Experimental Determination of Permissible Continuous Currents for 10 kV Power Cables with Polymeric Insulation

The continuous load current ratings for the cores of 10 kV three-core cables laid in the air are determined for the following cable design versions: with aluminum cores, XLPE insulation and PVC sheath; with copper cores, EPR insulation and halogen-free polymeric sheath. To check whether the cable cores can pass the design values of load current, field experiments were carried out by connecting the cables to three- and single-phase current sources. It has been determined that the permissible core heating temperature equal to 90ºC is reached when the load current exceeds the design or nameplate value by a factor of 1.1 for the cables with EPR insulation and by a factor of 1.35 for the cables with XLPE insulation in being connected to either three- or single-phase sources.