Powerline Safety Facts & Myths
Info-Facts & Myths /
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The public should be aware of potential shock hazards associated with electrical distribution equipment – follow safety signs, keep away from electrical transmission and distribution powerlines, look up when working near lines, and call before your dig.
High voltage transmission and distribution lines carry a lot of energy or power and if not treated with respect can be fatal. In addition, electrical substations and transformers are fenced, and covered to keep the public away from potential electrical shock hazards.
Partners Defining Safety Requirements:
Electrical Safety Authority – is responsible for public electrical safety in Ontario including enforcement of the Electrical Distribution Safety regulation 22/04.
Local Distribution Company – takes power from high-voltage transmission lines, “step down” the electricity to a low voltage level (50KV and under), and provides it to local customers of all sorts: homes, school, stores and factories.
Hydro One – manages and maintains Ontario’s high-voltage transmission system, and provides electricity directly to a number of customers as a Local Distribution Company. In addition, they provide electrical safety information; information about the provincial high-voltage electricity system; and information about the low-voltage distribution system.
Electricity Distribution Association – represents local distributors of electricity and provides information to the public about the electrical distribution system.
Info-Facts & Myths
Here are some important facts about electricity.
Basic Facts about electricity you should know ….
Electricity seeks the easiest and shortest path to the ground – when people or objects come too close to, or touch and electrical wire, they can become a part of an electrical circuit which can result in an instant flow of electricity through them to ground.
The flow of electricity through the human body can kill – less than one ampere of electricity can burn, severely injure or cause death.Electricity is fast – electricity travels at approximately 299,330 km per second. That leaves no room for mistakes – never put yourself into electricity’s path.
"conductors" conduct electricity readily and in large amounts – all metals, waters, humans and even non-metallic materials (trees, ropes etc.) can conduct electricity depending on moisture content and surface contamination – caution needs to be applied.
Birds land on wires, so they must be safe to touch.
Birds don’t get electrocuted when they land on wires because they don’t represent a path to ground. Electricity wants nothing more than to go to ground and will always do so by the easiest most direct route. A bird on a wire doesn’t give electricity anywhere to go but back to the wire – easier for the current to stay right where it is in the wire and continue on its way.
Power lines are insulated, so they’re safe to touch.
Not so fast. Many overhead power lines are insulated only to a level to prevent problems from incidental tree contact. They are usually not fully insulated to prevent injury to people.
As long as my ladder isn’t metal, it’s safe to rest on the power line.
Electricity wants a conductor. Metal is an excellent conductor and so metal ladders are a natural hazard around overhead power lines. But so is water. No matter what the ladder is made of, if it’s wet or can get wet, it represents a potential hazard – and most ladders contain metal parts as well. Be safe – keep all ladders away from overhead power lines.
As long as my ladder isn’t touching the line, I’m safe.
Maybe. Depends on how far away your ladder and you are from the line. Electricity can jump and often does when a potential conductor like a metal ladder comes within a certain proximity. Be safe, and keep well away – at least ten feet – from overhead power lines.
I’m just trimming my tree limbs; in fact, to keep them clear of the power lines. I won’t be using a ladder so I don’t need to worry.
Actually, there’s plenty to worry about. Remember, electricity doesn’t need metal. The moisture in the tree and in you will do nicely, thank you. Move a limb enough to come into contact with the line, and electricity now has a direct path to ground through the tree, your pruning tool, and you! Better call the utility company, or your local department of transportation if the limbs are over a roadway, for their assistance with the job.
I’m just digging a couple inches into the ground. I really don’t need to worry about the lines.
How long ago were those lines laid? How has the ground shifted in that time? Is it possible you might accidentally push your shovel deeper than you intended? Err on the side of caution – make the call.
The lines are marked; my job is near but not on top of the lines. I’m safe to dig away.
The ground maps are approximate and the person doing the marking may not be exact. Once the lines are marked, do any digging that comes within 24 inches of either side of the markers, with care and by hand. Buried lines are insulated and won’t be dangers to touch, but can be damaged and become dangerous by the blade of a shovel or any sharp object.
What is that mysterious big green metal box behind the hedge on the corner?
It may be electrical equipment installed there by the utility company to help deliver electricity to your home from the high voltage lines near your neighbourhood. They should be marked with yellow labels as an electrical hazard and children should be taught to leave them alone.
If the utility company put it there in the middle of a residential neighbourhood, it must be safe.
Yes, they are generally safe. However, if the equipment or its casing has been damaged due to vandals, careless landscapers or other causes, a potential hazard may exist. Children should be taught not to enter the equipment or investigate and to tell an adult right away so the utility company can be notified immediately.
I’m afraid to go near it or touch it, particularly with anything metal.
The current-carrying parts of pad-mounted equipment are securely locked inside the cabinet and pose no hazard to the public. Infrequently, however, vandalism or other occurrences may cause the access door to be ajar. In this case, avoid touching any part of the equipment and notify the utility company immediately.
How would a young child know to stay away?
The enclosures should have pictorial warning labels clearly visible that have been designed and tested to communicate a sense of danger to children even too young to read.
Be aware of overhead wires.
Take extra care when working near overhead power lines – maintain a safe distance of three meters or more from overhead power lines. If you need to be closer, contact your local Electric Utility for more information on safe limits of approach. Be careful with ladders, cranes, or diggers.
Don’t be fooled by the covering – coverings on overhead service wires to your home should not be trusted – these deteriorate with age and weathering which can result in exposed wires that can cause serious injury.
Plant trees away from power lines – make sure any trees you plant won’t grow up into power lines. If you have a tree that has grown into power lines call your Local Distribution Company – don’t attempt to prune trees around power lines yourself.
Keep kites and other flying toys away from overhead lines - check before you play – in the event that your kite or flying toy becomes entangled in electrical wires do not attempt to untangle.
Never climb Electrical Utility poles or towers.
Limits of Approach out of OHSA - March, 01, 2006
There may be power down below too!
Underground power equipment – out of sight, out of mind... Electrical wires and facilities maybe located underground. If you plan to excavate, call your Local Distribution Company to locate underground power lines.
Stay away from pad mount transformers – these are the green metal boxes that contain the above ground portion of an underground electrical installation. These transform high voltage electricity to low voltage electricity which is then carried in insulated underground power lines to your home. The public should stay away from these boxes. If you see a pad mount transformer that looks damaged or appears to have been tampered with please notify your Local Distribution Company.
Never touch a downed wire – keep 10 meters away from fallen wires and call your Local Distribution Company to notify them of any downed lines.
This section is brought to site visitors from the Electrical Safety Foundation International
“Many electric utility distribution systems involve switchgear and transformers pad-mounted at ground level. This equipment is part of the electricity delivery system that brings power to the neighbourhood and individual homes. This equipment takes power from high voltage lines to the low voltage required for safe use in your home. Although the green metal transformer boxes on your front lawn are safe children should be taught not to touch these boxes. Children and adults should always stay clear of switchgear, and should follow Utility safety signs, danger signs, and public warnings.”