What is the term used to describe the destructive effect of heat on porcelain when fault current flows across a bushing or insulator?

The term that accurately describes the destructive effect of heat on porcelain when fault current flows across a bushing or insulator is "Grenade." This term is used specifically in electrical engineering contexts to indicate the shattering or explosive-like failure that can occur in porcelain insulators.

When excessive current flows through an insulator, it generates significant heat, leading to rapid thermal expansion of the material. If the heat reaches a critical point, it can cause the porcelain to fracture violently, akin to an explosion, resulting in shrapnel-like pieces being ejected from the insulator. This phenomenon resembles that of a grenade explosion in terms of the sudden release of energy and fragmentation.

The other options do not capture this specific type of failure associated with electrical insulators and bushings. While "meltdown" can imply a severe overheating or degradation of a material, it is more commonly associated with metals and does not convey the explosive nature of porcelain breakage. "Fragmentation" focuses on breaking into pieces but lacks the connotation of a sudden and violent release of energy. On the other hand, "explosion," while it suggests a dramatic event, does not specifically refer to the context of porcelain insulator failure in electrical systems. Therefore, "Grenade"