ASTM_E_2047_-_10_2015.pdf

Designation:E204710(Reapproved 2015)Standard Test Method forWet Insulation Integrity Testing of Photovoltaic Arrays1This standard is issued under the fixed designation E2047;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 a procedure to determine theinsulation resistance of a photovoltaic(PV)array(or itscomponent strings),that is,the electrical resistance betweenthe arrays internal electrical components and is exposed,electrically conductive,non-current carrying parts and surfacesof the array.1.2 This test method does not establish pass or fail levels.The determination of acceptable or unacceptable results isbeyond the scope of this test method.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 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.2.Referenced Documents2.1 ASTM Standards:2E772 Terminology of Solar Energy ConversionE1328 Terminology Relating to Photovoltaic Solar EnergyConversion(Withdrawn 2012)3E1462 Test Methods for Insulation Integrity and GroundPath Continuity of Photovoltaic Modules3.Terminology3.1 DefinitionsDefinitions of terms used in this testmethod may be found in Terminologies E772 and E1328.3.2 Definitions of Terms Specific to This Standard:3.2.1 insulation resistance,nthe electrical resistance of aphotovoltaic arrays insulation,measured between the photo-voltaic circuit and exposed,electrically conductive non-current-carrying parts and surfaces of the array.3.2.2 metal oxide varistor MOV,na surge protectiondevice.3.2.3 photovoltaic circuitthe active electrical circuit thatconducts the photovoltaic generated power.4.Summary of Test Method4.1 A procedure is provided for testing the electrical isola-tion between the arrays internal electrical components and itsexposed,electrically conductive,non-current carrying partsand surfaces of the array.4.2 The procedure offers two ways to connect the arrayduring the test,either open-circuited or short-circuited.Eachoption has advantages and disadvantages(see 5.5).4.3 A wetting solution is applied to the array,then a voltageis applied between the PV circuit and the exposed,electricallyconductive,non-current carrying parts and surfaces of thearray,while monitoring the current or resistance,to findlocalized regions where the insulation resistance is signifi-cantly reduced by the wetting solution.The array is theninspected for evidence of possible arcing.5.Significance and Use5.1 The design of a PV module or system intended toprovide safe conversion of the suns radiant energy into usefulelectricity must take into consideration the possibility of hazardshould the user come into contact with the electrical potentialof the array.In addition,the insulation system provides abarrier to electrochemical corrosion,and insulation flaws canresult in increased corrosion and reliability problems.This testmethod describes a procedure for verifying that the design andconstruction of the array provides adequate electrical isolationthrough normal installation and use.At no location on the arrayshould the PV-generated electrical potential be accessible,withthe obvious exception of the output leads.The isolation isnecessary to provide for safe and reliable installation,use,andservice of the PV system.5.2 This test method describes a procedure for determiningthe ability of the array to provide protection from electrical1This test method is under the jurisdiction of ASTM Committee E44 on Solar,Geothermal and OtherAlternative Energy Sources,and is the direct responsibility ofSubcommittee E44.09 on Photovoltaic Electric Power Conversion.Current edition approved March 1,2015.Published April 2015.Originallyapproved in 1999.Last previous edition approved in 2010 as E204710.DOI:10.1520/E2047-10R15.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 hazards.Its primary use is to find insulation flaws that could bedangerous to persons who may come into contact with thearray.Corrective action taken to address such flaws is beyondthe scope of this test method.5.3 This procedure may be specified as part of a series ofacceptance tests invol