Woodward 723PLUS Technical Manual page 102

723PLUS Digital Marine Control
Symptom
Engines do not share
torque equally.
Engine does not share
torque with other unit (one
unit takes all of the load).
Engine does not maintain
constant speed
(isochronous).
92
Cause
1. Improper torque sensor
transducer or default
percent actuator
calibration.
2. Fuel limiter active.
3. Actuator linkage
problem.
4. Torque sharing line.
1. Improper torque
transducer calibration.
2. Clutch contacts.
3. Control LON lines.
4. LED #3 illuminated and
flashing.
5. LED #4 illuminated.
1. Fuel limiter in control.
2. Mechanical governor in
control.
3. Actuator linkage.
Test/Remedy
1. The 723PLUS control can only share load as well as the
torque sensor transducers, actuator linkages, and engine
torque or pump(s) are calibrated. With the hand held
programmer, verify the torque inputs are equal (±2.5%). A
small torque error between units is common and will never be
zero. If 723PLUS control indicates balanced torque sharing
(torque inputs on hand held programmer equal), the control is
functioning properly and the problem is with the torque
transducer calibrations or engine fuel system. If torques are
balanced, the problem exists in the engine (fuel pumps, etc.).
2. An active fuel limit will override the torque sharing and de-
rate the engine. Verify no fuel limiters are active.
3. Verify the actuator linkage is capable of controlling engine
fuel rack at that position.
4. There is no torque sharing line calibrations available to field
personnel. Verify ON TORQUE SHARING is true. Verify the
Control LON #1 and #2 wiring is correct and that node
addresses are properly set (see Chapter 5).
1. Verify the torque increases as the engine load is increased.
2. Verify that when both engines are clutched together, the
clutch contact inputs to both controls are closed. When both
contacts are closed, the 723PLUS controls begin torque
sharing as indicated by a closed internal torque sharing switch
(B**DISPLAY 2** prompt 10 ON TORQUE SHARING is true).
3. Verify that one or both LON ports are connected and
terminated. Verify the absence of any configured CLON CH1
ERROR or CLON CH2 ERROR alarms.
4. Verify the LED #3 is not illuminated. If it is, verify the
configured node addresses for LON Channel #1 and LON
Channel #2 within each 723PLUS control are the same but not
"0".
5. Verify the LED #4 is not illuminated. If it is, and both
723PLUS controls are powered up and one or both of the LON
ports are connected, verify that the communication line(s) are
working. If they are OK, then both units are configured with the
same node addresses for LON Channel #1 and LON Channel
#2. If this is the case, then one of them needs to be configured
with a different (but not "0") node address for LON Channel #1
and LON Channel #2.
1. Verify speed control is in control and no fuel limiter becomes
erroneously active.
2. Most mechanical governors have some amount of droop
built into the governor. Verify engine does not droop using
723PLUS control.
3. Engine speed droops off near rated speed (full load). Verify
actuator or fuel rack is not at its maximum fuel position.
Manual 26482
Woodward