The development of a guide on surge voltages in low-voltage ac power circuits

Surge voltages in ac power circuits become more significant with the increased application of miniaturized electronics in consumer and industrial products. A Working Group of IEEE has prepared a Guide describing the nature of these surges in ac power circuits up to 600 V, and is currently developing an Application Guide for using the environmental data defined in the Guide to improve protection. The Guide proposes two waveforms, one oscillatory, the other unidirectional, depending on the location within the power system. It also includes recommendations for source impedance or short-circuit current. This paper describes the data base and approach used by the Working Group and the recommendations proposed to represent typical surges, in order to obtain feedback for writing the Application Guide.