A comparison of North American (ANSI) and European (IEC) fault calculation guidelines

The need for accurate fault analysis studies for industrial and transmission systems necessitated development of specific guidelines for short-circuit computations in North America (ANSI) and in Europe (IEC). Differences in fault current duty types, system component modeling, and computational procedures encountered between these two guidelines raise the question of whether results produced by computations adhering to either one can accommodate both. Because engineering services exchange between continents is on the rise, this question has become increasingly pertinent. The salient features of the two fault computation guidelines are compared from the points of view of system modeling, computational procedures, and database requirements. Differences encountered in breaker rating structures between ANSI and IEC are not dealt with