Electrical networks experience surges wherein a voltage or a current rises rapidly to unsafe values and destroys the dielectric insulation. These along with partial discharges are blamed for the majority of failures of electrical equipment of all types.
Surge capacitors work by absorbing the energy from electrical surges, providing protection to the equipment. Lightning or Switching surges can cause damage to the turn-to-turn insulation of rotary machines, transformers. Connecting surge capacitors line to ground at the motor terminals prevents this damage. For a more comprehensive protection scheme, surge capacitors may be used in conjunction with surge arresters. This surge pack modifies both the wave shape and magnitude