A drive system for driving a screen in a fluid screening system comprises a hydraulic or pneumatic motor coupled to a drive shaft of the screen. The system is sized to provide the torque required to drive the screen throughout-the desired speed range, as well as providing additional torque as required to free lodged solids from the screen field. The hydraulic motor provides overload protection when lodged solids block the rotating rake bar. The drive system operates up to a predetermined pressure value before the overload protection is activated. The drive system may be operated in either a manual mode or an automatic mode.