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SASCO NFPA 70E Training

SASCO NFPA 70E Training. SASCO NFPA 70E Training. SASCO NFPA 70E Training. NFPA 70E—Standard for Electrical Safety in the Workplace Title: Standard for Electrical Safety for Employee Workplaces Began 1976 by NFPA. Guidance for OSHA. Electrical Hazards Addressed in NFPA 70E. Shock

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SASCO NFPA 70E Training

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  1. SASCO NFPA 70E Training

  2. SASCO NFPA 70E Training

  3. SASCO NFPA 70E Training

  4. NFPA 70E—Standard for Electrical Safety in the Workplace • Title: Standard for Electrical Safety for Employee Workplaces • Began 1976 by NFPA. Guidance for OSHA

  5. Electrical Hazards Addressed in NFPA 70E • Shock • Arc Flash & Arc Blast • Fire Ignition

  6. The Effects of Current on the Body

  7. Burns

  8. Two Types of Burns from Shock • Surface Burns • Entrance and exit of a electrical currents through the body • Can be a very small amount of current • 1st to 3rd degree

  9. Two Types of Burns from Shock • Internal Tissue burns • From current running through the organs of the body • Currents in excess of 1.5 amps • 3rd degree burns • Damage to internal organs • Often fatal

  10. One Type of Burn From Arc Flash • Surface Burns • From exposure to arc flash • Can cause more surface burns if the initial arc ignites other material, such as clothing • 1st degree to third degree burns • Has caused death

  11. Probability of Survival Theprobability of surviving burns decreases with age:

  12. How to Prevent Shock? • Place circuits in an electrically safe working condition by locking out and tagging out all energy sources • NFPA 70E-2004: Chapter 1, Section 120.2 (D) • Verify that no electrical energy is present • NFPA 70E-2004: Chapter 1, Section 120.2 (D)

  13. Exposure to Danger • The National Electric Code (NEC) was designed to protect individuals from shock hazards under normal conditions. • It is not designed to protect employees under abnormal conditions. • We need additional policies to protect us under abnormal conditions.

  14. This is normal somewhere in the world

  15. What NFPA 70E is designed to take into account: • Electrical arcs produce the highest temperatures on earth—up to 35,000ºF. That’s 4 times the temperature of the sun. • The intense heat from arc causes the sudden expansion of air that results in a blast with very strong air pressure. (Lightning is a natural arc.) • All known materials vaporize at this temperature. • Copper expands 67,000 times; Water expands 1670 times. Notes From Practical Guide to Arc Flash Hazards, By Chet Davis, P.E.; Conrad St. Pierre; David Castor, P.E.; Robert Luo, PhD; and Satish Shrestha

  16. Arc Flash Characteristics • Arcs in enclosures, such as Motor Control Centers (MCCs) or switchgear, magnify blast and energy transmitted as the blast is forced to the open side of the enclosure. • Arcs spray droplets of molten metal at velocity and pressure. Shrapnel can penetrate the body • Blast pressure waves have thrown workers across rooms and knocked them off of ladders. Pressure to the chest can exceed 2,000 lbs/sq. ft. Notes From Practical Guide to Arc Flash Hazards

  17. Arc Flash Characteristics • Clothing can be ignited from several feet away. Clothed areas can burn more severely than exposed skin. • Hearing loss from sound blast. The sound can have a magnitude as high as 140 dB at distance of 2 feet from the arc. • Energy released is a function of: • System voltage • Fault current magnitude • Fault duration Notes From Practical Guide to Arc Flash Hazards

  18. How to Protect Against Shock and Arc Flash/Blast? • NFPA 70E-2004 • Chapter 1, Section 130 • Justification for Live Work • Work Permits Secured—If Applicable • Approach Boundaries Established • Shock Protection • Limited Boundary Note: De-energization is covered in Section 120

  19. OSHA 1910.333 (a) (1) and NFPA 70E 130.1 • Qualified electrical workers shall not be asked to work on equipment that is “live” except for two demonstrable reasons: • Deenergizing introduces additional or increased hazards Example: Cutting ventilation to a hazardous location OR: 2. Infeasible because of equipment design or operational limits Example: Volt testing for diagnostics

  20. Energized Electrical Work Permit • NFPA 130.1 (A) (1): • “If live parts are not placed in an electrically safe work condition (i.e., for the reasons of increased or additional hazards of infeasibility per 130.1), work to be performed shall be considered energized electrical work and shall be performed by written permit only.”

  21. Exemptions to Work Permit • “Work performed on or near live parts by qualified persons related to tasks such as testing, troubleshooting, voltage measuring, etc., shall be permitted without energized electrical work permit, provided appropriate safe work practices and person protective equipment in accordance with Chapter 1 are provided and used.”

  22. Approach Boundaries to Live Parts Picture From Practical Guide to Arc Flash Hazards

  23. Approach Boundaries NFPA 70E-2004 Chapter 1, Sect. 130.2 • Flash Protection Boundary • Linear distance at which no more than 2nd degree burns possible from potential arc flash (typically 4 feet). • See table 130.2 (c) • Limited Approach Boundary • Entered only by qualified persons or unqualified persons who have been advised and are escorted by a qualified person • Restricted Approach Boundary • Entered only by qualified persons required to use shock protection techniques and P.P.E. • Prohibited Approach Boundary • Enter only by qualified persons requiring same protection as if in direct contact with live part

  24. Shock Hazard Analysis • How to Comply with NFPA 70E • 3. Determine Personal Protective Equipment • Determine Risk Category from Table 130.7 (C) (9) (a) on NFPA 70E-2004 • Determine Specific PPE & Clothing from Table 130.7 (C) (10) of NFPA 70E-2004

  25. Shock Hazard Analysis Determining Risk Category from Table 130.7 (C) (9) (a) on NFPA 70E-2004

  26. Determining PPE from Table 130.7 (C) (10) on NFPA 70E-2004

  27. Task: An electrician is to remove the covers to measure the voltage on a panel board operating at 480 V. Solution: Table 130.7 (C) (9): Hazard/Risk Category=2* (V-Rated Gloves & V-Rated Tools Required) Table 130.7 (C) (10) Specifies the following: Untreated Natural Fiber T-Shirt & Undergarments FR (8 cal/cm2) Long Sleeve Shirt and Pants Hard Hat Safety Glasses or Safety Goggles Arc-Rated Face Shield w/ Flash Hood Hearing Protection Leather Gloves Leather Work Shoes Flash Hazard Analysis Example No Fabric Softener or Bleach

  28. Personal Protective Equipment (PPE)

  29. Common PPE Terms • Incident Energy: Measurement of thermal energy at a specified distance for the arc (normally 18”). Energy is typically measured in cal/cm2. • Arc Thermal Performance Exposure Value (ATPV): The incident energy level (in cal/cm2) that would cause the onset of a second-degree burn. • V-rated: Tools and gloves tested for the line-to-line voltage at the area where the work is to be performed. • Flame-Resistant or Flame-Retardant: A term referring to fabric and its ability to limit severity of burning. • Break-open Threshold Energy (EBT): The highest incident energy level which did not cause flame resistant (FR) fabric break-open and does not exceed second-degree burn criteria.

  30. PPE Protection Ratings

  31. Review: Determining PPE by using NFPA 70E NFPA 70E Table 130.7(c)(9)(a) • Determine common work task from table that matches work to be performed. • Identify Hazard/Risk Category of task (0-4). • Refer to NFPA Table 130.7(c)(10): Protective Clothing and Personal Protective Equipment Matrix. • Read all applicable “Notes” that may apply. Note: Any task not covered in tables or exceed assumptions are required to have a Flash Hazard Analysis performed in accordance with NFPA 70E 130.3

  32. 0 +

  33. 1 Or

  34. 2 + Or

  35. 2* Or + +

  36. 3 + + OR: + +

  37. 4 + +

  38. And now you know the rest of the story…

  39. National Safety Council Hierarchy of Controls • Elimination/Substitution & Engineering Controls • Substitute for hazardous materials/reduce energy or speed • Machine guarding/sound enclosures/circuit breakers • Warnings • Signs/placards/alarms/back-up beepers/labels • Training/Procedures • Administrative Controls • Lockout-Tagout/Job Hazard Analysis • Rotation of workers P.P.E.

  40. 1. Insulated tools and equipment must be rated for the voltages on which they are used Insulated tools—designed and constructed for the environment and manner in which they are used. Other Protective Equipment: Insulated Tools

  41. 1. Physical barricades Signage Attendants “If barricades and signage fail to provide sufficient warning and protection from electrical hazards, an attendant shall be stationed to warn and protect employees.” Alerting Techniques

  42. 2002 NEC • § 110.16 Requires Arc Flash Labels

  43. ACCIDENT RESPONSE

  44. Response to an Electrical Accident • Personnel who are trained to perform First-Aid/CPR should be identified and available when work near or on energized part is being performed

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