Purpose: The present research purpose is the development of technical solutions on freight electric locomotives of “Yermak” family in the course of plant repairs aimed to energetic efficiency rise in a traction mode. Methods: To settle the stated task we applied methods of the following scientific disciplines: electric circuit theory, solid body dynamics, statistical processing of experimental data big arrays; thermal mode TED modeling; programming-apparatus modeling for research of TED work in regular and energy-effective modes (in program package SimInTech basis of domestic creation). Results: We’ve developed scientifically substantiated technical solutions on modernization of multi-motor traction drive of “Yermak” family freight electric locomotives in the course of plant repairs, aimed to energetic effectiveness rise. As a result, there will be achieved the cut of electric energy specific consumption in a traction mode with provision of collector traction motor reliability and working efficiency. Practical importance: Obtaining great economical effect at the expense of cut of energy consumption for a traction. It’s been established that the degree of the use of established capacity of freight electric locomotives on Likhaya-Krimskaya line (profile of 1st-2nd and 3rd type) is unsatisfactory: in traction motor regular working mode, it’s about 0.22 — for trains of 6300 tone mass and 0.12 — for ones with 1750 tone mass. At the expense of DAU algorithm use, by calculating, it’s been proved the possibility of electric locomotive energetic efficiency rise. Economic efficiency is 4.78 million Russian rubles per 1 electric locomotive (180 turns of locomotive per year at price level of 5 R rubles/kW·h.).