This book provides guidance on how to carry out the calculations required for circuit designs in compliance with the Wiring Regulations. It has been updated to take account of changes introduced by BS 7671: 2001 and Amendment 1 to the standard which included a new table of current-carrying capacities. The book makes extensive use of worked examples with the minimum discussion of theory. Chapters cover: ?cross-sectional areas of circuit live conductors

?voltage drop under normal load conditions

?earth fault loop impedances

?protective conductor cross-sectional areas

?short circuit conditions The final chapter combines all the calculations of the previous chapters, to enable the reader to achieve the complete design of a circuit. Published on behalf of the Electrical Contractors' Association, the book filled a significant gap when it was first published. It will continue to be invaluable for all electrical contractors, as well as for plant engineers and students.