A motor driven synchronizing device, figure "D" shown in the illustration, operated from the generator switchboard, initiates fine adjustments to the steam turbine speed by directly __________. Illustration SE-0009

Correct Answer: Option C — changing the vertical location of the pilot valve bushing

Adjusting the vertical position of the pilot valve bushing alters the neutral position of the hydraulic relay. This directly repositions the power piston, raising or lowering the nozzle block lifting beam to fine-tune turbine speed during generator synchronization.