Cables' Sheath Cross Bonding: An Overview of the Technique for The Medium Voltage Network of e-distribuzione

The effect of climate change drives seasons towards an extreme and less predictable behaviour expecially in urban areas: the electrical buried components of the network of e-distribuzione like cables' joints and sheaths are indeed subjected to a complete new pattern of load and a new operational regime. Among the actions taken by e-distribuzione to face these new challenges, a study on the seasonal intensity and frequency of the currents flowing in the cables' sheahts of Medium Voltage (MV) cables was carried out in 2021 within a project named Ca. Mis. Arm. (Harmonics Measurement Campaign). On the same MV feeders of the Ca. Mis. Arm., in 2022 e-distribuzione started to investigate the possibility of transposing the cables' sheaths (cross bonding) to reduce the total induced voltage and, consequently, the current flowing through the sheaths. In late 2022, three sections of a MV feeder were transposed using a transposition box with the same active current monitoring system inherited from the Ca. Mis. Arm. project. Since then, e-distribuzione planned to install other transposition boxes on different existing feeders so to understand if the component can be considered a preliminary solution to mitigate the thermal stress on the buried MV infrastructure or not.