Which phenomenon occurs when fault currents cause significant heat on porcelain insulators?

The phenomenon that occurs when fault currents cause significant heat on porcelain insulators is known as fragmentation. When a fault current flows through a porcelain insulator, the intense heat generated can lead to the material's degradation. In extreme cases, this heat causes the porcelain to either crack or break apart, leading to a state called fragmentation. This occurs because the thermal stress exceeds the material's ability to withstand it, resulting in the insulator disintegrating into smaller pieces.

Understanding the nature of porcelain as an insulating material is crucial. Porcelain has a high dielectric strength, but under conditions of excessive heat generated by fault currents, its structural integrity can be compromised. Thus, it is essential for operators to be aware of these effects and regularly assess insulators in their systems for any signs of deterioration that could lead to potential failures in electrical systems.