The portable cable test sets KPG 20kV VLF and KPG 36kV VLF are used for testing of medium voltage cables with extruded insulation (XLPE-, PE-, EPR-insulation) and nominal voltage up to 6.3/11kV (KPG 20kV VLF) or 12/20kV (KPG 36kV VLF) in accordance to DIN VDE 0276/620 (CENELEC HD 620 S1). Test is carried out with a low strain practice with very low frequency voltage of 0.1Hz and test voltage level of 3x U0 r.m.s. Test enables detection of damages of insulation within shortest test time. The devices are also able to test medium voltage cables with impregnated paper insulation. Cable sheath test with direct voltage is possible as well.