Accelerated Water Tree Test on EPDM Flat Samples: Methods and Electrical Characterization

Water treeing is a major cause of degradation in electrical cables operating under adverse conditions. The Accelerated Water Tree Test (AWTT) is a standard test for assessing resistance on cable, but its excessive cost and lengthy procedure limit its applicability. This study proposes a new measurement setup on polymer plates to make a preliminary selection of the most promising and performing materials for subsequent complete AWTT test. Through diagnostic tests, such as conductivity and dielectric spectroscopy (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\tan \delta$</tex> and capacitance), the progressive deterioration of the dielectric properties of the material can be monitored. The results confirm the effectiveness of the proposed approach in identifying materials with better resistance to water treeing, offering a reliable and costeffective alternative for preliminary selection.