GENERAL APPLICATIONS

Surge Protection capacitors are used mainly to protect costly and critical equipment's.

They are used on:

Bus Ducts across a Generator winding to prevent damage by lightning impulses transmitted from the lines through electro-magnetic coupling.

Tertiaries of EHT Transformers used as step down Transformers in the transmission systems

High H.P. and High voltage motors to safeguard the windings of motors controlled by Vacuum Circuit Breakers & subject to current chopping

Induction Furnaces particularly controlled by Vacuum Circuit Breakers with a danger of current chopping.

A modern Lightning Arrestor continuously carries a current proportional to the voltage and this current can rise very fast on a pulse & ground the pulse energy. It is well supported by a surge capacitor in as much as t = RC is the time for the wave to charge the capacitor to full voltage. This time is small, but it brings down the di/dt rate from almost infinity to a sizeable & acceptable value.