The book provides step-by-step guidance on the design of electrical installations, from domestic installation final circuit design to fault level calculations for LV/large LV systems. Apprentices and trainees will find it very helpful in carrying out the calculations necessary for a basic installation.The 2nd edition has been re-formatted to allow for ease of use, clearer diagrams and is fully updated to BS 7671:2008(2011).It has also been prepared to provide a design sequence, calculations and data for a complete design to be carried out. It is intended to include all necessary cable and equipment data to carry out the calculations. Consultants will be able to check the calculations of their design packages. It includes calculations and necessary reference data not found in the design packages, such as cable conductor and sheath temperatures and allowances for harmonics.