The electrical power distribution networks for industrial systems normally rely on cable feeders to distribute the necessary power to the various industrial processes. Some overhead lines are used, but these are normally only for the longer-length and higher-voltage circuits. Cables are similarly used to interconnect the various control and protection systems for both the electrical network and for the process. Each industrial plant has different physical constraints that result in different physical configurations for process and hence for the primary and secondary power distributions. Typical industrial distribution networks are illustrated and the design aspects quoted are discussed further in chapter 3.