The standard establishes an analytical method to calculate the air temperature rise inside an enclosure. It considers factors like:
Structure and principal contents of IEC TR 60890
The calculation method defined in the is highly accurate, but it cannot be applied universally to all control panels. It is strictly restricted to enclosures that meet the following prerequisites: IEC TR 60890:2014 - iTeh Standards
The methodology requires a structured assessment of physical variables divided into three distinct evaluation stages. iec tr 60890 pdf
The influence of IEC TR 60890 extends well beyond the pages of the standard itself. It is a practical tool widely used in product development, certification, and specifying equipment.
The 2022 edition (the current version) highlights the core benefit and expanded utility of this calculation method. The standard's introduction explicitly states that it offers a reliable alternative to testing, having been derived from measurements on numerous assemblies and verified by comparison with test results.
Switchgear and control devices (at their actual operating currents). Main and distribution busbars. Internal connection cables and wiring. 2. Enclosure Cooling Characteristics The standard establishes an analytical method to calculate
Internal air temperature ≈ 40°C (ambient) + 27 K = 67°C → acceptable for most devices.
This paper examines IEC TR 60890, a method for calculating the temperature rise of enclosed switchgear and controlgear assemblies under normal service conditions without requiring full-scale type tests. The report provides simplified calculation formulas and correction factors for enclosures with natural ventilation. This paper outlines the scope, assumptions, calculation steps, limitations, and practical examples of IEC TR 60890, highlighting its role in low-voltage assembly design and compliance with IEC 61439 series.
While physical laboratory testing is the gold standard for thermal verification, it can be prohibitively expensive and time-consuming for custom, low-volume, or large-scale panels. IEC TR 60890 fills this gap by offering a universally accepted, . It predicts the exact air temperature rise at the mid-height and top sections of an enclosure. This helps engineering teams verify compliance without stepping foot in a testing lab. Key Requirements for Applying the Calculation The influence of IEC TR 60890 extends well
If an assembly is tested according to IEC 61439, this calculation method may not be required. Key Technical Aspects of IEC TR 60890
Evaluating how nearby structures impact the cooling surface area.