The purpose of this guide is to give guidance to the substation engineer in established practices for the application and installation of metallic and optical cables in electric power transmission and distribution substations. This guide emphasizes reliable electrical service during the design life of the substation. Solutions presented in this guide may not represent the only acceptable practices for resolutions of problems. This guide should not be referred to or used as an industry standard. It is being presented to aid in the development of wire and cable system installations and should not be taken as a compliance standard.