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Limits of approach are the safe distances that people or equipment must maintain from exposed energized power lines or equipment, which vary depending on system voltage and the training and experience of the individual.

Where work is planned near energized high-voltage electrical conductors, Alberta OHS Code (Part 17, Overhead Power Lines) specifies the safe limits of approach that must be maintained by any worker, tool, machine, equipment or material. If the voltage is unknown and has not been verified by an EPCOR Safety Codes Officer, then maintain a clearance of at least 7 m.

Workers and equipment should adhere to the following guidelines:

  • Know the limits of approach for equipment and workers.
  • Mark the location of all overhead power lines and/or exposed underground cables on plans and drawings.
  • If your project might result in workers or equipment encroaching on minimum distances, you must contact EPCOR before beginning any work.
  • Email EPCOR at for clearance requirements specific to your area and the job.

Distances from overhead power lines for persons and equipment

Safe limit of approach if voltage is known

Operating voltage of overhead power line between conductors ​Safe limit of approach distance for persons and equipment
​0 - 750 Volts insulated or polyethelene covered connectors 1 ​300 millimetres
​0 - 750 Volts bare, uninsulated ​1.0 metres
​Above 750 Volts insulated conductors 1, 2 ​​1.0 metres
​0.75 kV to 40 kV ​​3.0 metres
​69 kV, 72 kV ​​3.5 metres
​138 kV, 144 kV ​​4.0 metres
​230 kV, 260 kV

​5.0 metres

​500 kV ​7.0 metres
​500 kV DC Pole-Ground 7.0 metres​


  1. Conductors must be insulated throughout their entire length to comply with these groups.
  2. Conductors must be manufactured to rated and tested insulation levels

Safe limit of approach if voltage is known