IEC TR 60890:2014

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Conditions for application
5 Calculation
6 Evaluation of the design
Annex A (informative) - Examples for the calculation
        of the temperature-rise of air inside the
        enclosures
Annex B (informative) - Operating current and power
        losses of conductors
Bibliography

IEC TR 60890:2014 specifies a method of temperature-rise verification of low-voltage switchgear and controlgear ASSEMBLIES by calculation. The method is applicable to enclosed ASSEMBLIES or partitioned sections of ASSEMBLIES without forced ventilation. It is not applicable where temperature rise verification to the relevant product standard of the IEC 61439 series has been established. This second edition cancels and replaces the first edition published in 1987 and its Amendment 1:1995. It constitutes a technical revision. This edition includes the following significant technical changes with respect to the last edition:
- alignment with IEC 61439-1:2011;
- revision of Annex B;
- general editorial review.