8 General Safe Work Practices for Work Around Overhead Power Lines
Here are some general precautions to take for work near overhead power lines:
1. Equipment operators and other workers must respect the safe minimum distances and always be aware of the position of their equipment in relation to overhead power lines.
2. The signaller’s only responsibility should be to ensure equipment doesn’t get any closer to the power line than the designated safe minimum distance.
3. No one should be allowed to touch any part of equipment or its load until the signaller indicates it’s safe to do so.
4. Other workers not directly involved in the work being performed should be kept away from the equipment while it’s being used near overhead power lines.
5. Ensure that equipment operators and signallers know that a long span of power line can rise and fall depending on the ambient temperature and swing in the wind, all of which can impact the safe work distance.
6. Don’t ground equipment in the area of a power line.
7. Mark out the route that a crane or similar equipment will follow before it’s moved, noting any uneven terrain that could increase the likelihood of contact with the power line.
8. When using tag lines to control an elevated load, the tag lines should be made of a non-conducting material such as dry rope.
Source: Explanation Guide to Part 17 of Alberta’s OHS Code 2009
Overhead power lines pose serious safety hazards, most notably the risk of electrocution. But workers, such as roofers, construction workers and others often forget about this hazard because, well, it’s literally over their heads. And electrocution isn’t the only danger. For example, workers in BC were installing a 56’ long section of metal gutter on a building when the end of the gutter touched an overhead power line. The resulting electric shock knocked one worker off a ladder and onto a concrete patio 22’ below. He died from the injuries he suffered in the fall—not from the shock. So here’s a look at the steps you should take to protect your workers when they work around or near overhead power lines and comply with the power line requirements in the OHS laws.
Defining Our Terms
This article covers the general requirements for work around overhead utility lines and doesn’t address the requirements for work on such lines, which typically must be done by specially trained and qualified workers. It also doesn’t cover the requirements that specifically apply to tree trimming or pruning work around overhead utility lines.
REGULATION OF WORK NEAR POWER LINES
The OHS laws take two basic approaches to regulating work around or near overhead power lines (See the bottom of post for the general requirements for such work in each jurisdiction.):
Specific overhead power line requirements. Most jurisdictions have specific requirements for work around overhead power lines. The requirements in some jurisdictions, such as AB, MB, ON and QC, are very detailed, while the others have very general or narrow requirements.
General requirements for work around high voltage equipment. A handful of jurisdictions—Fed, BC and YK—don’t have requirements specifically for work around overhead power lines. Instead, they address such work in their requirements for all work around high voltage equipment, which includes overhead power lines. (Note that the jurisdictions with specific overhead power line requirements also have general requirements for work around other kinds of high voltage equipment.)
Insider Says: The OHS regulations in NT and NU simply require all work near overhead electrical conductors to be carried out in compliance with the Electrical Protection Act and related regulations.
TAKE 4 STEPS TO PROTECT WORKERS
Naturally, you must comply with the specific requirements for work around overhead power lines in your jurisdiction’s OHS law. However, there are certain basic steps that all employers should generally take to protect workers working around overhead power lines:
Step #1: Contact Power Line Operator
When there’s any chance that workers, equipment or materials could contact an overhead power line, you should get in touch with the line’s operator for a few reasons. First, the particular safety measures you’ll need to take depend largely on the voltage of the overhead power line. So you’ll need to contact the operator for that information. Second, in some jurisdictions, you’re required to notify the operator of any planned work that’ll take place within designated distances (typically 3 to 7 metres) of overhead power lines.
Lastly, you may need the power line operator’s assistance in protecting workers. For example, if workers must conduct work closer to overhead power lines than the designated safe distance (more on this below), than you may need to get assurances from the operator that the line is either de-energized while that work is done or is adequately insulated or guarded. In some cases, the operator may need to relocate or reroute the line for the work to proceed.
Step #2: Determine Minimum Safe Distance
Once you know the voltage of the overhead power line at issue, you must determine how close workers can get to the line and still safely work. The so-called safe limit of approach or minimum safe distance varies by voltage and jurisdiction. Most OHS laws include a chart that spells out the minimum safe distance for lines of varying voltages. For example, in Ontario, equipment must be kept at least the following distances from live power lines:
Voltage of Live Overhead Power Line
Minimum Safe Distance
750 to 150,000 volts
150,001 to 250,000 volts
250,001 volts and over
So check your OHS law to determine the minimum safe distance for the voltage of the overhead power line impacting your work.
What To Do if Equipment Contacts an Overhead Power Line
Despite your best efforts, a piece of equipment could come into contact with overhead power lines. In that event, the operator of the equipment should stay put and warn others to stay away because the equipment, its load and surrounding ground could be electrified. Someone should call the power line company immediately. The operator should try to free the equipment by, say, lowering the crane boom or going in reverse. If the operator can’t free it, the safest course is for him to stay in the equipment until someone from the utility comes and says it’s safe for him to leave. If he has to get out because the equipment is on fire, he should jump free so his body doesn’t touch the equipment and the ground at the same time. He should then take short hops or shuffling steps, keeping both feet as close together as possible, and move at least 10 metres away from the equipment. Once the power line company has announced that the area and equipment are safe to access, have the equipment thoroughly inspected because exposure to electricity could compromise its structure and make it unsafe to use.
Step #3: Implement Appropriate Safety Measures
Now that you know the minimum safe distance, you can implement appropriate safety measures. Which measures to use largely depends on whether workers will be able to maintain that safe work distance, which isn’t always possible:
Work outside of minimum safe distance. Even if workers will be able to do their job without coming any closer to the overhead power line than the designated minimum safe distance, you still need to implement safety measures to protect them. As always, the specific requirements vary by jurisdiction. But one of the most common requirements is the use of a signaller to ensure that workers comply with the minimum safe distance, especially when operating machinery such as cranes, lifts or dump trucks.
The signaller or signal person should be a “competent” person trained to work as a signaller. (For more information on who qualifies as a “competent person,” see “Compliance 101: What Makes a Worker a ‘Competent Person’ under OHS Laws?” Sept. 2008, p. 11.) The signaller’s job is to alert equipment operators when they’re coming too close to the power line. Ideally, the signaller and the worker operating the equipment should have unobstructed views of each other. If that’s not possible, they should have an appropriate means of communication, such as a radio, or use a third person who can see both of them and relay signals between the signaller and the equipment operator. The signaller should also try to keep other workers and people out of the area if they don’t need to be there.
Other safety measures to consider include posting signs warning workers and others of the possible electrical hazard, barring the piling or storage of materials under or near power lines and barring the use of metal or wire-reinforced ladders in the area. Using a metal ladder near a live power line can have tragic consequences.
Example: A 22-year-old roofer in New Brunswick and a co-worker had just finished installing shingles on the roof of a building and were taking down an aluminum ladder. While his co-worker was holding the base down with his feet, the roofer stood under the ladder and pushed the top out so it was standing in a vertical position. He then turned the ladder 90 degrees and began walking backwards to lower it to the ground. That’s when he contacted a 7,200-volt overhead electrical line. He was electrocuted and died immediately. The WorkSafeNB investigating officer determined that, when vertical, the ladder was within 30 to 40 cm of the electrical line; turning it 90 degrees brought it within 10 to 15 cm; and the sideways movement of walking it down to the ground caused the fatal contact.
See the box to the upper right of this post for some additional general safe work practices for work around overhead power lines.
Work within minimum safe distance. Due to the nature of the work to be done, workers may not always be able to stay beyond the minimum safe distance. Because work within that designated distance is, by definition, unsafe, special measures must be taken to protect workers. In such circumstances, you should notify the operator of the power line that work has to be done within the minimum safe distance and get its assistance. In general, workers shouldn’t work within the minimum safe distance unless:
- The power line is de-energized;
- The operator provides assurances that the line is adequately insulated or guarded; or
- There’s an alternative method of protecting workers, such as relocating or rerouting the line.
In addition to these special measures to protect workers, you should also implement the safety measures discussed above for work outside of the minimum safe work distance. For example, even if the power line is turned off, you still don’t want equipment to contact or get entangled in it. (Watch this video to see what can happen when a load on a crane gets tangled in a de-energized power line.) So using a signaller is good practice.
Step #4: Train & Supervise Workers
Any workers who may have to work around overhead power lines should be trained on the safety procedures for such work, the minimum safe distances and what to do in the event that materials or equipment contact a power line (see the box on the upper right). And because work around power lines is so dangerous, it’s especially important that it be properly supervised.
Injuries and deaths from contacting overhead power lines are more common than they should be. For example, according to a 2009 Ontario Electrical Safety Authority report, power line contacts account for 49% of all electrocutions over the last ten years. So it’s critical that you implement proper safety measures when your workers have to work around or near overhead power lines.
KNOW THE LAWS OF YOUR PROVINCE
Here are the general requirements for work around overhead power lines in the OHS law in your jurisdiction:
|FED||No specific requirements for work around overhead power lines.|
|AB||OHS Code 2009:1) An employer must contact the power line operator before work is done or equipment is operated within 7.0 metres of an energized overhead power line to:
a) to determine the voltage of the power line; and
b) to establish the appropriate safe limit of approach distance listed in Schedule 4 [Sec. 225(1)].2) Except as provided for in Sec. 225(2), an employer must ensure that the safe limit of approach distance, as established above, is maintained and that no work’s done and no equipment’s operated at distances less than the established safe limit of approach distance [Sec. 225(1.1)].
3) An employer must notify the operator of an energized overhead power line before work is done or equipment is operated in the vicinity of the power line at distances less than the safe limit of approach distances listed in Schedule 4 and get the operator’s assistance in protecting workers involved [Sec. 225(2)].
4) An employer must ensure that earth or other materials aren’t placed under or beside an overhead power line if doing so reduces the safe clearance to less than the safe limit of approach distances listed in Schedule 4 [Sec. 225(3)].
5) A worker must follow the direction of the employer in maintaining the appropriate safe clearance when working in the vicinity of an overhead power line [Sec. 225(4)].
6) The safe limit of approach distances listed in Schedule 4 don’t apply to a load, equipment or building that’s transported under energized overhead power lines if the total height, including equipment transporting it, is less than 4.15 metres [Sec. 226].
|BC||No specific requirements for work around overhead power lines.|
|MB||Workplace Safety & Health Regs.:1) Part 25: Work in the Vicinity of Overhead Electrical Lines applies to every workplace where work is done:
a) within 3 m of an overhead electrical line; or
b) using equipment or machinery from a location from which it, or any part of it, is capable of coming within 3 m of an overhead electrical line [Sec. 25.1].
2) An employer must:
a) develop and implement safe work procedures for working near overhead electrical lines;
b) train workers who may perform work or operate equipment or machinery near overhead electrical lines in those safe work procedures; and
c) ensure that the workers comply with those safe work procedures [Sec. 25.2].
3) When a workplace is subject to this Part, an employer must ensure that the work’ s carried out, and equipment or machinery used is operated, in a manner that prevents:
a) contact with the overhead electrical line; or
b) electricity arcing from the line to the equipment or machinery [Sec. 25.3].
4) An employer must notify the electrical authority having jurisdiction over an overhead electrical line before authorizing or permitting a worker to:
a) work within 3 m of the line; or
b) use equipment or machinery from a location from which it, or any part of it, is capable ofcoming within 3 m of an overhead electrical line [Sec. 25.4(1)]. This notice must specify the site of the work and location of the line [Sec. 25.4(2)].
5) When the above notice has been given, an employer must receive the following from the electrical authority before authorizing or permitting the work to be commenced or the equipment or machinery to be used:
a) a written confirmation that complies with Sec. 25.5(2) that:
i) contacting the line won’t endanger the safety or health of the worker; or
ii) the electrical authority will, if contact would be sufficient to endanger the safety or health of the worker:
A) de-energize the line;
B) effectively guard the line against contact; or
C) reroute or displace the electricity from the worksite;
b) instructions on how to safely proceed, where:
i) contact with the line would be sufficient to endanger the safety or health of the worker; and
ii) the electrical authority is unable to take any of above measures [Sec. 25.5(1)].
6) A written confirmation must contain the following information:
a) the site where the work is to be done or the equipment or machinery is to be used;
b) the name of the employer;
c) if contact would be sufficient to endanger the safety or health of the worker, the date and time when the electrical authority will take one or more of the measures described above [Sec. 25.5(2)]
7) An employer must ensure that the written confirmation received from the electrical authority is available at the site where the work is to be done or the equipment or machinery is to be used [Sec. 25.5(3)].
8) When an employer receives instructions under Sec. 25.5(1)(b), it must:
a) ensure that those instructions are complied with when the work is done or the equipment or
machinery is used; and
b) without limiting the above, assign a signal person to give pre-arranged signals to the operator of equipment or machinery that’s used in the vicinity of the overhead electrical line [Sec. 25.6(1)].
9) A signal person responsible for giving signals to the operator of equipment or machinery under this section must:
a) have an unobstructed view of the operator;
b) signal the operator when the equipment or machinery being operated may come into contact
with the electrical line; and
c) make all reasonable efforts to:
i) notify persons who aren’t required to be engaged in the work that they are prohibited from entering the worksite; and
ii) prevent persons, other than the operator, from touching the equipment or machinery until it’s safe to do so [Sec. 25.6(2)].
10) When it isn’t possible for the signal person and the operator of the equipment or machinery to have an unobstructed view of each other, an employer must ensure that:
a) the signal person and the operator of the equipment or machinery are provided with a suitable means of communication; or
b) a person:
i) is posted in a location where he or she can see both the signal person and the equipment or machinery; and
ii) relays all signals between the signal person and the operator [Sec. 25.6(3)].
11) If equipment or machinery comes into contact with an energized overhead electrical line, an
a) ensure that a worker on the equipment or machinery:
i) remains on it; or
ii) if required to leave it, jumps clear of it, so that no part of the worker’s body touches the equipment or machinery and the ground at the same time; and
b) take immediate precautions to prevent any other worker from coming close to, or in contact
with, the electrical line or the equipment or machinery that’s in contact with it [Sec. 25.7].
12) An employer must ensure that a machine or any tool or equipment that has contacted an energized overhead electrical line is inspected to ensure that there’s no risk to the safety or health of a worker before permitting it to be used again [Sec. 25.8].
|NB||OHS Regs.:1) An employer must ensure that a worker who isn’t a qualified person doesn’t carry out any work, and no such worker may carry out any work, that’s liable to bring any person or object closer to an energized electrical utility line or utility line equipment than the distances specified in the included table [Sec. 289(1)].
2) Where a worker who isn’t a qualified person is about to commence work that’s liable to bring any person or object closer to an energized electrical utility line or utility line equipment than a designated distance, the employer must contact the authority owning or operating the energized electrical utility line or utility line equipment and ensure that the utility line or utility line equipment is:
a) de-energized; or
b) is adequately insulated or guarded before permitting the worker to commence the work [Sec. 289(2)].
3) Where a worker may come closer to an energized electrical utility line or utility line equipment than a designated distance, the employer must ensure that the worker doesn’t use and a worker may not use a metal ladder or wire reinforced ladder [Sec. 297].
|NL||OHS Regs.:1) An employer whose work activities result in a hit or damage to an overhead cable must notify the owner of the utility without delay [Sec. 11].
2) A worker must not cause or permit material to be piled, stored or handled, a scaffold to be erected or dismantled, or a mobile crane, boom truck or similar equipment to operate in an area where overhead or underground conductors are located that are capable of energizing the material, mobile equipment or its load unless the employer has obtained in writing the voltage and minimum clearance distance required by the power utility [Sec. 498(1)].
3) When the written clearance referred to above is unavailable from the power utility, a minimum 5.5 metres must be maintained [Sec. 498(2).
|NT/NU||General Safety Reg.: Work near overhead electrical conductors must be carried out in accordance with the Electrical Protection Act and related regulations [Sec. 96(1)].|
|NS||OHS General Reg.:1) No person may carry out work that may bring a person or object closer than 6.0 m to an overhead energized power line or power line equipment where the voltage of the overhead energized power line isn’t known to the person carrying out the work [Sec. 126(2)].
2) Where work is performed in close proximity to an energized overhead power line or power line equipment rated at less than 750 v phase to phase, the employer must ensure that the work’s performed at an adequate distance to ensure the safety of every person in the workplace from the electrical hazard [Sec. 126(3)].
3) An employer must ensure that no work’s carried out and no person may carry out work that may bring a person or object closer than the distances set out in the included table to an overhead energized power line or power line equipment rated at greater than or equal to 750 v phase to phase [Sec. 126(4)].
4) Despite the above, when a person is about to commence work that may bring a person or object closer than a specified safe distance to an overhead energized power line or power line equipment described above, the employer must not permit the person to commence work until it has contacted the authority owning or operating the energized power line or power line equipment and:
a) ensured that the energized power line or power line equipment is insulated or guarded in an adequate manner; or
b) provided an alternative means of protection from the electrical hazard that provides an equivalent level of safety [Sec. 126(5)].
5) An employer must designate one or more competent persons as a signaller to direct the safe movement of a load, hoist, industrial lift truck or powered mobile equipment where the operator of that hoist, industrial lift truck or powered mobile equipment isn’t able to see clearly where the hoist or its load may encroach the minimum distance specified in Sec. 126 or a hoist is positioned closer than the length of its boom to an overhead energized power line or power line equipment [Sec. 57(1)(d)].
|ON||Industrial Establishments Reg.:1) Except as prescribed by Sec. 42.2, when a vehicle, crane or similar equipment is operated near a live power line carrying electricity at more than 750 volts, every part of the equipment must be kept at least the minimum distance from the live power line as set out in the included table [Sec. 60(1)].
2) Subject to Sec. 42.2, when a vehicle, crane or similar equipment is operated near a live power line and it’s possible for any part of the vehicle, crane or similar equipment or its load to make contact with the live power line:
a) a worker must be stationed within the view of the operator to warn the operator when any part of the equipment is approaching the minimum distance from the live power line; and
b) clearance must be allowed for any change in boom angle and for any swing of the hoisting cable and load [Sec. 60(2)].Construction Projects Reg.:
1) No material or equipment to be moved by a crane or similar hoisting device may be stored under or in close proximity to an energized outdoor overhead electrical conductor [Sec. 37(2)].
2) No object may be brought closer to an energized overhead electrical conductor with a nominal phase-to-phase voltage rating set out in Column 1 of the included table than the distance specified opposite to it in Column 2 [Sec. 188(2)].
3) If a crane, similar hoisting device, backhoe, power shovel or other vehicle or equipment is operated near an energized overhead electrical conductor and it’s possible for a part of the vehicle or equipment or its load to encroach on the minimum distance permitted [Sec. 188(3)]:
a) the constructor must establish and implement written measures and procedures adequate to ensure that no part of a vehicle or equipment or its load encroaches on the minimum distance permitted and make a copy of the written measures and procedures available to every employer on the project [Sec. 188(4)];
b) the above written measures and procedures must include taking the following precautions to protect workers:
i) adequate warning devices, visible to the operator and warning of the electrical hazard, must be positioned in the vicinity of the hazard;
ii) the operator must be provided with written notification of the electrical hazard before beginning the work;
iii) a legible sign, visible to the operator and warning of the potential electrical hazard, must be posted at the operator’s station [Sec. 188(5)]
c) before a worker begins work that includes an activity described above, the employer must provide a copy of the written measures and procedures to the worker and explain them to him or her [Sec. 188(6)].
d) the worker must follow the written measures and procedures [Sec. 188(7)]
e) a competent worker, designated as a signaller, must be stationed so that he or she is in full view of the operator and has a clear view of the electrical conductor and of the vehicle or equipment, and must warn the operator each time any part of the vehicle or equipment or its load may approach the minimum distance [Sec. 188(8)].
f) Sec. 106 also applies to the signaller designated above [Sec. 188(9)].
4) Sec. 188 doesn’t apply if:
a) under the authority of the owner of the electrical conductor, protective devices and equipment are installed and written measures and procedures are established and implemented, which are adequate to protect workers from electrical shock and burn; and
b) the workers involved in the work use protective devices and equipment, including PPE, and follow written measures and procedures that are adequate to protect them from electrical shock and burn [Sec. 189].
|PE||OHS Regs.(Part 36—Electricity): Before an employer commences work that’s liable to bring any person, apparatus, machine, component, material or property closer to overhead electrical conductors than the distance stipulated in Sec. 36.20, it must, before proceeding, contact the electrical utility owning or operating the conductors and ensure that:
a) the conductors are properly de-energized; or
b) the energized electrical conductors or equipment are adequately insulated or guarded [Sec. 36.22].
|QC||Reg. respecting occupational health and safety: Any work carried out near an electric power line must be done in compliance with Division V of the Safety Code for the construction industry[Sec. 331].Safety Code for the construction industry(Division V—Work in the Proximity of Electrical Lines):1) This Division applies to any construction work carried out near an aerial electrical line [Sec. 5.1.1].
2) The employer must ensure that no one performs work liable to bring any part, load, scaffolding, machine component or person closer than the minimum approach distance specified in the included table [Sec. 5.2.1].
3) An employer who wishes to carry out work liable to bring any part, load, scaffolding, machine component or person closer to an electrical line than the minimum approach distance specified in Sec. 5.2.1, may proceed to such work provided that one of the following conditions is complied with:
a) that power line has been turned off. It must ensure that no one runs any risk of being electrocuted before turning the power on again;
b) the employer has come to an agreement with the electrical power company as to safety measures to be adopted. Before the work begins, it must transmit a copy of such agreement as well as its work plan to the Commission. Such measures must be carried out before the work begins and be maintained throughout the course of the work;
c) extensible construction equipment, such as a backhoe, a power shovel, a crane or a dump truck, must be equipped with a device that has two functions:
i) warns the operator or to stop the equipment from operating, so that the minimum approach distance specified in Sec. 5.2.1 is respected; and
ii) stops the equipment from operating, should the device fail to perform its first function.
The device referred to above must be the subject of a written declaration signed by a member of the Ordre des ingénieurs du Québec certifying that it performs the required functions and that it neither damages the equipment nor renders it unstable when it stops the equipment from operating. If the device fails to operate partially or completely, or is inoperative, the employer may continue to use the extensible construction equipment for a total of not more than eight hours of working time, provided that he’s assisted by a flagperson who has successfully completed the training course in the program described in Schedule 7 [Sec. 5.2.2].
4) The employer who carries out work less than 30 m away from an electrical line with a voltage higher than 250,000 V must ensure that the following requirements are respected:
a) refueling shall be done outside the area;
b) construction equipment on tires shall be equipped with an electrostatic link between the metallic part and the ground; and
c) during the installation or manipulation of a metal duct, fence or above ground structure, it shall be grounded every 30 m [Sec. 5.2.3].
5) Before carrying out work near an electrical line held at each supporting point otherwise than by one wooden post, the employer must obtain in writing the line voltage from the electrical power company [Sec. 5.2.4].
6) The employer must ensure that the owner or lessee of any piece of machinery used to lift a load and capable of vertical, lateral or rotational motion, posts on such machinery, in a conspicuous place so as to be seen by the operator, a warning sign reading: DANGER — N’APPROCHEZ PAS DES LIGNES ELECTRIQUES, in letters at least 12 mm in height [Sec. 5.3.1].
|SK||OHS Regs.:1) An employer or contractor must not require or permit a worker to be raised or lowered by any aerial device or elevating work platform or to work from a device or platform held in an elevated position unless overhead wires don’t create a danger to the worker [Sec. 192(2)(e)].
2) Where an excavation or trench is to be made in the vicinity of an overhead power line, an employer or contractor must ensure that the work is carried out in a manner that won’t reduce the original support provided for any overhead power line pole, unless permission has previously been obtained from the utility company responsible for the overhead power line [Sec. 260(5)].
|YT||No specific requirements for work around overhead power lines.|