IEC60909-4:2000 Short-Circuit Currents in Three-Phase a.c. Systems - Part 4: Examples for the Calculation of Short-Circuit Currents

Geneva, Switzerland: The International Electrotechnical Commission (IEC), 2000. — 140 p.This part of IEC 60909 is a technical report intended to give help for the application of IEC 60909-0 for the calculation of short-circuit currents in 50 Hz or 60 Hz three-phase a.c. systems.
This technical report does not include additional requirements but gives support for the modelling of electrical equipment in the positive-sequence, the negative-sequence and the zero sequence system (clause 2) and the practical execution of calculations in a low-voltage system (clause 3), a medium-voltage system with asynchronous motors (clause 4) and a power-station unit with its auxiliary network feeding a large number of medium-voltage asynchronous motors and low-voltage motor groups (clause 5).
The three examples given in clauses 3, 4 and 5 are similar to those given in IEC 60909 (1988) but they are revised in accordance with IEC 60909-0, which replaces it.