What is the main factor that determines the insulation thickness for different voltage ratings and conductor sizes?

The main factor that determines the insulation thickness for different voltage ratings and conductor sizes is the in-service voltage stress on the insulation. Insulation thickness is critical as it must withstand the maximum voltage it will encounter during operation without breakdown. Higher voltage ratings necessitate thicker insulation to ensure safety and reliability, as insulators must provide sufficient dielectric strength to prevent electrical breakdown.

As voltage increases, the level of electrical stress on the insulation also increases, demanding careful consideration of the materials used and their properties. This is essential for maintaining the physical integrity of the insulation over the lifespan of the cable and ensuring it operates effectively within specified voltage tolerances.

The type of industry standards, availability of commercial cables, and application requirements are certainly important factors in the overall cable selection process, but they do not directly dictate the necessary thickness of the insulation in relation to the voltage stress experienced during operation. The primary focus remains on the insulation's capacity to handle the applied electrical stress safely.