Why Insulators Cannot Carry Electric Current: Understanding The Nature Of Materials

The original function of dead end insulators is not to conduct current, but to maintain electrical isolation between components at different potentials in a circuit, which is quite different from that of a conductor. Electrons within insulating materials are tightly bound to their atomic structure and cannot move freely as they would in metallic conductors; therefore, charges cannot form a continuous flow path within the insulator.

In the construction of power transmission systems, this characteristic is a fundamental consideration in the design of dead end suspension insulators. On high-voltage lines, the conductors and towers connected by polymer deadend insulator have extremely high resistance in their surfaces and materials, causing any current to tend to travel along the conductor path rather than penetrate the insulation. If the porcelain dead end insulators could conduct current like a conductor, the transmission structure would lose its isolation function and cause short circuits or other systemic failures.