prBAS IEC TS 61641:2027

IEC TS 61641:2026 identifies methods used to verify the ability of the assembly:<br /> – to limit the risk of injury to personnel during an internal arc-fault;<br /> – to limit the damage to an acceptable level as a result of an internal arc-fault;<br /> – to improve the power availability following an internal arc-fault.<br /> This document takes into consideration:<br /> – the effects of the internal overpressure acting on covers, doors, etc.;<br /> – the thermal effects of the internal arc-fault or its roots on the enclosures and of ejected hot gases and glowing particles.<br /> – the correct function of the IAMS within the assembly;<br /> – the prevention of unintended operation of the IAMS within the assembly, for example caused by switching arcs;<br /> – the functioning behaviour of the IAMS immediately after the assembly is energized.<br /> This document describes different methods to assess the performance of an assembly or zones of an assembly in respect of arcing in air due to an internal failure:<br /> – with "passive" arc-fault protection (provided by mechanical construction, e.g. suitable door locks, hinges, pressure relief devices, barriers);<br /> NOTE 1 This approach corresponds to the method according to IEC TR 61641:2014.<br /> – with "active" arc-fault protection (with the integration of IAMS);<br /> NOTE 2 This approach corresponds to the method according to IEC TS 63107:2020.<br /> – with the use of an arc ignition protected zone (to make the ignition of an arc-fault an extremely remote possibility).<br /> NOTE 3 This approach corresponds to the method according to IEC TR 61641:2014.<br /> IAMS consist of internal arc-fault control devices (IACD), e.g. optical-based IACD's in accordance with IEC 60947-9-2 and internal arc-fault reduction devices (IARD), e.g. arc quenching devices (AQDs) in accordance with IEC 60947-9-1 and short-circuit protection devices SCPD's in accordance with IEC 60947-2 (see Figure EE.1). IAMS can be provided by a combined-type device according to IEC 60947-9-2.<br /> IEC 60364-4-42:2024 (Clause 427) provides guidance on the need for internal arc-fault protection.<br /> This document does not supersede any individual product standard. Individual devices are required to comply with their relevant standard.<br /> This document does not apply to integration of arc fault detection devices (AFDD) according to IEC 62606.<br /> Informative Annex AA gives guidance for the user (see IEC 61439-1:2020, 3.11) on internal arc-fault mitigation.<br /> Informative Annex BB gives guidance for the user (see IEC 61439-1:2020, 3.11) of assemblies with "active" arc-fault protection (with the integration of IAMS).<br /> Informative Annex CC gives guidance for the original manufacturer of an assembly when incorporating an integrated IAMS.<br /> This document does not consider other effects which can constitute a risk, such as emission of toxic gases, loud noises and/or intense light. Furthermore, this document does not consider conditions during maintenance work and the personal protective equipment used.<br /> This edition cancels and replaces IEC TR 61641:2014 and IEC TS 63107:2020. This edition constitutes a technical revision.<br /> This edition includes the following significant technical changes with respect to the previous edition:<br /> a) Introduction of the term "arcing class zone", using the term "arcing classes" from the previous document IEC TR 61641:2014.<br /> b) Structured using of the terms "zone" and "area". "Area" is used to describe the place of installation and the accessibility of the assembly (macro-environment). "Zone" is used in this document to describe a defined space within the assembly (micro-environment).<br /> c) Assembly protection is classified into two levels.