While you must obtain it legally from the IEC or a national body, the cost is minimal compared to the liability of an overheated switchboard. Whether you are designing a distribution board for a hospital or a control panel for a factory, this technical report is an essential reference for safe, compliant, and efficient design.
The third edition introduced substantial updates to handle modern configurations and environmental realities. Feature / Aspect IEC TR 60890:2014 (Old) IEC TR 60890:2022 (Current) Tied to IEC 61439-1:2011 Aligned with IEC 61439-1:2020 via the IEC Webstore Solar Radiation Minimal technical guidance
Whether the enclosure is sealed or has natural ventilation openings. Power Loss Data:
: Total heat dissipated by components like circuit breakers and busbars. iec tr 60890 pdf
Most major electrical enclosure manufacturers provide dedicated configuration software (such as Rittal Therm, Schneider ProClima, or Siemens SIMARIS design) that embeds the IEC TR 60890 algorithm directly into its backend. Users enter the dimensions, installation type, and component list, and the software automatically outputs a thermal verification report compliant with IEC 61439. Conclusion
Calculations addressing outdoor enclosures exposed to direct sunlight.
The effect of air movement within the enclosure. 3. Updates in the 2014 Edition While you must obtain it legally from the
Engineers can verify designs during the early planning stages using software or manual calculations.
IEC TR 60890 specifies a method for temperature-rise assessment by calculation for partially tested or untested low-voltage switchgear and controlgear assemblies.
(Enclosure Constant / Factor): A variable adjusting for the presence of ventilation openings (closed vs. ventilated enclosures). Temperature Distribution by Height Feature / Aspect IEC TR 60890:2014 (Old) IEC
Systems without (though the 2022 edition adds guidance for it).
The temperature rise ΔT at a specified point inside the enclosure is estimated using:
IEC TR 60890:2022 is a technical report providing a standardized, non-physical method for verifying temperature-rise in low-voltage switchgear and controlgear assemblies up to 3,200 A. This third edition offers updated guidance on environmental factors like solar radiation and material effects to support compliance with IEC 61439 standards. The full document can be purchased through the IEC Webstore IEC Webstore IEC TR 60890:2022
How the enclosure is mounted (e.g., against a wall, free-standing). Ventilation Design:
