National Renewable Energy Laboratory

Transcription

1 FireRatingsofPVSystems: AGuideforStakeholders Preparedfor: NationalRenewableEnergyLaboratory Golden,Colorado Preparedby: BrooksEngineering 3949JoslinLane Vacaville,CA November2014 Version1.2

2 PageLeftIntentionallyBlank

3 TableofContents Page 1 Background TheChangesinBuildingCodeRequirements IBCLanguage Changesto2012ICodes NewUL1703FirePerformanceTestsTutorial BackgroundontheFirstUL1703FireClassificationTests PVSystemFireClassificationwiththeNewUL1703Standard PVModuleTypesInsteadofFireClassifiedPVModules TheNewSpreadofFlameTests DetailsabouttheNewSpreadofFlameInterfaceTests TheNewBurningBrandTests ActionItemsforeachStakeholderGroup LaboratoriesCertifiedtoPerformUL1703FireTests PVModuleManufacturers PVRackManufacturers PVInstallingContractors AHJsEnforcingCodeRequirements ApplicationoftheNewUL1703TestStandard Residentialinstallationcasestudy Commercialinstallationcasestudy Conclusion...24 References...25 AppendixA:UL1703InterfaceFlameSpreadTests...26

4 PageLeftIntentionallyBlank

5 1 Background The2012InternationalBuildingCode(IBC) 2 isthefirstbuildingcodecyclewithspecific requirementsforbuildingswithphotovoltaic(pv)systems.historically,theonlywidely used code with specific PV requirements is the National Electrical Code, which introducedrequirementsforpvsystemsin1984.whilethesenewrequirementsinthe 2012 IBC have been published for some time now, the impact of these requirements haveonlyrecentlybeenkeenlyfeltbythoseaffectedbytheibc. Oneoftheareasofgreatestconcerntothesolarindustrythatrelatestothe2012IBCis the requirement that the fire rating of a newly installed PV system must match the requiredfireratingoftheroof.mostoftheunitedstatesdoesnotrequireafirerated roofforresidentialconstruction.officebuildingsgenerallyrequireclasscroofing,and assembly occupancy buildings (e.g. theaters, churches, restaurants, sports arenas) requireaclassbfireratedroof.sincemostpvmoduleshaveaclasscfirerating,using theoldunderwriterslaboratory(ul)firetest 1,veryfewlocaljurisdictionshaveraised questions about PV system fire ratings. This creates a problem for buildings requiring ClassBorAroofsandselectareasofUnitedStatesthatrequireClassAorBfirerated roofassembliesasofthedatethatthe2012ibcbecomesenactedinaparticulararea. Additionally,onJanuary1,2014,thestateofCalifornia,whichincludesalargeportionof ClassBandClassArooffireratingrequirements,enactedtheirversionofthe2012IBC. ThosejurisdictionsrequiredbylawtoenforceClassAandClassBfireratedroofsbegan requiringclassaorbfireratedpvsystemswhenfew,ifany,productsthatmeetthese requirementsexist. CaliforniaisnottheonlylocationintheUnitedStateswithClassAandBrooffirerating requirements.asalreadymentioned,buildingsthatareassemblyoccupancymusthave atleastaclassbroofassembly.otherstatesthroughoutthewesternunitedstateshave very high fire severity areas with Class B or Class A roof fire rating requirements. However, California is the state with the most PV activity that coincides with these higherfireratingrequirements.thefireserviceincaliforniahasbeensteadilymoving towardhigherfireratingsoverthepastfewdecades,andmanyotherstatesarelooking tofollowcalifornia sleadtoincreasefireratingrequirementsoverthenextfewyears. ClassAratedroofassembliesarenowreadilyavailablefromtheroofingindustry.Since thebuildingindustrywillnotbegreatlyimpactedbyhigherroofratingrequirements,it islikelythatthefireservicewillsuccessfullymakethecaseforhigherfireroofratings

6 acrosstheunitedstates.whilecurrentclassa andbfireratingrequirementsimpact lessthan50%ofcalifornia,andonlyafewpercentoftherestoftheunitedstates,itis likely that these percentages will rise dramatically over the next few years. The solar industrymustbepreparedtoupdatetheirproductstomeetthedemandforhigherfire ratedroofsystems. Inorderto provideapathwayforsolarproductstoimprovetheirfirerating,theu.s. Department of Energy (USDOE) funded the Solar America Board for Codes and Standards (Solar ABCs) 7 over the past five years to study and revise the PV module standardfireperformancerequirements. ThesafetystandardforPVmodulesthatincludesthefireperformancetestsisANSI/UL Std.1703,FlatPlatePhotovoltaicModulesandPanels(UL1703) 1,4.Thecurrentmethods forevaluatingthefireperformanceofpvmodulesservedtheindustrywellfornearly two decades, but research into these test methods showed deficiencies in fire performance results.asaresult ofthisinitialresearchfunded byusdoethroughthe SolarABCs 7,changesintheUL1703standardwererecommended.Afireperformance subcommittee was initiated by the UL1703 Standards Technical Panel (STP), and the official process to change the standard was engaged. Within three years of the formationofthesubcommittee,therevisedstandardwaspublishedinoctober, ThenewstandardincludesanewprocedurefordeterminingthefireclassratingofaPV system.thenewversionofthestandardaddressestheprimaryshortcomingsofthefire testinginthepreviousversionofthestandard.thisnewfiretestingprocedureincludes tests of the PV module, racking, and roof as a system to determine if the PV system impactsthefireratingoftheroof.

7 2 TheChangesinBuildingCodeRequirements The 2012 IBC and the 2012 International Residential Code (IRC) 3 introduced language regulatingthefireratingsofpvsystemsonrooftops.priortothe2012ibc,therewasno specific requirement for these systems to have a fire rating. The fact that most PV moduleshadaclasscfireratingwasreassuringtomostjurisdictionsacrosstheunited States.Untilrecently,theoldtestinUL wasdeemedsufficient.mostoftheunited States only requires a Class C or B roof fire rating when a fire rating is required. The 2012IBC 2 requirementsforapvsystemtomatchthe required fireratingoftheroof introducessomedifficultiesforassemblyoccupanciessincetheserequireclassbroof assemblies. With California and other western states requiring Class A roofing in wild landurbaninterfaces,andveryhighfireseverityareas,itwasclearthatthefiretestsin UL1703neededtobeupdatedinorderbeabletoprovidePVsystemsthatareClassAor Bfirerated. Only in parts of California, where Class A and B ratings are more common, did jurisdictionsquestiontheuseofclasscpvmodulesaboveclassaroofingsystems.prior to the 2012 IBC and IRC, the source of these questions originated from ambiguous languagerelatedtofireratingofpvmodulesintheulwhitebook(includedinversions published up through September, 2014) 8. This language in the White Book is found undertheproductcategory,photovoltaicmodulesandpanels,withtheproduct CategoryCode,QIGU.Theuseandinstallationsectionstates: Installationofmodulesonorintegraltoabuilding sroofsystemmayormaynot adverselyaffecttheroofcoveringmaterials resistancetoexternalfireexposureif themodulehasalesserornofireresistancerating.roofcoveringmaterialswillnot be adversely affected when the modules have an equal or greater fireresistance ratingthantheroofcoveringmaterial. TheuncertaintyaswhetherornottheinstallationofPVmodulesadverselyimpactsthe fireratingoftheroofisofconcerntoauthoritieshavingjurisdiction(ahjs).inthespring of 2008 concern over this uncertainty was raised by several California jurisdictional authorities in areas that required Class A or B fire rated roof systems. Solar ABCs commissionedaresearchprojectonthesubjectwithulthatbeganinmarchof2009. Overthecourseofthenextfouryears,over100firetestswereperformedandseveral reportswerepublishedonthesolarabcswebsite, 7.

8 IBCLanguage The2012IBC 2 isthefirstbuildingcodetomentionpvsystems.asaresultofconcerns raisedovertheulwhitebook 8 language,arequirementforfireratedpvsystemswas addedtothe2012ibcandirc.thelanguageisdifferentintheibcandirc Changesto2012ICodes The2012IBCcontainsachangeinSection1505thatrelatestothefireratingofPV systeminstallations.thenewrequirementreads: 2012IBC 2 language: Fireclassification.Rooftopmountedphotovoltaicsystemsshallhavethesame fireclassificationastheroofassemblyrequiredbysection1505. DifferentlanguagewasapprovedintheIRC. 2012IRC 3 language: M Roofmountedpanelsandmodules.Wherephotovoltaicpanelsandmodules areinstalledonroofs,theroofshallbeconstructedtosupporttheloadsimposedby suchmodules.roofmountedphotovoltaicpanelsandmodulesthatserveasaroof coveringshallconformtotherequirementsforroofcoveringsinchapter9.where mountedonorabovetheroofcoverings,thephotovoltaicpanelsandmodulesand supportingstructureshallbeconstructedofnoncombustiblematerialsorfireretardant treatedwoodequivalenttothatrequiredfortheroofconstruction. ThewordingintheIRCisanadaptationofpreviouscodelanguagethatfocusedonthe constructionofsolarthermalcollectorsandtheirsupportstructures.itisunclear whetherthecurrentconstructionofpvmodules,whichisusuallyglasscoverswith aluminumframingandplasticbacking,wouldcomplywiththenewirclanguagefor noncombustiblematerials.the2013californiabuilding 5 andresidential 6 Codes,which aregenerallybasedonthe2012icodes,iswordedinamoreconsistentandbetterway. CBCSection1505.9andCRCSectionR902.4havebeenrevisedtoreadasfollows:

9 1505.9Photovoltaicpanelsandmodules.EffectiveJanuary1,2015,Rooftopmounted photovoltaicsystemsshallbetested,listedandidentifiedwithafireclassificationinaccordance withul1703.thefireclassificationshallcomplywithtable1505.1basedonthetypeof constructionofthebuilding. R902.4Photovoltaicpanelsandmodules.EffectiveJanuary1,2015,Rooftopmounted photovoltaicpanelsandmodulesshallbetested,listedandidentifiedwithafireclassificationin accordancewithul1703.thefireclassificationshallcomplywithtable1505.1ofthecalifornia BuildingCodebasedonthetypeofconstructionofthebuilding. SomehaveexpressedconcernthatthelanguageisdifferentbetweentheCBCandthe CRC.ComparingtheCBCandCRClanguage,thetitleofbothsectionsareidentical, Photovoltaicpanelsandmodules andthetextofeachsectionisidenticalwithone exception.thecbc 5 statesthat, Rooftopmountedphotovoltaicsystemsshallbe tested,whereasthecrc 6 statesthat, Rooftopmountedphotovoltaicpanelsand modulesshallbetested. (boldemphasisadded)giventhetitleofeachsection relatingtopvpanelsandmodulesisunlikelythatthereisanyintentdifferenceinthe languageofeachsection.ifnointentdifferenceexistsinthetwostatements,itappears thattheoldul testthatfocusedontheperformanceofthepvmodulecouldbe usedtomeettherequirementforeitherthecbcorthecrc.itisalsolikelythatahjs willallowtestingdoneunderthenewlyrevisedul forclassa,b,orcfireratedpv systems. TheOctober2013editionandlatereditionsofUL specificallystipulatehowpv modulesandpanelsachieveafireclassificationforclassa,b,andcrequirements.the newul1703statesinsection16.1, SystemFireClassRatingsA,B,orCareonlyrelevant forpvmodulesorpanelswithmountingsystemsincombinationwithafireratedroof covering. ThisstatementinthenewversionofthestandardistoclarifythatPV modulesorpanelsarenowcertifiedwiththeirmountingsystemasanoverallsystem. ThePVsystemisrequiredtocomplywiththeTable1505.1CBCfireclassificationsthat arebasedonthetypeofbuildingconstructionandthefireseverityofthespecific location.californiahasmoreareasandbuildingsthatrequireclassaandbroofing productsthantherestoftheunitedstatescombined.whilethesechangesinthe buildingcodesimpactcaliforniamorethantherestofthecountry,otherstateswillalso havetoenforcethesenewcoderequirements.duetothelackofavailableclassaandb

10 fireratedpvproductstestedtothenewul1703,calfirepetitionedtodelay enforcementofthe2013cbcandcrcrequirementsuntiljanuary1,2015.thisgivesa short,butmeaningful,reprievetothepvindustrysothatproductscanbeevaluatedto thenewul1703fireperformancestandard.

11 3 NewUL1703FirePerformanceTestsTutorial FireratingshavebeenpartofthePVmodulestandardsincetheearlydraftsofUL1703. Since module products were routinely placed on roofs, the standard developed tests thatprovidedforclassifyingfireperformanceofpvmodulesinasimilarwaythatroofs arefireclassified.infact,buildingintegratedpvsystemsthatarearoofcoveringmust passtheverysamefireteststhatroofmaterialspass.thechallengehasbeenhowto properly evaluate the fire performance of frame modules mounted above a roof covering. 3.1 BackgroundontheFirstUL1703FireClassificationTests TheoriginalUL1703fireperformancetestsincludedtwotestsborrowedfromtheroof fire rating standard, UL790. These two tests were (1) the burning brand test on the surface of the module, and (2) the spread of flame test on the top surface of the module. Section 16 of the original UL1703 standard 1 required that these tests be performedoverafireratedroof. 16FireResistance 16.1Amoduleorpanelintendedforstandoff,rack,ordirectmountingincombinationwith a specified roof, or intended for integral mounting shall comply with the fire resistance requirementsforaclassa,b,orcroofcoveringwhenthemoduleorpanelisindicatedor implied as being firerated. Fora combination construction, the rating shall be coincident with, or at a lower level than, the rating of the basic roof covering material. The fire resistance shall be determined in accordance with the Standard for the Standard Test MethodsforFireTestsofRoofCoverings,UL790,asmodifiedbyFireTests,Section31. InitiallyforrackmountedPVsystemsthetestswereperformedwitharoofingsystem underthepvmodules,butitwasquicklylearnedthattheroofingsystemhadnoreal impactonthefireperformancetestsastheywereconducted.thefactthattheul1703 testmigratedtoatestthatdidnotincludearoofsystemwasduetoasimplificationof thetestprocedurebecauseofthepass/failcriteria. Initially, the main reason a module was rated Class C was more due to the pass/fail criteriaoftheburningbrandtest,ratherthanthespreadofflametest.particularlywith smaller36cell,5inchcellmodulesmanufacturedinthe1990sandintotheearly2000s,

12 thesemoduleswereoftenableto passthespreadof flametestsforaclassarating. However, the burning brand test was difficult for a plasticbacked module to pass becauseofthepass/failrequirement,whichstatesthattheproductfailsthetestifany materialfallsoffthemoduleduringthetest.giventherelativelylargeclassaandclass Bbrands(12 x12 x3 and6 x6 x3 respectively),noplasticbackedmoduleshavebeen documented to pass that burning brand test with Class A or B brands. Only glasson glass construction PV modules have been known to pass both the burning brand and spread of flame Class A tests (e.g. ASE300; ASE100; and Sanyo Bifacial). The only burning brand test that plastic backed modules have been known to pass is with the smallclasscbrandsthatare1 x1 x1. As a result of research testing performed during the Solar ABCs 7 fire performance researchproject,itbecameclearthattheexistingul1703testprocedurehadtwomain deficiencies.thefirstdeficiencywasthatthepass/failcriteriafortheburningbrandtest shouldbethefailureoftheroofdeckoftheroofingsystemunderthepvmodule,not thepvmodule.theseconddeficiencywasthatthetestsdidnotaddressfirespreading acrossaroofandthenencounteringapvsystem.asrevisionswereconsideredbythe UL1703 Standards Technical Panel (STP), it was clear that updates to the standard neededtoaddressthesetwodeficiencies. 3.2 PVSystemFireClassificationwiththeNewUL1703Standard The new fire performance tests in the October 2013 and later editions of UL includeaminimumoftwotests(foralowslopedapplicationonly)andamaximumofsix tests (for module mounting systems used in both steep and low sloped applications). TheoriginaltwotestsperformedonaPVmodule(spreadofflameandburningbrand) areretainedinthepvmoduletypingproceduresexplainedinsection3.2.1.themodule spreadofflametestisthesameasthefirstspreadofflametestinthefirstrowoftable 31.2 shown below. Systems restricted to lowslope applications need only test one additional spread of flame test at the interface to achieve a fire class rating. This interfacetestmayincludethreesetsoftestsifthemountingsystemdoesnotmountthe module parallel to the roof surface, called asymmetric mounting, which is detailed in section3.2.3.thetestsrequiredforsteepslopeandlowslopemountingsystems,and thepassingrequirementsforeachfireclassrating,areoutlinedintable31.2fromthe October2013versionofUL1703standard 4 shownbelow.

13 Table31.2 RequiredtestsforSystemFireClassRatingofPVModuleorPanelwithMountingSysteminCombination withroofcoverings Test TestsOverRepresentativeRoofCoverings ClassA ClassB ClassC SpreadofFlameOnTopSurfaceofModuleor Panel(Section31.1.2) a FlameSpread lessthan 6ft.in10 minutes Flamespread lessthan 8ft.in10 minutes Flamespread lessthan 13ft.in4 minutes SpreadofFlameatRoofandModuleorPanel InterfaceOverRepresentativeSteepSlopedRoof (Section a) b SpreadofFlameatRoofandModuleorPanel InterfaceOverRepresentativeLowSlopedRoof (Section b) b BurningBrandonSurfaceOverRepresentativeSteep SlopedRoof(Section a) b BurningBrandBetweenModuleorPaneland RepresentativeSteepSlopedRoof(Section b) b Pass Pass Pass Pass Pass Pass ABrand BBrand CBrand Pass Pass Pass a Requirementcanbemetbyeitheratypetestedmodule(16.4)orbyperformingthetestinSection onthetopsurfaceofamoduleorpanelinthemountingsystembeingqualifiedin31.2.fornontypetested products,theproductmustpasstwoconsecutivetestsforeachrequiredtest. b TwoconsecutivetestsforeachtestmustbepassedunlessnotrequiredbythetermsofSections , ,or Forthepurposeofthisstandard,SteepandLowSlopedRoofaredefinedinSections Forexample,thistableshowsthatallsixtestswouldberequiredforamountingsystem topassforbothlowslopedandsteepslopedapplicationstobeapprovedforclassa,b, orcfireratings.onlysteepslopedsystemsarerequiredtopasstheburningbrandtest since lowsloped roofing systems require a fire barrier that makes the burning brand test irrelevant. For lowsloped roof assemblies only the spread of flame on the top surfaceofthemodule(section31.1.2),andthespreadofflameatroofandmoduleor panel interface over a representative lowsloped roof (Section b) need to be performed. If a lowsloped mounting system is being tested with a module that has beentypetested,aprocessdescribedinsection3.2.1,thenthemountingsystemonly has to pass the one interface test, since the top surface of the module was already evaluatedbythemodulemanufacturer(section31.1.2).thisillustratesthesignificance

14 ofmoduletypetestingthatisdescribedinthenextsection PVModuleTypesInsteadofFireClassifiedPVModules Alegitimateconcernofthesolarindustryistheexpenseoffiretesting.Sinceaparticular mountingsystemcouldrequireuptosixdifferentteststoachieveafireclassificationit isimportantthatthisfireclassificationbeapplicabletomorethanonemodelofspecific PV modules. The challenge was how to categorize PV modules based on how they perform in a mounting system. A method was developed to categorize modules by constructionandfireperformancetypes.constructioniscategorizedby4items1)the superstratematerial;2)theencapsulantmaterial;3)thesubstratematerial;and,4)the frame type and geometry (if any). Fire Performance is categorized by two items 1) spread of flame on the top surface of the module; and, 2) burning brand on the top surface of the module. The two fire performance tests are identical to the tests that wereperformedintheolderversionoftheul1703standard.thisalsohelpstoprovide somecontinuitybetweenthepreviouspvmoduletestproceduresthatproducesafire classratingforthemodule,andthenewmodulefireperformanceteststhatproducea moduletype. Many Class C PV modules with this same construction have passed as Type 1 and 2 products.thisissignificantsinceitshowsthatmanyglassonpolymericconstructionpv modulesarecapableofpassingthemoststringentspreadofflametestofnomorethan six feet of flame spread in 10 minutes. For those glassonpolymeric constructions unabletopassthetype1or2spreadofflamerequirements,mostofthesemoduleswill beabletopasstheeightfeetofflamespreadin10minutesrequirementfortype7and 8. For those modules of similar construction unable to pass eight feet in 10 minutes spreadofflame,theyaremostlikelytopassthe13feetin fourminutesrequiredfor Type4and5.TheTable16.1belowisthematrixofcurrentmoduletypesprovidedin UL

15 Type Superstrate Encapsulant(Super/Cell) Encapsulant(Cell/Sub) Substrate SpreadofFlame BurningBrand Material/Thickness Material/Thickness Material/Thickness Material/Thickness 1 Glass/0.14±0.03" Polymer/0.018±0.008" Polymer/0.018± Polymer/0.012"(0.30mm) 6feet(1.82m)or (3.6±0.76mm) (0.45±0.2mm) 0.008"(0.45±0.2mm) thickness0.025"(0.64mm) lessin10minutes CBrand 2 Glass/0.14±0.03" Polymer/0.018±0.008" Polymer/0.018± Polymer/0.001"(0.025mm) (3.6±0.76mm) (0.45±0.2mm) 0.008"(0.45±0.2mm) thickness<0.012"(0.30mm) SameasType1 SameasType1 3 Glass/0.105±0.030" Polymer/0.035±0.02" Glass/0.105±0.030"(2.67 N/A (2.67±0.76mm) (0.9±0.5mm) ±0.76mm) SameasType1 SameasType1 4 SameasType1 SameasType1 SameasType1 SameasType1 13feet(1.82m)or lessin4minutes SameasType1 5 SameasType2 SameasType2 SameasType2 SameasType2 SameasType4 SameasType1 6 SameasType3 SameasType3 SameasType3 SameasType3 SameasType4 SameasType1 7 SameasType1 SameasType1 SameasType1 SameasType1 8feet(2.4m)or lessin10minutes SameasType1 8 SameasType2 SameasType2 SameasType2 SameasType2 SameasType7 SameasType1 9 SameasType3 SameasType3 SameasType3 SameasType3 SameasType7 SameasType1 10 SameasType3 SameasType3 SameasType3 SameasType3 SameasType1 BBrand 11 SameasType3 SameasType3 SameasType3 SameasType3 SameasType4 SameasType10 12 SameasType3 SameasType3 SameasType3 SameasType3 SameasType7 SameasType10 13 SameasType3 SameasType3 SameasType3 SameasType3 SameasType1 ABrand 14 SameasType3 SameasType3 SameasType3 SameasType3 SameasType4 SameasType13 15 SameasType3 SameasType3 SameasType3 SameasType3 SameasType7 SameasType13

16 3.2.2 TheNewSpreadofFlameTests Theoriginalversionofthespreadofflametestwasonlyappliedtothetopsurfaceof themodule.asaresultofresearchandtestingdonebyulforthesolarabcsprogram, concernwasraisedthatthismethoddidnotadequatelyaddresstheconditionofafire spreading across a roof that might encounter a PV system. An interface test was developedthatprovidesamethodtoevaluatehowafireonaroofsurfacerespondsas itprogressesintothevicinityofapvarray.differenttestsarerequiredforsteepsloped roofs and lowsloped roofs since the slope of the roof impacts how a particular mountingsystemrespondstoaprogressingfire.boththespreadofflameonthesurface ofapvsystemandthespreadofflameontheinterfacetestarenecessarytoreceivea fireratingwiththenewfireperformancetests. For PV mounting systems that can only be used with lowsloped roofs (e.g. ballasted mountingsystems)oronlyonsteepslopedroofs(i.e.someflashedpenetratingsystems) onlythelowslopedorsteepslopedinterfacetestsneedtobeperformedrespectively. Also,ifaPVmoduleisunabletopassthedesiredspreadofflametestonthesurfaceof themodulewithoutaspecificmountingsystem,thenewtestprocedureprovidesforan alternative.thespreadofflameonthesurfaceofthemodulecanbeperformedwitha specificmountingsystemincasethatmountingsystemisabletoimprovethespreadof flameperformanceonthesurfaceofthemodule.inotherwords,ifamodulereceivesa Type4,5,7,or8classificationbecauseitfailedtopassthespreadofflameofsixfeetin 10minutes,aspecificmountingsystemwiththatspecificmodulemaybeabletopass theclassatestsasasystem DetailsabouttheNewSpreadofFlameInterfaceTests As test laboratories and mounting system manufacturers have been familiarizing themselveswiththenewtestrequirements,misapplicationofthetestcanoccur.thisis common with new test protocols since those that developed the tests are not necessarily those that execute the tests. Also, test standards do not typically include much in the way of explanation about the tests. This section will attempt to provide someofthedetailslackinginthenewul fireperformancetests.thenewul1703 Section31doesinclude10diagramstodirecthowtoperformtheinterfacetestsonlow and steep slope roofs. These diagrams show how to determine the placement of the mountingsystemwithrespecttothetestflameandarepartofthestandard,notsimply

17 opinioncommentary.thediagramsalsoshowhowtolocatethemountingsystemwhen different deflectors and asymmetrical (tilted) systems are employed. A detailed explanation of how the new spread of flame interface tests are to be performed is providedinappendixaofthisdocument. Figure1showsatypicalmountingsystemforalowsloperoof.Thesemountingsystems oftenhavea515degreetiltforthepvmoduletoimproveannualproduction.these. 3.3 TheNewBurningBrandTests mounting systems often require wind deflectors on the North and East/West sides to reduce uplift. These deflectors areoftenbeneficialforfireperformance as well. The test protocol requires mounting systems with asymmetrical edges,suchastheoneshowninfigure 1,tobetestedontheNorth,South,and East sides (assuming the West side is the same configuration as the East side). The new burning brand test more accurately addresses the intention of the burning brand test which is to test the resistance of a roofing system from preventing a fire brand from penetrating a roof and igniting the attic construction materials that are oftenquiteflammable.sinceroofsgenerallyhavefireratingsinareasthatrequireroof fireratings,anypvmodulesmountedaboveafireratedroofshouldbenefitfromthe fireresistanceofboththepvmoduleandtheroofinaburningbrandtest.tothatend, the burning brand test was revised to include a systemlevel test where the pass/fail criteriawerenotthefailureofthemodule,but thefailureoftheroofdeck.thisnew testwasaddedtotheversionoful approvedinoctober,2013andreplacedthe oldburningbrandtestforthefireclassificationofapvsystem. InadditiontothemoretraditionalUL790burningbrandtestforroofcoverings,another burningbrandtestwasdevisedtotesttheconditionofaburningbrandthatmightgo betweenapvmoduleandtheroof.aspecialtaskwasaddedtotheulresearchproject funded by the U.S. Dept. of Energy, through the Solar ABCs 7. This specific research

18 showedthataclassbbrandmostcloselyrepresentedthefuelloadofburningmaterial thatmightgetcaughtbetweenapvmoduleandtheroof.thistestwasaddedtothe newversionoful1703approvedinoctoberof

19 4 ActionItemsforeachStakeholderGroup There are five major stakeholder groups involved with product development, testing, installation, and enforcement of the products certified to the new UL fire tests. Thesefivegroupsarediscussedinthissectionalongwiththeirroleintheprocessand immediateactionitemsforeachgrouptopursueforthesmoothimplementationofthe IBCandIRCrequirements. 4.1 LaboratoriesCertifiedtoPerformUL1703FireTests Since the new UL fire tests are only recently released, the laboratories that perform thesetestsarestillcominguptospeedonthetestingrequirements.aswithanynew testrequirements,thereareinterpretationdifferencesamongthelaboratories.whilea teststandardisintendedtominimizeanydifferencesamonglabs,thereisaneed for educationoflaboratoryengineersastothepropermethodsforconductingtests.oneof therolesofthisdocumentistoprovidecommentaryonthefiretestssothatboththe product manufacturers and the laboratories are on the same page.interpretations of the standard will need to be made, but the hope is that those interpretations be consistentwiththeintentoftheteststandard.thisiseasiersaidthandoneandseveral incidents have already occurred from more than one lab that represents departures fromlanguageintheteststandard. The key action item for certification laboratories is for these labs to develop a small groupofhighlyexperiencedtestengineerswhocarefullystudythelanguageofthetest standardandstrivetoaccuratelyexecutethetests.invariablymistakeswilloccurasthis experienceisdeveloped,buttestlaboratoriesshouldbequicktoresolvemistakesand worktoseethatmisunderstandingsareeliminated.hopefullythisdocumentwillhelp provideadditionalbackgroundtoreducemisinterpretationsofthestandard. 4.2 PVModuleManufacturers ThenewversionofUL fireperformancetestingrequirementsisverysimilartothe originalversionoffiretestingrequirements.twoofthefiretestsintheoriginalversion andthenewversionareidentical.thetwofiretestsareaspreadofflametestonthe surfaceofthemodule,andaburningbrandtestonthetopofthemodule.ratherthan obtainingafireclassratingfromthesetwotests,aswiththeoriginalul tests,the

20 new test regime uses the results of these two tests, along with several construction characteristicstoestablishwhichfireperformance type characterizesthepvmodule. IfamodulemanufactureronlymakesonePVmodulemodel,theymaydevelopaunique mountingsystemforthatmoduleandneverneedtodevelopatypetobeusedbyother manufacturersofmountingsystems. ItisnotrequiredforPVmodulestoreceivea type rating.thepurposeofestablishing module types is to form categories for PV modules so that it is not necessaryto test every PV module model with every mounting system. Simply put, a mounting system thathasbeentestedwithaspecificmoduletype,forexampletype1,willreceiveafire ratingforalltype1ratedpvmodulesthatarephysicallycompatiblewiththatmounting system.ifapvmodulemanufacturerwantstheirproducttoworkwithinasystem,and thepvmodulematchestheconstructioncharacteristicsofatype1module,theysimply havethetwofiretestsperformedonthemoduletocompletetheprocessofbecominga Type1module. Currently there are three main PV module constructions that are covered in the new UL1703moduletypingprocessasshowninTable16.1.Newconstructiontypeswillbe developedasneeded.sincecurrentlycertifiedmoduleswithaclasscfireratinghave passedtheburningbrandtestwithaclasscfirebrand,apvmodulemanufacturercan obtainatype1,type2,ortype3characteristicbypassingthespreadofflametestfor 6 in10minutes.pvmodulescanreceiveatype7,type8,ortype9characteristicby passingthespreadofflametestfor8 in10minutes.forcurrentclasscmodulesthat cannotpass8 in10minutes,theyautomaticallybecomeatype4,type5,or Type6 moduledependingonthephysicalconstructionofthemodule. MostPVmodulescurrentlycertifiedasClassCmoduleswillonlyneedtoperformone fire test and provide information on the thickness of their glass, encapsulant, and substratebacksheettoobtainatypenumber.theonefiretesttobeevaluatedisthe spread of flame test on the surface of the module. This is due to the fact that most existingpvmoduleswithglasssuperstratesandplasticsubstratesobtainaclasscrating from the burning brand test rather than the spread of flame test. Since the burning brandtestistheharderofthetwotestsforglassonplasticconstructedmodules,itis common for these modules to pass higher level spread of flame tests. Many current ClassCproductshavesuccessfullypassedthe6 in10minutesor8 in10minutesspread offlametests.

21 The key action item for the PV module manufacturers is to document their glass, encapsulant,andsubstratethicknesseswiththeirtestlaboratory,andhavethespread of flame test performed on the surface of the module. The sooner a module manufacturergetstheirproductthroughthisprocess,thesoonertheywillunderstand whattypetheirmoduleis.additionally,themodulemanufactureshouldalwaysmark theirmodulewiththemodule Typeinaccordancewiththeteststandard.Thismeans each module should state its module type in the following way Module Fire Performance: Type 1 for a Type 1 module. This marking is optional in the UL1703 standard.theimportanceofthethismarkingissothattheinstallingcontractorandthe AHJcanbotheasilyseethatwhattheproductTypeisandmakesureitispairedwitha compatiblerackproductthatachievesthedesiredfireclassratingforthepvsystem. 4.3 PVRackManufacturers Ultimately, the fire class rating of a PV module or panel is heavily dependent on the mountingsystem.whileitisnotrequiredtodevelopmountingsystemsthatworkwith generic module types, most companies manufacturing mounting systems for many differentmodulemanufacturerswillwanttousethepvmoduletypeprocess.mounting systemsdesignedfortype1,2,or3pvmodulesarenotrequiredtopassthespreadof flametestonthesurfaceofthemodulesincethattestwasalreadyperformedbythe modulemanufacturer.mountingsystemsfortype1,2,or3modulescanobtainaclass AfireratingbypassingtheremainingrequiredtestsintheClassAcolumnofTable31.2 from UL Ifthemountingsystemisrestrictedtosteepsloperoofs (greaterthan 2:12pitch),thelowslopedtestsarenotrequired.Ifthemountingsystemisrestrictedto lowsloperoofs(upto2:12pitch),thesteepslopedtestsarenotrequired. Forasteepslopemountingsystem,thekeytestisthesteepslopeinterfacetestwhichis thesecondtestlistedintable31.2.foraclassarating,asteepslopemountingsystems mustalsopassthetwoburningbrandtests.thefirstwithaclassabrandonthetopof the module over a Class A roof and the second with a Class B brand between the module and a Class A roof. The interface test and the two burning brand tests are pass/fail tests and characterize the fire performance of the PV system. A mounting system that passes the interface test and the two burning brand tests, and that is compatiblewithmountingpvmoduleswiththephysicalconstructionoftype1and2 modules, will be a Class A mounting system for Type 1 and 2 modules, a Class B

22 mountingsystemwithtype7and8modules,andaclasscmountingsystemwithtype 4and5modules.Intheseexamples,thefireclassratingofthePVsystemisdependent onthefireperformanceofthepvmodule. UL makesanimportantdistinctioninoneofthenotesfortable31.2.itallowsa specificpvmoduletobetestedinaspecificmountingsystem,regardlessofwhetherthe PVmodulehasbeentestedtoanyTypeornot.Theresultsofthespreadofflametest for this specific case are used for fire classifying this PV module/mounting system configuration.itispossibleto haveamodulethatcanonlypassthe8 in 10minutes spread of flame test, yet when installed in a specific mounting system, the PV module/mountingsystemconfigurationcanpassthe6 in10minutesspreadofflame test.inotherwords,apvmodulethatistype7or8,ortype4or5,isstilleligibleto achieveaclassafireratingifitistestedinaspecificmountingsystemthatimprovesthe spreadofflametestonthetopsurfaceofthemoduletopass6 in10minutes. Thekeyactionitemfortherackmanufactureristodetermineiftheirexistingproducts canbeusedinclassa,b,orcfireratedpvsystems,orifmodificationsarenecessaryto bring their products into compliance. The only way to truly understand whether modifications are necessary is to schedule lab time at a certified UL1703 fire lab and gain real experience. A logical approach for a rack manufacturer is to develop a test regimethatincludestestingofexistingdesignsforcompliancewiththeinterfacetest. Any products that fail the interface test could have an optional feature, such as the additionofperimeterdeflector,whichcouldbequicklyandeasilyincorporatedintothe designtodetermineiftheaddeddeflectormakesthemountingsystemcompliantwith theinterfacetest. Sincetheinterfacetestisrequiredforallthreefireclassratings,onceamanufacturer can show that they pass the interface test, all three fire Class ratings are achievable. Sincetheprimarydistinctionbetweenthethreeclassificationsistheperformanceofthe spreadofflameonthetopsurfaceofthemodule,themoduletypemaydictatethefire classrating. 4.4 PVInstallingContractors Installingcontractorsneedtoworkwiththeirequipmentsupplierstomakesurethatthe PV modules and support structures they typically use are certified and labeled to the

23 new fire performance requirements in UL For contractors working in California andotherwesternstates,itiscriticalthatproductsareevaluatedandcertifiedasearly aspossible.asstatedearlier,january1,2015istheenforcementdateincaliforniafor the2013cbc 5 andcrc 6 requirements. Iftheproductsthatacontractoriscurrentlyusingarenotfireclassrated,thecontractor needs to start researching other products to substitute, particularly in those areas of CaliforniaandotherstatesthatrequireClassAandBroofingsystems.SinceAHJswill requirecompliantproducts,contractorsneedtohavedocumentationreadilyavailable fortheproductcombinationstheyareinstalling.thedocumentsfromthemanufacturer must show that the mounting system has been evaluated for the required fire classificationintheregiontheyareinstallingtheirpvsystems. Fromasimplicitypointofview,itwouldbeeasiesttoselectaproductcombinationthat isclassarated.theadvantageofselectingaclassapvsystemcombinationisthatthe systemisautomaticallycompliantinalljurisdictionsandlocationssincenohigherrating isrequired.somejurisdictionsmayhaveveryhighfireseverityareas,requiringclassa productsthatareonlyafewblocksfromareasthatonlyrequireclasscproducts.the process of having to determine whether or not an address is in the very high fire severity area can take time and delay permit approval. To be clear, a Class A PV mounting system will always be good for a Class B or Class C required roof. It is not necessary to match the required roof rating. Also, if a Class A roof is mounted in a locationthatonlyrequiresaclasscroofsystem,accordingtothebuildingcodesitisnot necessaryforthepvsystemtohaveaclassafirerating.inthisexample,aclasscpv systemwouldmeetthecodefireperformancerequirementforthepvsystem. Configurations of fire rated mounting systems and module types may include specific optional components. It is important for the contractor to show that the correct optionalcomponentsweresourcedusingbillofmaterialsororderreceipts.inthefield, thesespecificcomponentsshouldbepointedouttothefieldinspectorsothattheycan verifycompliancewiththerequiredfireclassification. 4.5 AHJsEnforcingCodeRequirements AuthoritiesHavingJurisdiction(AHJs)aretaskedwithjobofverifyingthattheproducts permitted and installed are compliant with code requirements. Given that both the

24 codes,andthestandardssupportingthecodes,aresorecentlypublished,itiseasyto see that it will take time to fully develop proper enforcement of the codes. Good documentationiskeytomakingthejobofenforcementstraightforward.pvmoduleand rack manufacturers need to work closely with certifying agencies to produce documentation that clearly shows how their products meet the requirements. Vague statements about compliance do not provide clarity for those charged with verifying compliance. AnexampleofcleardocumentationisforaPVmodulemanufacturertoprintontheir listinglabel, ModuleFirePerformance:Type1.Thisisanoptionalstatementthatcan beputonthelistinglabelaccordingtoul1703 4,butitmakesthejobofenforcement much easier. With a clearly marked PV module, it only remains for the racking manufacturer to have a clear statement in their installation instructions stating, This mountingsystemisfireratedclassawheninstalledwithtype1pvmodulesinstalledin accordance with fire rated hardware configuration shown in these installation instructions. Thesearesimplyexamplesofclearstatements.AnytypePVmodulecan achieveaclassaorbsystemrating,dependingonthespecificsofthemountingsystem. It is likely that some mounting systems will have optional components that must be includedintheinstallationtoachievethecertifiedfirerating.thefieldinspectorshould ask the installing contractor to show both the documentation and the field evidence thatthesystemiscompliantwiththerequiredfireratings.

25 ThelanguageintheIBC 2 mentionspvsystemswhilethecaliforniacodes 5,6 specifyboth PV systems and PV modules and panels. Some have considered this a contradiction whenitactuallyisnota contradictionatall.thenewul fireperformancetests makeitclearthattheonlywayapvmoduleorpanelcanreceiveafireclassificationis whenitisevaluatedwithaspecificmountingsystem.therefore,apvsystemandapv moduleareevaluatedinthesamemanner.whatisimportanttoclarifyinthisdiscussion isthatpvmodules,independentofmountingsystems,cannotbefireclassifiedusingthe newul1703.whilemoduletypesaredifferentiatedwithtwofiretests,thesetestsare notintendedtorelatetorooffireclassifications. ThefollowingtwocasestudiesillustratehypotheticalproductofferingsandhowaPV systeminstallerwouldgetaprojectpermittedandinstalledinalocationwhereclassa PV systems are required by the building code as enforced by a local jurisdiction in California since California is the only location where Class A roofing systems are required. 5.1 Residentialinstallationcasestudy ThiscasestudywillfollowtheinstallationofaresidentialPVsysteminajurisdictionthat requiresaclassafireperformanceratingonroofingsystems.accordingtor902.4in the2013crc 6, EffectiveJanuary1,2015,Rooftopmountedphotovoltaicpanelsandmodulesshall betested,listedandidentifiedwithafireclassificationinaccordancewithul1703.thefire classificationshallcomplywithtable1505.1ofthecaliforniabuildingcodebasedonthetypeof constructionofthebuilding. ThismeansthatthePVsystemwouldalsoberequiredtobe ClassAfireratediftheroofisrequiredtobeClassA. TheinstallingcontractormustresearchandselectacombinationofPVmoduleand mountingsystemthathasbeencertifiedasaclassafireratedpvsystemforasteep slopedroof.forexample,abcsolarcompanyselectsasteepslopemountingsystem manufacturedbysolfabthatiscertifiedclassawhenmountedwithtype2pvmodules. Ofthe15differentPVmoduleproductsthatthismountingsystemcansupport,threePV modulemanufacturershavetype2modulesthatcanbeinstalledinthismounting system.thecontractorselectsanamericansolar sas255,255wattmodulethatis

26 certifiedasatype2pvmoduleandmatchestheinstallationfortherackmanufacturer andthepvmodulemanufacturerforpropersupport. TheinstallationinstructionsfromSolFabclearlystatehowtoinstalltheirmounting systemonasteepsloperoofwithtype2pvmodulestoachievethecertifiedclassa rating.atrimpieceisrequiredtobemountedonthebottomedgeofthearrayinorder tohaveacompliantpvsystem.themodulemanufacturer,americansolar,clearly includesthewording, FirePerformance:Type2 onthelistinglabelsothatboththe solarinstaller,andthefieldinspectorareabletoconfirmthattheproperpvmoduleis installedinthemountingsystem.themountingsysteminstructionsoutlininghowto achieveaclassaratingisincludedinthepermitpackagetothelocaljurisdiction.atthe finalinspectiontheinstallingcontractorproducesapictureofthelistinglabelshowing acknowledgementofthetype2performanceofthepvmoduleandshowstheinspector thattherequiredtrimpieceisinstalledonthebottomedgeofthearray.therestofthe PVsystemisalsodeterminedtobeincompliancewiththeapplicablecodesandthe installationreceivesasignedfinalapprovalbythelocaljurisdiction. 5.2 Commercialinstallationcasestudy ThiscasestudywillfollowtheinstallationofacommercialPVsysteminajurisdiction thatrequiresaclassafireperformanceratingonroofingsystems.accordingto1505.9in the2013cbc 5, EffectiveJanuary1,2015,Rooftopmountedphotovoltaicsystemsshallbetested, listedandidentifiedwithafireclassificationinaccordancewithul1703.thefireclassificationshall complywithtable1505.1basedonthetypeofconstructionofthebuilding. Thismeansthatthe PVsystemwouldalsoberequiredtobeClassAfireratediftheroofisrequiredtobe ClassA. Similartotheresidentialprocess,theinstallingcontractormustresearchandselecta combinationofpvmoduleandmountingsystemthathasbeencertifiedasaclassafire ratedpvsystemforlowsloperoof.forexample,abcsolarcompanyselectsaballasted lowslopemountingsystemmanufacturedbysolfabthatiscertifiedclassawhen mountedwithtype1pvmodules.ofthe25differentpvmoduleproductsthatthis mountingsystemcansupport,sevenpvmodulemanufacturershavetype1modules thatcanbeinstalledinthismountingsystem.thecontractorselectsanamericansolar s AS305,305wattmodulethatiscertifiedasaType1PVmoduleandmatchesthe

27 installationfortherackmanufacturerandthepvmodulemanufacturerforproper support. The installation instructions from SolFab clearly state how to install their mounting system on a low slope roof with Type 1 PV modules to achieve the certified Class A rating.winddeflectortrimpiecesarerequiredtobemountedonthesideedgeofthe array and on the back side of each row of modules in order to have a compliant PV system.themodulemanufacturer,americansolar,clearlyincludesthewording, Fire Performance:Type1 onthelistinglabelsothatboththesolarinstaller,andthefield inspector are able to confirm that the proper PV module is installed in the mounting system.themountingsysteminstructionsoutlininghowtoachieveaclassaratingare included in the permit package to the local jurisdiction. At the final inspection the installingcontractorproducesapictureofthelistinglabelshowingacknowledgementof thetype1performanceofthepvmoduleandshowstheinspectorthattherequired trimpiecesareinstalledonthearray.therestofthepvsystemisalsodeterminedtobe in compliance with the applicable codes and the installation receives a signed final approvalbythelocaljurisdiction.

28 TheintroductionoffireratingrequirementsforPVsystemsinthe2012buildingcodes 2,3 has created a need for improvements in PV standards and education of all the stakeholders impacted by these code changes. Certification laboratories need to become wellversed in the new fire test requirements in UL PV module manufacturersneedtolearnhowthenewbuildingcodeswillimpacthowtheirproducts are installed on building roofs. Racking manufacturers need to develop products that cover a majority of PV module products and comply with the new fire testing requirements in UL1703. Contractors must be aware of any building code roof fire classification requirements for the buildings they mount PV systems on. AHJs must understandthecoderequirementsandbeabletointerpretthecertificationinformation provided with PV system permit packages to assess compliance with the applicable codes. Wheneversignificantchangesoccurinbuildingcodesandstandards,thereisaneedto understandthechangeandunderstandhowaffectedproductsaddressthechange.the newbuildingcodes,andtheassociatednewul firetestrequirementsprovidefor apathwayforward,buttherewillbeatransitionperiod.existingclasscpvmoduleswill stillbepermittedtobemountedonamajority ofroofsintheunitedstatesuntilthe 2015buildingcodesbegintogointoeffect.Oncethe2015buildingcodes,andthenew UL1703firetestrequirementsbecomeeffective,thetransitionperiodwillbeover,and PVproductsonbuildingswillberequiredtomeetanyrequiredfireratingswithproducts tested to the new UL1703. It is hoped that this document will provide some of the necessaryeducationforasmoothtransitiontothenewfireratingrequirements.

29 1. UL1703,StandardforFlatPlatePhotovoltaicModulesandPanels,Underwriters Laboratories,April InternationalBuildingCode,InternationalCodeCouncil,May InternationalResidentialCode,InternationalCodeCouncil,May UL1703,StandardforFlatPlatePhotovoltaicModulesandPanels,Underwriters Laboratories,October CaliforniaBuildingCode,InternationalCodeCouncil,July CaliforniaResidentialCode,InternationalCodeCouncil,July FireClassificationRatingTestingofStandOffMountedPhotovoltaicModuleand Systems,SolarAmericaBoardforCodesandStandards,August testing/pdfs/solarabcs pdf 8. GuideInformationforElectricalEquipment:TheWhiteBook2014,Underwriters Laboratories,September2014.

30 Thefollowingusesdiagrams,similartothoseintheUL1703standard 4,toillustratehow the standard determines location of the mounting systems for the interface flame spreadtests.explanationaccompanieseachdiagramwhichisnotfoundinthestandard. Figure 2 shows how the distance from the flame source to the mounting system is determined.threebasecasetestsarerunonthechosenroofassembly,andanaverage distanceofthethreetestsisusedtodeterminethereferencelocationofthemounting system.themountingsystemlocationissetadistance12 closertotheflamesource thantheaverageofthethreebaselinetests.iftheaverageofthethreetestsis5feet,as showninfigure2,thenthelocationoftheedgeofthepvmountingsystemis12 closer totheflamesource,or4feetfromtheflamesource. Figure2:DiagramofhowlocationisdeterminedforaspecificClassAroofassembly ThedistanceofthePVmountingsystemtothetestflameisafunctionofthetestedroof construction, not the PV mounting system. The subsequent diagrams show how to locatepvmountingsystemswhenthedimensionsareasymmetricornotorthogonal.

31 Forasteepslopeapplicationwithnoedgetreatment,the4footdistancewouldbefrom the test flame origin to the edge of the PV module as shown in Figure 3. If the PV mountingsystemincludesatrimpieceoredgedeflector,thedistancewillbefromtest flameorigintotheedgeofthedeflectorasshowninfigure4. Figure3:Distancetomountingsystemforsystemwithnoedgedeflector Figure4Distancetomountingsystemforsystemwithedgedeflector Some test labs have expressed a concern that a manufacturer of a mounting system

32 mayfabricatealongdeflectorfortheexpresspurposeofmovingthesystemawayfrom thetestflametoimprovetestingresults.testlabsandmanufacturerswillneedtouse theirengineeringjudgmenttodetermineifatrimpieceisintendedforimprovingfireor windperformance.futureeditionsoful1703standardmayneedadditionaldefinition of edge treatments if problems begin to surface. Design elements in a PV mounting system must serve a real function (i.e. aesthetic, wind, fire) and should also pass a commonsensetest. Figure5showsanoverheadviewofalowslopemountingsystemwithanasymmetric crosssection(tiltedrelativetotheroof)andnosouthedgedeflector.figure6showsa similarasymmetricalmountingsystemwithasouthedgedeflector.thekeydifferenceis that the measurement for the placement of the test sample is to the edge of the deflector,nottheedgeofthemodule.figure7showshowalowslopemountingsystem withaneastandwestedgedeflectorwouldbetestedontheeastandwestedgesides. Thetestprotocolonlyrequirestheeastsideconfigurationtobetestedwhenbotheast andwestsidesareamirrorimageofeachother. Figure5:Lowslopemountingsystemwithnosouthdeflector

33 Figure6:Lowslopemountingsystemwithsouthdeflector Figure7:Lowslopemountingsystemwithsidedeflector(asymmetriccrosssection) Figure 8 shows the north side test that is performed on an asymmetric low slope mountingsystem.thisexampleshowsmountingsystemthatincorporatesanorthedge deflector.

34 Figure8:Lowslopemountingsystemwithnorthdeflector Currently many lowslope mounting products have different designs for their edge deflectors.theteststandardrecognizesthatthisisthecasewithexistingproductsand that future products will have even greater variations in edge deflector designs. In recognitionofthispotentialcomplicationwithinterpretingtheteststandard,avariation showinganedgedeflectorthatisangledisillustratedinthestandard.thisillustration showsthattheintentofthestandardistomeasuretothedeflectoratthepointwhere thedeflectorcrossesthecenterlineofmountingsysteminthenorth/southdimension. Thispointistheplacetolocatethemountingsystemrelativetothetestflameforthe east/westedgetest.figure9providesanexampleofhowthistypeofmountingsystem istobeevaluated.

35 Figure9:Lowslopemountingsystemwithangledeast/westdeflector Figure10showsasideviewofthemountingsystemtestshowninFigure7.Thisdiagram providesadditionalinformationabouthowtosupportamountingsystemthatextends beyondthelimitsofthe40 x96 testdeck.theprimaryconcernisthatthemounting system is supported consistent with manufacturer s directions. For instance, if the mounting system has four mounting plates to hold a module, that all four mounting platesbeinstalled.themountingplatescouldbesupportedbythestructureofthetest apparatusordirectlyfromtheground.thediagramalsoinstructsthetestlaboratoryto only perform the east edge test with a north deflector when the north deflector is installed oneachrow.formountingsystemsthatonlyincludethenorth deflectoron thenorthrowofanarray,thenorthdeflectorshouldnotbeusedinthistest. Figure10:Sideviewofeastedgelowslopetest