Overhead Power Lines and Safe Approach Distances

OSHA sets minimum clearance distances that grow with voltage. For most jobsite exposure to lines you don't control:

• Lines up to 50 kV — stay at least 10 feet away, in every direction.
• Over 50 kV — add 4 inches of clearance for every 10 kV above 50 kV.
• For cranes and lifting gear near lines up to 50 kV, OSHA requires a 10-foot minimum unless the line is de-energized and grounded or the clearance is increased for higher voltage.

Those distances count the whole reach: a raised dump bed, an extended boom, a swinging load, or a long piece of conduit on your shoulder. Measure the worst case, not where the machine sits parked.

Before equipment or elevated work goes anywhere near overhead lines, plan it out:

• Identify the lines and their voltage — call the utility if you don't know it.
• Keep equipment clear, or get the line de-energized, moved, or covered by the utility.
• Post a dedicated spotter whose only job is watching clearance, and mark a boundary with barricades or flags.
• Use non-conductive tag lines to control loads, and lower booms/beds before traveling.

A spotter only works if they have your full attention and a way to stop the operation instantly. If clearance can't be guaranteed, the work doesn't start.

If a machine contacts a line, the ground around it can be energized too. The operator should stay put:

• Stay in the cab if you can — you're safest not becoming the path to ground.
• Try to break contact by moving the equipment clear if it's safe to do so.
• If you must get off because of fire, jump clear with both feet together, don't touch the machine and the ground at once, and shuffle or hop away in small steps.

Everyone else stays back — the ground can be live for a good distance. Keep clear, keep others clear, and don't approach until the utility confirms the line is dead.