what is a surge
In general a surge is a transient wave of current, voltage or power in an electric circuit. In power systems in particular â and this is likely the most common context that we relate surges to â a surge, or transient, is a subcycle overvoltage with a duration of less than a half-cycle of the normal voltage waveform.urges are generally measured in microseconds. Every piece of electrical equipment is designed to operate at a specified nominal voltage such as 120 Vac, 240 Vac, 480 Vac, and so on.