Report on Industry Survey of Protective Gap Applications in High-Voltage Systems

The Working Group on Characteristics of Protective Gaps of the Lightning Protective Devices Subcommittee, IEEE Protective Devices Committee, carried out an industry survey on the use of spark gaps as surge protective devices in high-voltage systems. Of 91 utilities in the United States and Canada, 22 reported the installation of gaps in their systems, and 25, although not employing gaps at the present time, indicated their interest in gap applications. From the companies using gaps, information was received concerning gap construction, application, and service performance. Considerable variation in application practices is evident, depending upon individual system requirements and different approaches to the problem of station surge protection. The Working Group concludes that a recommendation or application guide for protective gaps would be of value to the industry.