Woodward ProAct I, Product Manual

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Manual 04121 ProAct I/II
Woodward 45
11. Droop is set as the percent rated speed will be decreased from no load to
full load. Droop will be included in the engine control schedule only when the
Isoch/Droop contact is open.
The percentage of Droop entered is based on 75° of actuator travel. If less
than full travel is used, the droop percentage must be increased
proportionally.
Figure 4-9. Droop Curve
12. Idle Droop combined with the Idle Droop Breakpoint is used to limit speed
undershoot when large decel rates are used from rated to idle.
Idle Droop is based on the actuator output when it drops below the Idle
Breakpoint setting. Dependencies on linkage make the Idle Droop
percentage relative, so large droop settings may be required to achieve the
desired results.
13. Idle Droop Breakpoint is normally set equal to the actuator output obtained
when the engine is unloaded and at low idle. When the output of the control
drops below this setting or goes to minimum fuel during rapid engine
deceleration, Idle Droop will raise the speed reference. This brings the
engine back under control sooner and reduces speed undershoot. Speed
undershoot may occur because the time required for the control to return to
the new fuel setting is dependent on control dynamics and linkage
adjustment.
14. Speed Switch A ON sets the rpm that will turn on Speed Switch A.
15. Speed Switch A OFF sets the rpm that will turn off Speed Switch A.
16. Speed Switch B ON sets the rpm that will turn on Speed Switch B.
17. Speed Switch B OFF sets the rpm that will turn off Speed Switch B.
18. Speed Switch C ON sets the rpm that will turn on Speed Switch C.