Electrical Hazards

Learn how electricity behaves. Know how to respond to an electrical accident or life-threatening situation.

Electrical Facilities can be dangerous...
  • Do not enter fenced and gated areas around electrical facilities.
  • Observe all danger and warning safety signs around electrical facilities.
  • Stay away from generating facilities, powerhouses and all electrical equipment.
Ground Potential Rise "Ripple Effect"
  • When a tree or an un-insulated boom truck touches a power line, or if a broken power line falls to the ground or lands on a vehicle, electricity will fan out in a circular motion from the point of contact.
  • This circular motion is similar to dropping a pebble into a pool of water and is known as the 'ripple effect'.
  • At the place where the electricity contacts the ground the voltage is very high. The level of intensity decreases as the electricity moves outward.
  • The radius of the hazard area depends on factors such as line voltage, ground conditions, metal fences and many other conditions. It is recommended to stay away from the point of contact by at least 30 metres (98 feet).
Touch Potential
  • Trees and ladders are good conductors of electricity.
  • If a power line ‘touches’ a tree, or touches a tree with a ladder leaning on it, electricity moves down to the ground using the tree and the ladder as the conductor.
  • If a person is ‘touching’ the tree or ladder that is in contact with a power line, this will force the electrical current to move down through his or her body to the ground.
  • This electrical movement from the tree or ladder through the body to the ground is known as touch potential and could easily result in serious injury or death.
  • Did you know electricity can also jump? Depending on voltage, you or your tools and equipment do not have to actually touch the energized line or apparatus to be shocked. The only way to stay safe around electricity is to know where the lines are and to keep the proper distance away.
  • For information on line voltages and safe limits of approach, please contact us.
Step Potential
  • The human body is a better conductor of electricity than the ground.
  • Electrical voltage decreases and increases as one ‘steps’ away or toward a source of electricity.
  • As a person ‘steps’ the electricity may travel through the body with dangerous consequences such as injury or death.
  • This electrical safety hazard is known as step potential.

Powerline Hazards, A Contractor Safety Handbook [PDF-391 KB]