ASTM_D_5637_-_05_2012.pdf

Designation:D563705(Reapproved 2012)Standard Test Method forMoisture Resistance of Electrical Insulating Varnishes1This standard is issued under the fixed designation D5637;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 parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the mechanical performance ofelectrical insulating varnishes subjected to high humidityconditions.1.2 The values stated in SI units are to be regarded asstandard.1.3 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 applica-bility of regulatory limitations prior to use.See 7.1.NOTE1There is not ISO or IEC equivalent.2.Referenced Documents2.1 ASTM Standards:2D2519 Test Method for Bond Strength of Electrical Insulat-ing Varnishes by the Helical Coil Test2.2 IEEE Standard:IEEE 117 Standard Test Procedure for Evaluation of Sys-tems of Insulating Materials for Randon-Wound AC Elec-tric Machinery33.Terminology3.1 See Test Method D2519.4.Summary of Test Method4.1 Flexural strength tests are made on varnish-treatedhelical coils to determine the force required to break the coilunder specified conditions both before and after exposure tohigh humidity conditions.5.Significance and Use5.1 This test method is useful for the evaluation of insulat-ing varnish performance in high humidity exposure.6.Apparatus6.1 Tensile Testing MachineSee Test Method D2519.6.2 Test FixtureSee Test Method D2519.6.3 Exposure ChamberA chamber capable of maintaininga minimum of 100%relative humidity with condensation,at30 6 1C.NOTE2The exposure chamber described in IEEE 117 has been foundsuitable.7.Safety Precautions7.1 It is unsafe to use liquid varnish at temperatures abovethe flash point without adequate ventilation,especially if thepossibility exists that flames or sparks are present.Storevarnish in sealed containers.8.Test Specimens8.1 Prepare a minimum of ten test specimens in accordancewith Test Method D2519 using a wire mutually agreed upon byinterested parties.9.Procedure9.1 Condition half of the test specimens in the exposurechamber maintaining a minimum of 98%relative humidity for336 6 1 h.9.2 Test specimens both conditioned and unconditioned asdescribed in Test Method D2519 at standard laboratory condi-tions.If possible,test conditioned specimens in the exposurechamber.When specimens are not tested in the exposurechamber,they should be removed one at a time from thechamber and tested as soon as possible.The time after removalfrom the chamber and room conditions will possibly affect testresults.Take care to minimize any change in humidity withinthe cabinet during testing.10.Report10.1 Report the following information:10.1.1 Description of varnish,10.1.2 Identification of wire used,1This test method is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.01 on Electrical Insulating Varnishes,Powders and Encapsulat-ing Compounds.Current edition approved Jan.1,2012.Published January 2012.Originallyapproved in 1994.Last previous edition approved in 2005 as D5637 05.DOI:10.1520/D5637-05R12.2For 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 Institute of Electrical and Electronics Engineers,Inc.,3 ParkAvenue,17thFloor,New York,NY 10017.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 10.1.3 Cure time and temperature and number of dips usedto prepare the coils,10.1.4 Average bond strength in newtons(pounds-force)ofunconditioned coils,10.1.5 Average bond strength in newtons(pounds-force)ofconditioned coils,and10.1.6 Percent retention of bond strength after conditioning:Percent retained bond strength5(1)average bond strengthconditioned!average bond strengthunconditioned!310011.Precision and Bias11.1 PrecisionNo information has been presented toASTM upon which to base a statement of precision.Noactivity has been planned to develop such information.11.2 BiasThis test method has no bias because the valuefor moisture resistance is determined solely in terms of this testmethod itself.12.Keywords12.1 bond strength;helical coils;moisture resistance;var-nishASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard.Users of this standard are expressly advised that determination of the validity of any such patent rights,and the riskof infringement of such rig