Which voltage requires a 20-foot minimum safe distance?

• A. 600kV
• B. 17.2kV
• C. 300,000V
• D. 1,000V

Answer: (C)

Higher voltages require greater clearance from energized equipment to prevent arcing and electric shock. Safety standards set a minimum approach distance that grows with voltage, and a baseline of about 20 feet is commonly used for lines in the hundreds of kilovolts range. The 300,000-volt level sits in that range where a 20-foot minimum is specified, making it the voltage that fits the guideline.

Lower voltages like 17.2 kV or 1,000 V generally have much smaller required distances, so they wouldn’t be described as needing a 20-foot minimum. A higher voltage, such as 600 kV, would typically require more than 20 feet, not exactly the baseline distance.