About the 9900-431
Woodwards 2301A Load Sharing and Speed Control series model 9900-431 is a 24-volt, reverse-acting control designed to be used with gasoline or diesel engines. In this reverse-acting control, the actuator typically calls for more fuel as the voltage of the actuator increases, and the reverse-acting control fuel increases as the voltage decreases. The external wiring for reverse-acting controls is indistinguishable from that of direct-acting controls. Unlike forward-acting controls, reverse-acting controls, such as this model, do not recommend a start-fuel limit.
It is crucial to note that the speed range on the 9900-431 is factory set to that of 2000 Hz to 6000 Hz; these speeds can be changed, but it is wise to leave these settings at the standard to not cause overspeed; if the speed range must be changed remove the cover and carefully determine which rocker switch needs to be switched on or off; for 500-1500 Hz turn rocker switch one on and have the remaining three switches in the off position.
Checking the speed sensor is vital when it comes to starting your control. Measure the voltage at terminals 28 and 29; the minimum voltage will be 1.0 Vrms at cranking speed and the rated speed at 30 Vrms. It is wise to note that if the rated speed setting that you have set on your control does not produce the correct output, return the setting to the standard start position of the control.
The 9900-431 model has a single printed circuit board and adjustable potentiometers located on the front of the chassis. The speed potentiometers will be set according to the speed sensor frequency.