Cables in ventilated conduits: experimental and numerical study of heat transfer and cable ratings

Accurate estimation of cable ampacity is of vital importance as it allows a better utilization of power cables while avoiding thermal degradation and potential failure. IEC 60287-2-3 is a recently developed standard for fast estimation of ampacity of cables in ventilated tunnels, its novelty being inclusion of longitudinal convective heat transfer. However, convective heat transfer is notoriously difficult to both model and characterize, which raises questions regarding the accuracy of the standard’s simplified analytic equations. In this paper, the standard is evaluated against experimental data for a single cable and for a flat configuration of three cables placed on the floor of a trough. The results show that the standard accurately estimates conductor temperatures under conditions…