Inspection of conductor connectors in the medium voltage grid

There may be many cases when it is necessary to repair broken conductors in the medium voltage grid. There are many types of conductor connectors to do that, but especially their long-term properties may vary in a wide range. In the High Voltage Laboratory of Budapest University of Technology and Economics, a set of mechanical tests have been executed to investigate the durability of these devices. Vibration tests, breaking and thermal aging were also the part of the inspections. Both conductor sleeves and conventional preformed connectors are included to the inspections to compare their short and long-term durability. Nature of failures was also an important aspect during the evaluation of the results. The main aim of the measurements was to declare some guidelines for distribution system operators (DSOs) to help the selection of the proper devices for the safe operation of their grid. Although many of the inspected samples provided promising results just after the installation, during some cycles of thermal, mechanical and electrical aging their properties started to deteriorate significantly. One of the most important aim of this research is to determine the root causes of failures and to prevent the grid from malfunctions caused by conductor connectors.