基本的电气安全(1)

1BasicElectricalSafety基本的电气安全PRODUCTIONTECHNICALTRAININGTEAM生产技术培训组2GeneralOpeningComments前言SubpartSoftheOSHAGeneralIndustryStandardscontainstheOSHArulesthatgovernelectricalsafety-relatedworkpractices.Withinthesestandards,OSHA29CFR1910.331-.335arerequirementsthatrelatetothetrainingof“Qualified”and“Unqualified”personsinelectricalsafeworkpractices.职业安全与卫生条例OSHA一般工业标准的S部分包含OSHA的规定，这些规定指导和管理与电气安全相关的工作实践。在这些标准中，OSHA29CFR1910.331－.335对培训电气安全工作中的“合格”和“不合格”人员的培训提出了要求。AccordingtoOSHA,“Qualified”personsforthisfacilityareemployeesthatfunctionintheinstrumentandelectricalcraftsoftheMaintenanceDepartment.“Unqualified”persons,arethoseemployeeswho,intheirroutineworkduties,mayencounterarelativelyhighriskofinjuryduetoelectricalhazards.按OSHA的规定，工厂中的“合格”人员是指维修部门从事仪表和电气工艺的雇员，而“不合格”人员是指那些在履行他们的日常工作职责时相对容易受电气危险伤害的雇员。3Siteemployeessuchas,OperationsDept.processunitpersonnel,MaintenanceDept.mechanicalcraftsandothermaintenancefieldpersonnel,laboratorytechnicians,andWarehousefieldpersonnelwouldbeconsideredbyOSHAtobeinthe“Unqualified”category.Inaddition,someEngineeringandTechnicaljobclassificationsbyassignmentordutiesmayalsobeconsideredinthe“Unqualified”categoryforpurposesofthistraining.现场的雇员，如生产部工艺装置人员、维修部机械专业和其它方面的维修人员、实验室技术人员和仓库方面的人员，在OSHA看来是属于“不合格”人员一类。另外，为培训的目的，被分配或从事设计和技术工作的人员也可以划入“不合格”人员一类。ThistrainingmodulehasbeenpreparedtoaddresstheOSHA29CFR1910.332requirementsfortrainingof“Unqualified”employeesinelectricalhazardsandworkpracticesnecessaryfortheirsafety.这个培训模块的编写是为了达到OSHA29CFR1910.332的要求，培训在电气危险和工作实践方面“不合格”的人员，以增强他们在安全方面的能力。Topicsincludetheeffectsofelectricalshockonthehumanbody,hazardsassociatedwithelectricity,localsourcesofelectricalhazard,causesofelectricalaccidents,protectivemeasurestopreventelectricalinjuries,andareviewoflocalplantpoliciesandproceduresthataddresselectricalsafety.下面介绍的内容包括：触电对人体的影响，有关电的危险，装置内的电气危险源，电气事故发生的原因，防止电气伤害的措施，以及SECCO关于电气安全方面的方针和程序。4INTRODUCTION引言Itiswellknownthatthehumanbodywillconductelectricity.Theelectricalcurrentflowsthroughthebodyandexitsattheothercontactpoint,usuallycalledtheground.众所周知，人体是导电的。电流流经人体后进入大地，对人体造成伤害的触电事故。Eachyearmanyworkerssuffersomeseriousinjuries,and/ordeathfromelectricshock.Itisestimatedthattherearemorethan1000electricalfatalitiesingeneralindustryeachyear,andover30,000injuries.Someadditionalstat’s:每年有许多工人因触电而受重伤或死亡。据估计，每年一般工业行业因触电死亡有1000多人，30000多人受伤。另外还有一些统计数字：99%ofthefatalitiesinvolvedmales.99%的死者是男性64%diedpriortotheageof35.64%的亡者死前年龄不到35岁。41%wereonthejoblessthan1year.41%的人参加工作还不到1年。1personiselectrocutedinthehomeevery25hrs.And1everydayatwork.人们在家里，平均25小时有1人触电死亡，而在工作时每天就有1人触电死亡Infact,electrocutionisconsideredtobethefifthleadingcauseofworkrelatedinjuryanddeath事实上，人们已经把触电死亡列为第5位因工作伤亡的原因。5TheEffectsOfElectricalShock触电的影响Theeffectsthatelectricshockwillhaveonanindividualwilldependuponthetypeofcircuit,itsvoltage,resistanceamperage,thepathwaythroughthebody,andthedurationofthecontact.Electricshockproducedbyalternatingcurrentsofpowerlinefrequency(normally50Hertz)passingfromhandtofootforonesecondcanproducethefollowingeffects:触电对人体产生的影响要视电路的类型，电压，电阻大小，电流流经人体的路线以及接触持续的时间而定。由电源线（通常为50赫兹）的交流电从手流到脚1秒钟的触电会产生以下的后果：1milliamp-barelyperceptible1毫安－刚能觉察到（手指麻刺）9-25milliamps-Interruptionofmuscularcontrol.9－25毫安－对肌肉的自控中断（手迅速麻痹，呼吸困难）75milliamps-interruptionofheartfunction75毫安－心脏功能中断（心室开始颤动）4amps-Immediatecardiacarrest4安培－心搏立即停止6Nearlyinstantaneousfatalitiescanoccurfrom20milliampsorgreater.Eveniftheshockingcurrentdoesnotpassthroughvitalorgansornervecenters,severeinternalburnscanoccur,andinsomecasesinjuriessuchasthesecanbethecauseofdelayedfatalities.在电流强度为20毫安或以上时，就有可能会出现瞬间死亡。即使触电的电流没有流经致命的器官或神经中枢，也会出现体内的严重烧伤，在有时候，这样的烧伤会导致以后的死亡。Burnssufferedinelectricalaccidentsareofgreatconcern.Theseburnsmaybeofthreebasictypes:因电气事故引起的烧伤引起了人们的特别关注。这类烧伤有三种基本的类型：wElectricalburns电烧伤wArcburns电弧灼伤wThermalcontactburns热烫伤7Electricalburnsaretheresultofelectriccurrentpassingthroughbodytissuesandresultingdamageiscausedwhentheenergysourceheatissohighthatthebodycannotdissipateitandthetissueisburned.电烧伤是电流流经人体组织产生的结果，它造成对人体的伤害是因为当电能相当高时，人的身体无法把热量散发，将人体组织灼伤。Typically,suchelectricalburnsareslowtoheal.特别是这类电烧伤治愈是很慢的。Arcburns,ontheotherhand,aretheresultofhightemperaturesproducedbyelectricarcsoccuringclosetothebody.Theseburnsaresimilartotheburnsandblistersproducedbyanyhightemperaturesource.另一方面，电弧灼伤是离人体很近的电弧产生的高温造成的。这类烧伤与任何高温引起的烧伤和水泡相类似。8Finally,thermalcontactburnsarethosenormallyexperiencedfrommakingskincontactwithhotsurfacesofoverheatedelectricconductors,conduits,orotherenergizedequipment.最后，热烫伤通常是皮肤接触高温电导体、导管或其它带电设备的热表面所引起的。Itispossibleforavictimofelectricshocktoexperienceallthreetypesofburnssimultaneously.触电的人有可能同时受到这三种类型的烧伤。Secondaryinjuriesarefrequentlyassociatedwithelectricalshock.Theseinjuriesarenormallyassociatedwithfallsorcollisionsrelatedtotheelectricalshockcausinginvoluntarymusclereactions.Obviously,inthecaseoffallstheresultcanalsobefatal.触电还会经常引发二次伤害。这类伤害通常与因触电，引起肌肉不自觉的反射而跌倒或碰撞。显然，如果跌倒的话，也会引起死亡。9HAZARDSASSOCIATEDWITHELECTRICITY有关电的危险Ifanindividualcomesincontactwithanungroundedconductorwhiletheyareincontactwiththegro