A COMPARISON OF NORTH-AMERICAN (ANSI) AND EUROPEAN (IEC) FAULT CALCULATION GUIDELINES

The need for accurate fault analysis studies in industrial and transmi ssion systems necessitated development of specific guidelines for shor t-circuit computations in North America (ANSI) and in Europe (IEC). Di fferences in fault current duty types, system component modeling, and computational procedures encountered between these two guidelines rais e the question of whether results produced by computations adhering to either one can accommodate both. Because engineering services exchang e between continents is on the rise, this question has become increasi ngly pertinent. This article compares the salient features of the two fault computation guidelines from the points of view of system modelin g, computational procedures, and database requirements. Differences en countered in breaker rating structures between ANSI and IEC are not de alt with.