INJURY PREVENTION ARC FLASH

1. INJURY PREVENTIONARC FLASH REGIONAL SAFETY MEETING

2. Arc Flash & Arc Blast • Arc Flash – electrical short circuit thatoccurs when air flashes from an exposed live conductor, to either another conductor or to ground. • Arc Blast – pressure wave caused by the arc flash

3. Arc Flash/Blast • Concentrated energy explodesoutward • High intensity flash • Temperatures can reach 35,000 (skin ignites 480) • Pressure wave can reach 200lbs/sq. inch • Vaporizes conductors and copper with exploding particles.

4. SEVERITY FACTORS

5. Arc Flash Effects • Severe burns • Broken bones • Vision damage • Hearing loss • Brain/internal injuries • Puncturesand lacerations • Death

6. SCOPE OF THE PROBLEM • Each year, MSHA identifies about 100 injuries as“non-contact electricarc burns” • 55% are in bituminous coal • 84% are on systems of 600V or less MSHA DATA

7. Causes of Arc Flash • Improper training • Improper work procedures • Dropped tools • Accidental contact with electrical systems • Installation failure • Improper Design/Repair • Voltage testingwith inappropriate equipment

8. Causes of Arc Flash (cont.) • Buildup of dust, corrosion oninsulating surfaces • Lack of maintenance • Sparks produced during racking of breakers, replacement of fuses and closing into faulty lines. • Over confidence

9. Resource Documents

11. MSHA 75 and 77 All power circuits and electrical equipment shall be deenergized before work is done on such circuits and equipment, except when necessary for trouble shooting or testing.

12. Trouble shooting andTesting • Only low and medium voltage circuits • Purpose is to determine voltage and current • Qualified person with protective gloves

13. ARC FLASHPREVENTION The best way to prevent arc flash incidents is to DE-ENERGIZE and LOCK/TAG circuits before beginning work.

14. How is your Lock out program?

15. If we are Locking out properly, then when do we haveexposure/risk? • Trouble shooting and testing • Removing covers, doors and lids with energized parts. • Inadequate Barriers between circuits.

18. Energized WorkApproval • Description of the task to be performed • Justification for energized work • Job specific hazards • PPE Can be verbal or written (AMS Operator) Adds accountability/ Helps define SAFE

19. PERSONAL PROTECTIVE EQUIPMENT

20. Low/Medium rated Gloves • Can use dry Leather work gloves in Good Condition • Over 120 volts systems must be intrinsically safe

23. What is a Calorie?

24. IEEE Standard 1584 Systems rated below 240 V to ground and below about 400A (125kVA) are notconsidered ARC FLASH Hazards. These systems still present a SHOCK Hazard.

25. Arc-Rated FR Clothing & PPE • Layering • Outer layers must be flame resistant • Under layers must be non-melting • Coverage – Clothing must cover potentially exposed areas (wrist, neck) • Care & Maintenance • Inspect before use • Launder according to mfg’s instructions

26. PPE - Hazard Risk Category 00-1.2 cal/cm2 • 100% cotton long sleeve shirt • Long pants • Safety glasses • Hearing protection • Leather and insulated gloves (as required) • Leather work boots

27. PPE - Hazard Risk Category 11.2 - 4 cal/cm2 • 4+ cal long sleeve shirt & long pants (or) coveralls • Hardhat • Safety glasses • Arc rated faceshield • Hearing protection (inserts) • VR gloves • Leather gloves • Leather work boots

28. PPE - Hazard Risk Category 24 - 8 cal/cm2 • 8+ cal long sleeve shirt & long pants (or) coveralls • Hardhat • Safety glasses • Arc rated faceshield • Hearing protection (inserts) • VR gloves • Leather work boots

29. PPE - Hazard Risk Category 38 - 25 cal/cm2 • 25+ flashsuit w/ hood over long sleeve shirt and long pants • Safety glasses • Arc rated faceshield • Hearing protection (inserts) • VR gloves • Leather gloves • Leather work boots

30. PPE - Hazard Risk Category 425 - 40 cal/cm2 • 40+ flashsuit w/ hood over FR long sleeve shirt and long pants • Safety glasses • Arc rated faceshield • Hearing protection (inserts) • VR gloves • Leather gloves • Leather work boots

31. BEST PRACTICES

32. Analyze your ELECTRICAL System

33. Low arc flash circuit breakers

34. Current Limiting Fuses

35. Equipment Design

36. VOLT METER- SWITCHES TO PROPER VOLTAGE

37. Label Hazard/PPE Requirements

38. Make Lock Out Easy

39. Use Good Safety Practices

40. Summary • Lock and Tag Program • Identify activities with exposure • Determine potential of injury • Look for alternative methods • Put administrative controls in place • Train and provide appropriate PPE • Evaluate the effectiveness of your process

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