Capacitor failure analysis

This article investigates capacitor failures and fuse operations in an automatically switched capacitor bank in an industrial facility. The fuses that cleared were protecting individual capacitor steps in the bank. It was initially believed that harmonics were the source of the problem. The investigation determined that the failures were occurring due to capacitor energization transients from an unexpected source. Capacitor analysis reveals that capacitors must be built to tolerate voltages and currents in excess of their ratings according to IEEE standards