IEC 60502-4 Ed 4.0 Power cables with extruded insulation and their accessories for rated vo ltages from 1 kV (Um = 1,2 kV) up to 30 kV (Um = 36 kV) - - Part 4; Test requirements on accessories for cables with rated voltages from 6 kV (Um = 7,2 kV) up to 30 kV (Um = 36 kV)