Ampacity Analysis of Low Voltage Underground Cables in Different Conduits

This paper presents the ampacity analysis of low voltage underground cables in the different conduits using the thermal finite element method. The conduit consists of a steel conduit, HDPE conduit, RTRC conduit, and PVC conduit. Underground conduits are installed below ground level 0.3 - 0.75 m. that are buried in the sand. The highest temperature is considered in Bangkok at 40.8°C. The results showed that the underground cable ampacity in various conduits that can be carried high ampacity were as follows: steel conduit, RTRC conduit, HDPE conduit, and PVC conduit, respectively. While the ampacity of underground cables decreased when the depth level of conduits was increased. On the other hand, the ampacity of underground cables increased when the ground temperature was decreased. Furthermore, this study revealed the limits and the environment that impact the underground cable ampacity and the need to find the optimal conditions for improving and following the installation standard regulation.