The problems of guide bush wear and high thrust bush temperature occurred in a three-fulcrum horizontal Francis turbine generator set after C-stage overhaul. Field tests were carried out to solve the problems.In the paper

the possible hydraulic

mechanical and electrical factors affecting the unit are analyzed

and the wrong overhaul strategy of the maintenance unit is corrected. The key parameters such as the axis of the unit

the level of the main shaft

the center of the unit

the concentricity of the guide bush and the clearance at the side of the bearing bush are corrected

and the clearance at the top of the bearing bush is adjusted. The lubrication condition of bushing is improved. After treatment

the vibration and swing of the unit are greatly reduced

the tile temperature is stable

and the unit runs well.