The fact that the Keban Hydroelectric Power Plant has been operating for approximately 45 years has brought along the fact that the electro-mechanical equipment of the power plant has completed its economic life, the measurement-control systems have lost their sensitivity, the problems in operation-maintenance and the difficulties in supplying spare materials. In this context, it has been considered that it would be appropriate to carry out the rehabilitation works of Keban HEPP generators and auxiliary systems, within the framework of the general policies of our country, with local and national means, through the engineers and workers of our Institution. Thereupon, the works on the 1st Unit of Keban HEPP started on 30.05.2017 by the Central Workshop, which is under the Sarıyar Hasan Polatkan HEPP Operations Directorate, which is affiliated to the Hydroelectric Power Plants Department. The windings produced by its own means in Sarıyar HEPP Central Workshop have been partially used in order to eliminate the malfunctions that occurred in many power plants of our Enterprise before, and with the use of the windings produced for Keban HEPP, the entire winding and core of a large generator will be changed for the first time. Within the scope of this work these studies take part: Determining many parameters such as the dimensions, molds, insulation parameters of the unit windings, material selection according to operating temperatures, test types and procedures, and planning the manufacturing process according to them, renewal of Keban I stator windings (insulation class will be increased from class B to class F), renewal of stator cores , maintenance of the rotor, renewal of Keban II stator windings, maintenance of the rotor. In the rehabilitation of Generator Manufacturing and Assembly Works Keban HEPP, considering the age of the generator, it was decided to replace the stator core in order to ensure a smoother formation of the electromagnetic field and to reduce the heating problems in the generator by reducing the losses. The windings of the Keban HEPP units were wrapped in the Central Workshop, and the disassembly and assembly works of the unit started with the contributions of the Keban HEPP Operations Management personnel and the Sarıyar HP HEPP Operations Management personnel. All the windings and core of the first 2 units of Keban HEPP were re-manufactured and assembled and the 1st Unit whose assembly was completed, was successfully put into operation on 25.11.2019 and the 2nd Unit on 23.03.2020. Currently, the works on the 3rd unit are continuing, and the remaining 5 units are being planned to be done with the same method. Up to now, approximately 200,000 sheets and 1728 windings have been renewed, manufactured and assembled in the generators of 2 units.