This popular guide provides an understanding of basic design criteria and calculations, along with current inspection and testing requirements and explains how to meet the requirements of the IET Wiring Regulations. The book explains in clear language those parts of the regulations that most need simplifying. There are common misconceptions regarding bonding, voltages, disconnection times and sizes of earthing conductors. This book clarifies the requirements and outlines the correct procedures to follow.This provides an affordable reference for all electrical contractors, technicians and other workers involved in designing and testing electrical installations. The content covers the requirements for both City & Guilds and EAL courses, and contains sample exam questions and answers. It also makes an ideal revision guide. Fully up to date with the 18th Edition of IET Wiring Regulations. Simplifies the advice found in the Wiring Regulations, explaining what they mean in actual working practice for design and testing. Expert advice from an engineering training consultant, supported with colour diagrams, examples and key data.