Overhead Powerlines
A sign is shown that says, “Danger Overhead Power Lines.”
Date Posted: 05/30/2024
According to the Electrical Safety Foundation, between 2011 and 2020, 39% of all electrically related workplace fatalities were caused by overhead power lines. 53% of all fatal electrical injuries occurred in the Construction industry. The Construction industry has remained the leading source of fatal electrical injuries, with 82, about three times the amount of the second-highest industry.
Working with or near power lines can expose workers to electrical hazards, but these dangers can be avoided through safe work practices. Exposure to overhead power line hazards is not limited to employees of electrical utilities—workers in industries like construction and agriculture can also be exposed to them. Accidental contact with live overhead power lines can cause severe injuries and even death. Electricity can jump if equipment or machinery gets too close to powerlines, and fatal injury can be sustained, even without direct contact with a powerline.
What are the Types of Overhead Powerlines?
Generally, there are three types of lines:
Transmission lines: Carry more than 69,000 volts of current.
Subtransmission lines: Carry from 34,500 volts to 69,000 volts of current.
Distribution lines: Carry less than 34,500 volts of current.
What are Common Construction Exposures to Overhead Powerlines?
Use elevating equipment, like dump trucks, backhoes, or cranes.
Carry long conductive objects like piping or ladders.
Work at elevation, from ladders and scaffolds, aerial lifts, or in bucket trucks.
A crane is shown operating near overhead powerlines.
Hazards of Exposure to Overhead Powerlines
When workers are near overhead power lines, they may be exposed to hazards that include:
Electric shock: Direct contact with live electrical current results in electric shock, which can kill or injure.
Electrocution: Electrocution occurs when a worker receives a powerful enough electric shock to kill.
Electrical burns: A person who comes into contact with electricity but is not electrocuted may suffer electrical burns on the skin or internally.
Arc flash: Electricity can arc through the air to reach a conductive object. Sometimes, an arc produces an explosion (an arc flash or arc blast) powerful enough to melt metal and ignite clothing and flesh.
How Far Should You Stay Away from Overhead Powerlines?
At no time should any person or piece of equipment come within the safe distances shown in the table below. This is in any direction – from under, above, or either side. If it is needed to work within the safe clearance zone near an overhead power line, first consult with the utility owner and shut the lines down or develop an alternative safe work plan. The minimum safe approach distances are shown below:
|
Powerline Voltage Phase to Phase (kV) |
Minimum Safe Clearance (ft) |
|
50 or below |
10 |
|
Above 50 to 200 |
15 |
|
Above 200 to 350 |
20 |
|
Above 350 to 500 |
25 |
|
Above 500 to 750 |
35 |
|
Above 750 to 1,000 |
45 |
Powerline Voltage Phase to Phase (kV)
Minimum Safe Clearance (ft)
50 or below
10
Above 50 to 200
15
Above 200 to 350
20
Above 350 to 500
25
Above 500 to 750
35
Above 750 to 1,000
45
Methods to Avoid the Hazards of Overhead Powerlines
Identify all overhead power lines before any work by conducting a hazard assessment to identify potential overhead powerline safety hazards.
Stay at least 10 feet away from overhead power lines (see “How Far Should You Stay Away from Overhead Powerlines” for additional detail). When using the forklift with a winch or a hook to lift a suspended load, the contractor must follow the power line rules found in the construction crane rule, which are more stringent and have more requirements. See WAC 296-155-53408 - Powerline Safety for more details.
Work with the electrical company to de-energize and ground powerlines if you need to be closer than the safe distance.
Assume that all overhead powerlines are energized unless you can positively confirm otherwise.
Only operate equipment around overhead powerlines if you have been authorized and trained to do so.
Use non-conductive or fiberglass ladders when working near power lines or service drops.
Wear personal protective equipment (PPE), such as rubber insulating gloves, insulating sleeves, and electrical protective head protection.
Ensure that all workers have been trained on overhead power-line safety.
Before beginning any work, survey the worksite for overhead power lines.
If a machine or equipment has come into contact with an overhead powerline, stay away and do not allow anyone to touch or come near the machine or equipment.
Work with the local utility company when overhead power lines are present at the worksite.
Never touch an overhead powerline if it has fallen or been knocked down.
When using the forklift with a winch or a hook to lift a suspended load, the contractor must follow the power line rules found in the construction crane rule, which are more strict and have more requirements. WAC 296-155-53408.
Resources
Working Too Close to Overhead Power Lines - DOSH Hazard Alert (wa.gov)
WAC 296-155-53408 - Powerline Safety
