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.
9900-431 Speed Sensor Diagnostic
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
- 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.