ASTM_D_3455_-_11.pdf

Designation:D345511Standard Test Methods forCompatibility of Construction Material with ElectricalInsulating Oil of Petroleum Origin1This standard is issued under the fixed designation D3455;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 These test methods cover screening for the compatibilityof materials of construction with electrical insulating oil for usein electrical equipment.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety problems,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.2.Referenced Documents2.1 ASTM Standards:2D877 Test Method for Dielectric Breakdown Voltage ofInsulating Liquids Using Disk ElectrodesD924 Test Method for Dissipation Factor(or Power Factor)and Relative Permittivity(Dielectric Constant)of Electri-cal Insulating LiquidsD971 Test Method for Interfacial Tension of Oil AgainstWater by the Ring MethodD974 Test Method for Acid and Base Number by Color-Indicator TitrationD1500 Test Method for ASTM Color of Petroleum Products(ASTM Color Scale)D2413 Practice for Preparation of Insulating Paper andBoard Impregnated with a Liquid DielectricD3487 Specification for Mineral Insulating Oil Used inElectrical Apparatus3.Significance and Use3.1 The magnitude of the changes in the electrical propertiesof the insulating oil are of importance in determining thecontamination of the oil by the test specimen.3.2 Physical and chemical changes in the oil such as color,interfacial tension and acidity,also indicate solubility or otheradverse effects of the test specimen on the oil.3.3 Physical changes of the test specimen such as hardness,swelling,and discoloration show the effect of the oil on the testspecimen and are used to determine the suitability of thematerial for use in insulating oil.3.4 A material meeting the criteria recommended does notnecessarily indicate suitability for use in electrical equipment.Other properties must also be considered.Additionally,certainmaterials containing additives may meet the requirements ofthese test methods,yet be unsatisfactory when subjected tolonger term evaluations.Examples of such materials arepolyvinyl chloride(PVC)based compounds,nylon and elasto-meric compounds.4.Apparatus4.1 Sample-Handling Apparatus:4.1.1 Oven,forced-draft,adjustable to 100 6 1C,and adrying oven,adjustable to 105 6 5C.4.1.2 Glass Containers,1-L,fitted with glass or aluminumfoil covers.NOTE1Other materials have been found to be suitable as covers.4.2 Sample-Testing Apparatus:4.2.1 Tensile StrengthAs specified in appropriate testmethod.4.2.2 HardnessAs specified in appropriate test method.4.2.3 Dimensional ChangeMicrometer and caliper.4.2.4 Weight ChangeAnalytical balance.5.Preparation of Test Specimen5.1 Test specimen size shall be such that the ratio of surfacearea to oil volume is four times as large as the ratio encoun-tered in normal use in electrical equipment unless there is somespecial reason for using a different ratio(Note 2).Somesuggested ratios are as follows:1These test methods are under the jurisdiction of ASTM Committee D27 onElectrical Insulating Liquids and Gasesand are the direct responsibility of Subcom-mittee D27.06 on Chemical Test.Current edition approved June 1,2011.Published July 2011.Originally approvedin 1975.Last previous edition approved in 2002 as D3455 2002 which waswithdrawn January 2011 and reinstated in June 2011.DOI:10.1520/D3455-11.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.1.1 If the test specimen can be measured,no less than 52cm2are used with each 800 mL of oil.5.1.2 If the test specimen is insoluble in oil and the surfacearea cannot be measured,the test specimen shall be used in theamount of 1%by the weight of the oil.5.1.3 If the material is soluble in the oil,the test specimenshall be used in the amount of 0.5%by the weight of the oil.5.1.4 Varnishes and materials used as dip coatings shall becured on aluminum foil or paper known to be compatible withinsulating oil.They should be tested at a ratio of 14 g orapproximately 1300 cm2of surface area per 800 mL of oil.5.1.5 Core steel and core-steel coatings shall be tested at aratio of 3100 cm2for each 400 mL of oil,for transformerapplications.A realistic core