Final answer:
The minimum clearance distance when working near energized overhead power lines up to 50 kV is 10 feet. This ensures safety from potential electric shocks or arcs, considering even moderate voltages can cause sparks over small air gaps.
Step-by-step explanation:
The minimum clearance distance necessary when working near energized overhead power lines up to 50 kV is 10 feet. This safety standard helps prevent possible electric shocks or arcs that could occur between power lines and workers or their equipment. To maintain safety and prevent electrical hazards, maintaining adequate distance from high-voltage lines is imperative.
High-voltage power lines, such as those carrying 240 kV, are typically transmitted over long distances to limit energy losses and are hung from grounded metal towers using ceramic insulators. These insulators have high resistance to ensure that the high voltages do not result in unwanted electrical discharges or harm the tower structure. The provided figures also discuss the phenomenon that a significant voltage, such as 75 kV, is required to make a spark jump across a relatively small air gap, which reinforces the requirement for safe distances around power transmission lines.