This book shows the trainee electrician how to carry out all the calculations needed for the City and Guild 236 Certificates in Electrical Installation Competences, and similar courses leading to the award of a National Vocational Qualifications. Volume One contains examples covering all topics needed to satisfy the Part 1 Competences, while the calculation skills required to pass Part 2 are dealt with in Volume Two. Now fully revised to take account of the 16th Edition of the IEE Wiring Regulations, these two volumes have also been updated to include the latest tariffs, materials and terminology.