Duke Energy
A shocking fact – almost 200 construction workers die each year from contact with electrical energy, the fifth-leading cause of workplace death. Direct or indirect contact with power lines is the most common cause of electrocution, according to the Occupational Safety and Health Administration (OSHA). Yet many roofing company employees aren’t aware of the danger overhead power lines can pose when they are located near a roof. Below are simple practices that can be implemented into their daily routine.
Electricity travels in closed circuits, usually through a conductor. A conductor is a substance with little resistance to the flow of energy. Metal equipment, roofs, steps on a ladder, and even your body are potential conductors.
Electrical shock occurs when a person’s body contacts an electrical circuit and provides a path for electricity to leave the circuit and travel to the ground. On the jobsite, this can happen when you contact one wire of an energized circuit and the ground at the same time or, you touch equipment that’s in contact with an energized wire while you’re also in contact with the ground.
Lower voltages (and lower amperages) can cause muscle spasms that inhibit your ability to “let go” of the object you’re touching that’s completing the circuit. The degree of injury increases with every second your body is conducting electricity.
Higher voltages (and higher amperages) can throw you clear, interrupting the circuit, but, injury or death can still result from the electrical shock or fall.
There is a risk of serious injury or death anytime you come into contact with an energized circuit, whether low or high voltage. That’s why it’s important to stay away from all energized conductors, thus avoiding contact with any electricity.
Solar panels and equipment are easily damaged, and they may carry live electrical current even when the sun is not shining. Follow these tips to protect system components and to protect yourself from electrical shock.
■ Locate all equipment. Ask the building owner or property manager to point out solar panels, conduits, batteries and all related equipment. Once you know the location of system components, take care to keep ladders, tools and supplies away from them.
■ Watch out for conduits. The conduits that lead away from an array of solar panels carry electrical current at voltages strong enough to severely injure or kill you if you contact the wires inside. Note that conduits may run from a rooftop down the outside of a building.
■ Stay away from solar panels. The top surfaces of solar panels are made of glass that will crack or break if a heavy object falls on them. If possible, maintain a two- to three-foot safety perimeter around panels and mounts.
■ Protect thermal systems. Thermal solar systems move water through an array of narrow pipes on which sunlight is focused through glass. Take care around these installations and their input and output pipes.
Maintaining the proper clearance from overhead power lines is not only critical to a safe work environment, it’s the law. So, how do you determine the correct clearance distance? Here are some good rules of thumb:
■ If the overhead line is 50 kV or less, stay at least 10 feet away. This clearance distance is 20 feet for cranes and derricks used in construction unless you have taken OSHA-mandated encroachment prevention precautions.
■ Keep all equipment at least 20 feet away from lines carrying 50 kV to 350 kV. For lines carrying more than 350 kV, keep a minimum distance of 50 feet.
■ If you are unsure of the power line’s voltage, contact the local utility provider before work begins. For specific clearance requirements visit www.osha.gov.
Power lines are not covered by or wrapped in insulation. Always consider them energized and dangerous. Any contact with overhead lines could cause serious injury to operators and ground crew.
A typical distribution line along a roadway may contain voltages ranging from 7,000 volts up to 138,000 volts. Major transmission lines can be as high as 500,000 volts. Direct and indirect contact with power lines is the most common cause of electrocution. OSHA analysis has determined that nearly 45 percent of major cases of crane accidents include boom or crane contact with energized power lines.
You’ve followed all mandatory safety guidelines but, despite your best efforts, your equipment still contacts an overhead power line. What do you do now?
■ Immediately try to move the equipment clear, but only if you can do so safely.
■ Tell others to stay away and not to approach or touch the equipment.
■ Have someone immediately call 911 and the local utility provider.
■ Stay on the equipment until utility workers say it is safe to get off.
If you must leave your equipment due to fire or other danger:
■ Jump as far away as possible so you don’t touch the equipment and the ground at the same time.
■ Land with your feet together.
■ Shuffle away with your feet close together and on the ground, or hop away on two feet, keeping both feet together.
■ Once you’re clear of your equipment, don’t return for any reason until you are advised by electric utility workers that the area is safe.
Utility contacts can be costly – and deadly. Implementing the simple steps outlined below can help you and your crew work safely around electric utilities.
Examine the Site – Look Out for Power Lines
Search carefully for overhead power lines, poles, guy wires, and pad-mounted equipment. Conditions can easily change, so check the site frequently. Look for lines that may be blocked from view by trees or buildings, and electrical equipment on the ground that may be hidden by bushes or small trees. If you suspect hidden hazards, talk to the utility company, inspectors, and experienced colleagues about your concerns
Alert Others About Lines at Your Pre-Job Briefing
Make sure everyone at the jobsite knows about nearby overhead and underground utilities and where they are located. Whether they are operating heavy equipment, using handheld tools, or climbing ladders, all workers on site must be aware of power lines.
Assume All Lines are Energized and Potentially Dangerous
This includes overhead and underground lines, and the service drops that run from utility poles to buildings.
Clearly Mark Boundaries
Use tape, signs, or barricades to keep workers and equipment the required distance away.
For Equipment Operators, Visibility is Limited
When you operate hoisting equipment, it is often hard to judge the distance from your equipment to power lines overhead. Certain weather conditions and bright or dim lighting can make it even harder to see.
A Spotter Helps You Stay Clear of Overhead Lines
Someone on the ground has a much better view of the power lines near you. You should work with a dedicated spotter on the ground whose only job is to watch your equipment and make sure you stay a safe distance from overhead lines and other hazards.
For crane and derrick operators, maintain continuous contact with a dedicated spotter to comply with electric line clearance requirements. Make sure your spotter is not doing double duty by spotting and guiding a load at the same time.
When You Guide a Load, You are At Risk of Electric Shock
If the crane or other piece of equipment you are guiding hits an overhead power line, electricity can travel down the tag line that you are holding and through you. In the event of power line contact, workers on the ground are in the greatest danger of shock.
Don’t Try to Guide a Load and Spot at the Same Time
Assign a spotter whose only job is to make sure the equipment stays clear of power lines. Spotting effectively needs someone’s full attention.
“BET” Yourself – Wager on Safety
Power lines are common on the jobsite and have become a familiar part of our surroundings. Perhaps, because of this, they often go unnoticed. How can you reduce your risk? Play a betting game with yourself.
■ BET yourself that you’ll remember the safety rules and regulations associated with working around power lines.
■ BET yourself that you’ll lead by example and show coworkers proper safety procedure.
■ BET yourself that you’ll remain accident free.
Always create a boundary around power lines to serve as a clearance reminder and to minimize risks to other workers in the area. When using tall or long equipment around power lines, maintain the required safe work distances and encroachment prevention precautions.
Examine the Site
Before work begins every day, examine the site and conduct a safety briefing to alert everyone on the jobsite about nearby overhead and underground power lines. Assume all lines are energized and potentially dangerous.
Train Your Crew
Educate everyone on your jobsite about the dangers of working near power lines. Assist your coworkers by showing them how to maintain a safe work environment.
Are Overhead Power Lines Insulated?
Most overhead power lines are made of highly conductive aluminum with a steel core, or are copper—and they are NOT insulated. If you look up at a utility pole or tower you may not be able to identify which lines are communication cables and which are energized wires. You should assume that any wire on a utility pole or tower is energized and dangerous, and stay away. All downed wires should also be considered energized and dangerous—stay far away from them as well.
Don’t Be Fooled by the Covering
Don’t be fooled by the covering on the service drop wires that go from utility poles to homes. This coating is designed to protect the service drop from the elements, but it is not true insulation and will not prevent injury to people. This covering will NOT protect you from electrical shock.
Tall and Long Equipment– Keep Vehicles Clear of Lines
Long-bed trucks, cranes and material conveyors can contact overhead power lines. Make sure you know the required safe work distances and encroachment prevention precautions for all power lines at your jobsite, and respect all marked safety boundaries. Work with a dedicated spotter to comply with line clearance requirements.
Take Care with Ladders and Long Handheld Tools
Carry ladders, paint rollers, rain gutters, and other long objects so they are parallel to the ground. When it’s time to use them, raise and lower them carefully to avoid power lines.
Adjust ladders and tools cautiously. Before adjusting extension ladders, paint rollers, or other long tools, add your own height and make sure the total height will remain a safe distance of at least 10 feet away from overhead lines of 50,000 volts or less. When climbing a single or extension ladder, you should never stand above the third rung from the top of the ladder or above the point where the ladder touches the wall or ledge. As voltage increases, clearance distances also increase. Consult your local utility and the OSHA regulations at www.osha.gov for specific safety clearance requirements.
If a Co-Worker Hits a Power Line – Stay Away
Stay clear of any person or any object that is in contact with a power line. Call 911 and the electric company immediately. Don’t try to rescue the victim. Stay away until rescue workers assure you the power has been turned off.
Protect Yourself
If you touch someone who is in contact with electricity, you could be shocked too. You can also be shocked if you touch the vehicle or equipment that person is in, or the tool they are holding. Again, the best thing to do is to stay far away and call for help.
It’s human nature to want to help someone who is hurt. But when a power line is involved, you can’t help without endangering yourself. Do not try to use non-conductive ropes or tools to push an electrical contact victim clear of a power line—power line voltages can be strong enough to travel through non-conductive objects.
If You Hit a Power Line
If you MUST get off the equipment due to fire or other danger, jump clear, keeping both feet together and without touching the ground and the equipment at the same time. Shuffle away with small steps, keeping your feet close together and on the ground, or hop away on two feet, keeping both feet together.
Even after you’ve jumped from equipment with a power line on it, the danger may not be over. Electricity can spread out through the ground in all directions from any downed line. The voltage drops as you move away from the point of contact. However, if you touch a high-voltage and a low-voltage zone at the same time (which can happen if you take big steps or run), electricity can travel up one leg and down the other, and you can be shocked. This is why you should shuffle away from the line, keeping your feet close together and on the ground.
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