IEC 60909:1988

FOREWORD
PREFACE
Clause
1 Scope
2 Object
3 Definitions
4 Symbols, subscripts and superscripts
4.1 Symbols
4.2 Subscripts
4.3 Superscripts
5 Calculation assumptions
6 Equivalent voltage source at the short-circuit location
SECTION ONE - SYSTEMS WITH SHORT-CIRCUIT CURRENTS HAVING NO A.C.
              COMPONENT DECAY (FAR-FROM-GENERATOR SHORT CIRCUITS)
7 General
8 Short-circuit parameters
8.1 Balanced short circuit
8.2 Unbalanced short circuit
8.3 Short-circuit impedances
8.4 Conversion of impedances, currents and voltages
9 Calculation of short-circuit currents
9.1 Calculation method for balanced short circuits
9.2 Calculation method for line-to-line and line-to-earth short
      circuits
9.3 The minimum short-circuit currents
SECTION TWO - SYSTEMS WITH SHORT-CIRCUIT CURRENTS HAVING
              DECAYING A.C. COMPONENTS (NEAR-TO-GENERATOR SHORT
              CIRCUITS)
10 General
11 Short-circuit parameters
11.1 General
11.2 Balanced short circuit
11.3 Unbalanced short circuit
11.4 Equivalent voltage source at the short-circuit location
11.5 Short-circuit impedances
11.6 Conversion of impedances, currents and voltages
12 Calculation of short-circuit currents
12.1 General
12.2 Calculation
12.3 Calculation method for line-to-line and line-to-earth short
      circuits
12.4 The minimum short-circuit currents
13 Influence of motors
13.1 Synchronous motors and synchronous compensators
13.2 Asynchronous motors
13.3 Static converter fed drives
14 Consideration on non-rotating loads and capacitors
14.1 Parallel capacitors
14.2 Series capacitors
APPENDIX A - Calculation of short-circuit currents, examples

This standard is applicable to the calculation of short-circuitcurrents:-in low-voltage three-phase a.c. systems,-in high-voltage three-phase a.c. systems with nominal voltages upto 230 kV operating at nominal frequency (50 Hz or 60 Hz).This standardized procedure is given in such a form as tofacilitate as far as possible its use by non-specialist engineers.