UL840-电气产品安全距离的要求

UL840ISBN1-55989-391-5InsulationCoordinationIncludingClearancesandCreepageDistancesforElectricalEquipmentUnderwritersLaboratoriesInc.(UL)333PfingstenRoadNorthbrook,IL60062-2096ULStandardforSafetyforInsulationCoordinationIncludingClearancesandCreepageDistancesforElectricalEquipment,UL840SecondEdition,DatedMay20,1993Revisions:ThisStandardcontainsrevisionsthroughandincludingSeptember7,2000.ULisintheprocessofconvertingitsStandardsforSafetytotheStandardGeneralizedMarkupLanguage(SGML),andimplementinganSGMLcompliantdocumentmanagementandpublishingsystem.SGML-aninternationalstandard(ISO8879-1986)-isadescriptivemarkuplanguagethatdescribesadocument’sstructureandpurpose,ratherthanitsphysicalappearanceonapage.SignificantbenefitsthatwillresultfromUL’suseofSGMLandthesenewsystemsincludeincreasedproductivity,reducedturnaroundtimes,anddataandinformationconsistency,reusability,shareability,andportability.However,thefonts,pagination,andgeneralformattingofUL’snewelectronicpublishingsystemdifferfromthatofUL’spreviouspublishingsystem.Consequently,whenrevisionpagesareissuedforaStandardwiththenewpublishingsystem,thesedifferencesmayresultintheprintingofpagesonwhichnorequirementshavebeenchanged-theseadditionalpagesresultfromrelocationoftextduetorepaginationandreformattingoftheStandardwiththenewpublishingsystem.Textthathasbeenchangedinanymannerismarkedwithaverticallineinthemargin.Changesinrequirementsaremarkedwithaverticallineinthemarginandarefollowedbyaneffectivedatenoteindicatingthedateofpublicationorthedateonwhichthechangedrequirementbecomeseffective.TherevisionsdatedSeptember7,2000includeareprintedtitlepage(page1)forthisStandard.TherevisionsdatedOctober6,1999wereissuedforeditorialcorrections.Thesecorrectionsincludeanycombinationofthefollowing:UpdatedForeword(itemD);UpdatedScope;titlechangestoUL489and/orUL1950;Withdrawnstandards,UL519andUL547,beingreplacedbyUL2111;Removalofthe“94”flammabilityclassification.Theserevisionsmayalsoincludeothermiscellaneouseditorialcorrections.Asindicatedonthetitlepage(page1),thisULStandardforSafetyisanAmericanNationalStandard.AttentionisdirectedtothenoteonthetitlepageofthisStandardoutliningtheprocedurestobefollowedtoretaintheapprovedtextofthisANSI/ULStandard.ThemasterforthisStandardatUL’sNorthbrookOfficeistheofficialdocumentinsofarasitrelatestoaULserviceandthecomplianceofaproductwithrespecttotherequirementsforthatproductandservice,oriftherearequestionsregardingtheaccuracyofthisStandard.UL’sStandardsforSafetyarecopyrightedbyUL.NeitheraprintedcopyofaStandard,northedistributiondisketteforaStandard-on-DisketteandthefilefortheStandardonthedistributiondisketteshouldbealteredinanyway.AllofUL’sStandardsandallcopyrights,ownerships,andrightsregardingthoseStandardsshallremainthesoleandexclusivepropertyofUL.Allrightsreserved.Nopartofthispublicationmaybereproduced,storedinaretrievalsystem,ortransmittedinanyformbyanymeans,electronic,mechanicalphotocopying,recording,orotherwisewithoutpriorpermissionofUL.RevisionsofULStandardsforSafetyareissuedfromtimetotime.AULStandardforSafetyiscurrentonlyifitincorporatesthemostrecentlyadoptedrevisions.SEPTEMBER7,2000−UL840tr1ULprovidesthisStandard″asis″withoutwarrantyofanykind,eitherexpressedorimplied,includingbutnotlimitedto,theimpliedwarrantiesofmerchantabilityorfitnessforanypurpose.InnoeventwillULbeliableforanyspecial,incidental,consequential,indirectorsimilardamages,includinglossofprofits,lostsavings,lossofdata,oranyotherdamagesarisingoutoftheuseofortheinabilitytousethisStandard,evenifULoranauthorizedULrepresentativehasbeenadvisedofthepossibilityofsuchdamage.InnoeventshallUL’sliabilityforanydamageeverexceedthepricepaidforthisStandard,regardlessoftheformoftheclaim.ULwillattempttoanswersupportrequestsconcerningelectronicversionsofitsStandards.However,thissupportserviceisofferedonareasonableeffortsbasisonly,andULmaynotbeabletoresolveeverysupportrequest.ULsupportstheelectronicversionsofitsStandardsonlyiftheyareusedundertheconditionsandoperatingsystemsforwhichitisintended.UL’ssupportpoliciesmaychangefromtime-to-timewithoutnotification.ULreservestherighttochangetheformat,presentation,filetypesandformats,deliverymethodsandformats,andthelikeofbothitsprintedandelectronicStandardswithoutpriornotice.PurchasersoftheelectronicversionsofUL’sStandardsforSafetyagreetodefend,indemnify,andholdULharmlessfromandagainstanyloss,expense,liability,damage,claim,orjudgement(includingreasonableattorney’sfees)resultingfromanyerrorordeviationintroducedwhilepurchaserisstoringanelectronicStandardonthepurchaser’scomputersystem.Ifasingle-userversionelectronicStandardwaspurchased,onecopyofthisStandardmaybestoredontheharddiskofasinglepersonalcomputer,oronasingleLANfile-serverorthepermanentstoragedeviceofamultiple-usercomputerinsuchamannerthatthisStandardmayonlybeaccessedbyoneuseratatimeandforwhichthereisnopossibilityofmultipleconcurrentaccess.Ifamultiple-userversionelectronicStandardwaspurchased,onecopyoftheStandardmaybestoredonasingleLANfile-server,oronthepermanentstoragedeviceofamultiple-usercomputer,oronanIntranetserver.