Describes how live conductors are protected by one or more devices for automatic interruption of the supply in the event of overload (see clause 433) and short-circuits (see clause 434) except in cases where the overcurrent is limited in accordance with clause 436 or by the conditions described in 433.4, 443.5 or 443.3 are met. Further, protection against overload and against short-circuits shall be co-ordinated in accordance with clause 436.The contents of the corrigendum of August 2002 have been included in this copy.