A liquid-filled transformer has a primary voltage of 12,470 volts. The transformer is surrounded by a 6-foot-high fence. The overall height of the fence must be extended 1 foot with at least ___ strands of barbed wire on top of the fence.

A liquid-filled transformer has a primary voltage of 12,470 volts. The transformer is surrounded by a 6-foot-high fence. The overall height of the fence must be extended 1 foot with at least ___ strands of barbed wire on top of the fence.

• A. 2
• B. 3
• C. 1
• D. no minimum required

Answer: (B)

Safety barriers for high‑voltage equipment rely on more than just fence height. When the primary voltage is sufficiently high, standards require adding barbed wire to the top to deter climbing and prevent entry into energized areas. A 12,470-volt transformer falls into that high‑voltage category, so extending the fence by one foot to seven feet and adding three strands of barbed wire on top provides the necessary extra barrier. Three strands offer a stronger deterrent than fewer strands and align with typical safety practice for this voltage level. Fewer than three strands would not meet the standard, and stating no minimum would ignore established safety requirements.

Safety barriers for high‑voltage equipment rely on more than just fence height. When the primary voltage is sufficiently high, standards require adding barbed wire to the top to deter climbing and prevent entry into energized areas. A 12,470-volt transformer falls into that high‑voltage category, so extending the fence by one foot to seven feet and adding three strands of barbed wire on top provides the necessary extra barrier. Three strands offer a stronger deterrent than fewer strands and align with typical safety practice for this voltage level. Fewer than three strands would not meet the standard, and stating no minimum would ignore established safety requirements.