The limited approach boundary distance for a task involving a fixed circuit part operating at 480 volts, nominal, is ?

• A. 2 ft 6 in
• B. 3 ft 6 in
• C. 4 ft
• D. 5 ft

Answer: (B)

Understanding approach boundaries helps you know how close you can work to energized parts safely. The limited approach boundary is the distance within which only a qualified person with proper training and arc-flash PPE should operate, because the risk of electric shock or arc energy is highest there. For a fixed circuit part operating at 480 volts nominal, this boundary is specified as 3 ft 6 in. That exact distance comes from NFPA 70E tables that link voltage levels to safe working separations, balancing protection with practical workspace. So the correct distance is 3 ft 6 in. The other options are either closer or farther than the required limit for this voltage and boundary type, which is why they aren’t the correct choice for this scenario.