North American and IEC Standards for Circuit Breakers

Which standards are appropriate for molded-case circuit breakers in North America—North American or International Electrotechnical Commission (IEC) standards? It seems a strange question to ask until we recognize that various entities are wondering whether IEC standards are appropriate to apply to products in North America. Multinational organizations may wish to use one electrical system worldwide, including interchangeable components. Then again, some countries may not want the burden of maintaining a country standard. Since IEC stands for “International Electrotechnical Commission,” its name implies international usage. Though IEC standards are generally international, they are not adopted worldwide. In contrast, it is not always recognized that the National Electrical Code (NEC or code) is also international [1], Although the NEC is the installation code for the United States, versions of the NEC are used in Mexico, the Philippines, Panama, Costa Rica, Venezuela, and Puerto Rico and are being considered elsewhere. The installation code for Canada is in close correlation with the NEC. Further, the product standards for molded-case circuit breakers in the three North American countries are largely identical to each other, but not equivalent to the IEC standards for circuit breakers. These product standards could also be considered international, at least in content.