Woodward 9905 Series User Manual (English)

Questions and Answers:

T
taylorkarenAug 20, 2025
What to do if my Woodward 9905 Control Unit prime mover will not start and the actuator isn't moving?
- G
  Gabrielle HowardAug 21, 2025
  If your prime mover isn't starting and the actuator isn't moving to the start-fuel position, here are a few things to check: * First, ensure proper voltage from terminals 16 (+) to 15 (–). If it's a DC system and the polarity is incorrect, reverse the leads. * If there's voltage at control terminals 20 (+) and 21 (–) but the actuator remains still, inspect the wiring to the actuator for any opens or shorts. * Also, the start fuel limit might be set too low. Try turning the start fuel limit clockwise until the prime mover starts. * Make sure that actuator moves approximately 2/3 of its travel from no load to full load. * Check the magnetic-pickup output voltage at speeds above idle—it should be at least 1.0 Vrms.
M
Martin YoungAug 22, 2025
Why does my Woodward 9905 prime mover overspeed only on starts?
- D
  Devin LeeAug 22, 2025
  If your prime mover overspeeds only when starting, try increasing the RAMP TIME clockwise. This adjustment can help control the acceleration during startup.
J
Jose ThompsonAug 25, 2025
What should I do if there is no actuator voltage at terminals 20 and 21 on my Woodward 9905?
- T
  Thomas DuncanAug 25, 2025
  If you find no actuator voltage at terminals 20 and 21, check for shorted or grounded actuator leads by disconnecting the wires from these terminals.
O
ofosterAug 26, 2025
How to adjust the GAIN on my Woodward Control Unit for stable response?
- K
  kdunlapAug 27, 2025
  To adjust the GAIN for the fastest stable response, slowly adjust the GAIN. Making the GAIN adjustment too quickly can cause issues, so proceed gradually.
S
Sandy LewisAug 28, 2025
What to do if the speed setting is too low on initial start of my Woodward 9905?
- J
  Jessica BowmanAug 28, 2025
  If the speed setting is too low on initial start, it's possible the control is the wrong speed range. Check the speed sensor frequency against the control part number. Also, the speed setting may be lower than the cranking speed.
R
rcooperAug 29, 2025
What to do if the LOW IDLE SPEED setting is too low on my Woodward Control Unit?
- M
  Michele HoodAug 29, 2025
  If the LOW IDLE SPEED setting appears to be too low, adjust the LOW IDLE SPEED potentiometer clockwise to increase it.
K
Kathryn CalderonAug 31, 2025
What to check if the Minimum Fuel contact is open on my Woodward 9905 Control Unit?
- B
  brownjosephAug 31, 2025
  If the Minimum Fuel contact is open, check T 17. For normal operation, the minimum-fuel contact must be closed.
F
Frank DavisSep 2, 2025
What to do if terminals 23 and 24 are open on my Woodward 9905 Control Unit?
- J
  jamiedorseySep 2, 2025
  If you find that terminals 23 and 24 are open, verify that they are jumpered if an optional external speed trim is not being used.
M
Michelle PerrySep 4, 2025
How to troubleshoot a faulty speed trim potentiometer in a Woodward 9905 Control Unit?
- D
  Dr. Vickie RoySep 4, 2025
  To troubleshoot a faulty speed trim potentiometer, turn the power OFF and then check the speed trim potentiometer(s) using an ohmmeter.
C
Christine KelleySep 5, 2025
What to do if the speed sensor signal isn't clearing the failed speed signal circuit on my Woodward Control Unit?
- D
  Darlene CaseySep 5, 2025
  If the speed sensor signal isn't clearing the failed speed signal circuit, check the wiring for a proper connection.

Woodward 9905 Series Specifications

General

Type	Control Unit
Operating Temperature	-40°C to 70°C
Storage Temperature	-40°C to 85°C
Humidity	5 to 95% RH, non-condensing
Vibration	2 g
Shock	15 g, 11 ms half-sine
Input Voltage	24 VDC (18 to 32 VDC)
Communication Protocols	Modbus TCP, Modbus RTU, Ethernet/IP