A distinction is made between Lightning and Switching impulses on the basis of duration of the wave front. Impulses with wave-front durations of up to a few tens of microseconds are in general considered to be lightning impulses. Those having durations
A protective device used to open or close electrical circuits when certain limits, such as temperature or pressure, are reached.
An approach limit at a distance from an exposed live part within which a shock hazard exists.
The distance required to complete one revolution of helically laid strands of wires.
1) The direction in which the wires of a conductor are twisted. 2) The twist of conductors in a cable.