All amperes are not created equal-a comparison of current ratings of high-voltage circuit breakers rated according to ANSI and IEC standards

The internationalization of the electrical power equipment market has required engineers to apply equipment designed and built to unfamiliar standards. For high voltage circuit breakers, the two best known standards are the ANSI and IEC standards. Since ratings with similar names have different meanings in the two series of standards, it is vital that application engineers understand the differences. The continuous current, interrupting, short-time and closing current ratings are examined, and these ratings in the two series of standards are compared