IEC TR 61641-2014 PDF

Full title and description

IEC TR 61641:2014 — Enclosed low-voltage switchgear and controlgear assemblies — Guide for testing under conditions of arcing due to internal fault. This technical report gives guidance on test methods for assemblies subjected to internal arcing in air, with the purpose of assessing the assembly’s ability to limit risk of personal injury, damage to the assembly and its suitability for further service after an internal arcing fault.

Abstract

This technical report (3rd edition, 2014) describes voluntary test procedures and acceptance criteria for evaluating the behaviour of enclosed low-voltage switchgear and controlgear assemblies when an internal arc occurs. It defines arcing classes and performance levels (including two personnel-protection levels), introduces the concept of arc-ignition-protected zones, and sets out minimum performance requirements while taking into account overpressure and thermal effects produced by an arc. The guidance applies primarily to enclosed, floor-standing or wall-mounted assemblies installed with doors/covers closed and secured.

General information

• Status: Published / Current (Technical Report — in force; stability date listed to 2026).
• Publication date: 9 September 2014 (2014-09-09).
• Publisher: International Electrotechnical Commission (IEC).
• ICS / categories: 29.130.20 (Low-voltage switchgear and controlgear assemblies).
• Edition / version: Edition 3.0 (2014).
• Number of pages: 46 pages.

Scope

IEC TR 61641:2014 applies to enclosed low-voltage switchgear and controlgear assemblies (primarily power switchgear and controlgear assemblies manufactured according to IEC 61439‑2). The test procedure is intended for assemblies with doors and covers closed and correctly secured. The report addresses internal overpressure effects on covers and doors, thermal effects of arcs and ejected hot gases/particles, but does not cover some other risks such as toxic gases, loud noises or conditions encountered during maintenance with open doors. The report may be used as guidance for other products with adaptations where appropriate.

Key topics and requirements

• Definition of arcing classes to describe different protection outcomes (personnel protection; damage limited to part of the assembly; assembly suitable for limited further service).
• Two levels of personnel protection based on expected access (areas restricted to skilled persons vs areas accessible to ordinary persons).
• Option and requirements for creating an arc-ignition-protected zone by insulating live conductors (formerly described as "arc free zone").
• Requirement to assess arc effects on front, back and sides of assemblies (normal requirement) and to consider minimum performance for arc-ignition-protected zones.
• Test procedures that consider internal overpressure, thermal effects and ejection of hot particles; acceptance criteria to limit risk to personnel and equipment.
• Scope limitations and exclusions (toxic gases, loud noise, maintenance/open-door scenarios, access to top/bottom of assembly) and statement that testing is voluntary and agreed between manufacturer and user when applied.

Typical use and users

Primary users are switchgear and controlgear manufacturers, independent test laboratories, certification and conformity assessment bodies, electrical design and safety engineers, and asset owners specifying acceptance criteria for equipment. The report is used to develop factory and type-test procedures, to inform product design for safer arc behaviour, and to support compliance assessment in jurisdictions or schemes that reference IEC guidance.

Related standards

IEC TR 61641 is closely associated with IEC 61439‑2 (power switchgear and controlgear assemblies — requirements for PSC assemblies) and references assembly requirements in that series. Earlier editions and related material referenced IEC 60439‑1 (superseded by IEC 61439 series). The technical report is complementary to product and safety standards that address low-voltage switchgear performance and electrical safety.

Keywords

arc fault; internal arcing; arc flash; enclosed low-voltage switchgear; controlgear assemblies; arc-ignition-protected zone; personnel protection; overpressure; IEC 61641; IEC 61439-2.

FAQ

Q: What is this standard?

A: IEC TR 61641:2014 is a Technical Report from the IEC that provides guidance on testing enclosed low-voltage switchgear and controlgear assemblies under conditions of internal arcing in air, to assess risks to personnel and equipment and the assembly’s suitability for further service.

Q: What does it cover?

A: It covers test methods, arcing class and protection-level definitions, options for arc-ignition protection (e.g., insulating live conductors), and minimum performance considerations for assemblies tested with doors and covers closed. It explicitly excludes some hazards (toxic gases, loud noise) and scenarios such as open-door maintenance conditions.

Q: Who typically uses it?

A: Manufacturers of low-voltage switchgear and controlgear assemblies, independent test laboratories, certification bodies, electrical safety and design engineers, and purchasers or asset owners who need to specify or verify arc-fault behaviour.

Q: Is it current or superseded?

A: The 2014 edition (3rd edition) supersedes the 2008 edition and is the current IEC technical report for this subject; the IEC webstore lists the 2014 edition as the active publication (stability date shown to 2026).

Q: Is it part of a series?

A: Yes — IEC TR 61641 is a Technical Report related to the IEC product/assembly standards series for low-voltage switchgear and controlgear (notably IEC 61439 series). It complements type/test requirements of the IEC 61439 family rather than replacing product standards.

Q: What are the key keywords?

A: Arc fault, internal arcing, arc-ignition-protected zone, low-voltage switchgear, controlgear assemblies, IEC 61439-2, personnel protection, overpressure, thermal effects, testing guidance.