OSHA 10-Hour Construction ReviewFocus Four HazardsHard
During a construction project, a worker is operating a forklift near an overhead power line. The power line is not de-energized and there is no protective covering. What is the minimum clearance distance that must be maintained between any part of the forklift and the power line if the line's voltage is 50 kV?
- A20 feet
- B10 feet
- C15 feet
- D8 feet
Show answer & explanationAnswer & explanation
Correct answer: C. 15 feet
OSHA regulations (1926.1408(c)(1)(i)) for power lines not de-energized and not insulated state that for voltages over 35 kV up to 50 kV, a minimum clearance distance of 15 feet must be maintained. This distance is critical to prevent electrocution hazards from arcing.
Why the other options are wrong
- A. This clearance might be required for much higher voltages (e.g., over 345 kV), but not specifically for 50 kV.
- B. This is the minimum clearance for lines up to 350 kV if the voltage is known to be 50 kV or less, but for lines not de-energized/insulated, the 10-foot rule applies to lines up to 50 kV (not 50 kV itself).
- D. This is the minimum clearance for lines up to 50 kV when the voltage is unknown, but not for known 50 kV.
Overhead Power Line Clearance (50 kV)
OSHA mandates specific minimum clearance distances for equipment operating near overhead power lines, depending on the line's voltage, to prevent accidental contact and electrocution. For uninsulated, energized lines between 35 kV and 50 kV, this distance is 15 feet.
- Contact with overhead power lines is a leading cause of electrocution fatalities on construction sites.
- The clearance distance increases with voltage.
- If the voltage is unknown, a minimum of 10 feet is required for lines up to 50 kV, but 15 feet is for known 35-50 kV.
Memory trick: Keep Clear, Know Your kV, Call Before You Go.