Overhead Powerlines

Many workers in construction face a common safety hazard: electrical contact with overhead power lines. Every year many workers are killed or disabled after accidentally coming in contact with the lines. 

What precautions can you take to avoid this type of accident? 

No work shall be performed, no material shall be piled, stored or otherwise handled, no scaffolding, commercial signs, or structures shall be erected or dismantled, nor any tools, machinery or equipment operated within the specified minimum distances from any energized high voltage electrical conductor capable of energizing the material or equipment; except where the electrical distribution and transmission lines have been de- energized and visibly grounded at point of work, or where insulating barriers not a part of or an attachment to the equipment have been erected, to prevent physical contact with the lines, equipment shall be operated proximate to, under, over, by, or near energized conductors only in accordance with the following: 

  • For lines rated 50 kV. or below, minimum clearance between the lines and any part of the equipment or load shall be ten feet. 
  • For lines rated over 50 kV. minimum, clearance between the lines and any part of the equipment or load shall be ten feet plus 0.4 inch or each 1 kV. over 50 kV., or twice the length of the line insulator but never less than ten feet. 

Safety Tips

  • Do not store tools, machinery, and equipment near live high voltage overhead lines if it is possible for them to come within the minimum clearance of 6 feet when they are being moved or used.
  • When moving boom-type equipment with boom lowered and no load attached, keep the end of the boom at least 6 feet away from high voltage lines. 
  • When operating boom-type lifting or hoisting equipment, the minimum clearance is 10 feet when the overhead line is carrying between 600 and 50,000 volts. Post warning signs of equipment warning the operator to not work close to power lines.
  • If you don't know whether an overhead line is live, assume that it is until whoever owns or operates the line verifies that the power is not on. If you are working near a dead (power off) line, make sure it is clearly grounded at the worksite. or a grounding rod. 

Presenter tips

  • Pre-read the Toolbox Talk. Your comfort level and confidence will be higher if you know your topic.
  • Discuss related tasks, work areas or events that make the Toolbox Talk relevant to your job site.
  • Involve the workers by asking questions and input that drives discussion.

Questions for Discussion

  • Is there danger on this job site of coming into contact with high voltage overhead lines? 
  • What can be done to prevent such contact? 
  • Are the requirements of the state regulations being followed on this site? If not, how are they being violated?