Testing for medium-voltage cables encompasses a multidimensional range of parameters, including electrical performance, mechanical and physical properties, and material characteristics. Key test items include the measurement of conductor DC resistance, insulation resistance, and absorption ratio; partial discharge detection and localization; AC/DC withstand voltage testing; measurement of the dielectric loss tangent (tanδ); and insulation resistance and withstand voltage testing of the cable's outer sheath.
Furthermore, the scope includes structural dimension verification, integrity testing of metal sheaths, and material-specific tests-such as hot-set testing and post-aging mechanical property analysis-for insulation materials like cross-linked polyethylene (XLPE). The testing regime generally covers extruded-insulation power cables with rated voltages ranging from 6 kV to 35 kV (extending up to 66 kV), including those with XLPE or ethylene-propylene rubber (EPR) insulation. These procedures apply to factory acceptance testing of new products, on-site receiving inspections, commissioning tests following installation, as well as preventive maintenance testing and fault diagnosis for cables already in service.
