The IEC 61643-41:2025 standard was officially published on May 23, 2025 .

 

This standard specifies the requirements and test methods for **surge protection devices (SPDs)** connected to DC low-voltage power systems and applies to devices intended to protect against lightning and other transient overvoltages.

 

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

IEC 61643-41:2025 applies to **surge protection devices (SPDs)** that protect against indirect and direct effects due to lightning or other transient overvoltages .

This device is designed to be connected to DC power circuits and equipment rated up to 1500 V DC . This document specifies performance and safety requirements, test methods, and ratings.

 

Key Contents

SPD Components : Contains non-linear components to limit surge voltage and dissipate surge current .

Test conditions : Tests are based on the assumption that the SPD is connected to a power circuit providing linear voltage-current characteristics.

Considering short-circuit current , TOV (Tempolary Overvoltage) stress , etc.

 

Specific industry applications : Applicable even in fields where no relevant product standards exist, such as railway systems .

 

Requirements apply based on risk assessment :

For certain power applications (e.g., low power circuits, non-linear power supply circuits, protective isolation circuits), some requirements may not apply.

 

Excluding photovoltaic (PV) systems :

SPDs for PV applications are specified in IEC 61643-31 .

 

This International Standard is used together with IEC 61643-01 .

 

Failure to adopt the IEC 61643-41 technical standard can result in several serious hazards in DC low voltage power systems. The main hazards are:

• Equipment Damage : Transient overvoltages (surges) that are not properly managed can damage sensitive electronic equipment within the power system, leading to increased maintenance costs and decreased system reliability.

• Operational disruption : Without surge protection devices (SPDs) or without proper installation, lightning strikes or other transient voltages can cause sudden system disruptions. This can cause serious problems in railway systems, energy storage systems (ESS), electric vehicle charging infrastructure, etc.

• Safety Issues : Overvoltages can increase the risk of fire, which can potentially result in personal injury. Compliance with IEC 61643-41 can help reduce this risk.

• Legal and Regulatory Issues : Once IEC 61643-41 officially comes into effect, non-compliant design and construction may result in legal issues and difficulties in the certification and approval process.

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Therefore, compliance with IEC 61643-41 is essential to ensure the stability and safety of the system.