Electrical-accessory design

According to the 14th edition of the IEE 'Wiring regulations', an accessory may be defined as 'any device, other than a lighting fitting, associated with the wiring and current-using application, e.g. a switch, a fuse, a plug, a socket outlet, a lampholder or a ceiling rose'. There are, of course, other accessories in common use for wiring installations. Most are covered by individual British Standards; some are not. All of them call for careful design if the maximum benefit is to be derived at a reasonable capital cost.