1. Electrical Hazards and Arc Flash Awareness Instructor: Brian Terry

2. Class Outline Welcome/Overview Accident Statistics Electrical Terminology Introduction to Electrical Hazards –Electrical Shock / Electrocution –Electrical Burns –Arc Flash –Arc Blast Industry Standards Arc Hazard Analysis

3. Class Outline Arc Hazard Boundary Four Approach Boundaries –Limited Approach Boundary –Restricted Approach Boundary –Prohibited Approach Boundary –Flash Protection Approach Boundary Qualified and Unqualified Persons Energized Electrical Work Permit Arc Flash Hazard Marking Requirements

4. Class Outline Hazard Risk Categories PPE / FR Clothing Safe Work Practices Identifying Other Electrical Hazards –Inadequate Wiring Hazards –Overload Hazards –Grounding Hazards –Identifying Disconnects –Clear Spaces –Ground Paths –Guarding Live Parts –Clues that Electrical Hazards Exist

5. Accident Statistics

6. National Safety Council Statistics 30,000 electrical shock accidents occur each year. 1,000 fatalities due to electrocution occur each year. 5 to 10 arc flash explosions occur in electrical equipment every day. 2,000 workers are sent to burn centers with severe injuries each year.

7. Electrical Injuries In 2010 – –1,537,600 All industries, all occupations –3,394 persons injured from contact w/current –2,000 injured from electrical burns From 1992 – 2001 (9 year period) –44, 363 injuries –27,262 from shock –17,101 from arc flash burns

12. Introduction to Electrical Hazards

13. Hazards of electricity There are five main types of electrical injuries: –Electrical shock –Electrocution (death due to electrical shock) –Electrical Burns –Arc Flash –Arc Blast

14. Electrical Shock Received when current passes through the body Severity of the shock depends on: –Path of current through the body –Amount of current flowing through the body –Length of time the body is in the circuit LOW VOLTAGE DOES NOT MEAN LOW HAZARD

15. Dangers of Electrical Shock Currents greater than 75 mA* can cause ventricular fibrillation (rapid, ineffective heartbeat) Will cause death in a few minutes unless a defibrillator is used 75 mA is not much current – a small power drill uses 30 times as much * mA = milliampere = 1/1,000 of an ampere

16. How is an electrical shock received? When two wires have different potential differences (voltages), current will flow if they are connected together If you come into contact with an energized (live) wire, and you are also in contact with a Neutral, grounded wire, a conductor with a different phase voltage, current will pass through your body and YOU WILL RECEIVE A SHOCK

17. How is an electrical shock received? If you are in contact with an energized wire or any energized electrical component, and also with any grounded object, YOU WILL RECEIVE A SHOCK! You can even receive a shock when you are not in contact with a ground –If you contact both wires of a 240-volt cable, YOU WILL RECEIVE A SHOCK and possibly be electrocuted

18. Electrocution Accidental death by electric shock. An average of one worker is electrocuted on the job every day. NSCS states that 1,000 fatalities due to electrocution occur each year.

19. Electrical Burns Most common shock-related, nonfatal injury Occurs when you touch electrical wiring or equipment that is improperly used or maintained Typically occurs on the hands Very serious injury that needs immediate attention

20. Arc Flash Arc flash occurs when an electrical current passes through air. It creates temperatures up to 30,000 o F It burns skin and ignites clothing causing additional burns. It can create an explosion It can create dangerous vapors

21. Arc Blast Arc blast occur when the extreme temperatures of the electrical arc cause explosive expansion of both the surrounding air and the metal in the arc’s path. It creates extremely high air pressure A very loud sound The force sends flying shrapnel and molten metal in a 270 o outward radius.

22. What happens during an Arc Flash /Blast? An Arc Flash is the result of a rapid release of energy due to an arcing fault between a phase bus bar and another phase bus bar, Neutral or a Ground. During an arc fault, The ionized air is the conductor. After the short burns away, the arc fault is then sustained by the establishment of highly conductive plasma. This massive energy discharge burns the bus bars, vaporizing the copper, expanding rapidly into an explosive volume of approximately 40,000 to 1. This explosion devastates everything in its path, creating deadly shrapnel as it dissipates.

23. Laboratory Controlled Arc Blast

24. Arc Fault ABAB Short Circuit

25. Electrical Arc Flash Pressure Waves Copper Vapor: Solid to Vapor Expands by 67,000 times Molten Metal Intense Light Hot Air-Rapid Expansion 35,000 °F Shrapnell Sound Waves

33. > Indicates Meter Pegged Results SoundSound 141.5 db @ 2 ft. T2 >225°C / 437°F T3 50°C / 122°F P1 >2160 lbs/sq.ft > 225°C / 437°F T1

34. What about Circuit Protection? The arc fault current is usually much less than the available bolted fault current and below the rating of circuit breakers. Unless these devices have been selected to handle the arc fault condition, they will NOT trip and the full force of an arc flash will occur.

35. Are there any circuit protection devices that can suppress fault currents during arc flash conditions? The answer is Yes!, some companies incorporate transformers and other arc fault suppression devices in there circuit breakers that limit the amount of fault current available during an Arc flash condition. These are being developed and may be available for certain applications. But by NO means, this takes the complete arc flash hazard away.

36. Why focus on Arc Flash? In the early 1980’s Ralph Lee published a paper in the IEEE Transactions on Industrial Applications, titled“ The Other Electrical Hazard: Electric Arc Blast Burns” The effect of this paper caused industry to realize that protection was needed against this electrical hazard and four industry standards were developed.

37. Industry Standards

38. Industry Standards for arc flash prevention OSHA 29 Code of Federal Regulations (CFR) part 1910 Subpart S NFPA 70 National Electrical Code NFPA 70E Standard for Electrical Safety Requirements for Employee Workplaces. IEEE Standard 1584 Guide for Performing Arc Flash Hazard Calculations.

39. Compliance with OSHA involves adherence to a six-point plan: 1. A facility must provide, and be able to demonstrate, a safety program with defined responsibilities. 2. Calculations for the degree of Arc Flash Hazard. 3. Correct personal protective equipment (PPE) for workers. 4.Training for workers on the hazards of Arc Flash. 5. Appropriate tools for safe working. 6. Warning labels on equipment. (provided by the owner of the equipment, Not manufacturers)

40. OSHA 29CFR1910.335 (a) (1) (i) Employees working in areas where there are potential electrical hazards shall be provided with, and shall use, electrical protective equipment that is appropriate for the specific parts of the body to be protected and for the work to be performed.

41. Requirements for safe work practices Addresses hazards: –Shock –Arc Flash Requirements for shock and arc flash boundaries Requirements personal protective equipment NFPA 70E Standard for Electrical Safety

42. NFPA 70A Layout

43. Mitigation of Electrical Hazards What do you thinks is the best practices to use when managing the electrical hazards in your workplace? Knowing your environment and being aware of your surroundings Know the electrical system and associated hazards Be mindful of your coworkers and their locations Use proper PPE for the conditions and equipment Know the proper procedures for installations and maintenance of equipment

44. Qualified vs Unqualified Qualified Person. A qualified person shall be trained and knowledgeable of the construction and operation of equipment or a specific work method and be trained to recognize and avoid the electrical hazards that might be present with respect to that equipment or work method. One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved. A person can be considered qualified with respect to certain equipment and methods but still be unqualified for others.

45. Qualified vs Unqualified Unqualified Persons. Unqualified persons shall be trained in, and be familiar with, any electrical safety related practices necessary for their safety. A person who is not a qualified person.

46. Why a Safety Program Safer work environment Personnel Safety Fewer work related injuries Fewer days missed due to work injuries Lower insurance rates Fewer medical cost to employee and employer A more confident workforce The saving of lives of qualified and unqualified personnel

47. Identifying Electrical Hazards Electrical Hazard. A dangerous condition such that contact or equipment failure can result in electric shock, arc flash burn, thermal burn, or blast. Three Types of Electrical Hazards Electrical Shock Arc-flash or Arc-blast Secondary Injury

48. Shock Hazard Shock Hazard. A dangerous condition associated with the possible release of energy caused by contact or approach to energized electrical conductors or circuit parts. Shock: Sudden stimulation of nerves and contractions of muscles caused by the discharge of electricity through the body. Most electrical fatalities are caused by shock not arc flash

49. Arc Flash Hazard Arc Flash Hazard. A dangerous condition associated with the possible release of energy caused by an electric arc. Arc Flash Hazard Analysis. A study investigating a worker’s potential exposure to arc flash energy, conducted for the purpose of injury prevention and the determination of safe work practices, arc flash boundary, and the appropriate levels of personal protective equipment (PPE).

50. Secondary Injury Hazards Burns and Ignition Falls resulting from shock or arc flash Smoke inhalation Risk of personnel during a confined space rescue

51. Hazard Video http://www.youtube.com/watch?v=4bBvmP Rqfmo

52. Safety Related Work Practices What is an Electrically Safe Work Condition? A state in which an electrical conductor or circuit part has been disconnected from energized parts, locked/tagged in accordance with established standards, tested to ensure the absence of voltage, and grounded if determined necessary.

53. Step to Insure an Elec. Safe Condition DISCONNECT THE ELECTRICITY FROM THE CIRCUIT LOCK-OUT / TAG-OUT PLACED ON THE DISCONNECT TEST THE CIRCUIT TO INSURE ALL POWER HAS BEEN REMOVED ADD AN ADITIONAL SAFETY GROUND IF YOU FEEL IT IS NESSESARY

54. Two Types of Lockout/tagout Simple All lockout/tagout procedures that involve only a qualified person(s) de-energizing one set of conductors or circuit part source for the sole purpose of safeguarding employees from exposure to electrical hazards shall be considered to be a simple lockout/tagout. Simple lockout/tagout plans shall not be required to be written for each application. Each worker shall be responsible for his or her own lockout/tagout.

55. Two Types of Lockout/tagout Complex A complex lockout/tagout plan shall be permitted where one or more of the following exist: (1) Multiple energy sources (2) Multiple crews (3) Multiple crafts (4) Multiple locations (5) Multiple employers (6) Multiple disconnecting means (7) Particular sequences (8) Job or task that continues for more than one work period

56. Two Types of Lockout/tagout (b) All complex lockout/tagout procedures shall require a written plan of execution that identifies the person in charge. (c) The complex lockout/tagout procedure shall vest primary responsibility in an authorized employee for a set number of employees working under the protection of a group lockout or tagout device (such as an operation lock). The person in charge shall be held accountable for safe execution of the complex lockout/tagout.

57. Approach Boundaries to Energized Electrical Conductors or Circuit Parts

60. Arc Hazard Analysis

61. Heat Energy Incident Energy level –Measured in (Cal/cm 2 ) –(Calories per square centimeter) –Determined by Arc Hazard Analysis Exposure to 1.2 Cal/cm 2 for 1/10 sec, unproductive skin reaches a temperature of 176 o F (80 o C). This is the onset of second degree burns.

62. Bus Report

63. Arc Hazard Boundary The distance from arc where unprotected persons would only be exposed to temperatures that is limited to the onset of a second degree burn. Only qualified persons wearing the proper PPE may cross this boundary.

64. Four Approach Boundaries Flash Protection Boundary Limited Approach Boundary Restricted Approach Boundary Prohibited Approach Boundary

65. Approach Boundaries – NFPA 70E

66. Limited Approach Boundary Unqualified persons must stay a safe distance called the Limited Approach Boundary. –3.5 ft. for fixed circuit parts ( 50 to 750 volts) –10 ft. for exposed movable conductors ( 50 to 750 volts) –Boundaries increase as voltage gets higher to more than 23 ft in some cases.

67. Restricted Approach Boundary Access limited to qualified persons. Increased risk of shock due to arc-over combine with inadvertent movement. Requirements include shock protection techniques, careful movement, an approved written work plan an appropriate PPE. Restricted approach limits are one foot at 301V to 750 V, and increase quickly to 15 feet at higher voltages.

68. Prohibited Approach Boundary Crossing this is considered the same as touching the live part. Work is limited to qualified persons, only when absolutely necessary. Documented plan needed to explain why you must work that close. Plan must include a risk analysis and have management approval. Requires appropriate PPE. Prohibited approach boundaries range from one inch at 301 V to 750 V level, to 14 feet, 5inches at 75 to 800 kilovolts.

69. Setting The Flash Protection Boundary Flash Protection Boundary –Distance from exposed, energized conductor that would cause incident energy of 1.2 cal/cm 2 1.0 cal/cm 2 is amount of heat produce by a match on finger tip for 1 second –If Boundary is crossed, must wear flash protective equipment. In most systems 600 V or less the boundary is 4 feet. The Flash Protection is listed on the Energized Electrical Work Permit.

70. ELECTRICAL HAZARD BOUNDARIES Note: shock boundaries dependent on system voltage level

71. Qualified and Unqualified Persons Personnel are divided into two groups, qualified and unqualified for safety purposes. Qualified means: that you have the training and knowledge to do the task safely. Unqualified means: you do not

72. An Unqualified Person Never performs Lockout/Tagout. Never works with energized equipment. Never enter high-risk areas. Never comes too close to certain hazardous equipment.

73. A Qualified Person Knows how to use special precautionary techniques. Knows how to use Personal Protective Equipment. Knows how to use Arc Flash insulating and shielding equipment. Knows how to use insulated tools and test equipment. Knows how to work on or near exposed live parts 50 volts and above.

74. A Qualified Person Knows how to tell exposed energized parts from others. Has learn the nominal voltage of exposed live parts. Knows the safe approach distances for various voltages. Be able to Identify hazards of the task, the PPE you will need and job planning necessary to work safety.

75. Minimum Required Labeling

78. 24 inchFlash Hazard Boundary 3cal/cm 2 Flash Hazard at 18 inches 1DFPPE Level,1 Layer 6 ozNomex®, Leather GlovesFaceshield 480 VACShock Hazard when Cover is removed 36 inchLimited Approach 12 inchRestricted Approach -500 V Class 00 Gloves 1 inchProhibited Approach -500 V Class 00 Gloves Equipment Name:Slurry Pump Starter WARNING ! Arc Flash and Shock Hazard Appropriate PPE Required Courtesy E.I. du Pont de Nemours & Co.

79. Hazard / Risk Category Classifications

80. Hazard Risk Categories List the Minimum requirements based on Potential Incident Energy Levels determined by Arc Hazard Analysis. The Hazard Risk Categories range from 0 through 4. Hazard Risk Category 4 is the most dangerous having the greatest risk due to the magnitude of the Potential Incident Energy Levels involved.

81. Hazard Category Zero Long sleeve shirt and long pants made from non-melting natural fiber, 100% cotton or 100% wool. –This provides no protection from heat energy, but will not melt into the skin. Non-conductive safety eyewear. Example: Reading a door mounted meter while the panel door remains closed.

82. Hazard Category One Clothing with a minimum Arc Rating: 4 Cal/cm 2 100% cotton Jeans min weight (12 oz/yd 2 ) or FR rated pants. FR rated Shirt or FR rated coveralls. Electrically rated Hard Hat. Non-conductive safety eyewear. Example: Removing bolted cover to expose live parts on panel boards rated 240V and below.

83. Hazard Category Two Clothing with a minimum Arc Rating: 8 Cal/cm 2 Under layer of 100% non-melting natural fiber (cotton/wool). FR rated shirt / pants or coveralls. FR rated Face shield or flash suit hood. Electrically rated Hard Hat, Eye protection, Boots and gloves. Example: Performing diagnostic testing or voltage measurements on 600V switchgear.

84. Hazard Category Three Clothing with a minimum Arc Rating: 25 Cal/cm 2 Two Under layers of 100% non-melting natural fiber (cotton/wool) rated at 15 Cal/cm 2 which will give a combine protection of 30 Cal/cm 2 or a multi-layer flash suit rated at 40 Cal/cm 2. FR rated flash suit hood. Electrically rated Hard Hat. Eye protection. Boots with dielectric overshoes. Electrically insulated FR rated gloves. And hearing protection for exposure to 200 dB or better.

85. Hazard Category Four Clothing with a minimum Arc Rating: 40 Cal/cm 2 40 Cal/cm 2 Flash suit. FR rated flash suit hood. Electrically rated Hard Hat. Eye protection. Boots with dielectric overshoes. Electrically insulated FR rated gloves. And hearing protection for exposure to 200 dB or better.

86. So, What Do I Do If I’m (Way) Above 40 cal/cm 2

87. Solutions Above 40 cal/cm2 –Label equipment warning that no PPE is available –Refer to safety procedures –Must use engineered solution Current limiting fuses Arc Resistant switchgear Remote racking Remote operation through Smart Equipment Zone Interlocking IP20 shrouding Re-coordinating protective devices Increasing distance Enabling instantaneous function De-energizing before operation

90. Prohibited Clothing Polyester Nylon Rayon Any blend of the above fabrics Any metallic or conductive clothing. Metal/ Plastic Jewelry

91. Personal Protective Equipment (PPE) Anytime your body crosses the Restrictive Approach Boundary or the Flash Protection Boundary, You Must wear PPE to protect you from Arc Flash and Electrical Shock.

92. Depending on the task, you may need: Rubber insulated gloves and insulated tools to protect against electrical shock. Leather hand and arm covers ro protect against arc flash burns and flying debris. Head, face, neck, chin, eye and body protection. Hearing protection Dielectric overshoes A full multi-layer flash suit, including hood, face shield and suplied air may be needed for higher risk.

93. Category One Clothing 5 Cal/cm 2

94. Category Two Clothing 11 Cal/cm 2 kit

95. Category Three Clothing 25 Cal/cm 2

96. Category Four Clothing 40 Cal/cm 2

97. 100 Cal/cm 2 FR rated Clothing

100. Safe Work Practices

101. Safe work Practices Remove conductive articles. Wear natural fibers (100% cotton/100% wool). Clothing should be loose-fitting and FR rated. Wear eye protection – safety glasses or goggles under Face shields or hoods. Get an Energized Electrical Work Permit.

102. Safe work Practices Double check tools and equipment voltage ratings. Keep tools and equipment from accidentally coming in contact with live parts. All parts are considered Live until you test to make sure. Work in adequate lighting.

103. Safe work Practices Never reach blindly into equipment. Never be put into a position where you could fall into live parts. Keep vehicles and mechanical equipment 10 feet from energized overhead lines. Do not touch Vehicles that could accidentally become energized without proper PPE.

104. Safe work Practices Keep unqualified persons out of the area beyond the Limited Approach Boundary. Use attendants to keep unqualified people out of the area. Attendants may be needed to observe the qualified worker for safety reasons.

105. Identifying Other Electrical Hazards

106. Clear Spaces Must have access to working space around electrical equipment. Must have at least 3’ in front of switch boards or motor control centers

107. Grounding Path The path to ground from circuits, equipment, and enclosures must be permanent and continuous

108. Guarding of Live Parts Must guard live parts of electric equipment operating at 50 volts or more against accidental contact by: –Approved cabinets/enclosures, or –Location or permanent partitions making them accessible only to qualified persons, or –Elevation of 8 ft. or more above the floor or working surface Mark entrances to guarded locations with conspicuous warning signs

109. Clues that Electrical Hazards Exist Tripped circuit breakers or blown fuses Warm tools, wires, cords, connections, or junction boxes GFCI that shuts off a circuit Worn or frayed insulation around wire or connection

110. Fuses and Circuit Breakers Molded-Case Circuit Breakers. Molded-case circuit breakers shall be maintained free of cracks in cases and cracked or broken operating handles.

111. Fuses and Circuit Breakers Circuit Breaker Testing After Electrical Faults. Circuit breakers that interrupt faults approaching their interrupting ratings shall be inspected and tested in accordance with the manufacturer’s instructions.

112. Rotating Equipment Guards, Barriers, and Access Plates. Guards, barriers, and access plates shall be maintained to prevent employees from contacting moving or energized parts.

113. Portable Elect Tools and Equip 245.1 Maintenance Requirements for Portable Electric Tools and Equipment. Attachment plugs, receptacles, cover plates, and cord connectors shall be maintained such that the following criteria are met:

114. Portable Elect Tools and Equip (1) There are no breaks, damage, or cracks exposing energized conductors and circuit parts. (2) There are no missing cover plates. (3) Terminations have no stray strands or loose terminals. (4) There are no missing, loose, altered, or damaged blades, pins, or contacts. (5) Polarity is correct.

115. Personal Safety and Protective Equipment 250.2 Inspection and Testing of Protective Equipment and Protective Tools. (A) Visual. Safety and protective equipment and protective tools shall be visually inspected for damage and defects. (B) Testing. The insulation of protective equipment and protective tools, shall be verified by the appropriate test.

116. Personal Safety and Protective Equipment 250.3 Safety Grounding Equipment. (A) Visual. Personal protective ground cable sets shall be inspected for cuts in the protective sheath and damage to the conductors. Clamps and connector strain relief devices shall be checked for tightness. (B) Testing. Prior to being returned to service, temporary protective grounding equipment that has been repaired or modified shall be tested.

117. Conclusion Arc Flash Awareness is an important part of any electrical workers training. The standards used are to protect qualified electrical workers and the Unqualified. Proper PPE should always be used for the Hazard Category established for the equipment. Safe work practices should always be followed on and off the Job… Your life may depend upon it.

118. Quiz True False 1. Electric shock is the most frequent cause of electrical injury and death. True False 2. Arc Flash temperatures never get higher that 2,000 degrees Fahrenheit. True False 3. An Arc blast can burst your eardrums and harm your hearing. True False 4. A job briefing is designed to help you get the job done quickly and correctly.

119. Quiz True False 5. Equipment in an electrically safe work condition is not, and cannot be energized. True False 6. A written permit is required any time live parts over 300 volts are not placed in an electrically safe work condition.

120. Quiz True False 7. The energized electrical work permit list practices, procedures, and equipment needed to protect employees from arc flash and from contact with live parts.

121. Quiz True False 8. The results of the hazard analyses for shock and for arc flash are listed on the energized electrical work permit.

122. Quiz True False 9. The Limited Approach Boundary for voltages between 50 and 750 volts is 3.5 feet for fixed circuit parts and 10 feet for exposed movable conductors.

123. Quiz True False 10. Unqualified personnel must stay inside the Limited Approach Boundary. True False 11. Crossing the Prohibited Approach Boundary is considered the same as touching the live part.

124. Quiz True False 12. An arc flash can burn skin and clothes, damage hearing, and knock you off your feet … or ladder. True False 13. A Flash Hazard Analysis predicts the risk of an arc flash occurring and set a Flash Protection Boundary.

125. Quiz True False 14. In most of 600 volts or less, the Flash Protection Boundary is 15 feet. ( it is 4 Feet) True False 15. Any time any part of your body crosses either the Restricted Approach Boundary or Flash Protection Boundary, you must wear PPE to protect you from arc flash and shock.

126. Quiz True False 16. Your employer may use NFPA guidelines to determine the correct PPE needed for a specific job. True False 17. The PPE you need for a specific job is listed on the Flash Hazard Analysis. (PPE is listed on the Energized Electrical Work Permit) True False 18. You may use PPE contaminated with grease or oil as long as you clean it as soon as possible.

127. Quiz True False 19. You should wear synthetic fibers next to you skin because it does not melt and stick like cotton does. True False 20. In some cases you will need to wear Flame-resistant clothing even when you wear a full flash suit.

128. Arc Flash Video https://www.youtube.com/watch?v=hfnEuR A7-vo

129. End of Lecture