NFPA 70E – Electrical Safe Work Practices.ppt

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1、NFPA 70E Standard for Electrical Safety in the WorkplaceDan LazorcakWill Rogers,Objectives,NFPA 70E Overview and BackgroundNFPA 70E vs-OSHA complianceNFPA 70E Safety Related Work Practices&DefinitionsImplementation 3 Step ProcessLabeling and PermitsCase Study,What is NFPA 70E?,A document that addres

2、ses electrical safety standards for employees who install,maintain or repair electrical systems2004 Edition has an introduction,4 Chapters and 13 AnnexesChapter 1 Safety-Related Work Practices is the core of 70EChapters 2-4:2-Safety-Related Maintenance Requirements3-Safety Requirements for Special E

3、quipment4-Installation Safety RequirementsAnnexes A M:Lots of good information and examples,NFPA 70E A little background,First published in 1979 as a joint effort between NFPA and OSHA1995 Edition(5th edition)included many of the current workplace safety requirements2000 Edition(6th edition)added re

4、quirements for Flash Protection Boundaries&Flame Retardant Clothing2004 Edition(7th edition)emphasizes Safe Work Practices,NFPA 70E A little background,OSHA bases its electrical safety mandates,found in 1910 and 1926 on the information found in NFPA 70ENFPA 70E is recognized as the tool that illustr

5、ates how an employer might comply with OSHA standards re:electrical safe work practicesRelationship can be described as:OSHA is the“SHALL”NFPA 70E is the“HOW”,Is Compliance with 70E Mandatory?,Simple answer:NO!70E is a national consensus safety standard published by the NFPA to assist OSHA in prepar

6、ing electrical safety standardsBUTOSHA has proposed to use the 2000 edition of 70E as the basis for future revisions to its electrical safety-related work practices(4/5/04 Federal Register),Can I be cited for failing to comply with the requirements of NFPA 70E?.,YES!.In the event of an electrical sh

7、ock or arc flash burn incident,history has shown OSHA will cite under:1910.335,which requires the use of PPE when working where a potential electrical hazard exists1910.132,which requires the employer to assess the workplace for hazards and the need for PPEGeneral Duty Clause,Is Compliance with 70E

8、Mandatory?,Bottom line.The employer is expected to use consensus standards to help achieve compliance with OSHA regulationsIn a 2003 Standards Interpretation letter,OSHA stated that 70E can be used as evidence of whether or not an employer acted reasonably,NFPA 70E Details&Definitions,Definitions,Fl

9、ash Hazard:A dangerous condition associated with the release of energy caused by an electric arcCan result in temperatures up to 35,000 degrees F4 times hotter than the surface of the sunCan produce fatal burns up to 5ft.from the arc and severe burns up to 10ft.away,Definitions,Arc-Blast:Results fro

10、m the rapid heating of air and the vaporization of metalCreates a pressure wave that can damage hearingCauses a concussion resulting in memory lossCan result in flying metal,some of which may be molten and/or toxic,Definitions,Flash Hazard Analysis:A study investigating a workers potential exposure

11、to arc-flash energy.Conducted for:Determination of Injury PreventionDetermination of Safe Work PracticesAppropriate levels of PPE,Definitions,Flash Protection Boundary:An approach limit(distance from exposed live parts)which a person could receive a second degree burn if an electrical arc flash were

12、 to occurIncident Energy:Amount of energy impressed on a surface,a certain distance from the source,generated during an electrical arc event(cal/cm2),Chapter 1:Safety-Related Work Practices,Training requirements for Qualified and Unqualified personsRequires an Electrical Safety Program and specifies

13、 its contentStresses the need to work on equipment that is de-energized via Lockout/TagoutOSHA only allows work on live electrical parts under 2 special circumstances:When continuity of service is requiredWhen de-energizing equipment would create additional hazards,Chapter 1:Safety-Related Work Prac

14、tices,Electrical Hazards Analysis for Shock and FlashApproach Boundaries for ShockArc-Flash BoundariesSelection of PPE for Working on Energized Electrical EquipmentEnergized Electrical Work Permits,NFPA 70E-Implementation,Three Step Process,Conduct both a shock and flash hazard analysis to determine

15、 incident energy potential within the Flash Protection BoundaryDetermine PPE clothing needs based upon the incident energy level associated with the taskSelect PPE matching the hazard to the arc rating of the garment/equipment,Step 1:Conduct a Hazards Analysis-Shock Hazard Analysis,Determines the vo

16、ltage to which personnel will be exposed,boundary requirements and PPE necessary to minimize electrical shockApproach boundaries specified in Table 130.2(C),Step 1:Conduct a Hazards Analysis Flash Hazard Analysis,Determine the Flash Protection Boundary(FPB)based upon calculations found in Section 13

17、0.3(A)Determine the necessary Protective Clothing and PPE to be used for work performed within the FPBBased upon the incident energy exposure of the worker,Step 1:Conduct a Hazards Analysis Flash Hazard Analysis,PPE for use inside the FPB can be determined two ways:Method A:Estimates the incident en

18、ergy level by determining hazard risk category classifications from tables of common work tasks(Table 130.7(C)(9)Method B:Estimates the incident energy level based on knowledge of the electrical system and work practices(Annex D)Note:Annex H Lays out a suggested simplified two category FR clothing s

19、ystem that provides 2 PPE clothing categories,You could memorize 100s of equations,use 200+variables,and pages and pages of calculations,.it seems complex,but several freeware Excel templates make it a little easier.,Heres a couple of examples,And more.,Lets do one real quick.But first well need to

20、define a couple of variables.,Definitions:(with the freeware,you only need to know a few things to get started),DistanceSeems obvious,but the standard is 18”Arc DurationFrom fuse manufacturer(.0084 sec)orBreaker manufacturer(.25 sec),Definitions(continued),Impedance(%Z)at transformerUsually labeled

21、on transformerBolted FaultThis is where TRW needed help.We used the MVA method with our EE.The available amps-NOT a bolted fault,MVA method was best for TRW,Think of a large pipe filled with water,OK,lets do a live example,“Nutshell”version,Get the bolted fault for major systemsDetermine your time(b

22、reaker or fuse)Decide your approach distance(18”?)Plug it in get cal/cm2Determine PPEApply labeling,Why do we do it?.,It seems like a lot of troubleIt takes too longIt costs moneyIts not exactly stimulatingIt not actually the law(yet)Youll get a LOT of resistanceso,WHY?,Just a moment(.0084 seconds t

23、o be exact),Step 1:Conduct a Hazards Analysis Flash Hazard Analysis,Method B ADD WILLS INFO HERE,Step 2:Determine PPE based on Hazards Analysis,There are 5 Hazard/Risk Categories with 0 being the least hazardous and 4 being the most hazardousThe Hazard/Risk Category is determined by the incident exp

24、osure level you calculated in Step 1Compare the Hazard/Risk Category with Table 130.7(C)(11)to determine Protective Clothing needs,Step 3:Select Protective Clothing,Garments are based upon their ability to protect against electric arcsStandard requires that garments have a minimum Arc Rating(maximum

25、 incident energy resistance)General reminderClothing made from meltable fibers(such as acetate,nylon,polyester,etc)are not permitted in fabric underlayers(underwear)next to the skin,Step 3:Select Protective Clothing,Flame Retardant Clothing Pants/Shirts/Cover-allsVoltage Rated Gloves w/Leather Prote

26、ctorsHearing Protection,HardhatArc-Rated FaceshieldLeather Work ShoesFlash SuitsSafety Glasses,PPE Label Example,PPE LEVEL 3,Caution:Arc Flash and Shock Hazard,Minimum PPE Required:FR pants,FR long sleeve shirt,hard hat,safety glasses,arc-rated faceshield,hearing protection,voltage-ratedgloves with

27、leather protectors,leather work shoes,NFPA 70E,Labeling 2002 NEC 110.6,Requires all switchboards,panel boards,industrial control panels and motor control centers to be field marked.Equipment installed after 2002 needs to be labeled.Equipment installed prior to 2002,must be labeled if ANY modificatio

28、ns or upgrades take place.,Energized Electrical Work Permit,Required when working on live electrical equipment 50VPermits shall include the requirements of Article 130(A)(2)Example in Annex JExemptions for qualified persons performing troubleshooting,testing,voltage measuring,etc,Case Study,Case Stu

29、dy:Ford Motor Co.,Electrical incident in Buffalo NY Stamping Plant Sept.1999Electrical apprentice sustained serious burn injuries while attempting to sever cables feeding through a junction boxEmployee cut into a live 460V cable,Case Study:Investigation found,Employee did not lockout all energy sour

30、ces or perform voltage check prior to cuttingFord provides FR coveralls;doesnt require them to be worn under 600VFord doesnt require insulated gloves,faceshields or non-conductive headwear under 440VEmployee wearing safety glasses,non-conductive footwear and non-FR coverallsEmployee was not wearing

31、insulated gloves,faceshields or non-conductive headwear,Case Study Citations,Ford violated 1910.335(a)(1)(i)by not requiring employees to wear FR clothing and insulated glovesFord violated 1910.335(a)(1)(v)by not providing or requiring electricians to wear appropriate face protection.Full faceshield

32、s should have been used.Fined$14,000,Case Study Outcome,Ford agreed to develop,document and implement hazard analysis evaluating plant specific tasks that create the potential for exposure to electrical hazards performed by one or more of Fords 4,000 electriciansAgreement covers all 37 manufacturing

33、 and distribution centers in the US.Agreed to use NFPA 70E to develop the Hazard Analysis,In Closing,Ask Yourself:,Are my employees adequately protected when dealing with energized electrical components?If yes,what means have you used to determine adequacy?Do my employees have the necessary PPE available?If yes,do they know why,when and where to use it?If the answer to either of these questions is NO,you may want to look into NFPA 70E,