IEC 61643-41:2025

Low-voltage surge protective devices - Part 41: Surge protective devices connected to DC low-voltage power systems – Requirements and test methods

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.

Parafoudres basse tension - Partie 41: Parafoudres connectés aux réseaux basse tension en courant continu - Exigences et méthodes d’essai

IEC 61643-41: 2025 s’applique aux dispositifs de protection contre les effets indirects et directs de la foudre ou contre les surtensions transitoires.
Ces dispositifs sont destinés à être connectés à des circuits d’alimentation ou à des équipements en courant continu de tension assignée allant jusqu’à 1 500 V en courant continu. Les exigences de performance et de sécurité, les essais et les valeurs assignées sont spécifiés dans le présent document. Ces dispositifs comportent au moins un composant non linéaire et sont utilisés pour limiter les surtensions et écouler les courants de foudre.
Les exigences d’essai prévues par le présent document reposent sur l’hypothèse que le parafoudre est connecté à un circuit d’alimentation en courant continu alimenté par une source d’alimentation présentant une caractéristique tension-courant linéaire. Lorsque le parafoudre doit être connecté à un autre type de source, une attention particulière est exigée, notamment s’agissant des conditions de réseau et des conditions de défaut qui peuvent être attendues dans un tel réseau (par exemple le courant de court-circuit prévu, les contraintes TOV).
Le présent document peut s’appliquer aux applications ferroviaires, lorsqu’il n’existe pas de normes de produits connexes pour ce domaine ou pour certaines applications.
Sur la base d’une évaluation des risques, il peut ne pas être nécessaire d’appliquer toutes les exigences du présent document aux parafoudres conçus uniquement pour des applications électriques spécifiques, par exemple les circuits ayant une faible capacité électrique, les circuits alimentés par des sources non linéaires, les circuits avec une séparation de protection de l’alimentation électrique.
NOTE 1 Des informations supplémentaires sur l’évaluation des risques sont données dans le Guide 116 de l’IEC.
Les parafoudres pour les applications photovoltaïques ne sont pas couverts par le présent document.
NOTE 2 Les parafoudres pour les applications photovoltaïques sont couverts par l’IEC 61643-31.
NOTE 3 D’autres exclusions fondées sur des réglementations nationales sont possibles.
La présente Norme internationale doit être utilisée conjointement avec l’IEC 61643-01.

General Information

• Status: Published
• Publication Date: 22-May-2025
• ICS: 29.240.10 - Substations. Surge arresters
• Technical Committee: SC 37A - Low-voltage surge protective devices
• Drafting Committee: WG 5 - TC 37/SC 37A/WG 5
• Current Stage: PPUB - Publication issued
• Start Date: 23-May-2025
• Completion Date: 23-May-2025

Standards Content (Sample)

IEC 61643-41 ®
Edition 1.0 2025-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Low-voltage surge protective devices –
Part 41: Surge protective devices connected to DC low-voltage power systems –
Requirements and test methods
Parafoudres basse tension –
Partie 41: Parafoudres connectés aux réseaux basse tension en courant continu –
Exigences et méthodes d’essai
ICS 29.240.10  ISBN 978-2-8327-0447-9

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– 2 – IEC 61643-41:2025 © IEC 2025
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and abbreviated terms . 7
4 Classification . 7
5 Void . 7
6 Marking and other product information . 7
7 Service conditions . 8
8 Requirements . 8
9 Tests . 9
Annex AA (normative) Application of annexes from IEC 61643-01 . 20
Annex BB (normative) Test voltages for SPDs – U . 21
test
Annex CC (normative) TOV test values for DC power systems . 23
Annex DD (informative) DC power systems . 25
Bibliography . 31

Figure 100 – Procedure for sample preparation for dedicated overstress test . 16
Figure 101 – Example of a test circuit for the TOV tests . 18
Figure 102 – Timing diagram for the TOV tests . 18
Figure DD.1 – TT DC distribution system . 25
Figure DD.2 – TT DC distribution system with a mid-point. 26
Figure DD.3 – TN-S DC distribution system . 26
Figure DD.4 – TN-S DC distribution system with a mid-point . 27
Figure DD.5 – TN-C DC distribution system with a mid-point . 27
Figure DD.6 – TN-C DC distribution system. 28
Figure DD.7 – TN-C-S DC distribution system . 28
Figure DD.8 – TN-C-S DC distribution system with a mid-point . 29
Figure DD.9 – IT DC distribution system . 29
Figure DD.10 – IT DC distribution system with a mid-point . 30

Table 100 – Type test requirements for SPDs . 10
Table 101 – Prospective short circuit current and time constant . 14
Table AA.1 – Application of annexes from IEC 61643-01 . 20
Table BB.1 – Test voltage values . 22
Table CC.1 – TOV test values for DC power systems . 23
Table CC.2 – Prospective short-circuit currents for TOV tests . 24

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE SURGE PROTECTIVE DEVICES –

Part 41: Surge protective devices connected to DC low-voltage power
systems – Requirements and test methods

FOREWORD
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IEC 61643-41 has been prepared by subcommittee 37A: Low-voltage surge protective devices,
of IEC technical committee 37: Surge arresters. It is an International Standard.
This first edition only contains the specific requirements for SPDs for DC applications.
This International Standard is to be used in conjunction with IEC 61643-01.
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.
Numbering of clauses follows the numbering of IEC 61643-01, but, dependent on the application
of clauses from IEC 61643-01, does not necessarily follow sequentially.

– 4 – IEC 61643-41:2025 © IEC 2025
If a clause in IEC 61643-01 is not explicitly called up or referred to in this document, then this
clause does not apply to SPDs covered by this document. Any instructions in this document
calling up clauses from IEC 61643-01 are written in Italic type.
NOTE In other words, if e.g. Clause 4 is called up in this document all subclauses of Clause 4 of IEC 61643-01 are
applied without modification. But, if e.g. some modifications are required on subclauses of Clause 9 of IEC 61643-01,
then the relevant second level subclaus
...