AFCIs—From a Standards Perspective

Arc-fault circuit interrupters (AFCIs) are required by the National Electrical Code (NEC) to further reduce the hazards resulting from residential electrical fires. The Underwriters Laboratories (UL) 1699 Standard contains the testing and certification requirements for various types of AFCIs. Both the NEC and UL 1699 Standards are American National Standards Institute (ANSI) documents, established through the ANSI consensus process. Using the UL 1699 Standard as the base, this paper will explain various differences between combination- and branch/feeder-type AFCIs. It will provide detailed explanations for some of the required tests, which should help the reader to better understand why the widely used industry terms of “series arcs” and “parallel arcs” are an oversimplification when describing the actual performance of these devices. An explanation about ground-fault requirements, or lack thereof, will also be provided. Lastly, this paper will challenge the readers to identify other potential applications of arc-fault technology, with the intent being to further increase overall electrical safety by expanding this technology beyond its present residential applications.