The modern world is so dependent on electricity that it is always around us, supporting and promoting every aspect of human life. The major attributes that make electricity the ideal source of power, for a wide variety of applications are: Electricity is efficiently produced, transported and distributed Electricity is easily converted into useful work, light or heat at the final destination Electricity supply systems are very reliable and Electricity is easily controlled. A well planned and carefully installed electrical system can be a pleasure to operate. These will reward us with many years of safe, efficient and reliable service. On the other hand a poorly designed, badly executed electrical system can be dangerous to human lives and property, unreliable and a never ending source of problems and extra expenses. Although safety is the primary objective of a good Electrical System Design, the information given in this book is not intended to be a substitute for the national or manufacturer's safety guidelines. This book presents a comprehensive coverage of Electrical Systems Design useful to the engineering degree students as well as practising engineers. A basic knowledge of electrical engineering is required to understand the concepts. Even though the current practice is to use software tools for every design process, this book provides the background information to help the users to understand how to use electricity efficiently, safely and economically.