This design activity aims to be a reference material in the power supply practicum and medium voltage and facilitate the
implementation of the practicum of the electrical engineering study program of the Ujung Pandang State Polytechnic. The construction of distribution substations is designed based on cost optimization of the purpose and purpose of their use which sometimes must be adjusted to the conditions where the substation wants to be installed. Pole mounted substation is a type of one-pole-shaped distribution substation whose installation is carried out outside (out-door) with a maximum transformer capacity of 50 kVA with CSP (completely self protected). This type of electrical substation has a transformer that is attached to the electric pole, the strength of the pole is at least 500 daN. Like distribution substations in general, pole mounted substations distribute electric power to medium and low voltage consumers