DIN EN 61439-1 Beiblatt 2:2016-02

IEC 61439-1 specifies as one of the design verifications a verification of temperature-rise for low-voltage energy switchgear and controlgear assemblies. This verification may be carried out by means of testing, but under defined boundary conditions alternatives are also permitted. Selection of the method for the verification of temperature-rise is the responsibility of the original manufacturer. This Supplement describes a procedure for verification of the temperature-rise of low-voltage switchgear and controlgear assemblies by calculation. The method is applicable for switchgear and controlgear assemblies in closed design or for sections of switchgear and controlgear assemblies divided by partitions without forced ventilation. It serves to determine the temperature-rise of the air inside the enclosure. However, it is not applicable if verification of temperature-rise has been provided in accordance with the relevant product standard of the IEC 61439 series. If necessary, the information from this Supplement may also be used to prove the temperature-rise for similar products according to other standards. The factors and coefficients specified herein have been derived from measurements on a large number of switchgear and controlgear combinations and the verification procedure has been confirmed by comparison with test results. The responsible committee is DKE/UK 431.1 "Niederspannungs-Schaltgerätekombinationen" ("Low-voltage switchgear and controlgear assemblies") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.