1、Designation:D424521Standard Specification forOzone-Resistant Thermoplastic Elastomer Insulation ForWire and Cable,90 C Dry/75 C Wet Operation1This standard is issued under the fixed designation D4245;the number immediately following the designation indicates the year oforiginal adoption or,in the ca
2、se 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.Scope*1.1 This specification covers an ozone-resistant insulatingcompound for electrical wire and cables
3、14 AWG and larger.This compound consists substantially of a thermoplastic elas-tomer.1.2 This type of insulation is suitable for continuous opera-tion at conductor temperatures not exceeding 90 C in drylocations and 75 C in wet locations.Operating voltages arenot to exceed 2000 V.The minimum install
4、ation temperatureis 40 C.1.3 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.4In many instances the insulation material cannot betested
5、unless it has been formed around a conductor or cable.Therefore,tests are done on insulated wire or cable in thisdocument solely to determine the relevant property of theinsulation material and not to test the conductor or completedcable.1.5 This international standard was developed in accor-dance w
6、ith internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2
7、D470 Test Methods for Crosslinked Insulations and Jacketsfor Wire and CableD1711 Terminology Relating to Electrical InsulationD2633 Test Methods for Thermoplastic Insulations andJackets for Wire and Cable3.Terminology3.1 Definitions:3.1.1 For definitions of terms used in this specification referto T
8、erminology D1711.3.2 Definitions of Terms Specific to This Standard:3.2.1 aging,nexposure of materials to air at 121 C for168 h.4.Physical Properties4.1 Requirements for physical properties are listed in Table1.4.2 Thickness of InsulationTable 1A(Conductor Sizes,Insulation Thicknesses,and AC Test Vo
9、ltages for RubberInsulations)of Test Methods D470 lists the minimum averagethickness for the insulation.The required minimum thicknessis 90%of the specified average thickness.5.Electrical Requirements5.1 Order of TestingPerform the ac voltage withstand test,insulation resistance,and dc voltage withs
10、tand test in that orderwhen any of these tests are specified.The sequence of othertesting is not specified.5.2 AC Voltage Withstand TestUnless otherwise specified,omit this test if the dc voltage withstand test described in 5.4 isto be performed.Test each insulated conductor for 5 min at theac withs
11、tand voltage given in Table 1A(Conductor Sizes,Insulation Thicknesses,and AC Test Voltages for RubberInsulations)of Test Methods D470 under the columns labeled“Ozone-Resisting Insulation.”5.3 Insulation Resistance5.3.1 The insulated conductor shall have an insulationresistance value of at least that
12、 corresponding to a constant of10 000 at 60 F(15.6 C).5.3.2 If the water temperature at the time measurement wasmade differs from 60 F(15.6 C),correct the insulationresistance to 60 F.Table 2,(Temperature Correction Factorsfor Insulation Resistance at 60 F),of Test Methods D470,1This specification i
13、s under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.07 on Electrical Insulating Materials.Current edition approved Jan.1,2021.Published February 2021.Originallyapproved in 1983.Last previous edition appro
14、ved in 2013 as D4245 08(2013).DOI:10.1520/D4245-21.2For 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.*A Summary of C
15、hanges section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,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 Decis
16、ion on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1contains the correction factors.Use the procedure given in TestMethods D470 to determine the 1 F coefficient for theinsulation material.Multiply the measured value by the cor-rection factor to obtain the insulation resistance value correctedto 60 F.5.3.3 If the insulated conductor is covered with a non-metallic sheath so that
