IEC TR 60890-2022 PDF

Full title and description

IEC TR 60890:2022 — A method of temperature-rise verification of low-voltage switchgear and controlgear assemblies by calculation. This technical report specifies a calculation method for assessing air temperature rise inside enclosures for low-voltage switchgear and controlgear assemblies (or similar products) and is available in a Redline (RLV) edition that highlights changes versus the previous edition.

Abstract

IEC TR 60890:2022 defines a calculation-based method to verify internal air temperature rise in enclosed or partitioned low-voltage switchgear and controlgear assemblies, primarily for assemblies without forced ventilation. The 2022 (third) edition updates alignment with the IEC 61439 series and adds multiple annexes and calculation clarifications; it cancels and replaces the 2014 edition.

General information

• Status: Published.
• Publication date: 29 September 2022.
• Publisher: IEC (International Electrotechnical Commission).
• ICS / categories: 29.130.20 (Low voltage switchgear and controlgear).
• Edition / version: Edition 3.0 (2022).
• Number of pages: 57 (IEC publication record for the base technical report PDF edition).

Details above and publication metadata are taken from the IEC product record for IEC TR 60890:2022.

Scope

IEC TR 60890:2022 applies a calculation procedure to determine air temperature-rise inside enclosures of low-voltage switchgear and controlgear assemblies (or similar products) in accordance with the relevant product standard. The method is primarily intended for enclosed assemblies or partitioned sections without forced ventilation; it provides guidance where temperature-rise verification by calculation is needed (for partially type-tested assemblies or design verification) and complements the IEC 61439 series requirements. The technical report also extends the validity area of the calculation and introduces limits and guidance for several real-world effects (see Key topics).

Key topics and requirements

• Calculation method for internal air temperature rise in enclosed or partitioned low-voltage assemblies (primary scope: without forced ventilation).
• Alignment and consistency with IEC 61439-1:2020 (requirements for assembly design and verification).
• Addition of individual annexes addressing: uneven power distribution; solar-radiation effects; different enclosure materials; natural and forced ventilation management; detailed power-loss calculations; and the impact of an adjacent wall on cooling surfaces.
• Specification of a maximum internal ambient temperature limit for assemblies and extension of the calculation’s validity up to 3 200 A (previously up to 3 150 A).
• Provision of algebraic expressions (equations) corresponding to graphical curves used in previous editions to support computational implementation and automation.
• Guidance for both natural and forced ventilation cases (including recommendations when forced ventilation is present).

Typical use and users

Engineers and designers of low-voltage switchgear and controlgear assemblies use this report to verify thermal performance during design, for partial type testing (PTTA) assessments, and for compliance demonstrations where calculation-based temperature-rise verification is allowed or required. Other users include manufacturers, test laboratories, certification bodies, utilities, specifiers, and standards committees responsible for product safety and thermal management of electrical distribution assemblies.

Related standards

Primary related documents include the IEC 61439 series (particularly IEC 61439-1:2020) for general assembly requirements and verification procedures; previous editions of IEC TR 60890 (2014, first editions and amendments) provide historical context; other IEC product standards for specific equipment and safety requirements may be relevant when applying temperature-rise calculations to particular assembly types.

Keywords

temperature rise, thermal verification, low-voltage switchgear, controlgear assemblies, enclosure thermal analysis, natural ventilation, forced ventilation, power loss calculation, IEC 61439, PTTA.

FAQ

Q: What is this standard?

A: IEC TR 60890:2022 is a technical report providing a calculation method to verify internal air temperature rise in low-voltage switchgear and controlgear assemblies; it is a guidance/technical-report document rather than a prescriptive product standard.

Q: What does it cover?

A: It covers a step-by-step calculation approach and supporting explanatory annexes for estimating temperature rise in enclosed or partitioned assemblies (primarily without forced ventilation), including effects such as uneven power distribution, solar radiation, enclosure materials, ventilation management, power-loss determination, and adjacent-wall effects.

Q: Who typically uses it?

A: Design engineers, assembly manufacturers, test laboratories, certification bodies, and utilities—anyone needing to demonstrate or check thermal performance of low-voltage assemblies by calculation.

Q: Is it current or superseded?

A: The 2022 edition (Edition 3.0) is the current published edition and cancels/replaces the 2014 edition. The IEC product record shows publication on 29 September 2022 and a recorded stability period. Users should verify any national adoption or amendments for local application.

Q: Is it part of a series?

A: It is a Technical Report associated with the IEC TC 121 work on low-voltage switchgear and controlgear assemblies and is closely related to the IEC 61439 series of standards for assembly design and verification.

Q: What are the key keywords?

A: temperature rise; low-voltage switchgear; controlgear; enclosure thermal calculation; natural ventilation; forced ventilation; power-loss calculation; IEC 61439.