ASTM_D_877_-_D_877M_-_19.pdf

Designation:D877/D877M19Standard Test Method forDielectric Breakdown Voltage of Insulating Liquids UsingDisk Electrodes1This standard is issued under the fixed designation D877/D877M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method describes two procedures,A and B,fordetermining the electrical breakdown voltage of insulatingliquid specimens.The breakdown test uses ac voltage in thepower-frequency range from 45 to 65 Hz.1.2 This test method is used to determine the electricaldischarge voltage of in-use electrical liquids.It is no longerapplicable to new insulating liquids upon receipt,in which caseTest Method D1816 shall be used.NOTE1It is understood that long-term histories for this test methodexist,but this test method is no longer considered applicable as numerousdeficits exist that affect its usefulness.It is recommended to move all newand in-service electrical discharge voltage testing of electrical insulatingliquids to Test Method D1816.1.3 Limitations of the Procedures:1.3.1 The sensitivity of this test method to the generalpopulation of contaminants present in a liquid sample de-creases as applied test voltages used in this test method becomegreater than approximately 25 kV rms.1.3.2 If the concentration of water in the sample at roomtemperature is less than 60%of saturation,the sensitivity ofthis test method to the presence of water is decreased.Forfurther information refer to RR:D27-1006.21.3.3 The suitability for this test method has not beendetermined for a liquids viscosity higher than 900 cSt at 40C.1.4 Procedure Applications1.4.1 Procedure A:1.4.1.1 Procedure A is used to determine the breakdownvoltage of liquids in which any insoluble breakdown productseasily settle during the interval between the required repeatedbreakdown tests.These liquids include petroleum oils,hydrocarbons,natural and synthetic esters,and askarels(PCB)used as insulating and cooling liquids in transformers,cables,and similar apparatus.1.4.1.2 Procedure A may be used to obtain the dielectricbreakdown of silicone fluid as specified in Test MethodsD2225,provided the discharge energy into the sample is lessthan 20 mJ(milli joule)per breakdown for five consecutivebreakdowns.1.4.2 Procedure B:1.4.2.1 This procedure is used to determine the breakdownvoltage of liquids in which any insoluble breakdown productsdo not completely settle from the space between the disksduring the 1-min interval required in Procedure A.ProcedureB,modified in accordance with Section 17 of Test MethodsD2225,is acceptable for testing silicone dielectric liquids if therequirements of 1.4.1.2 can not be achieved.1.4.2.2 Procedure B should also be applied for the determi-nation of the breakdown voltage of liquid samples containinginsoluble materials that settle from the specimen during testing.These may include samples taken from circuit breakers,loadtap changers,and other liquids heavily contaminated withinsoluble particulate material.These examples representsamples that may have large differences between replicatetests.The use of Procedure B will result in a more accuratevalue of breakdown voltage when testing such liquids.1.4.2.3 Use Procedure B to establish the breakdown voltageof an insulating liquid where an ASTM specification does notexist or when developing a value for an ASTM guide orstandard.Procedure A may be used once the single operatorprecision of 13.1 has been demonstrated.1.5 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system are not necessarily exact equivalents;therefore,toensure conformance with the standard,each system shall beused independently of the other,and values from the twosystems shall not be combined.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1This test method is under the jurisdiction of ASTM Committee D27 onElectrical Insulating Liquids and Gases and is the direct responsibility of Subcom-mittee D27.05 on Electrical Test.Current edition approved.Published December 2019.Originally approved in1946.Last previous edition approved in 2013 as D877/D877M13.DOI:10.1520/D0877_D0877M-19.2RR:D27-1006,Round-Robin Data Using Modified VDE Electrode Cell forDielectric Strength Tests on Oil,is available from ASTM Headquarters.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was