Understanding Arc Flash_For Video_1 hour

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Understanding Arc Flash Hazards & Electrical Safety Regulations : 

Understanding Arc Flash Hazards & Electrical Safety Regulations Presented by: American Safety & Equipment

Slide 2: 

2 Electrical Hazards What are the hazards as you approach electrical equipment to perform work?

Electrical Hazards : 

Electrical Hazards Shock Arc flash Heat Fire Arc blast Pressure Shrapnel Sound Example of an arcing fault

Electric Shock : 

Electric Shock Over 30,000 non-fatal electrical shock accidents occur each year Between 600 and 1000 people die from electrocution each year Electrocution remains the fourth (4th) highest cause of industrial fatalities Most injuries and deaths could be avoided Statistics are from the National Safety Council in the U.S.

Arc Flash : 

Arc Flash As much as 80% of all electrical injuries are burns resulting from an arc-flash and ignition of flammable clothing Arc temperature can reach 35,000°F - this is four times hotter than the surface of the sun Fatal burns can occur at distances over 10 ft Over 2000 people are admitted into burn centers each year with severe electrical burns

Arc Blast : 

Arc Blast An arc fault develops a “pressure wave” Sources of this blast include: Copper expands 67,000 times its original volume when vaporized Heat from the arc, causes air to expand, in the same way that thunder is created from a lightning strike This may result in a violent explosion of circuit components and thrown shrapnel. The blast can destroy structures, knock workers from ladders, or across the room Arc blasts release dangerous levels of heat energy, fire , molten materials, vaporized solids that can be inhaled, flying shrapnel and the rapid expansion of air, all capable of causing severe and sometimes fatal injuries.

Arc Flash Incident #1 : 

Arc Flash Incident #1 7 Click on video to play

Arc Flash Incident #2 : 

Arc Flash Incident #2 8 Click on video to play

Arc Flash/Arc Blast : 

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

Over current Protection Role : 

Arc Flash hazards and calculations are dependent upon: Duration of arc-fault or time to clear Speed of the over current protective device Arc-fault current magnitude Available fault current Over current Protection Role

Arc Flash Safety Categories : 

Arc Flash Safety Categories

Electrical Safety Regulations : 

Electrical Safety Regulations What are the regulations that govern electrical safety in the work place? First in the hierarchy of standards is Federal OSHA in the U.S. and the Ministry of Labor in Canada. State or Provincial – may be more restrictive than federal regulations. This needs be evaluated by employer location. Industry consensus standards that are much more specific than OSHA. Like NFPA-70E & CSA Z462 Corporate safety policies must meet the requirements listed above, but may be better.

The OSHA – NFPA 70E/CSA Z462 Connection : 

The OSHA – NFPA 70E/CSA Z462 Connection Several of the OSHA regulations are written in general terms leaving the details up to the employer on how to comply. (An example is requirements for personal protective equipment and clothing in 1910.132(a).) The employer is expected to use consensus standards to help in the selection of the best method to achieve compliance with OSHA regulations. NFPA 70E & CSA Z462 are “how to comply” standards for specific OSHA regulations.

The OSHA – NFPA 70E/CSA Z462 Connection : 

The OSHA – NFPA 70E/CSA Z462 Connection 70E & Z462 – Standards for Electrical Safety in the Workplace cover the full range of electrical safety issues from safety-related work practices to maintenance, special equipment requirements, and installation. OSHA 1910 Subpart S and OSHA 1926 Subpart K are based on this standard. "It certainly seems to me that if I’m an employer, and I want to comply with a general requirement for protecting my employees from electric shock and electric arc, that the first place I’m going to look is NFPA 70E“ David Wallis, OSHA Director Region 5 News Release 04-479-CHIMarch 24, 2004Milwaukee Company Penalized $193,500 for Failing to Protect Workers from Electrical Hazards……three employees were severely burned by an arc flash and explosion that occurred while they were testing an electrical switchgear unit. OSHA cited the firm for a serious violation of federal training requirements and willful violations of lack of personal protective gear and for failing to de-energize or effectively guard exposed live equipment parts. Fines can also be given using the general duty clause of OSHA 1910 or Section 25(2)(h) in Ontario.

How do I protect employees and comply with the standards? : 

How do I protect employees and comply with the standards? Safety related work practices Employee training Written electrical safety program Analysis for shock and arc flash hazards Energized electrical work permits Approach boundaries Personal protection equipment (PPE) & Tools Safety related maintenance requirements Safety requirements for special equipment Installation safety requirements

Training : 

Training A good training program should include: Hazards created by Shock, Arc Flash and Arc Blast Arc Flash regulations (NFPA 70E & CSA Z462) How to protect workers and comply with the standards Review of existing safety practices and resources Electrically safe work conditions (more than LOTO) Appropriate safety related work practices Qualified versus unqualified personnel Reducing the risks of shock and arcing hazards Using the proper PPE and tools Trainer should be certified and/or experienced Continued education is also a requirement

Written Electrical Safety Policies : 

Written Electrical Safety Policies This is a requirement of NFPA 70E & CSA Z462 Should include written policies for working on energized equipment such as Lockout rules, work permits, PPE requirements, tools, boundaries etc. Meet or exceed all OSHA and consensus requirements Establishment of an Arc Flash Mitigation Program

Electrical Power System Analysis : 

Electrical Power System Analysis Survey and data collection of all electrical panels. Get available energy into the facility from the local utility. Short circuit and duty calculations to ensure all equipment is properly rated to withstand a short circuit current. Protective device coordination (breakers, fuses, etc.) to ensure that each device will work properly when needed. Arc Flash hazard analysis for Incident energy, total clearing time, PPE requirements, Flash Hazard Boundaries and Shock Hazard. Installation of Arc Hazard labels – Vinyl, UV rated

Electrical Power System Analysis : 

Electrical Power System Analysis Up-to-Date One-line Drawings used to: Help workers identify equipment voltage levels Identify system configurations that impact hazard calculations Help plan future electrical system work Determine alternate sources, capacitate back feeds and energized sources

Electrical Power System Analysis : 

Electrical Power System Analysis A good report should identify inadequate short circuit ratings, coordination problems and dangerously high arc flash hazards. It should also include recommendations to correct any of these problems

Energized Electrical Work Permits : 

Energized Electrical Work Permits Energized work permits are used in the same manner as “Hot Work” permits. They should include all of the appropriate information to work safely.

Approach Boundaries : 

Approach Boundaries There are requirements for two types of boundaries – shock and arc flash In practice it is best to address both boundary types in an integrated manner

Slide 23: 

Prohibited shock boundary: Qualified persons only - PPE as if direct contact with live part Restricted shock boundary: Qualified persons only Limited shock boundary: Qualified or unqualified persons* *only if accompanied by qualified person Note: shock boundaries dependent on system voltage level Flash Protection Boundary (FPB) Must wear appropriate PPE FPB dependent on fault level and time duration. Equipment

Approach Boundaries : 

Approach Boundaries Linear distance from exposed live parts with which a person could receive burns resulting from an arc flash. Each boundary is a sphere to be observed in all directions three dimensionally.

Personal Protection Equipment : 

Personal Protection Equipment 8 cal/cm²

Arc Flash Hazard Categories & PPE : 

Arc Flash Hazard Categories & PPE

Reducing the Risk of Arc Flash : 

Reducing the Risk of Arc Flash Follow the appropriate safe work practices Use electrically safe work conditions (more than Lockout/Tag out) Restrict access to high risk panels Make sure current devices are set properly Use current limiting fuses and or electronic trip circuit breakers to lower the hazard

Arc Flash Summary : 

Arc Flash Summary Employee training Written electrical safety program Analysis for shock and arc flash hazards Energized electrical work permits Approach boundaries Personal protection equipment (PPE) & Tools Schedule electrical safety related maintenance Determine safety requirements for special equipment Plan & require safe electrical installations Get experts to help

Contact Us : 

Contact Us For more information concerning a quality Arc Flash program please contact American Safety & Equipment at 866-522-2300 or visit us on the web at www.asesafety.com

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