Whenever machinery is being used near electrical equipment, all workers in the vicinity shall be instructed to remain clear and avoid contact with the frame of the equipment, hoisting lines, the hoisted load, and anything else contacting the equipment. Power lines can hang as low as 4 m from the ground.
When working near electrical equipment, "Keep clear - working near electrical lines and apparatus" signs must be displayed on the exterior of machines. A notice giving the following shall be posted in the cabs of machines working near electrical equipment:
- The limits of approach to overhead power lines for persons and equipment.
- The machine shall not be moved near electrical equipment without the aid of a signaler.
- Maximum height and reach of the machine with the peripheral devices fully extended shall be posted in view of the operator of the machine.
A signaler shall direct the moving of equipment near overhead power lines or other electrical equipment. The signaller shall be identified by a bright traffic vest and/or cuff. The designated signaller shall not be assigned any other duties during the times when the equipment is near the limits of approach. The operator and the signaller should know all crane and hoist hand signals.
The important consideration in signalling is that the signaller and operator understand each other completely and communicate effectively. The signaller shall know the limits of approach distances to overhead lines and ensure that at no time is there a Limit of Approach encroachment.
Source: Alberta Occupational Health and Safety Code Explanation Guide, Part 6, Section 71, Hand Signals.