Protection from Overhead Power Lines
Before working under or near overhead power lines, ensure that you maintain a safe distance to the lines. Additionally, for very high-voltage lines, it's important to ground any equipment, like cranes, that could become energized.
When working on power lines, it's important to confirm that the lines have been de-energized and grounded by the owner or operator. Additionally, implementing protective measures such as guarding or insulating the lines is essential to prevent accidental contact.
Employees who are not qualified to work with electricity, as well as mechanical equipment, should remain at least 10 feet away from overhead power lines. For power lines carrying more than 50,000 volts, the required clearance distance increases by an additional 4 inches for every 10,000 volts beyond 50,000.
When mechanical equipment is operated near overhead lines, employees standing on the ground should avoid contact with the equipment unless it is located outside the danger zone. When factoring the safe standoff distance, be sure to consider the equipment's maximum reach.
Remember these important safe practices when working around downed power lines:
- Do NOT assume that a downed conductor is safe simply because it is on the ground or it is not sparking.
- Do NOT assume that all coated, weatherproof or insulated wire is just telephone, television or fiber-optic cable.
- Low-hanging wires still have voltage potential even if they are not touching the ground. So, don't touch them. Everything is energized until tested to be de-energized.
- Never go near a downed or fallen electric power line. Always assume that it is energized. Touching it could be fatal.
- Electricity can spread outward through the ground in a circular shape from the point of contact. As you move away from the center, large differences in voltages can be created.
- Never drive over downed power lines. Assume that they are energized. And, even if they are not, downed lines can become entangled in your equipment or vehicle.
- If contact is made with an energized power line while you are in a vehicle, remain calm and do not get out unless the vehicle is on fire. If possible, call for help.
- If you must exit any equipment because of fire or other safety reasons, try to jump completely clear, making sure that you do not touch the equipment and the ground at the same time. Land with both feet together and shuffle away in small steps to minimize the path of electric current and avoid electrical shock. Be careful to maintain your balance. Watch this video.
Knowledge Check Choose the best answer for the question.
2-8. If you must exit a vehicle because of fire when contact is made with an energized power line, _____.
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