Which of the following is NOT a contributor to mechanical load on an insulator string?

• A. Dielectric strength of the insulator material
• B. Weight
• C. Wind
• D. Ice or movement

Answer: (A)

Dielectric strength is the insulator’s ability to resist electrical breakdown under high voltage. That is an electrical property, not a mechanical one, so it does not add or contribute to the physical forces on the insulator string. On the other hand, weight adds vertical tension, wind introduces lateral and dynamic loading, and ice or movement increases mass and causes bending or vibration. These are the forces that create mechanical load on the string. So dielectric strength doesn’t contribute to mechanical load, making it the correct choice.