OHS Code Explanation Guide

Published Date: July 01, 2009
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Part 17 Overhead Power Lines

Section 225 Safe limit of approach distances

Subsection 225(1)

Safe limit of approach distances for overhead power lines are intended to prevent power line contacts, injuries and fatalities (see the “Overview” to this Part for a discussion of power line contacts).

If work is done or equipment is operated within 7 metres of an energized overhead power line, the employer must contact the power line operator to determine the voltage of the power line. As shown in Table 17.1, the power line voltage determines the safe approach distance. Until the power line operator verifies the voltage, the employer must maintain a safe clearance distance of 7 metres. The distances listed in Schedule 4 have been taken from Alberta’s Electrical and Communication Utility Code (ECUC), 2nd Edition, 2002.

Table 17.1 Safe limit of approach distances from overhead power lines for persons and equipment (appears as Schedule 4 in the OHS Code)

Operating voltage between conductors of overhead power line

Safe limit of approach distance for persons and equipment

0-750 volts Insulated or polyethylene covered conductors (1)

300 millimetres

0-750 volts Bare, uninsulated

1.0 metre

Above 750 volts Insulated conductors (1)(2)

1.0 metre

750 volts-40 kilovolts

3.0 metres

69 kilovolts, 72 kilovolts

3.5 metres

138 kilovolts, 144 kilovolts

4.0 metres

230 kilovolts, 260 kilovolts

5.0 metres

500 kilovolts

7.0 metres


  1. Conductors must be insulated or covered throughout their entire length to comply with this group.
  2. Conductors must be manufactured to rated and tested insulation levels.

Subsection 225(1.1)

An employer must ensure that the appropriate distance as listed in Schedule 4 is maintained as a limit at all times and that no worker or equipment comes any closer than that distance. This can only be varied wit the permission and assistance of the power line operator in accordance with subsection 225(2).

Subsection 225(2)

Situations may arise in which work must be done or equipment operated near an energized power line at distances less than the safe limit of approach distance for that particular voltage. In such cases, the employer must notify the operator of the power line before beginning the work and obtain the operator’s assistance in protecting workers involved in the work. The operator may protect workers by de-energizing the power line, relocating it, isolating it, or performing some other equally effective action.

Subsection 225(3)

This subsection is intended to prevent safe limit of approach distances being reduced by piles of earth or other materials placed beneath or adjacent to an overhead power line.

Subsection 225(4)

As required by section 8 of the OHS Code, the employer is responsible for making workers aware of the hazards associated with work near energized overhead power lines. The employer should make workers aware of the safe limit of approach distances included in the OHS Code. Workers must follow the employer’s directions to maintain the appropriate safe clearance distances.