The paper describes the basic guidelines for the design of TS 10(20)/0, 4 kV, taking into account the specifics related to the design of typical urban, prefab suburban, or pole substations. The basic dispositions and characteristics of MV and LV facilities, the method of protecting the element and the method of grounding the substation are described. The method of sizing equipment in distribution substations is described. On the concrete example of a typical city substation with one dry transformer of 1MVA power, the plant elements were selected and dimensioned. The TS 10(20)/0, 4 kV solution includes an MV plant with two water lines and one transformer field in the "ring main unit" design with SF6 gas. The LV plant is equipped with 12 LV outlets.