What is the minimum distance of high voltage lines to ground where there is a possibility of contact from equipment passing underneath?

What is the minimum distance of high voltage lines to ground where there is a possibility of contact from equipment passing underneath?

• A. 10 feet
• B. 20 feet
• C. 30 feet
• D. 40 feet

Answer: (B)

Maintaining enough vertical clearance under overhead high-voltage lines is about preventing contact as equipment passes underneath and accounting for line sag and movement. Twenty feet gives a safe buffer for typical line sag when the conductor expands with heat, wind-induced sway, and the reach of heavy equipment like booms or loads that might extend toward the line. If the clearance were only ten feet, contact could occur during normal operations or when equipment is operating near the line. Larger distances are not usually required for standard underground exposure, and twenty feet strikes a practical balance between safety and workable space for mine operations.

Maintaining enough vertical clearance under overhead high-voltage lines is about preventing contact as equipment passes underneath and accounting for line sag and movement. Twenty feet gives a safe buffer for typical line sag when the conductor expands with heat, wind-induced sway, and the reach of heavy equipment like booms or loads that might extend toward the line. If the clearance were only ten feet, contact could occur during normal operations or when equipment is operating near the line. Larger distances are not usually required for standard underground exposure, and twenty feet strikes a practical balance between safety and workable space for mine operations.