NFPA 70E Electrical Safety in the Workplace KTR Associates Joseph Deane, PE Engineering Solutions
Goal for Today � Better understanding of NFPA 70E � Raise the awareness of Electrical Hazards � Why the sudden focus � What one must do to become “70E” compliant
Topics To Be Discussed � Define Electrical Hazards � Safety Numbers � Industry Standards/Government Regulations � What is an Arc Flash? � Sample Arc Flash Study � PPE Requirements
Why do we need Electrical Safety? � Provide a safe work environment � Reduce injuries � Comply with regulations � Reduce liability � Reduce operating costs
What are the Electric Hazards? � Shock � Arc Flash � Arc Blast
Terms and Definitions • Electric Shock (Contact) : Occurs when electricity (electric current) passes through the human body. Electric current passing through the chest area may result in death.
Terms and Definitions Arc Flash : Short circuit through air; defined as the rapid release of energy due to an arcing fault between two phase conductors (such as bus bar) or neutral or ground. Arc Blast : Heating of the air and vaporization of metal creates a pressure wave than can damage hearing and other injuries. Flying metal parts are a hazard.
Terms and Definitions I ncident Energy : Energy dissipated during an arc fault, or arc flash event. Measured in cal/cm 2 . Arc Thermal Performance Value (ATPV) : Minimum energy causing the predicted onset of second degree burns. A second degree burn is 1.2 cal/cm 2 .
Why the Recent Focus? NFPA 70E standard now recognizes Arc Flash as a serious consequence and requires a Flash Hazard analysis be performed on facilities. OSHA has updated its Electrical Safety Procedures for the first time in 25 years. Effective date of OSHA’s updated regulations is August 13, 2007
Electrical Statistics At least one person a day is electrocuted in the workplace everyday � Over half of the deaths are from working “live” electrical circuits less than 600 volts. Average of 4000 non-disabling and 3600 disabling electrical injuries occur in the US.
Electrocutions by Year (Construction Safety Council) 700 664 600 544 486 500 480 474 440 395 400 # Electrocutions 300 200 100 0 1992 1994 1996 1998
Electrical Statistics Five to 10 arc flash explosions occur in electrical equipment every day in the US. Fourth leading cause of occupational fatalities. Over 2000 workers are admitted to burn centers each year.
Burn Costs Average burn case costs $12 to $20 Million Average hospital burn unit costs $400K per month Average hospital burn unit stay 3 months
Electrical Statistics General Industry � One fatality per 300 recordable injuries. Electrical Industry � One fatality per 10 recordable injuries.
Electrician Survey 97% had experienced an electrical shock. 26% had witnessed an injury. 58% were exposed to the possibility of an injury every day.
Facts on Electrical Incidents 80% of electrically related accidents and fatalities among Qualified Workers are caused by Arc Flash. 80% of electrically related accidents and fatalities among Unqualified Workers are caused by Electrocutions. Age 34 is the median age for someone killed working around electricity.
OSHA & NFPA 70E OSHA was created in 1969. It incorporated the National Electric Code (NFPA 70 standard 1971) into its electrical standard. NFPA 70E Standard was created at the request of OSHA in 1979 to recognize the difference between design and workplace safety. � NFPA 70 (NEC) applies to installations (design). � NFPA 70E addresses workplace safety.
OSHA Regulations OSHA bases its electrical safety mandates on: � CFR 1910 Subpart S (General Industry) � CFR 1926 Subpart K (Construction) OSHA recognizes NEC and NFPA 70E as an industry standards.
OSHA Regulations OSHA requires companies to follow its regulations and will cite companies for non-compliance under the General Duty Clause: � which states, “each employer shall furnish to each of its employees a place of employment that is free from recognized hazards that are likely to cause death or serious physical harm.”
OSHA Regulations OSHA is also citing companies for the following: � 29 CFR 1910.335 (a)(1)(i): requires the use of protective equipment when working where a potential electrical hazard exists. � 29 CFR 1910.132 (d)(1): requires an employer assessment of all workplace hazards and the use of personal protective equipment.
Who is the NFPA? The National Fire Protection Association (NFPA) develops, publishes, and disseminates more than 300 consensus codes and standards intended to minimize the possibility and effects of fire and other risks. Virtually every building, process, service, design, and installation in society is affected by the NFPA documentation (Ex. the National Electric Code…NFPA 70).
National Electric Code (NFPA 70) Utilized for design and installation of electric facilities � Wiring and Protection � Wiring Methods and Material � Equipment for General Use � Special Equipment and Conditions
Intent of NFPA 70E Objective is to minimize exposure to electrical hazards for personnel working around electricity. This includes: � Electricians � Mechanics � HVAC technicians � Painters � Plumbers � Carpenters � Production Workers
Intent of NFPA 70E Define Safe Work Practices to avoid injury. Define the requirements for an Electrical Safety Program. Define the requirements for Training Define the requirements for PPE Applies to all types of employers and facilities, including employees, contractors, and construction workplaces.
NFPA 70E Electrical Safety Standard in the Workplace Chapter 1 – Safety Related Work Practices Chapter 2 – Safety Related Maintenance Requirements Chapter 3 – Safety Requirements for Special Equipment Chapter 4 – NEC Related Installation Material
NFPA 70E covers… Public and private buildings Carnivals Industrial Substations Any installation of electrical equipment to the supply of electricity
NFPA 70E does not cover… Utilities Ships Mines Railways Communication equipment under control of communication utilities
NFPA 70E Chapter 1 Article 110 – Provides General Requirements � Responsibility � Electrical Hazard Analysis � Training Requirements � Electrical Safety Program Article 120 – Emphasizes Working De- energized & Describes the Work Practices Article 130 – Provides Requirements for Working On or Near Electrical Components
Chapter 1 Responsibility Employers are responsible for providing work practices and procedures. Employees are responsible for implementing them.
Chapter 1 Multiemployer Relationship Recognizes that more than one employer may be responsible for hazardous conditions on a worksite. Outside contractors are contractually obligated to the onsite employer. Both employers must share their Electrical Safety Programs with each other.
Chapter 1 Multiemployer Relationship Onsite employers and outside contractors shall inform each other: � Of existing hazards � PPE requirements � Safe work practice procedures � Emergency procedures Coordination should include a meeting and documentation
Chapter 1 Electrical Safety Program What needs to be in it? Scope Philosophy Principles Responsibilities Safety Procedures
Chapter 1 Electrical Safety Program PPE Requirements Controls Training Requirements Auditing Other?
Chapter 1 Training Requirements Trained to understand the specific risks associated with electric energy. Trained on safe work practices and procedures. Trained on emergency procedures. Training may be both classroom and on the job.
Training Session Misc. Real World Examples � Refeeding Panels (What needs to be checked?) � Transformer Connections (Why they are important) � Types of Grounding Systems � Explain how voltage is a difference in potential
Chapter 1 Electrical Hazard Analysis Requires an electrical hazard analysis, which is a study of a worker’s potential exposure to: � Shock � Arc Flash/Blast It determines the appropriate levels of Personal Protective Equipment (PPE) and work practices.
Electric Shock The original purpose of NFPA 70E Determine the voltage to which personnel will be exposed. Boundary Requirements PPE Requirements
Exposure to Shock Requires exposure to a difference of potential The National Electric Code reduces this risk under normal conditions. NFPA 70E reduces the risk under abnormal conditions
NEC Protects - Normal Conditions
70E Protects - Abnormal Condition
Effects of Electric Current on the Human Body Amps < 1 mA Barely perceptible 5 - 10 mA Tingling sensation (annoying) 10 - 20 mA “Let Go” threshold (discomfort) 20 – 50 mA Painful, cannot “Let Go” 50 - 100 mA Ventricular fibrillation Amps > 100 mA Cardiac arrest
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