WORK IN PROXIMITY TO LIVE ELECTRICAL INSTALLATIONS


Produced by:
Construction Health and Safety Program,
Ontario Ministry of Labour.
Alert #C4/1239R Revised 12/95
ISSN 1195-5228

Without adequate protective equipment and procedures, work 
carried out in proximity to electrical transmission or outdoor 
distribution lines may endanger workers.

This was demonstrated recently in the deaths of two workers.  In 
both cases, the workers were electrocuted when equipment they 
were operating contacted an electrical line rated at over 4,800 
volts.

A major cause of accidents of this type is failure to identify th 
extreme hazards associated with live electrical installations.

Employers and supervisors have a responsibility to identify any 
hazard that is likely to endanger a worker.  They must also 
ensure that the worker, while working in proximity to electrical 
transmission or outdoor distribution lines, maintains the minimum 
distances set out in the table under section 186 of the 
Regulations for Construction Projects:

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  Nominal phase-to-phase voltage rating       Minimum distance
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          750 to 150,000 volts                    3 metres

   more than 150,000 to 250,000 volts           4.5 metres

        more than 250,000 volts                   6 metres
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The minimum distances apply to all objects, including scaffolds, 
hand tools, ladders, heavy equipment, etc.

Where the voltage is unknown, contact Ontario Hydro or the local 
power utility.  If in doubt, assume it is 750 volts or greater.

Sections 181 through 195 of the Regulations for Construction 
Projects set out the provisions applying to construction work in 
proximity to live electrical installations.