FSCs comprise the actual capacitor banks and parallel arresters (metal oxide varistors, MOVs), spark gaps, and a bypass switch. Surge arresters, spark gaps and bypass switch have a protecting function in a Fixed Series Capacitor bank installation. The bypass switch protects the spark gap which defends the arrester from excessive energy absorption. The surge arresters in turn protect the capacitor from overvoltages during and after transmission system failures. Three high-voltage switches serve to integrate the FSC into and isolate it from the transmission line (e.g., for maintenance purposes).