Work purpose is calculation and a rational design of transformer substation with the choice of transformers a class of voltage of 10/0,4 kV with the cable lines adjoining to it for technology joining of the applicant (a sport complex or gym) on the second category of reliability in the city of Moscow. Subject of inquiry of this work is transformer substation like "block compact two transformer substation" with group of connection of windings a triangle/star. The Transformer Substation is connected from the distribution transformer substation № 1 and distribution transformer substation № 2. Voltage class to which technology joining of the consumer is implemented is 0,4 kV. Quantity of points of accession is 2. Points of joining of the consumer are customer’s gears. The reserve power supply is absent.