What causes an outage?

This article was published in November 2020 and may be outdated.

The reasons for outages vary, and depending on the damage, the time it takes to safely restore power also varies.

Many outages are unpredictable. Others can be easily avoided.

The main causes of outages are:

  • Bad weather: Wind, lightning, freezing rain, and snow are the top causes. High winds can bring down trees and branches and cause them to contact power lines or cause pole fires. Heavy snow or ice on power lines can cause them to break.
  • Equipment failure: Although we continually maintain and upgrade our system throughout the province, poles, power lines, transformers, switches, fuses, and other types of equipment can fail.
  • Animals: Squirrels, ravens, and geese can cause short circuits by contacting power lines or equipment at a substation. Animal contact is one of the leading causes of outages in North America.
  • Human error: Farm machinery and construction equipment inadvertently contact power lines, poles, and transmission towers, or cut underground wires by digging without proper line locations and clearances. Vehicles also often collide with poles.

All equipment can fail. Still, many outages are preventable.

When a passenger car, construction equipment or farm machinery hits power lines and poles, it’s often because the driver isn’t paying attention. When someone contacts a pole or power line, they can be held liable for the cost of repairs. They also put their lives and the lives of others at risk of electrocution.

In September, there were 94 cases of people and machines hitting poles and wires. Not all resulted in outages. Some examples:

  • Sept. 15, 2020: A truck hauling large square hay bales contacted overhead lines when leaving a field near Stony Mountain. Power lines were de-energized to free the truck and trailer. Broken pole crossarms were replaced. An outage to 198 customers lasted about three hours.
  • Sept. 17, 2020: A Jeep hit a street light pole on Mandalay Drive in Winnipeg and left the scene. A nearby homeowner saw what happened and picked up the Jeep’s licence plate, which had fallen off in the collision. Later, a person driving a Jeep came back looking for the plate. The light standard was knocked off its base and left hanging in the trees, destroyed, and scheduled to be replaced.
  • Sept. 19, 2020: A man fell asleep while cultivating a field near Pilot Mound and took out a pole, snapping it off at ground level and pushing it into a ditch. The operator backed up the tractor, breaking the pole into several pieces. The broken pole was replaced five hours later.
  • Sept. 22, 2020: A large steel bin being moved on a property near Portage la Prairie hit an overhead line, “knocking” the mover to the ground. After noticing what he did, he lowered the bin and moved away from the line. He suffered burns to his hands and feet. First responders were called. They told him to see his doctor.
  • Sept. 22, 2020: A combine contacted overhead lines near Cartwright. The lines caught on the combine, undetected by the operator. He continued driving, unknowingly breaking four poles before the lines got tangled in the combine and finally noticed by the operator. Four poles and all hardware had to be replaced. The work took about 12 hours to complete.
  • Sept. 23, 2020: A man on a ladder was trimming spruce branches near Killarney using an electric chainsaw. When he couldn’t reach higher branches, he climbed the trunk using branch stubs as steps. He climbed higher than a nearby power line and cut a branch. It fell on the line and he received a shock when he tried to remove it. He called Manitoba Hydro to safely remove the branch. The man refused to see a doctor.

To prevent serious situations like these when operating equipment around overhead power lines, stay alert, look up and maintain a safe distance of at least three metres between your equipment and the line.

And stay clear of downed power lines – they could be energized. Also avoid contact with sagging lines, trees, branches, fences or anything else the line is touching. Report downed lines to Manitoba Hydro or call 911.

Learn more about downed power lines.