Which factor determines the operating voltage of an insulator?

The operating voltage of an insulator is primarily determined by the number of layers or skirts the insulator has. Each layer adds to the dielectric strength of the insulator, allowing it to handle higher voltages without breaking down. Skirts increase the creepage distance, which is the shortest path between two conductive parts along the surface of an insulator, effectively enhancing performance in polluted or harsh environments.

As the number of layers increases, so too does the insulator's ability to withstand voltage without electrical breakdown occurring. This makes understanding the importance of each layer critical to ensuring that insulators perform adequately under varying electrical stress conditions.

Although the material make-up, support design, and pin type play significant roles in the overall performance and physical stability of insulators, they do not directly relate to the voltage rating in the same way that the number of layers does. The number of skirts directly influences the insulator's efficacy to maintain a safe operational voltage level.