What size or colour fuse should I use?
Lighting circuits are generally 5 or 6 Amp and are sometimes coloured black or white. If your fuse board uses a 5 Amp cartridge (Barrel) fuse it will be a different physical size to the 5 Amp fuse sometimes found in a 13A plug. Attempting to use a plug fuse will damage the fuse holder. (and possible the fuse board). A 5 amp fuse wire is about the thickness of a hair. 15 Amp circuits power Immersion heaters, small power circuits (e.g. garage, loft) are coloured blue. A 15 amp fuse wire is about the thickness of a small sewing needle. 20 Amp circuits are sometimes coloured yellow and are used for medium power circuits and fixed storage and some warm air heaters. 20 Amp fuse wire is not very common and 15 amp wire can be used as a substitute. 30 or 32 Amp circuits are for socket outlet circuits, cookers, small electric showers and other instantaneous hot water heaters. a 30 amp fuse wire is about the same thickness as a paperclip. A PAPERCLIP OR OTHER STEEL WIRE MUST NOT BE USED AS A SUBS
