Which distance is used to determine the limited approach boundary for an overhead line conductor at 480 V nominal?

Which distance is used to determine the limited approach boundary for an overhead line conductor at 480 V nominal?

• A. 8 feet
• B. 10 feet
• C. 12 feet
• D. 6 feet

Answer: (B)

The distance used for the limited approach boundary is based on the system voltage, because higher voltages can produce dangerous shock or arc-flash energies even with small gaps. For a nominal overhead line of 480 V, the standard tables specify a 10-foot limit. Keeping at least 10 feet from the live conductor helps ensure that, under normal conditions and with appropriate procedures and PPE, the risk of electrical shock or a damaging arc is minimized. The other distances don’t align with the 480 V category in the established safety tables, so they aren’t the correct boundary for this voltage.

The distance used for the limited approach boundary is based on the system voltage, because higher voltages can produce dangerous shock or arc-flash energies even with small gaps. For a nominal overhead line of 480 V, the standard tables specify a 10-foot limit. Keeping at least 10 feet from the live conductor helps ensure that, under normal conditions and with appropriate procedures and PPE, the risk of electrical shock or a damaging arc is minimized. The other distances don’t align with the 480 V category in the established safety tables, so they aren’t the correct boundary for this voltage.