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Limits of Approach

Remember these safe distances when working near overhead and underground power lines.

When work is planned near overhead or underground power lines, it's crucial to consider the safe limits of approach that must be maintained.

While limits of approach vary depending on system voltage and the training and experience of the worker, follow these general guidelines for working safely near power lines:

  • Take steps to learn the limits of approach for you and your equipment
  • Mark the location of all power lines on worksite plans and drawings
  • Use a spotter to ensure that equipment never gets closer than the safe limit of approach distance
  • Keep any workers who aren't directly involved in the work being performed at least 10 metres away
  • Be aware that the height of overhead power lines can change over time as temperatures rise and fall, affecting safe limits of approach
  • If a job requires workers or equipment to infringe on the safe limits of approach, contact your local utility company before any work begins

In cases where the voltage is unknown, always maintain a clearance of at least 7 metres from any overhead power lines and locate all underground utilities before you dig.

Limits of Approach for Overhead Power Lines
Operating Voltage of Overhead Power Line Between Conductors Safe Limit of Approach Distance for Person and Equipment
0 - 750 Volts of insulated or polyethylene 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

As required by the OHS code, your employer is responsible for making sure that everyone on the worksite is aware of any hazards associated with working near energized power lines, as well as the safe limits of approach.

Contact Map

Think power line contacts are few and far between? Think again.
Keep track of overhead and underground contacts occurring across Alberta.

The Joint Utility Safety Team (JUST) is a partnership between the following Alberta electric utilities with contributions from local municipalities, formed to address the frequency of power line contacts across the province.