Protection of distribution transformers from failure due to lightning

USUAL methods of connecting arresters for the protection of distribution transformers often are inadequate, resulting in flashover of bushings or windings due to lightning, even though the arrester in itself is capable of protecting the transformer with a large factor of safety. Such flashover may be attributed to the fact that surge current flowing to ground through the ground leads of the arrester gives rise to inductive drop and resistance drop which add to the arrester voltage.