Low voltage surge protective devices - Part 21: Surge protective devices connected to telecommunications and signalling networks - Requirements and test methods

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.