legs to make the electrical connections.8.3 For each test, prepare a solution of distilled water and sodium chloride in which the s
28、odium chloride is at a concentrationof 3.5 6 0.1 % by weight.8.4 Set up the appropriate circuit as outlined in Section 5. Connect the specimen to the electrical circuit. Then submerge thespecimens so that approximately 76 mm (3 in.) of the twisted sections of the specimens are submerged in the sodiu
29、m chloridesolution.8.5 Apply 120 6 5 V dc between the specimen and the sodium chloride solution.8.6 Check for failures daily or more often if possible and then record the total elapsed time from the application of the testvoltage to when failures are detected. The length of time of the test is 100 h
30、 unless otherwise agreed upon between the user andthe manufacturer.8.7 ifIf seven of the nine unvarnished test specimens do not fail within the test time, repeat the test with a different enamelledmagnet wire as specified in 7.1.9. Report9.1 Report the following information:9.1.1 Identification of t
31、he varnish used,9.1.2 Identification and film build of the magnet wire used,FIG. 2 Test SpecimenTypical Setup Without Salt Water BathFIG. 3 Test SpecimenD4880 1839.1.3 The number of unvarnished specimens failed at the end of the test time and the elapsed time when each failure wasdetected,9.1.4 The
32、number of unvarnished specimens that did not fail at the end of the test time,9.1.5 The number of varnished specimens that failed at the end of the test time and the elapsed time when each failure wasdetected, and9.1.6 The number of varnished specimens that did not fail at the end of the test time.1
33、0. Precision and Bias10.1 PrecisionThis test method has been in use for many years, but no statement of precision has been made and no activityis planned to develop such a statement.10.2 BiasThis test method has no bias because the value for salt water proofness is defined in terms of this method.11
34、. Keywords11.1 electrical insulating ; enamelled wire; magnet wire; salt water; varnishSUMMARY OF CHANGESCommittee D09 has identified the location of selected changes to this test method standard since the last issue,issue (D4880 08D4880 14,) that may impact the use of this test method. standard. (A
35、pproved May 1,2014Nov. 1, 2018).)(1) Added new Fig. 2 and renumbered subsequent figure.(2) Revised Fig. 3 (previously Fig. 2).(3) Revised 5.1.3, 7.1, and 8.7.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standa
36、rd. 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 committee and must be reviewe
37、d every five years andif not revised, either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible t
38、echnical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consho
39、hocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 184
