ABSTRACT
Any design to the 16th Edition of the IEE Wiring Regulations BS 7671 must be primarily concerned with the safety of persons, property and livestock. All other considerations such as operation, maintenance, aesthetics, etc., while forming an essential part of the design, should never compromise the safety of the installation. The selection of appropriate systems and associated equipment
and accessories is an integral part of the design procedure, and as such cannot be addressed in isolation. For example, the choice of a particular type of protective device may have a considerable effect on the calculation of cable size, or shock risk or the integrity of conductor insulation under fault conditions. Perhaps the most difficult installations to design are those
involving additions and/or alterations to existing systems, especially where no original details are available, and those where there is a change of usage or a refurbishment of a premises, together with a requirement to utilize as much of the existing wiring system as possible. So, let us investigate those parts of the Wiring Regulations that
considered in the early stages procedure.
