ABSTRACT
Since the publication of IEC 909 for the calculation of short-circuit currents in 1988 [1-3], it has attracted much attention and the different methodology compared to ANSI methods of calculation has prompted a number of discussions and technical papers. This chapter analyzes and compares the calculation procedures in IEC and ANSI standards. Using exactly the same system configurations and impedance data comparative results are arrived at, which show considerable differences in the calculated results by the two methods. Some explanation of these variances is provided based on different procedural approaches. Neither standard precludes alternative methods of calculation, which give equally accurate results.
