A drive system for driving a screen in a fluid screening system comprises an electric gear motor equipped with a mechanical torque limited coupling. 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 mechanical torque limited coupling provides overload protection when lodged solids block the rotating rake bar. The coupling operates up to a predetermined torque value before the overload protection is activated. The drive system may be operated in either a manual mode or an automatic mode.