Which option is NOT listed as a major SPD site entrance?

• A. AC Power
• B. Telco/Data
• C. Fiber Optic Cable
• D. Tower Lighting Systems

Answer: (C)

Surge protection is placed at points where transient voltages can enter a site along conductive paths, so the focus is on the electrical and copper signal entry points. The major SPD site entrances typically include the AC power service, copper Telco/Data lines, and external systems such as tower lighting circuits. These paths are conductive and can carry surge currents into equipment, so they’re the places where SPDs are installed to clamp and divert those surges.

Fiber optic cables, on the other hand, carry light signals and do not form a conductive path for electrical surges in the same way. Because of that, fiber optic cables are not considered major SPD site entrances. Protection for fiber-related components focuses on optical devices and ensuring proper isolation rather than SPD devices at a site entrance.

So fiber optic cable is not listed as a major SPD site entrance, while AC power, copper Telco/Data lines, and tower lighting circuits are.