IEC 60364-4-43:2008 provides requirements for the protection of live conductors from the effects of overcurrents. IEC 60364-4-43:2008 describes how live conductors are protected by one or more devices for the automatic disconnection of the supply in the event of overload (Clause 433) and short-circuit (Clause 434) except in cases where the overcurrent is limited in accordance with Clause 436 or where the conditions described in 433.3 (omission of devices for protection against overload) or 434.3 (omission of devices for protection against short-circuit) are met. Coordination of overload protection and short-circuit protection is also covered (Clause 435). This third edition cancels and replaces the second edition, published in 2001, and constitutes a technical revision. The main changes with respect to the previous edition are:
- Introduction of new informative Annexes B, C and D.
- Information concerning flexible cables added to Scope.
- Requirements added for overload detection for the neutral conductor for harmonic currents.
- Requirement that devices for protection against short-circuit current be capable of making as well as breaking short-circuit current added.
- Information added to clarify protection against overload current.
- Requirements where devices for protection against overload need not be provided expanded.
- Requirements where devices for protection against short-circuit need not be provided expanded.
- Requirements for short-circuit current ratings of busbar trunking systems added. The contents of the corrigendum of October 2008 have been included in this copy.