Estudo de caso do aterramento elétrico de um prédio misto com subestação abrigada - Santa Maria - RS

Abstract

This paper presents a study on the electrical grounding of a building with a sheltered substation in the city of Santa Maria, RS. The building in question is composed of 196 individual residential units and a commercial unit, with a service entrance consisting of two energy inputs, one in low voltage and one in medium voltage. In the literature review, the types of substations allowed by regulation in the region are listed in the biographical review, as well as the types of grounding that can be installed at the service entrance. The paper presents in its body the installed load calculations and the building demand, as well as the dimensioning of the service entrance. The calculations to determine the power of the commercial unit's transformer are also presented, as well as the model of the transformer station used in this installation, with all the requirements demanded by the norms of the region. Finally, in the body, the design of the grounding system for the building's substation is presented, interconnected to the building's foundations. This project was developed with a soil resistivity measurement, grid conductor section calculation, grid sizing, grid ground resistance calculation, and maximum grid potential check. It was possible to conclude that in this case study the soil resistivity was low, being possible to carry out a grounding mesh with only 6 rods of 7,87ft and total area of approximately 220,12ft.