WG 4 - TC 37/SC 37A/WG 4

IEC 61643-21:2025 is applicable to devices for surge protection against indirect and direct effects of lightning or other transient overvoltages.
These devices are intended to be connected to telecommunications and signalling networks, and equipment rated up to 1 000 V RMS and 1 500 V DC.
These telecommunications and signalling networks can also provide power on the same line, e.g. Power over Ethernet (PoE).
Performance and safety requirements, tests and ratings are specified in this document. These devices contain at least one voltage-limiting component (clamping or switching) and are intended to limit surge voltages and divert surge currents.
This second edition cancels and replaces the first edition published in 2000, Amendment1:2008 and Amendment 2:2012. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) New structure of IEC 61643-21 based on IEC 61643-01:2024;
b) Several safety requirements based on IEC 61643-01:2024 have been added.
This International Standard is to be used in conjunction with IEC 61643-01:2024.

IEC 61643-22:2015 describes the principles for the selection, operation, location and coordination of SPDs connected to telecommunication and signalling networks with nominal system voltages up to 1 000 V r.m.s. a.c. and 1 500 V d.c. This standard also addresses SPDs that incorporate protection for signalling lines and power lines in the same enclosure (so called multiservice SPDs). This second edition cancels and replaces the first edition published in 2004. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- Update the use of multiservice SPDs (Article 8);
- Comparison between SPD classification of IEC 61643-11 and IEC 61643-21 (7.3.3);
- Consideration of new transmission systems as PoE (Annex F);
- EMC requirements of SPDs (Annex G);
- Maintenance cycles of SPDs (Annex I). Keywords: SPD, surge protective devices

Describes the principles for the selection, operation, location and coordination of SPDs connected to telecommunication and signalling networks with nominal system voltages up to 1 000 V r.m.s. a.c. and 1 500 V d.c. Also addresses SPDs that incorporate protection for signalling lines and power lines in the same enclosure.

Is applicable to devices for surge protection of telecommunications and signalling networks against indirect and direct effects of lightning or other transient overvoltages. The purpose of these SPDs is to protect modern electronic equipment connected to telecommunications and signalling networks with nominal system voltags up to 1 000 V (r.m.s.) a.c. and 1 500 V d.c. The contents of the corrigendum of March 2001 have been included in this copy.