Which statement best describes shield wires?

• A. They serve to shield the energized phase conductor from lightning
• B. They carry primary current
• C. They are never grounded
• D. They provide only mechanical support

Answer: (A)

Shield wires, often called static or shield lines, sit above the energized conductors and are designed to intercept lightning strikes and carry the discharge safely to ground. The key point is that their primary function is to protect the phase conductor from lightning, not to carry load current. They are normally grounded at the towers, and on many systems may also house fiber optic cables for communications, but this does not change their protective purpose. While they may provide some incidental physical support, their main role is lightning protection, not mechanical support.