Woodward ProAct I, Product Manual

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ProAct I/II Manual 04121
20 Woodward
Return Spring
The ProAct actuator has an internal return spring designed to move the actuator
toward minimum fuel in case the electrical control should fail, or power is
removed. Spring scale may not be enough to move the engine to shutdown.
The fuel system should be equipped with a spring return to minimum
fuel capable of moving the fuel control in case of failure in the ProAct
system, the connections between the ProAct actuator and the fuel
control, or loss of electrical power. The return spring should be of
sufficient force to return the fuel system to minimum fuel on loss of
actuator control, but should not limit the actuator's ability to properly
control the engine under all operating conditions.
The Feedback Device
The feedback device is located on the closed shaft of the actuator. The older
actuators use a rotary transducer which changes resistance proportional to the
actuator shaft angle. The new replacement actuators use a rotary Hall Effect
position sensor which changes output voltage proportional to the actuator shaft
angle. The device is a non-contacting unit, thereby eliminating most wear
problems.
ProAct 75 Actuator Selection
The actuator installed must match the system requirements. Select the actuator
with either an MS connector or a conduit fitting with clockwise or
counterclockwise rotation*.
*—Directions are determined by looking at the actuator shaft and the rotation to
increase fuel.