Electrical equipment of transformer and distribution substations and switchgears, their standard electrical diagrams, organization and maintenance of electrical equipment of electrical substations and switchgears are considered. The main diagrams of substations and schematic diagrams of operated electrical installations, conventional graphic and letter designations of elements of electrical circuits are given. The main provisions of the rules for technical operation of consumer electrical installations, types of technical, technological and reporting documentation, the procedure for filling it out during maintenance of electrical substations are highlighted.