Basic Electrical Safety Construction makes up 7% of the work force in the US, but 45% of the electric fatalities each year. One person is electrocuted in the workplace every day, says Ken Mastrullo, safety and health manager for Region 1 OSHA, who spoke at a recent professional development conference sponsored by the Nutmeg Chapter of the American Society of Safety Engineers (ASSE). Some 4,000 workers suffer non-disabling electrical injuries every year, 3,600 workers suffer disabling electrical injuries every year, and 2,000 workers are sent to burn units every year with electrical injuries, he says. Before coming to OSHA, Mastrullo was associated with the National Fire Protection Association (NFPA). He was the lead author of The Electrical Safety Program Book and co-author of the NFPA 70E Handbook, the standard for electrical safety in the workplace.

Objectives Basics of Electricity Conductors and Insulators “Play It Safe, It’s The Law” This discussion is designed to be an initial, not an in-depth discussion on the hazards of electricity. I will not be able to cover all of the hazards in your workplace, but instead will focus on working around high voltage lines and the restrictions set forth by OSHA and the state of Texas.

Objectives Not designed to qualify you to work on electrical systems Not designed to be inclusive of all regulations regarding working near electrical lines/facilities As a reminder, if you identify problems with electrical systems, please report them immediately Qualified workers are those with the training and equipment that allow them to work on high and low voltage lines and to get closer than the minimum approach distances we will discuss later. Qualified workers from an electric utility use rubber goods (gloves, blankets, covers) to protect themselves against accidental contact.

Basics Electricity flows in a completed path or loop Electricity will not flow until there is a complete loop Electricity will take the easiest and all paths to ground Electricity flows through conductors such as metal or water Because the human body is mostly water, it is a conductor of electricity In order to avoid electrical hazards, it’s important to understand some basic characteristics and terms about electricity. Electricity is the flow of electrons. Ohms Law is E (voltage) = I (amperage) x R (resistance). All electricity follows Ohms Law. The path the electrical current takes through the body is very important; however, a person often does not have control over the specific path once the electricity enters the body. The severity of the electrical shock depends on: Amount of current, with higher current more dangerous Duration of shock, with longer being more dangerous Path in body, with passage through the heart the most dangerous

Basics Electricity is measured in different ways Volts Amperes (Amps) Watts Volts measure the “pressure” under which electricity flows. Amps measure the amount of electric current. Watts measure the amount of work done by a certain amount of current at a certain pressure or voltage. To understand how they are related, think of water in a hose. Turning on the faucet supplies the force, which is like the voltage. The amount of water moving through the hose is like the amperage. You would use lots of water that comes out really hard (like a lot of watts) to wash off a muddy car. You would use less water that comes out more slowly (like less watts) to fill a glass. From a safety perspective, electricity can be compared to water in a piping system to explain the relationship between voltage, amperage and resistance. The higher the voltage, the more “pressure” in the electrical equipment that can cause injury. The analogy is a water hose with high pressure versus low. The higher the amperage, the more “flow” of electricity through the electrical equipment that can cause injury. The analogy is that a large diameter hose will allow much more water flow than a small hose. The lower the resistance, the more electricity can flow. When electricity has resistance, heat is generated, which can result in fires or damaged equipment. The analogy can be a straight hose with no restrictions or a kinked hose that restricts water flow.

Effect on the Human Body Shock Burns Electrocution Electrical hazards include: Shock Arc flash Arc blast Other hazards Shock injuries typically occur to the hands. Workers should not rely solely on V-rated tools to protect their hands, but need personal protective equipment as well. Arc flash accidents are life-altering events because they can cause horrendous second- and third-degree burns as well as other injuries. An arc flash can ignite or melt clothing, resulting in further burns. Victims sometimes require skin grafts or amputations. A high-amperage arc can produce a pressure wave blast with a force of up to 1,000 pounds, strong enough to throw a victim and result in injuries from falling or colliding with nearby objects. Hearing loss may also occur. Shock occurs when you touch a live wire—or a tool or machine part with poor insulation—and the ground. You are, in effect, becoming a conductor—the shock you feel is the electrical current running through your body.

Have you ever been shocked? More than 3 ma painful shock More than 10 ma muscle contraction “no-let-go” danger More than 30 ma lung paralysis- usually temporary More than 50 ma possible ventricular fibrillation (heart dysfunction, usually fatal) 100 ma to 4 amps certain ventricular fibrillation, fatal Over 4 amps heart paralysis; severe burns. Usually caused by >600 volts Shock can cause symptoms that range from mild to severe. They include: Pain Loss of muscle control/coordination Internal bleeding Nerve, muscle, tissue damage Cardiac arrest, and even Death The longer you’re in contact with live electricity, the greater the damage to your body. And, it doesn’t take a large amount to hurt you—as little as 50 milliamperes (mA), just one-third the amount of electricity used to power a transistor radio, is enough to cause death. Many people assume that the electrical voltage is what injures or kills a person, when, in fact, it is the amperage that injures and kills. Amperage is determined by voltage and resistance. When voltage goes up, amperage goes up. When resistance goes up, amperage goes down. Here’s the formula: Amperage = (Voltage)/(Resistance). The human body has a certain amount of natural resistance. Resistance can be increased by wearing insulated gloves and boots, and by using insulated tools. Even low-voltage electricity can cause severe damage. A typical home circuit carries 120 volts of electricity. For the average person with 2000 ohms of resistance, this will result in the person being struck by 60 mA (1-1,000th of an amp). Using the information on this slide, you can see that even the seemingly low voltage at home can be extremely dangerous. Even 1 mA can be felt by the human body. 2-10 mA can result in a minor shock. What if this person was working on an elevated platform without proper fall protection? This minor shock could cause the person to fall from the elevation and be seriously injured or killed. At 10-25 mA, the person may lose muscle control and may not be able to release or let go of the circuit. This situation is especially dangerous if there are no other employees in the area that can break the circuit (remember, never touch a person that is being shocked; use a piece of nonconducting wood to pry them away from the electrical current). 25-75 mA is painful and may lead to collapse or even death. The longer the person is exposed to this electrical current, the more likely death will occur. 75-300 mA for even a quarter of a second is almost always immediately fatal. Death is often the result of ventricular fibrillation (twitching heart). 15 Amp Lowest overcurrent protection of common fuse or circuit breaker

OSHA and State Plans The following states have approved State Plans: Alaska, Arizona, California, Connecticut, Hawaii, Indiana, Iowa, Kentucky, Maryland, Michigan, Minnesota, Nevada, New Jersey, New Mexico, New York, North Carolina, Oregon, Puerto Rico, South Carolina, Tennessee, Utah, Vermont, Virgin Islands, Virginia, Washington, and Wyoming NOTE: The Connecticut, New Jersey, New York and Virgin Islands plans cover public sector (State & local government) employment only. OSHA governs safety of workers in the US and the US possessions. Some states, and PR, have state plans and state OSH agencies. These state agencies will adopt OSHA’s regulations and in some cases make more restrictions for employers and workers. The most restrictive plans include California. As Texas does not have a state agency/plan, we follow 29CFR for regulations regarding workers.

The Law Chapter 752 of the Texas Health & Safety Code makes it unlawful for unauthorized persons to: move to, or place any objects, within six feet of any high voltage overhead electric line (over 600 volts), or to operate certain machinery or equipment within six feet of any high voltage overhead electric line Chapter 752 also requires unauthorized persons to contact the owner of the lines 48 hours before work within these zones is started Note these are the rules for high voltage lines. High voltage is defined as being over 600 volts. Distribution lines will carry varying amounts of electricity based on the state and provider.

Low Voltage Power Lines Low Voltage is 600 volts or less Residential structures will be fed by single phase lines from a transformer Commercial structures will be fed by three phase lines from a transformer The minimum approach distance for low voltage lines is 3 feet for insulated lines The minimum approach distance for low voltage lines is 10 fee for uninsultated lines When a residential structure is connected to the “grid”. A transformer will “step down” the voltage to the structure. A single phase line will enter the house and is connected to the breaker. The breaker’s bus provides electricity for the dwelling/structure.

Know Before You Dig Electric cables can also be buried underground Under streets Under alleys Buried in residential yards Call before you dig 1-800-DIG TESS (344-8377)

Items to Consider Scaffolding Extension ladders Metal poles Trenching machines Shovels Tools Overhead power lines Stay at least 10 feet away Keep equipment at least 10 feet away Buried power lines Don’t dig until verified that buried lines and other utilities are not in the area Because of the rugged nature of your business, normal use of electrical tools causes wear and tear that may cause the insulation of tools to break or tear resutling in short circuits and exposed wires. Without ground fault protection, it could send a shock through your body. Use GFCI on all 120-volt single phase, 15- 20- ampere receptacles. Use double-insulated tools and equipment. Visually inspect all equipment before uses. Remove any tool with frayed cords, missing ground prongs, cracked tool casings, etc. Never remove a ground prong as it provides the path back to complete the loop. Without the prong, you increase your risks. Casey – a stud was missing on a drill and he received a fatal shock.

Do and Do Not Do plug power equipment into wall receptacles with power switches in the “Off” position. Do unplug electrical equipment by grasping the plug and pulling. Do not pull or jerk the cord to unplug the equipment. Do not drape power cords over hot pipes, radiators or sharp objects. Do check the receptacle for missing or damaged parts. Do not plug equipment into defective receptacles. Do check for frayed, cracked, or exposed wiring on equipment cords. Ground Fault Circuit Interrupters (GFCIs) provide a high level of protection as they will trip before a serious electric shock can occur. GFCIs trip at about 5 milliAmps in a fraction of a second. A person may still get a brief shock before it trips. Don't permit… Overloaded outlets or circuits. Loose electrical connections. Dust or dirt buildup on machinery. Blind reaches into any areas that may contain energized parts. Combustible trash on or around electrical equipment or circuits. Anyone who isn't trained and qualified to repair electrical equipment. Attempts to use or start locked or tagged out electrical equipment. Unauthorized removal or a lockout device or tag. Any hesitation in calling trained emergency responders for electrical fires, shock, or serious burns. Don't wait for an accident to tackle your electrical safety problem areas. Take steps today to make your department shockproof.

Do and Do Not Do check for defective cords clamps at locations where the power cord enters the equipment or the attachment plug. Do not use extension cords in office areas. Do not use “cheater” plugs, extension cords with junction box receptacle ends. Do know the location of electrical circuit breaker panels that control equipment and lighting in their respective areas. Circuits and equipment disconnects must be identified. Don't use… Cords or wires with damaged or worn insulation. Electrical equipment that smokes, sparks, shocks, smells, blows a fuse, or trips a circuit. Any non-GFCI outlet in a wet area. Cords or electrical equipment in areas with explosive or flammable materials that are not approved for this specific use. A cord with a bent or missing grounding plug. A metal ladder or hard hat when you are working near electricity. Metal tools to work on electrical equipment. Electrical cords to raise or lower equipment. Extension cords unless necessary, and then, only a cord that is rated high enough for the job. Don't touch… Anything electric when your hands are wet, when you're standing on a wet floor, or when you're in contact with a wet surface. A victim of an electrical fire or an electrical shock. Don't place… Cords where they can be stepped on, run over by material handling equipment, or damaged in any other way. Cords near heat or water. Sharp fasteners or nails on electrical cords.

Questions? Jeff O’Connor TXU Electric Delivery Safety Coordinator 500 N Akard LP 11041 Dallas, TX 75201