Designing distribution substation earthing systems to perform safely

This paper uses two examples of distribution substation earthing arrangements to help illustrate some of the issues which must be considered in the design process. The paper assumes a reasonable knowledge of earthing system performance and the effects of earth fault current flow. The examples described focus on the actual substation earth grid design, but it is most important to place the earthing grid within the context of the whole earthing system if over-design is to be avoided