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ARC FLASH HAZARDS

ARC FLASH HAZARDS. Construction Safety Association of Ontario. Purpose of this Presentation. Introduction to: Hazard of arc flash New CSA Standard on electrical safety Arc flash prevention and protection. Five Main Topics. 1. Introduction to arc flash 2. Arc flash injuries

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ARC FLASH HAZARDS

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  1. ARC FLASH HAZARDS Construction SafetyAssociation of Ontario

  2. Purpose of this Presentation • Introduction to: • Hazard of arc flash • New CSA Standard on electrical safety • Arc flash prevention and protection Arc Flash Hazards -- Construction Safety Association of Ontario

  3. Five Main Topics 1. Introduction to arc flash 2. Arc flash injuries 3. Codes and standards 4. Protective clothing and equipment 5. Prevention Arc Flash Hazards -- Construction Safety Association of Ontario

  4. Topic 1 – Introduction to Arc Flash 4

  5. What is an Arc Flash Hazard? “. . . a dangerous condition associated with the release of energy caused by an electric arc.” Arc Flash Hazards -- Construction Safety Association of Ontario

  6. What is an Electric Arc? • An electric arc is a short circuit through the air. Arc Flash Hazards -- Construction Safety Association of Ontario

  7. Characteristics of an Electric Arc • An electric arc will oscillate and escalate if not constrained. • A single-phase electric arc can engulf a second or third conductor in only two cycles. • An electric arc’s current propels the arc away from the power source. Arc Flash Hazards -- Construction Safety Association of Ontario

  8. What Causes Arc Flash? • Dust, impurities, corrosion, condensation, animals • Spark discharge from: • Accidental touching • Dropping tools • Over-voltages across narrow gaps • Failure of insulating materials • Equipment failure Arc Flash Hazards -- Construction Safety Association of Ontario

  9. What is Arc Blast? • The flash causes an explosive expansionof air and metal. • For example: When copper vapourizes it expands by a factor of 67,000. • The blast produces dangerous: • Pressure waves • Sound waves • Molten steel and shrapnel. Arc Flash Hazards -- Construction Safety Association of Ontario

  10. Video Clip 1 – Arc Flash Demo Arc Flash Hazards -- Construction Safety Association of Ontario

  11. Arc Flash Events Electric arc Arc flash Arc blast Compliments of Salisbury Electrical Safety L.L.C. Arc Flash Hazards -- Construction Safety Association of Ontario

  12. Forms of Arc Flash Energy • Noise • Expansion • Vaporization • Thermal radiation Arc Flash Hazards -- Construction Safety Association of Ontario

  13. Topic 2 – Arc Flash Injuries 13

  14. Arc Flash Injuries • Electric shock • Severe burns • Blindness • Blast injuries • Shrapnel wounds • Lung blast injuries • Ruptured eardrums • Pressure wave injuries Arc Flash Hazards -- Construction Safety Association of Ontario

  15. Severity Factors • Power– amount of energy at the arc • Distance – of the worker to the arc • Time – duration of the arc exposure Arc Flash Hazards -- Construction Safety Association of Ontario

  16. Video Clip 2 – “Not Safe at 18 inches” Arc Flash Hazards -- Construction Safety Association of Ontario

  17. Video Clip 3 – “Not Safe Working Near” Arc Flash Hazards -- Construction Safety Association of Ontario

  18. Electric Shock Injury – Burn Arc Flash Hazards -- Construction Safety Association of Ontario

  19. Severe Burns from Arc Flash Arc Flash Hazards -- Construction Safety Association of Ontario

  20. Probability of Surviving Burns % Survival Age Range, Years Arc Flash Hazards -- Construction Safety Association of Ontario

  21. Blindness • Flash of light is so intense it can damage vision. Arc Flash Hazards -- Construction Safety Association of Ontario

  22. Shrapnel Wounds Material and molten metal can hit the body at over700 miles per hour. Arc Flash Hazards -- Construction Safety Association of Ontario

  23. Blast Lung Injury (BLI) • Arc blast can cause inhalation injuries.For example: • Inhaling high temperaturecopper vapour. • More than 100 toxicsubstances can be foundin the fumes. BLI + Burns = Greater chance of death Arc Flash Hazards -- Construction Safety Association of Ontario

  24. Hearing Damage Arc Flash Hazards -- Construction Safety Association of Ontario

  25. Pressure Wave Injuries • Arc blast can throw a worker: • Off a ladder • Into nearby walls or equipment. • 2000 lbs/ft2 pressure on the body can cause: • Concussion • Collapsed lungs • Other internal injuries Arc Flash Hazards -- Construction Safety Association of Ontario

  26. Topic 3 – Codes and Standards 26

  27. US National Fire Protection Association -Standard NFPA 70E Occupational Health & Safety Act -Applicable regulations Canadian Standards Association -Standard Z-462 Canadian Electrical Code -Rule 2-306 Institute of Electrical & Electronics Engineers -Standard 1584 US Occupational Safety & Health Administration Standards Arc Flash Hazards -- Construction Safety Association of Ontario

  28. What is NFPA 70E? National Fire Protection Association • “Standard for Electrical Safety in the Workplace” • Standard for electrical safety in United Sates • “Harmonized” with CSA Z462 Arc Flash Hazards -- Construction Safety Association of Ontario

  29. What is CSA Standard Z462? • The standard for workplace electrical safety in Canada. • “Harmonized” with NFPA 70E. Arc Flash Hazards -- Construction Safety Association of Ontario

  30. CSA Standard Z462 addresses: • Electrical Safety Program • Arc Flash Hazard Analysis • Flash Protection Boundary • Fault Current Calculations • Arc Fault Clearing Time • Incident Energy Exposure • Required PPE Arc Flash Hazards -- Construction Safety Association of Ontario

  31. What is IEEE Standard 1584? Institute of Electrical and Electronics Engineers • Offers a method for performing arc flash hazard calculations. Arc Flash Hazards -- Construction Safety Association of Ontario

  32. What is CEC Rule 2-306? Canadian Electrical Code “Rule 2-306 Shock and Flash Protection” • A requirement for field-marking electrical equipment to warn persons of potential electric shock and arc flash hazards. Arc Flash Hazards -- Construction Safety Association of Ontario

  33. Sample label that complies with CEC Rule 2-306. Required Warning Label Arc Flash Hazards -- Construction Safety Association of Ontario

  34. Optional Warning Label Arc Flash Hazards -- Construction Safety Association of Ontario

  35. Topic 4 – Protective Clothingand Equipment 35

  36. Flame-Resistant (FR) Clothing • Protects a worker from receiving severe burns if the worker is exposed to a flame. • Is self-extinguishing when the source of the flame is removed. Arc Flash Hazards -- Construction Safety Association of Ontario

  37. What is a Calorie? • A calorie is the amount of heat needed to raise the temperature of one gram of water by 1°C. • Thermal energy is measured in calories/cm². 1.2 calories/cm² = Holding your finger in the blue part of the flame for one second. Arc Flash Hazards -- Construction Safety Association of Ontario

  38. FR Rated Clothing • Limit the ‘Incident Energy’ level of the arc flash to 1.2 cal/cm²against the worker’s chest. • Look for a label that states: • 1506 approval (ASTM F1506) • Arc rating of the garment. • All materials in the garment should be FR Rated: • Thread • Buttons • Insulation • Zippers, etc. Photo compliments ofSalisbury Electrical Safety L.L.C. Arc Flash Hazards -- Construction Safety Association of Ontario

  39. Typical PPE Requirements Arc Flash Hazards -- Construction Safety Association of Ontario

  40. Typical Protective Clothing Arc Flash Hazards -- Construction Safety Association of Ontario

  41. Synthetic Clothing • Synthetic clothing that melts shall not be worn, such as: • Acetate • Nylon • Polyester • Polypropylene • Spandex. Arc Flash Hazards -- Construction Safety Association of Ontario

  42. Arc Flash Rated PPE • Required minimum clothing: • Non-melting, flammable material, • Fabric weight of at least 4.5 oz/yd. • PPE must also providearc flash protection: • Face shield • Gloves, etc. Photo compliments ofSalisbury Electrical Safety L.L.C. Arc Flash Hazards -- Construction Safety Association of Ontario

  43. Video Clip 4 – 100% Cotton Clothing Arc Flash Hazards -- Construction Safety Association of Ontario

  44. Video Clip 5 – Polyester/Cotton Clothing Arc Flash Hazards -- Construction Safety Association of Ontario

  45. Video Clip 6 – FR Clothing Arc Flash Hazards -- Construction Safety Association of Ontario

  46. FR Clothing Can Be Layered • Increases level of protection. • May be lighter than a singleheavy garment. • Manufacturer must providethe new combined arc ratingafforded by layering. Photo compliments ofSalisbury Electrical Safety L.L.C. Arc Flash Hazards -- Construction Safety Association of Ontario

  47. When Purchasing PPE • Tell the supplier that you needarc flash rated PPE and clothing. • PPE must have some resistance to: • Flame • Ignition • Melting. • obtain PPE from a known and trusted supplier. Photo compliments ofSalisbury Electrical Safety L.L.C. Not all FR clothing is tested to ASTM F1506 Arc Flash Hazards -- Construction Safety Association of Ontario

  48. Topic 5 – Prevention 48

  49. Tasks with Potential for Arc Flash • Operating a switch or circuit breaker • Inserting or removing a circuit breaker • Opening an enclosure door • Removing a cover (bolted or hinged) • Testing for voltage In each task:Worker is interacting with energized equipment. Arc Flash Hazards -- Construction Safety Association of Ontario

  50. Arc Flash Hazard Analysis • Conduct a Flash Hazard Analysis to determine the • Flash Protection Boundary • Incident Energy exposure • Type and arc rating of PPE If work must be done on or near energized electrical equipment,identify the potential for arc flash. Arc Flash Hazards -- Construction Safety Association of Ontario

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