BS EN IEC 61643-11:2025+A11:2025 - Low-voltage Surge Protective Devices

Introducing the BS EN IEC 61643-11:2025+A11:2025, a comprehensive standard that sets the benchmark for surge protective devices connected to AC low-voltage power systems. This essential document is a must-have for professionals in the electrical and electronics industry, ensuring that your systems are safeguarded against unexpected surges and spikes.

Overview

This standard, released on November 28, 2025, is a critical update in the field of low-voltage surge protection. It provides detailed requirements and test methods for surge protective devices (SPDs) that are connected to AC low-voltage power systems. With a total of 50 pages, this document is packed with valuable information that will guide you in implementing effective surge protection strategies.

Key Features

• Standard Number: BS EN IEC 61643-11:2025+A11:2025
• ISBN: 978 0 539 29371 5
• Status: Standard

Why Choose This Standard?

Surge protective devices are crucial for maintaining the integrity and reliability of electrical systems. The BS EN IEC 61643-11:2025+A11:2025 standard provides a robust framework for the design, testing, and implementation of these devices. By adhering to this standard, you can ensure that your systems are protected against voltage transients, which can cause significant damage to electrical equipment and infrastructure.

Comprehensive Requirements

The standard outlines specific requirements for SPDs, ensuring that they meet the necessary performance criteria. This includes guidelines on the construction, operation, and testing of these devices, providing a clear path to compliance and safety.

Rigorous Test Methods

Testing is a critical component of the standard, with detailed methods provided to evaluate the performance of SPDs under various conditions. These tests are designed to simulate real-world scenarios, ensuring that the devices can withstand and mitigate the effects of electrical surges effectively.

Who Should Use This Standard?

This standard is ideal for:

• Electrical engineers and designers
• Manufacturers of surge protective devices
• Quality assurance professionals
• Compliance officers
• Facility managers responsible for electrical systems

Benefits of Compliance

By implementing the guidelines and requirements of the BS EN IEC 61643-11:2025+A11:2025 standard, organizations can achieve several benefits:

• Enhanced Safety: Protects personnel and equipment from the dangers of electrical surges.
• Increased Reliability: Ensures the continuous operation of critical systems by preventing surge-related failures.
• Cost Savings: Reduces the risk of costly downtime and equipment replacement due to surge damage.
• Regulatory Compliance: Meets industry standards and regulatory requirements, avoiding potential fines and penalties.

Conclusion

The BS EN IEC 61643-11:2025+A11:2025 standard is an indispensable resource for anyone involved in the design, implementation, and maintenance of low-voltage power systems. By following the comprehensive guidelines and test methods outlined in this document, you can ensure that your systems are well-protected against electrical surges, enhancing safety, reliability, and compliance.

Invest in the future of your electrical systems with the BS EN IEC 61643-11:2025+A11:2025 standard, and take the first step towards a safer, more reliable power infrastructure.

BS EN IEC 61643-11:2025+A11:2025

This standard BS EN IEC 61643-11:2025+A11:2025 Low-voltage surge protective devices is classified in these ICS categories:

• 29.240.10 Substations. Surge arresters
• 29.240.01 Power transmission and distribution networks in general

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.