Power Factor Controlling Capacitors are generally switched by contactors. But due to this uneven switching of contactors, inrush currents get developped. These inrush currents, decreases the life of capacitors. As contactor is a mechanical device, it has a definite life based on its number of switchings. Also due to mechanical contacts, there are limitations of switching time.
To solve these limitations of capacitor switching by contactors, krish engineers has come up with thyristor switching modules. These modules are switched by zero crossing detection algorithm.