This application guide presents a practical method to be used when calculating short-circuit currents in low-voltage networks. The method corresponds strictly with IEC 60909 and leads to conservative results with sufficient accuracy. Two short-circuit currents which differ in magnitude are to be calculated: -the maximum short-circuit current which causes the maximum thermal and electromagnetic effects on electrical equipment and determines the required capacity or rating; -the minimum short-circuit current which may be a basis for the adjustment of protective devices.

SS IEC 781 Ed. 1 (1991) - Identical

UNE 21240:1997 - Identical

BS 7638:1993 - Equivalent

HD 581:1992 - Equivalent

VDE 0102 SUPP 2:1992 - Identical

CEI 11-28 Ed. 1 (1998) - Identical