For a system operating at 480 volts with exposed live parts on one side and grounded parts on the other side, what is the minimum working clearance between the live parts and the grounded parts?

For a system operating at 480 volts with exposed live parts on one side and grounded parts on the other side, what is the minimum working clearance between the live parts and the grounded parts?

• A. 1 ft
• B. 2 ft
• C. 3 ft 6 in
• D. 4 ft

Answer: (C)

Working clearance is the safe gap you must keep between exposed live parts and grounded surfaces while working. It gives you room to maneuver, use insulated tools, and stay out of the path where an arc or shock could reach you if something faults. For a system operating at 480 volts, the minimum required distance is three feet six inches. This specific distance reflects the higher energy and greater risk at this voltage level, ensuring there’s enough space to work safely without accidentally bridging to grounded parts. Distances like one or two feet are not adequate at this voltage, while four feet would exceed the minimum but is not the standard requirement. Safety standards set this minimum to provide a practical, enforceable rule for protecting workers.

Working clearance is the safe gap you must keep between exposed live parts and grounded surfaces while working. It gives you room to maneuver, use insulated tools, and stay out of the path where an arc or shock could reach you if something faults.

For a system operating at 480 volts, the minimum required distance is three feet six inches. This specific distance reflects the higher energy and greater risk at this voltage level, ensuring there’s enough space to work safely without accidentally bridging to grounded parts. Distances like one or two feet are not adequate at this voltage, while four feet would exceed the minimum but is not the standard requirement. Safety standards set this minimum to provide a practical, enforceable rule for protecting workers.