What is the purpose of a dead-end insulator?

• A. To anchor and insulate the conductor at the end of a line section where large mechanical loads occur.
• B. To insulate only the middle of a line.
• C. To connect two lines in parallel.
• D. To insulate underground segments only.

Answer: (A)

The main function of a dead-end insulator is to anchor and insulate the conductor at the end of a line section where large mechanical loads occur. At the end of a span, the conductor experiences the full tension from the line, wind, and other forces, so the dead-end insulator assembly provides a strong anchor to the supporting structure and keeps the energized conductor isolated from that structure. It’s typically a stacked assembly that can withstand both the electrical voltage and the high mechanical pull.

This differs from insulators used mid-span, which are designed to allow some movement of the conductor and to support the line under less extreme tension. It’s not about connecting two lines in parallel, and it’s not limited to underground segments—the dead-end purpose is about end-of-span support and insulation in overhead lines.