It could extend the capacitor service life if we reduce the discharge inrush current of capacitors. Flair Electronics is professional in power capacitors for industrial induction heating melting applications and power network. We propose some measures on how to effectively limit the inrush current of power capacitors, especially for induction heating/melting industries. 

1.Regularly clean conductive dust

It is necessary to shut down the machine regularly to clean the conductive dust that accumulated on the capacitors. Conductive dust may cause short circuits at the terminal blocks, which in turn can trigger huge discharge inrush currents. Cleaning the dust can prevent such short circuits from occurring and the casing from discharging to ground

2.Increase the Insulation performance

One of the fundamental causes of inrush current is insulation breakdown in capacitor cells. Therefore, it is necessary to maintain the insulation performance of the capacitor by controlling the operating voltage and frequency (to prevent excessive reactive power output caused by over-voltage and over-frequency), ensuring good cooling conditions (to prevent overheating, aging, and capacitor bulging and then oil leakage from the shell),  etc., consequently maintain the insulation performance of capacitors to reduce short circuits and inrush currents caused by insulation breakdown from the source

3.Install fuses for rapid isolation

Due to the harsh operating environment of the induction heating melting furnace and the fact that capacitor units usually do not have dedicated protective components, it is recommended to install fuses on capacitor units when conditions permit. When a capacitor suffers insulation damage or a short circuit occurs at the terminal due to the accumulation of conductive dust, the fuse can quickly isolate the faulty unit, preventing all the energy storage on the intact capacitor unit from being released through the fault point, thereby avoiding the huge discharge inrush current from damaging other intact capacitors. 

Through the above measures, the impact of inrush current on the capacitor bank can be effectively reduced, preventing good capacitors from experiencing shell cracking or damage due to energy exceeding their rated energy tolerance level, thereby extending the overall service life.