The following topics are dealt with: Calculation of impedance of electrical equipment; calculation of short-circuit current in AC three-phase HV-systems; influence of neutral earthing on single-phase short-circuit currents; calculation of short-circuit currents in low-voltage systems; double earth-fault and short-circuit currents through earth; factors for the calculation of short-circuit currents; calculation of short-circuit currents in DC auxiliary installations; effects of short-circuit currents; limitation of short-circuit currents; special problems related to short-circuit currents; and data of equipment. Author J. Schlabbach