Best Practices in Distribution System Surge Protection by Jonathan Woodworth

As demand for more reliable power continues to grow worldwide, improving the lightning reliability of distribution systems is becoming a more important exercise. In North America, for example, distribution systems are often a 4-wire configuration, with three phase conductors and one neutral. The neutrals are typically grounded at equipment locations. For systems located in areas of high lightning activity, the neutral is also grounded where the line arresters are installed. The two most common distribution system configurations are 4-wire solidly grounded and three-wire grounded at source only. This presentation discusses the options available to distribution engineers and reliability engineers to improve a system’s reliability by means of optimized application of surge arresters. Most of the ways this can be accomplished are based on distribution systems found in the United States and Canada but in fact are also applicable to any system.