NFPA 70E Electrical Safety in the Workplace

1. NFPA 70E Electrical Safety in the Workplace PA Chamber Presentation � May 19, 2009 Jacque R. Creamer, Jr. PPL Corporation

2. 2 Introduction Current Trends show a rise in accident rates Arc flash incidents OSHA has been citing under General Duty Clause 4 categories of NFPA 70E Rescue Apparel Attendant Ground Testing

3. 3 Introduction Five to 10 arc flash explosions occur in electric equipment every day in the United States. This number does not include cases in which the victim is sent to an ordinary hospital. Instead, these incidents are so severe the victims require treatment from a special burn centers.

4. 4 Standards / Interaction OSHA 29CFR1910 Subpart S National Electrical Code � NFPA 70 IEEE Standard 1584-2002 NFPA 70E

5. 5 NFPA 70E Standard National Consensus Standard Can be cited by OSHA Provides guidance on electrical safety-related work practices and maintenance of electrical systems and equipment

6. 6 NFPA 70E Standard and OSHA Work is to be Performed on De-Energized Equipment Equipment must be put in an electrically safe work condition prior to performing maintenance It�s the Law But� We have to be able to test live circuits before repairs We must verify absence of voltage �not dead until tested dead� We may have to troubleshoot

7. 7 NFPA 70E Standard and OSHA Necessary Loophole Exceptions to the �RULE� 1. Where removing the power is not feasible due to the equipment design or operational limitations (example � voltage testing). 2. Where de-energizing would introduce and increased or additional hazard.

8. 8 Arc Flash Causes Dust and impurities on insulating surfaces can provide a path for current, allowing it to flashover and create an arc across the surface. Corrosion of equipment creates impurities on insulating surfaces. Corrosion can also weaken the contact surface between conductor terminals increasing resistance causing heat, producing sparks and arcing faults to closest ground source. Improper work procedures. Accidental contact; dropped tools. Overvoltage across narrow gaps. Failure of insulating materials.

9. 9 Arc Flash Hazard A dangerous condition associated with the explosive release of energy caused by an electrical arc due to either a phase to ground or phase to phase fault. The explosive energy release resulting from an arcing fault can consist of: Heat Pressure Wave Vaporized Metal (Plasma) Molten Metal Projectiles

10. 10 Arc Flash Hazard Electrical arcs produce some of the highest temperatures known to occur on earth � approximately 35,000 degrees Fahrenheit. This is four times greater than the surface of the sun. All known materials vaporize at this temperature. When any material vaporizes it expands in volume (Water 1670 times, Copper 67,000 times) The air blast produced can spread molten metal great distances by the force produced. Rapidly expanding gases, molten metal, metal plasma, extreme pressure and sound waves are produced.

11. 11 Arc Flash Hazard Blast pressure waves can throw workers across rooms, knock workers off ladders. Clothing can be ignited several feet away. Depending on the clothing, burns can be severe when clothing continues to burn and melts to the skin. Hearing loss can occur from the sound blast. Magnitude can be as high as 140dB at a distance of 2 feet from the arc/blast.

12. 12 Arc Flash Hazard Potential Arc Flash injuries can include: Burns Concussions Collapsed Lungs Loss of Limb

13. 13 Arc Flash Hazard An arc flash hazard exists when you are within a certain distance of work that is being done around energized equipment. The distance is determined by the amount of fault current that is available.

14. 14 Electrical Shock Hazard An electric shock is a jarring, shaking sensation resulting from current passing through your body. Electrical shock hazards exist when you approach within a certain distance of an energized component or come in contact with energized components. The distance is determined by the voltage value of the components that are being worked on.

15. 15 Reducing Shock & Arc Flash Hazards Boundary A distance established to limit the approach to work areas having electric shock or arc-flash hazards Two Distinct Boundaries Restricted Approach Boundary (Observed) Flash Protection Boundary (Physical)

16. 16 Working Near and Working On You are working �near� an exposed energized part when you are close enough to inadvertently touch the part or cause a short circuit by not being in control of your tools, loosing your balance, etc. You are not working near or on an energized electrical facility when simply walking by or visually inspecting it at a safe distance.

17. 17 Responsibility Two things you need to remember: Each employer has a responsibility to provide the appropriate training and personal protective equipment. 2. Employees have the responsibility to inform their supervisor when they do not feel adequately trained, skilled, and/or knowledgeable to safely perform a work assignment.

18. 18 Responsibility Facility owner / employers must calculate the hazardous energy available if a short circuit occurs while performing a variety of different electrical tasks. The results of these calculations are used to determine the FR clothing and PPE requirements to perform task safely. These minimum requirements are necessary to greatly reduce exposure to injury in the event of a short circuit and arc flash.

19. 19 A Qualified Employee is� One who has skills and knowledge related to the construction and operation of certain electrical equipment and installations, and has received safety training on the hazards involved Note: On a task basis, an employee is either qualified or unqualified depending on the individual�s training and/or work experience. For example, it is possible to be qualified with all the electrical equipment in a particular work area, and yet unqualified with a new piece of equipment

20. 20 Training Technical Classroom On-the-Job Training (OJT) Job Performance Measures (JPMs) This does not mean that an individual must be formally trained to perform every job or task they do.

21. 21 Flash Hazard Analysis A Flash Hazard Analysis Shall Determine Flash Boundary Approach boundary from exposed energized parts within which an individual without proper PPE could receive the onset of a 2nd degree burn. Incident heat energy of possible arc flash based on: Available fault current Fault clearing time Distance from exposed equipment Directional dissipation of energy (arc in a box scenarios) PPE Requirements within the Flash Boundary Flash Boundary > Shock Boundary for higher Voltages

22. 22 Protective Boundaries and Clearances

23. 23 Protective Boundaries and Clearances

24. 24 Protective Boundaries and Clearances

25. 25 Protective Boundaries and Clearances Establish a Flash Protection Boundary when working on or near energized facilities. This visual boundary provides an alert to unqualified persons when there is a potential for arc-flash or shock hazards at the work site. Only qualified workers wearing FR apparel and the proper PPE, can enter this boundary. Unqualified workers, also wearing the proper FR apparel and PPE, may enter this boundary�.but only when escorted by a qualified worker.

26. 26 Establishing Boundaries Maintain the Flash Protection Boundary at all times while there are exposed energized parts Flash Protection Boundary may be less than specified if the work area is a room, vault or manhole where the boundary size is limited by the walls Change boundary to while there are activities being performed.Change boundary to while there are activities being performed.

27. 27 Protective Boundaries and Clearances When working on or near exposed energized lines or equipment >50 volts, qualified workers must remain outside the Restricted Approach Boundary distances wear proper PPE while using approved work methods. Unqualified workers must not encroach on these boundary distances.

28. 28 Protective Boundaries and Clearances

29. 29 Protective Boundaries and Clearances Assign a Trained Watchperson when a qualified worker is inside the Restricted Approach Boundary and working on energized facilities >600 volts. The trained watchperson�s duties are: 1. Continuously observe the qualified worker(s), and provide an alert in anticipation of a dangerous situation. 2. Stage the proper tools, PPE, and equipment to perform a rescue. 3. Stage the arc-flash apparel that is necessary to perform the rescue. 4.Be qualified and ready to perform CPR/ First Aid if necessary. The only exception to this rule is emergency work to protect life and property.

30. 30 Rescue Equipment Equipment placed at the work site for the sole purpose of removing a person from an energized conductor. This may include but is not limited to insulated hooks, certain hot line tools, or insulating gloves.

31. 31 Protective Boundaries and Clearances When a Flash Protection Boundary is required, use one of these methods: A. Make a barricade of cones, flagging, banner tape, signs, or rope to mark off the area. - or - B. Post an attendant to control access to the work area.

32. 32 Attendant Primary duty is to keep unqualified persons outside of a hazardous work area where they may be exposed to electrical shock or arc-flash Must be on guard as long as there is a potential for unqualified persons to be exposed to electrical shock or arc-flash hazards.

33. 33 Protective Boundaries and Clearances Prior to working within the Restricted Approach Boundary, remove conductive articles of jewelry or render them non-conductive if they increase the risk of electrical contact.

34. 34 Using Protective Rubber Goods While working on energized facilities within the Restricted Approach Boundary, use the rubber goods and/or tools shown below (minimum).

35. 35 Using Protective Rubber Goods Inspect all protective rubber goods and gloves for defects, both inside and out, and air test gloves before each use. Do not use rubber goods beyond their test date. Inspect leather protector gloves for defects and contamination before each use, and do not use leather protectors for any other purpose. Wear leather protectors over all insulating rubber gloves. One exception: Class 00 gloves can be used without protectors at voltages below 250�volts when high finger dexterity is required. Have the gloves dielectrically tested before using them again.

36. 36 Using Protective Rubber Goods Put on the appropriate personal rubber protective goods before work on energized facilities, and do not remove them or exchange class until you are out of the Restricted Approach Boundary. When working on facilities <600 volts, cover all exposed energized parts in the immediate work area, and within arms-reach, including the extended reach of any non-insulated hand-held tools. When working on energized facilities >600-15kV, cover all exposed parts and paths to ground in the immediate work area, and within arms-reach, including the extended reach of any non-insulated hand-held tools.

37. 37 Working on Electrical Equipment Wear the proper PPE when testing or doing any other type of work on energized metering equipment: Class O rubber gloves for <600 volts, Class� 2 >600 volts, Arc-flash apparel, Eye and face protection, Tested overshoes or insulating mats in wet areas or if the floor is metal.

38. 38 Temporary Protective Grounding When applying or removing grounds, use the proper rubber protective equipment and/or tools for the expected operating voltage. Verify the circuit or equipment is de-energized at the ground connection point before installing. Test for absence of voltage using the appropriate voltage testing device. Check the voltage detection device before and after each use to assure reliability.

39. 39 Temporary Protective Grounding Inspect grounds before each use, and test grounding devices on a periodic basis. Do not use a ground set with an expired test date or with defects. Inspections - not to exceed 1 year. Inspect more often as service conditions may require. Testing - not to exceed 3 years. Service conditions, standards, or manufacturer�s instructions may require more frequent testing. Test repaired or modified grounds before returning them to service.

40. 40 Temporary Grounding Inspections should include: Look for cuts in the protective sheath and damage to the conductors. Check clamps and connector strain relief devices for cracks and tightness. Check cables and clamps before and after each use. Testing requirements: Heavy usage, service conditions, site procedures, or manufacturer�s instructions may require more frequent testing. Electrical resistance must not exceed the acceptable range as shown on the equipment tag or as stated by the manufacturer. Return high-resistance ground sets for repair or replacement. Test repaired or modified grounds before returning them to service.

41. 41 Temporary Protective Grounding Attach temporary safety grounds to a proper ground point. System Neutral Existing driven ground rod Existing guy rod Driven bull point Do not ground through fuses, transformers, or switching devices where you cannot visually verify the circuit continuity. Ensure that safety ground cables and attachment clamps are capable of conducting the anticipated fault currents. Install either single-point or multi-point grounding to provide an Electrically Safe Work Condition.

42. 42 Arc Flash PPE System

43. 43 Wearing Arc Flash Apparel DO NOT wear clothing made from synthetic materials or blends of natural and synthetic fibers inside a Flash Protection Boundary. Such as acetate, nylon, polyester and spandex Wear arc-flash apparel rated for the potential arc-flash conditions. The ATPV rating must be on the garment label. Clothing worn under a flash suit or under FR apparel must also be flame resistant, or made of 100% natural fiber Such as cotton, wool, or silk as labeled by manufacturer. Button FR clothing at the wrist and neck.

44. 44 Wearing Arc Flash Apparel NOTE: Layering increases the effective level of protection (e.g. 2 layers of class 2 FR = class 3 protection) Arc-flash apparel / FR clothing should not fit tightly when layered. The air gap between layers provides additional protection.

45. 45 Wearing Arc Flash Apparel Inspect all arc-flash PPE products for damage before and after every use. Check for rips and tears, as well as any soiling (especially oil or other combustible) which could adversely impact the arc-thermal protective characteristics of the product. Return damaged products to the manufacturer for repairs or cleaning. Follow the garment manufacturer�s instructions for cleaning and maintaining arc-flash apparel / FR clothing. The surfaces of arc face shields and hood shields are not scratch or chemical resistant. Use only warm, soapy water for cleaning. Pat dry using a soft cloth.

46. 46 Arc Flash Apparel Highest level of protection A complete FR clothing system that covers the entire body, except for the hands and feet. The system includes a jacket, pants, and a bee keeper type hood fitted with a face shield. Flash suits also have a specific ATPV rating

47. 47 Eye and Face Protection Face shield worn for protection against electric arc must have a minimum Arc Thermal Performance Value (ATPV) of 8 cal/cm2. The requirements for face protection are specified in NFPA 70E

48. 48 Task Matrix (Example)

49. 49 NFPA 70E Electrical Safety in the Workplace

50. 50 NFPA 70E Electrical Safety in the Workplace

51. 51 NFPA 70E Electrical Safety in the Workplace Questions? Jacque R. Creamer, Jr. Sr. Staff Safety & IH PPL Services � Safety Operations jrcreamer@pplweb.com