January ToolBox Talk: High Voltage Overhead Lines

People are injured and killed each year by accidental contact with overhead electrical lines. Most of these accidents occur when cranes, excavators, tipper trucks, crane mounted lorries, mobile extendable machinery, scaffolding, ladders, farm machinery, concrete delivery trucks, etc., come close to or touch live overhead lines. Such accidents are caused by failure to take all practicable precautions to prevent accidental contact with these lines.
What kind of precautions can you take to avoid contact with overhead lines?
Cal/OSHA regulation 2946(b)(4) prohibits the storage of irrigation pipe or any other materials or equipment near high voltage lines if they are long enough to reach the lines. With some exceptions, work done over "live" overhead lines is a violation of California Title 8 regulations. Workers should never allow themselves or any tools or equipment within ten feet of lines carrying between 600 - 50,000 volts.

Do not store tools, machinery, or equipment near live high voltage overhead lines if it is possible for them to come within the minimum clearance distance when they are being moved or used.

When an employee is using boom-type lifting or hoisting equipment, the minimum clearance is ten feet from overhead lines carrying between 600 - 50,000 volts. An exception for this requirement exists when the equipment is in transit with the boom lowered and no load attached. When these conditions exist, the minimum clearance must be six feet.

If you don't know whether a line is live, assume that it is until whoever owns or operates the line verifies that the power is not on. If you are working near a dead line, make sue that it is clearly grounded at the work site.
Before work begins, be sure that:

• All equipment/activity is located a safe working distance from power lines.
• The utility company has de-energized and visibly grounded the power lines or installed insulated sleeves on the power lines.
• Flagged warning lines have been installed to mark horizontal and vertical power line clearance distances.
• Tools and materials used are non-conductive.