Applies to internal fuses which are designed to isolate faulty capacitor elements or capacitor unit, in order to allow operation of the remaining parts of that capacitor unit and the bank. Such fuses are not a substitute for a switching device such as a circuit-breaker, or for external protection of the capacitor bank. This publication, together with IEC 60871-4 (1996) cancels and replaces IEC 60593 (1977).