
335Electrical Incidents andLightning
Oen, the destructive eect of the return stroke is induced onto the power distribution
system of a building. e high currents produce lightning overvoltages in the neighbor-
hood of a million volts. ese overvoltages distribute the damage to a building’s electrical
system in a pattern following terminations and junctures. is damage is usually hidden
but may be found through careful observation. When testing electrical systems that are
suspected of having been compromised by lightning, the most useful instrument is the
HighPot tester. is device will determine the relative dielectric strength of the insu ...