NLC Electric Systems Practice Exam 2025 - Free Electric Systems Practice Questions and Study Guide

The choice of porcelain and polymer insulators for transmission lines is based on their superior electrical and mechanical properties. Porcelain insulators have long been a traditional choice due to their excellent dielectric strength, ability to withstand high temperatures, and resistance to weathering and chemical corrosion. They are also strong enough to support the weight of conductors in various environmental conditions.

Polymer insulators, made from materials such as silicone rubber, offer additional benefits, including lighter weight and enhanced pollution performance. This makes them particularly advantageous in areas with high levels of atmospheric contamination, where they can be easier to maintain and offer improved long-term performance.

Both porcelain and polymer insulators effectively prevent electrical leakage and failure, maintaining the integrity of the transmission system. Their use reflects a balance of durability, functionality, and cost-effectiveness, which is crucial in the context of high-voltage transmission lines where reliability is essential.