Describes the service conditions, rated characteristics, general structural requirements and test methods of HV/LV or LV/HV prefabricated substations, which are cable-connected, to be operated from inside (walk-in type) or outside (non-walk-in type) for alternating current of rated voltages above 1 kV and up to and including 52 kV on the HV side, and for one or more transformers for service frequencies up to and including 60 Hz for outdoor installation in locations with public accessibility.