Specialists of Yuzhnoe and Dimitrovgradskoe Production Departments of Ulyanovsk Distribution Grids, a branch of IDGC of Volga, JSC (a member of Rosseti Group of Companies), performed alternating current de-icing operations using the most simple and reliable schemes. Trial melting of glaze-ice and rime depositions on power transmission lines is carried out every year according to the available schedule as an exercise for operational staff intended to practice de-icing cables and ground wires and to check the preparedness of the necessary equipment for operation during the autumn-winter period. The program of preparation for de-icing of power transmission lines affected by icing phenomenon involves issuing of de-icing schemes, installation of jumper wires in prescribed places and simulation of short circuits (single-, two- and three-phase short circuits depending on the length of de-iced power transmission line). The current running through the wires warms up the wires thus removing glaze-ice accretions. In actual operating conditions, it takes just half an hour to melt the ice. Trial de-icing is carried out for one-two minutes in order to check the conditions and performance of the equipment. To de-ice short power transmission lines, a single-phase short circuit method with spiral connection of power line wires (the current runs through wires of all three phases connected in series) is used. The program of preparation for the period of wind and ice loads also involved inspection of sectional and ring switches of 10 kV power transmission lines and bypass switches at substations. These measures contribute to higher reliability of power supply to consumers during the peak load season.