WG 5 - TC 37/SC 37A/WG 5

IEC 61643-11:2025 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 AC power circuits and equipment rated up to 1 000 V RMS, the preferred frequencies taken into account in this document are 50/60 Hz. Other frequencies are not excluded. Performance and safety requirements, tests and ratings are specified in this document. These devices contain at least one nonlinear component and are intended to limit surge voltages and divert surge currents.
The test requirements provided by this document are based on the assumption that the SPD is connected to an AC power circuit fed by a power source providing a linear voltage-current characteristic. When the SPD is to be connected to a different kind of source or to a different frequency, careful consideration is required. This mainly applies with regard to system and fault conditions to be expected in such a system (e.g. expected short circuit current, TOV-stresses).
This document can apply for railway applications, when related product standards do not exist for that area or for certain applications.
Based on a risk assessment it might not be necessary to apply all requirements of this document to SPDs designed for specific power applications only, e.g. circuits with a low power capability, circuits supplied by nonlinear sources, circuits with protective separation from the utility supply.
NOTE 1 More information on risk assessment is provided in IEC Guide 116.
NOTE 2 Other exclusions based on national regulations are possible.
This edition includes the following significant technical changes with respect to the previous edition:
a) Specific requirements for SPDs for AC applications are now contained in this document, whereas the common requirements for all SPDs are now contained in IEC 61643-01;
b) Clarification on test application either to a complete SPD, to a "mode of protection", or to a complete "SPD assembly";
c) Additional measurement of voltage protection level on "combined modes of protection" between live conductors and PE;
d) Additional duty test for T1 and T2 SPDs with follow current to check variation of the follow current value at lower impulse currents;
e) Modified and amended short circuit current test requirements to better cover up to date internal SPD disconnector technologies;
f) Improved dielectric test requirements for the SPD's main circuits and added dielectric test requirements for "electrically separated circuits";
g) Additional clearance requirements for "electrically separated circuits".
The requirements of this document supplement, modify or replace certain of the general requirements contained in IEC 61643-01 and shall be read and applied together with the latest edition of IEC 61643-01, as indicated by the undated normative reference in Clause 2 of this document.

IEC 61643-41:2025 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 DC power circuits and equipment rated up to 1 500 V DC. Performance and safety requirements, tests and ratings are specified in this document. These devices contain at least one nonlinear component and are intended to limit surge voltages and divert surge currents.
The test requirements provided by this document are based on the assumption that the SPD is connected to a DC power circuit fed by a power source providing a linear voltage-current characteristic. When the SPD is to be connected to a different kind of source, careful consideration is required. This mainly applies with regard to system and fault conditions to be expected in such a system (e.g. expected short circuit current, TOV-stresses).
This document can apply for railway applications, when related product standards do not exist for that area or for certain applications.
Based on a risk assessment it might not be necessary to apply all requirements of this document to SPDs designed for specific power applications only, e.g. circuits with a low power capability, circuits supplied by nonlinear sources, circuits with protective separation from the utility supply.
NOTE 1 More information on risk assessment is provided in IEC Guide 116.
SPDs for PV applications are not covered by this document.
NOTE 2 Such SPDs for PV applications are covered by IEC 61643-31.
NOTE 3 Other exclusions based on national regulations are possible.
This International Standard is to be used in conjunction with IEC 61643-01.

IEC 61643-01: 2024 contains the common requirements for all SPDs. This document is applicable to devices for surge protection against indirect and direct effects of lightning or other transient overvoltages, hereafter referred to as Surge Protective Devices (SPDs). SPDs are intended to be connected to circuits or equipment rated up to 1 000 V AC (RMS) or 1 500 V DC. Performance and safety requirements, tests and ratings are specified in this document. SPDs contain at least one nonlinear component and are intended to limit surge voltages and divert surge currents. This document, together with IEC 61643-11:— (second edition), cancels and replaces the first edition of IEC 61643-11 published in 2011. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the first edition of IEC 61643-11:
a) Clarification on test application either to a complete SPD, to a "mode of protection", or to a complete "SPD assembly";
b) Additional measurement of voltage protection level on "combined modes of protection" between live conductors and PE (see new Annex F);
c) Additional duty test for T1 SPD and T2 SPD with follow current to check for increased follow current at lower impulse current amplitude (see 9.3.5.5);
d) Modified and amended short circuit current test requirements to better cover up-to-date internal SPD disconnector technologies (see 9.3.6.3);
e) Improved dielectric test requirements for the SPD’s main circuits and added dielectric test requirements for "electrically separated circuits" (see 9.3.7 and 9.3.8);
f) Additional clearance requirements for "electrically separated circuits" (see 9.4.4);
g) Additional information and details for SPDs for DC installations.

IEC 61643-31:2018 is applicable to Surge Protective Devices (SPDs), intended for surge protection against indirect and direct effects of lightning or other transient overvoltages. These devices are designed to be connected to the DC side of photovoltaic installations rated up to 1 500 V DC. These devices contain at least one non-linear component and are intended to limit surge voltages and divert surge currents. Performance characteristics, safety requirements, standard methods for testing and ratings are established. SPDs complying with this standard are exclusively dedicated to be installed on the DC side of photovoltaic generators and the DC side of inverters. SPDs for PV systems with energy storage (e.g. batteries, capacitor banks) are not covered. SPDs with separate input and output terminals that contain specific series impedance between these terminal(s) (so called two-port SPDs according to IEC 61643-11:2011) are not covered. SPDs compliant with this standard are designed to be permanently connected where connection and disconnection of fixed SPDs can only be done using a tool. This standard does not apply to portable SPDs.
The contents of the corrigendum of June 2022 have been included in this copy.

IEC 61643-11:2011 is applicable to devices for surge protection against indirect and direct effects of lightning or other transient overvoltages. These devices are packaged to be connected to 50/60 Hz a.c. power circuits, and equipment rated up to 1 000 V r.m.s. Performance characteristics, standard methods for testing and ratings are established. These devices contain at least one nonlinear component and are intended to limit surge voltages and divert surge currents. This first edition of IEC 61643-11 cancels and replaces the second edition of IEC 61643-1 published in 2005. The main changes with respect of the second edition of IEC 61643-1 are the complete restructuring and improvement of the test procedures and test sequences. NOTE: The attention of National Committees is drawn to the fact that equipment manufacturers and testing organizations may need a transitional period following publication of a new, amended or revised IEC publication in which to make products in accordance with the new requirements and to equip themselves for conducting new or revised tests. It is the recommendation of the committee that the content of this publication be adopted for national implementation not earlier than 12 months from the date of publication. In the meantime, the previous edition can still be ordered by contacting your local IEC member National Committee or the IEC Central Office.

Is applicable to devices for surge protection against indirect and direct effects of lightning or other transient overvoltages. These devices are packaged to be connected to 50/60 Hz a.c. and d.c. power circuits, and equipment rated up to 1 000 V r.m.s or 1 500 V d.c. Performance characteristics, standard methods for testing, and ratings are established for these devices that contain at least one nonlinear component that is intended to limit surge voltages and divert surge currents.