Replacement of appliance flexes
For flexes to be protected by the fuse in a BS1363 plug there is no limit to their length, providing their cross-sectional areas are below:
3A 0.5mm2
13A 1.25mm2
Other considerations such as voltage drop may limit flex lengths. Smaller csa's than those given are acceptable if flex lengths are restricted. However, for replacement purposes the above simplified guidance is appropriate. The maximum lengths recommended for extension leads are not applicable to appliance flexes or cord sets.