OHS Code Explanation Guide

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

Overview

Contacts with energized overhead power lines are a common occurrence in Alberta. In the 12-month period ending March 31, 2003, 369 contacts with overhead power lines were reported to Alberta Municipal Affairs. An additional 68 contacts with underground power lines were reported in the same time period. The 437 contacts are believed to represent just a small fraction of the total number of annual power line contacts – most go unreported.

Regulations under the Safety Codes Act require all electrical accidents and power line contacts to be reported to Alberta Municipal Affairs, Safety Services. The telephone number of the Safety Services office to which reports should be made is 780‑427‑8256. The email address for Safety Services is safety.services@gov.ab.ca. An on-line Incident Occurrence Form is available online.

If a power line contact occurs at a mine or mine site, the Director of Inspection having responsibility for mines must also be notified. This is required by section 544 of the OHS Code.

Table 17.3 presents historical power line contact data for the 15-year period ending in March 2007. Table 17.4 lists the type of contact or damage associated with the contacts that occurred in the 12-month period ending December 31, 2007. Table 17.5 summarizes power line fatality information for the 15-year period ending in March 2007. Complete summary reports for other time periods and years can be found at:

Incident Reports
Alberta Municipal Affairs.

Precautions to take when working near overhead lines

The following is a list of suggested practices that should be followed when working near overhead power lines.

(1) Equipment operators and users must respect the safe limit of approach distances specified in section 225 of the OHS Code.

(2) A competent signaller as described in section 191 of the OHS Code should be used. The signaller’s only responsibility is to make sure that the equipment operator does not get closer than the safe limit of approach distance.

(3) No one should be allowed to touch the load or any part of the equipment until the signaller indicates it is safe to do so.

(4) Other workers not directly involved in the work being performed should be kept away from equipment when it is being used near overhead power lines.

(5) Equipment operators must always be aware of the position of their equipment in relation to overhead power lines. They should not depend on safety devices such as hook insulators, insulating blankets, etc.

(6) Equipment operators should be aware that a long span of power line can rise and fall as the ambient temperature changes, affecting safe limit of approach distances. Wind-induced swing can also affect these distances.

(7) Grounding equipment in the area of the power line is not a safe practice.

(8) The route that a crane or similar equipment will follow should be marked out before it is moved. Uneven terrain can cause the boom or other structure to weave or bob, increasing the likelihood of power line contact.

(9) When using tag lines to control an elevated load, the tag lines should be made of a non-conducting material such as dry rope.

Table 17.3 Historical summary of reported power line contacts in Alberta

 

92/ 93

93/ 94

94/ 95

95/ 96

96/ 97

97/ 98

98/ 99

20 00

20 01

20 02

20 03

20 04

20 05

20 06

20 07

Overhead Contacts

414

457

430

265

371

477

349

230

386

346

390

471

368

353

264

Underground Contacts

102

95

65

45

133

122

86

52

66

54

78

79

70

63

80

Total

516

552

495

310

504

599

435

282

452

400

468

550

418

416

344

Table 17.4 Type of contact or damage associated with overhead power line contacts that occurred in the 12-month period ending December 31, 2007

Type of Contact or Damage

Number of Line Contacts

Vehicle-mounted equipment (booms, hoists, cranes, etc)

48

Trucks with raised boxes and vehicles transporting high loads

86

Excavating or earth moving vehicles

67

Farm implements

63

Relocating structures (grain bins)

9

Vehicles out of control

124

Aircraft, parachutes, kites, etc.

4

Falling, brushing or trimming trees
  1. Utility tree trimmers/workers
  2. Others

11
30

Drilling and seismic equipment

7

Other inadvertent contacts

22

Total

471

Source: Alberta Municipal Affairs, Safety Services

Table 17.5 Historical summary of fatalities associated with power line contacts in Alberta

  92/
93
93/
94
94/
95
95/
96
96/
97
97/
98
98/
99
20
00
20
01
20
02
20
03
20
04
20
05
20
06
20 07
Due to Contact with Overhead Power Line

4

3

0

0

1

7

1

1

1

1

1

1

1

1

1

Due to Contact with Underground Power Line

0

0

0

0

0

0

0

0

0

0

0

0

1

1

1

Total

4

3

0

0

1

7

1

1

1

1

1

1

1

1

1

Source: Alberta Municipal Affairs, Safety Services