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Electrical Safety This material was produced under a grant (SH22249SH1) from the Occupational Safety and Health Administration, U.S. Department of Labor. It does not necessarily reflect the views or policies of the U.S. Department of Labor, nor does the mention of trade names, commercial products, or organization imply endorsement by the U.S. Government.
Why do we need to talk about Electrical Safety? • From Bureau of Labor /NIOSH • 8,000 electrical contact injuries per year. • One person is electrocuted each working day. • 2,000 workers are sent to burn centers each year with greater than 2nd degree burns that are electrically related. • Survey of 1200 electricians. • 97% had experienced a shock • 27% had witnessed an electrical injury. • Electrocution remains the fourth (4th) highest cause of industrial fatalities. • Approximately 3,000 arc flash burn incidents reported annually along with 250 deaths.
Now that we discovered the need, here is what we will discuss: • Basic Electricity • Terms such as volt and amp • Basic Electrical Theory (How does it work?) • Hazards associated with Electricity • Electrical Shock • Burns • Etc.
Now that we discovered the need, here is what we will discuss: • Protection against Electricity • Overcurrent/Undercurrent Protection • Administrative Controls such as Lock-out/Tag-out (LOTO) • Training • Personal Protective Equipment • Etc.
Electrical Safety • Introduction to Electrical Safety • Hazards Associated with Electricity • Arc Flash/Arc Blast • Electrical Safety Program • Who is Responsible for Safety? • Employer/Worker Rights and Responsibilities
Introduction to Electrical Safety What is electricity and how does it work?
How does electricity work? • Electricity is the flow of energy from one place to another • Requires a source of power: usually a generating station • A flow of electrons (current) travels through a conductor • Travels in a closed circuit
How does electricity work? • Operating an electric switch is like turning on a water faucet. • Behind the faucet (or switch) there is a source of water (or electricity) with a way to transport it, and pressure to make it flow. The faucet’s water source is a reservoir or pumping station. A pump provides enough pressure for the water to travel through the pipes. For electricity the source is the power generating station. A generator provides the pressure (voltage) for the electrical current to travel through electric conductors (wires). • Volts – the electrical pressure (measure of electrical force) • Amps – the volume or intensity of the electrical flow • Watts – the power consumed • Resistance – the restriction to electrical flow
Intro to Electrical Safety • Now that we have a basic understanding of how electricity moves, we must look at the dangers we face when working near it. • In the next few slides, we will talk about the different terms associated with electricity and what they mean to us.
Match the term to the definition. • Conductors • Insulators • Grounding • a conductive connection to the earth which acts as a protective measure • substances with high resistance to electricity like glass, porcelain, plastic, and dry wood that prevent electricity from getting to unwanted areas • substances, like metals, with little resistance to electricity that allow electricity to flow
Match the term to the definition. • Conductors • Insulators • Grounding • a conductive connection to the earth which acts as a protective measure • substances with high resistance to electricity like glass, porcelain, plastic, and dry wood that prevent electricity from getting to unwanted areas • substances, like metals, with little resistance to electricity that allow electricity to flow
Match the term to the definition. • Conductors • Insulators • Grounding • a conductive connection to the earth which acts as a protective measure • substances with high resistance to electricity like glass, porcelain, plastic, and dry wood that prevent electricity from getting to unwanted areas • substances, like metals, with little resistance to electricity that allow electricity to flow
Match the term to the definition. • Conductors • Insulators • Grounding • a conductive connection to the earth which acts as a protective measure • substances with high resistance to electricity like glass, porcelain, plastic, and dry wood that prevent electricity from getting to unwanted areas • substances, like metals, with little resistance to electricity that allow electricity to flow
Match the term to the definition. • Current • Circuit • Resistance • complete path of the current. Includes electricity source, a conductor, and the output device or load (such as a lamp, tool, or heater) • restriction to electrical flow • electrical movement (measured in amps)
Match the term to the definition. • Current • Circuit • Resistance • complete path of the current. Includes electricity source, a conductor, and the output device or load (such as a lamp, tool, or heater) • restriction to electrical flow • electrical movement (measured in amps)
Match the term to the definition. • Current • Circuit • Resistance • complete path of the current. Includes electricity source, a conductor, and the output device or load (such as a lamp, tool, or heater) • restriction to electrical flow • electrical movement (measured in amps)
Match the term to the definition. • Current • Circuit • Resistance • complete path of the current. Includes electricity source, a conductor, and the output device or load (such as a lamp, tool, or heater) • restriction to electrical flow • electrical movement (measured in amps)
Hazards Associated with Electricity Warning some slides contain pictures which are graphic. Viewer discretion is advised.
Electrical Hazards • There are 4 potential dangers involved with contacting electricity: • Direct • Shocks • Burns • Electrocutions • Indirect • Falls
Electrical Hazards - Shocks • Severity of the shock depends on: • Path of current through the body • Amount of current flowing through the body (amps) • Duration of the shocking current through the body, • LOW VOLTAGE DOES NOT MEAN LOW HAZARD
Electrical Hazards - Burns • Another danger associated with electricity is electrical burns. • Severity of the electrical burns depends on: • Duration the body is exposed to the current, • Amount of current and • Path to ground
Severity of damage to the body depends on the path to ground. • Where did the electricity enter the victims body? • Where did the electricity exit the victims body?
Electrical Hazards - Electrocutions • When the electrical shock has taken the life of the victim, electrocution is the result. • Electrocution is death due to electrical shock. • 76 workers were killed while at work in 2010.
Electrical Hazards - Falls • The number one cause of injuries and fatalities in the construction industry is falls. • Most injuries and fatalities involved with electricity are falls directly related to working from a ladder or at a height. • If you were working with electricity while on a ladder and you get shocked, what would your reaction be?
What is Arc Flash/Blast? • An arc flash is an electrical breakdown of the resistance of air resulting in an electric arc which can occur where there is sufficient voltage in an electrical system and a path to ground or lower voltage. An arc flash with 1000 amperes or more can cause substantial damage, fire or injury. Temperatures can reach or exceed 35,000 degrees (Fahrenheit) at the arc terminals.
Arc Flash/Arc Blast • What causes Arc Flash? • Dust and impurities • Corrosion • Condensation • Spark discharge • Overvoltage across narrow gaps • Failure of insulating materials • Improper work procedures
The Electrical Safety Program Shall include: • Update training • Policies generated by the management structure. • Current procedures that guide workers actions. • Review process. • PPE necessary to protect workers. • Auditing process to monitor developing knowledge. • Controls that establish expectations for workers. • Processes that define and execute enforcement of the program.
OSHA • Before workers are exposed to electrical hazards, the following must be done prior to exposure: • Live parts must be de-energized • Circuits must be de-energized • Controls must be tagged • Equipment and/or circuits must be rendered inoperative and tagged
The employer is responsible for: • Following OSHA requirements • The Electrical Safety Program • Safety Policies and Procedures • Safety Training and Re-Training
The worker is responsible for: • Implementing Procedures • Following the employers safety policies and procedures
What is the best Way to Prevent the Hazards of Electricity? • Stop • Think • Options • Protection
Employers and Workers • Employers: • If workers will be expected to maintain or install electrical equipment, additional training must be done prior to exposure. • Workers: • If your work changes or you are asked to do additional work involving electricity, additional training must be completed prior to exposure.
We have learned about: • The basics of electricity • Hazards associated with electricity • The Electrical Safety Program • Employer/worker rights responsibilities with electrical safety
Employee Rights and Responsibilities • You have the right to: • A safe and healthful workplace • Know about hazardous chemicals • Information about injuries and illnesses in your workplace • Complain or request hazard correction from employer
Employee Rights and Responsibilities • You have the right to: • Training • Hazard exposure and medical records • File a complaint with OSHA • Participate in an OSHA inspection • Be free from retaliation for exercising safety and health rights
Employee Rights and Responsibilities • OSHA website: http://www.osha.govand OSHA offices: Call or Write (800-321-OSHA) • Compliance Assistance Specialists in the area offices • National Institute for Occupational Safety and Health (NIOSH) – OSHA’s sister agency • OSHA Training Institute Education Centers • Doctors, nurses, other health care providers • Public libraries • Other local, community-based resources