The rapid fragmentation of porcelain when a fault current travels along an insulator surface is known as a porcelain ______.

• A. Grenade
• B. Fragment
• C. Arc
• D. Fuse

Answer: (A)

When fault current travels along the surface of a porcelain insulator, the energy concentrates in a narrow path, causing intense local heating and mechanical stress. The porcelain can crack and shatter abruptly, throwing fragments outward in a rapid, explosive manner. This destructive fragmentation is what engineers and field crews refer to as a porcelain grenade. It’s different from arcing along the surface, which describes a conductive discharge path rather than a physical breakup of the insulator. The other terms don’t capture the violent, explosive breakup of the porcelain, which is why porcelain grenade is the best fit.