Video: Tree Branches in Contact with a Medium-Voltage Line
January 2015, freezing rain in southern Québec. Tree branches weighed down by ice come too close to a medium-voltage line and catch fire.
Shock, fire and short-circuit hazards
Medium-voltage lines don’t have an insulating sheath: The air around them provides insulation. That’s why they need to be kept clear.
Vegetation and tree branches that are too close to medium-voltage lines can also cause short circuits, even without any direct contact. They can endanger people by starting a fire or, in some cases, causing an electric shock.
Risks related to weather events
Most power outages caused by falling branches or trees result from major weather events like strong winds, freezing rain and wet snow.
Strong winds can occur at any time of the year and may be combined with snow, freezing rain or thunderstorms. The risks for the power system are highest when there are leaves on the trees because they catch the wind.
Ice buildup on branches is a heavy weight that can make a tree or branch bend until it breaks. A tree or branch that falls on a power line can cause short circuits, damage and power outages.
A thick layer of wet snow can make conifers bend until they break or become uprooted, posing a number of risks for the power system.
You may also be interested in these pages
- What to do before pruning or cutting down a tree
- How to avoid damaging power lines connecting my home to the grid
- When will the power lines in my area be cleared?
- Request an assessment for work on trees near power lines (tree owner only)
- What to check before doing any outdoor work
- Hydro-Québec’s servitudes and property rights near distribution lines
- Dangerous activities near power lines