Impact of electrical cables embedded into oriented strand board on critical heat flux

The paper deals with the research of electrical cables embedded in surface grooves of OSBs and its impact on the critical heat flux. An OSB type 3 board (structural board for use in dry or humid environments) and an electrical cable with fire reaction class B2ca have been investigated. Four different configurations of grooves were investigated. The first configuration consisted of an OSB without grooves (control sample). The second configuration consisted of an OSB with a single groove in the centre in which the electrical cable was mounted. In the third and fourth configurations, there were three and five grooves, respectively in which the electrical cables were mounted (the width of the grooves and the spacing between them was 9 mm). The critical heat flux was calculated from the ignition times at five different heat fluxes (30, 35, 40, 45 and 50 kW.m-2) by using a cone calorimeter. The obtained data showed that the OSB without grooves (first configuration) shows the lowest critical heat flux (8.6 kW.m-2) and the lowest standard deviation of ± 0.5 kW.m-2 (lower ignition resistance) compared to the other configurations (critical heat flux in the range from 9 to 10 kW.m-2 and standard deviation from 3.1 to 3.2 kW.m-2).