ABB”s Contrac intelligent electric modulating rotary actuator offers 90-degree rotary movement for such applications as dampers and butterfly valves. These compact actuators are suitable for continuous duty, modulating, or pulse input control. Features include:
• Stall-proof without the need for position or torque-dependent switch-off.
• Sturdy, oil-lubricated gearing with high mechanical efficiency.
• Adjustable mechanical limit stops for defined operating range.
• Local pushbuttons and hand wheel for emergency operation.
• Configurable microprocessor-based power electronics.
• Extensive diagnostics and self monitoring.
The actuators transfer torque via a lever/linkage bar assembly. Alternatively, the actuator is directly coupled to the driven shaft. A special power electronics unit controls the actuator and acts as the interface between actuator and control system. During continuous positioning the power electronics unit varies the motor torque without stopping until the actuator force and the restoring process forces are balanced. High response sensitivity and high positioning accuracy with short positioning time ensure control quality and a long actuator life.