MT 6 - TC 121/SC 121A/MT 6

IEC 60947-3:2020 applies to switches, disconnectors, switch-disconnectors and fuse-combination units and their dedicated accessories to be used in distribution circuits and motor circuits of which the rated voltage does not exceed 1 000 V AC or 1 500 V DC. This fourth edition cancels and replaces the third edition published in 2008, Amendment 1:2012 and Amendment 2:2015. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
- addition of critical load current tests for DC switches (see 9.3.9);
- addition of requirements for a conditional short-circuit rating for disconnectors, switches, and switch-disconnectors protected by circuit-breakers (see 9.3.7.2);
- addition of new categories for high-efficiency motors switching (see Annex A);
- addition of new Annex E for connection to aluminium conductors;
- addition of new Annex F for power losses measurement.
The contents of the corrigendum of October 2021 have been included in this copy.

IEC 62626-1:2023 applies to enclosed switches-disconnectors with rated voltages up to 1 000 V AC for repair and maintenance work or cleaning work in load circuits. Devices within the scope of this document are switch-disconnectors in accordance with IEC 60947-3 with specific additional requirements. Enclosed switch-disconnectors in this document are suitable for isolation in accordance with the IEC 60947 series and are not equipped with means for remote control or automatic switching to avoid unexpected or accidental start. These devices are not used for operational switching, for example quick start and stop, jogging. This second edition cancels and replaces the first edition published in 2014. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) update of this document based on IEC 60947-1:2020.

IEC 62626-1:2014 applies to enclosed switches-disconnectors with rated voltages up to 1 000 V a.c. for repair and maintenance work or cleaning work in load circuits. Devices within the scope of this standard are derived from switch-disconnectors according to IEC 60947-3. Enclosed switch-disconnectors in this standard are suitable for isolation according to IEC 60947 series and are not supposed to be equipped with means for remote control or automatic switching to avoid unexpected or accidental start. These devices are not intended to be used for operational switching, quick start and stop or jogging.

The contents of the corrigendum of November 2013 have been included in this copy.

IEC 60947-3:2008 applies to switches, disconnectors, switch-disconnectors and fuse-combination units to be used in distribution circuits and motor circuits of which the rated voltage does not exceed 1 000 V a.c. or 1 500 V d.c. This part does not apply to equipment coming within the scope of IEC 60947-2, IEC 60947-4-1 and IEC 60947-5-1; however, when switches and fuse-combination units coming into the scope of this part are normally used to start, accelerate and/or stop an individual motor they shall also comply with the additional requirements given in Annex A. The requirements for single pole operated three pole switches are included in Annex C. Auxiliary switches fitted to equipment within the scope of this part shall comply with the requirements of IEC 60947-5-1. This part does not include the additional requirements necessary for electrical apparatus for explosive gas atmospheres. This edition includes the following significant technical changes with respect to the previous edition:
- alignment with the fifth edition of IEC 60947-1;
- a switching operation without current allowed between making and breaking operation (Table 3);
- increased number of operations for AC-23 allowed with agreement of the manufacturer (Table 3);
- simplified test procedure amended, f) added to 8.3.2.1.3;
- temperature rise test shall be made at the rated operational current /e instead of the conventional enclosed thermal current /the (8.3.3.1).