低压电气装置.第4-43部分:安全防护.过电流保护

[中文适用范围]： IEC 60364 的这一部分提供了保护带电导体免受过电流影响的要求。本标准描述了如何通过一个或多个设备保护带电导体，以便在发生过载（第 433 条）和短路（第 434 条）时自动断开电源，但根据第 436 条限制过流的情况除外或者满足433.3（省略过载保护装置）或434.3（省略短路保护装置）中描述的条件。还涵盖了过载保护和短路保护的协调（第 435 条）。注 1：根据第 433 条针对过载进行保护的带电导体也被认为针对可能导致与过载电流类似的过电流的故障进行了保护。注2：本标准的要求没有考虑外部影响。注3：根据本标准对导体的保护不一定能保护与导体连接的设备。注4：通过插头和插座将设备连接到固定装置的软电缆不属于本标准的范围，因此不一定具有过流保护。注5：在本标准中，断开并不意味着隔离。 [外文原描述]： 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.