CHARACTERIZATION OF THE THERMAL EXPOSURE IN THE EN 50399 CABLE TEST APPARATUS

摘要

The EN 50399 cable test is used for classification of cables within the European construction products regulation. Means to predict a cables performance in this test, based on material data and small scale test results is of great value for the development of new cable materials. A first step in developing a prediction tool should be to understand the heat exposure on the cables in the EN 50399 test apparatus. The heat load in e.g. the cone calorimeter is very well characterized whereas for EN 50399 only the burner power (20.5 kW) is known. In the cone calorimeter the heating is solely by radiation, whereas for the EN 50399 test a large fraction of the heat exposure depends on feed-back from the cable fire. This paper presents a measuring method for characterizing the thermal exposure inside the EN 50399 cable test apparatus without cables and with a cable rated Euroclass Dca. A new instrument for measuring thermal exposure simultaneously in several directions was developed for the purpose, and thereby the non-isotropic exposure on the cables at different position on the ladder could be investigated.