Low-voltage switchgear and controlgear - Part 2: Circuit-breakers

IEC 60947-2:2024 applies to circuit-breakers, intended to be installed and operated by instructed or skilled persons, the main contacts of which are intended to be connected to circuits, the rated voltage of which does not exceed 1 000 V AC or 1 500 V DC; it also contains additional requirements for integrally fused circuit-breakers. This document also applies to circuit-breakers with ratings at or below 1 000 V AC, additionally having one or more ratings above 1 000 V AC but not exceeding 1 500 V AC. This sixth edition cancels and replaces the fifth edition published in 2016 and its Amendment 1: 2019. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) suitability for isolation (see Clause 1); b) removal of the classification according to the interrupting medium, according to the design, according to the suitability for isolation (see Clause 4); c) adjustment of current settings with an external device connectable to the release (see 5.7.3); d) requirements for circuits with protective separation (see 8.2.3.8); e) additional tests for ground-fault overcurrent releases (see 9.3.4.2.5); f) additional tests concerning dielectric properties in tripped position (see 9.3.4.3); g) use of DC voltage for dielectric tests (see 9.3.4.6.2 and 9.4.6); h) tests of individual pole breaking capacity under phase-to-neutral AC voltage (see 9.3.11); i) improvement of measurement of power loss in Annex G; j) changes in EMC tests (see Annex J); k) introduction of CBI class W in Annex L.