Surge Protection Techniques in Low-Voltage AC Power Systems

Designers involved in the ac power side of telecommunications equipment have been justifiably concerned with surge protection because field experience is rich in case histories of failures attributable to transient overvoltages. Insufficient knowledge of the exact nature of these overvoltages, however, has made their task difficult in the past. After several years of data collection by a number of organizations, a more definitive understanding of the surge environment is emerging. The next few years' publications from the IEEE, the IEC, NEMA, and other interested groups will document that understanding. This paper presents an overview of the results of data collection and environment descriptions from the point of view of telecommunications power supply problems, as well as a review of applicable techniques and devices.