Thermal behaviour of cables installed via directional drilling

The permitted ampacity for a MV-cable is currently based on tables [1] which hold into account the placement of the cables and derive the permitted load. These tables are limited to the most used placement setups and load cycles. In recent years it is also possible to simulate the core-temperature of the MV-cable by using simulation software. This software can hold into account more complex burying principles and can simulate the temperature based on different and more complex load cycles. Eandis uses this software to simulate the thermal effects of cables installed at greater depths, using directional drilling. Due to the greater burying depth, the software indicates that the ampacity of the cable is decreased significantly (up to 50% in some cases). By using a fibre optic (FO) cable and measuring device, the theoretical results, as simulated by the software, can be compared with real-time measurements.