Actuator - Westerbeke 8.0KW-60Hz Service Manual

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ENGINE ADJUSTMENTS
ACTUATOR (ELECTRONIC GOVERNING)
The BCU (Electronic Control Unit) in the control box on the
generator controls the engine speed electronically. The BCU
senses engine speed from a signal sent to it from a MPU
(Magnetic Pick Up) positioned on the flywheel bellhousing
over the.flywheel's ring gear teeth. The BCU continuously
monitors this signal and if there is any discrepancy in this
signal the BCU adjusts the DC voltage to the ACTUATOR
positioning its plunger to let the injection pump fuel rack to
allow more or less fuel delivery to maintain a constant engine
speed depending on the amperage load on the generator.
Maintaining a steady Hertz operation of the AC generator.
The following instructions are for adjusting or replacing the
actuator.
1.
Tum OFF the DC breaker on the control box.
2. Unplug the actuator from the engine hamess. Back off
the 1 7/16 jam nut that secures the actuator and
unscrew it from the engine block.
3. Apply a small amount of teflon sealant to the actoators
threads and screw it into the engine block 4 to 5 full
turns. Just snug up the jam nut. Reconnect the actuator
to the engine harness. Turn ON the DC breaker on the
control box. NOTE: Tum OFF the AC circuit breaker
on the generator.
4.
Start the engine. Monitor the generator output
frequency that it is operating
at
the selected frequency ..
5. With the engine ronning, depress the STOP switch to
test for proper engine shut down. If the engine does
not shut down and only goes to a slow idle speed,
loosen the jam nut and thread the actuator in slowly
until a full shut down takes place. Then thread the
actuator in 112 turn and secure it in place with a jam
nut. Un-twist the actuator wires as needed. This
adjustment should now allow the engine to start and
stop under normal operating conditions. .
A final adjusiment may be necessary after tllegenset has
operated approximately
20
minutes and has teached its
normal operating temperature. If tlle engine shuts down
properly under normal operating conditions, but fails to shut
down fully under more extreme conditions sUch· as miming at
high amperage loads for a long period of time and/or under
extreme ambient temperatures. The actuator may need to be
turned in an additional 112
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. MAGNETIC
PICK~UP
[MPU] INSTALLATION
The MPU is installed in the threaded opening on the side
of the flywheel bellhousing. This positions the MPU over
the teeth of the flywheel ring gear.
Viewing through this opening, manually rotate the engine
crankshaft so as to position the flat of one of the ring
gear's teeth directly under the opening. Thread the MPU
into the opening until it gently contacts the flat of this
tooth (Thread is 3/8" x 24). Back the MPU out of the
opening one tom and then lock it in this position with the
jam nut. This will position the end of the MPU
approximately 0:030 inches away from the flats of the ring
gear teeth.
'Ib ensure the MPU is positioned correctly, slowly rotate
the crankshaft by 360 0 by hand to assure there is no
.physical contact between the MPU and the ring gear teeth.
If contact is felt between the MPU and the flywheel teeth,
the MPU may be· damaged. Remove the MPU and inspect
it. Replace if necessary and repeat the above
installation procedure.
Resislance (al resl) 950 ·1000 ohm
m~
~
0.03Din
-----
NOTE:
If replacing the Magnetic Pick-Up (MPU) it MUST
be replaced without cutting and splicing into the existing
wiring cable. Doing so will cause an erratic AC signal to
the controller.
GOVERNOR CIRCUIT VOLTAGES
Below are the voltages normally found in the governor
circuit when the system is functioning normally. These
voltages are an approximate and should be of help in
troubleshooting a system that is not functioning correctly.
DC Voltage into Controller
Bat
+
to Bat· (battery charging voltage 13.5 . 14.5 VDC)
(Terruinal block #1 and #2)
DC Voltage to Actuator
ACT to ACT (5.5 - 6.5 VDC)
(Terruinal block #5 and #6)
AC Voltage from MPU into Controller
MPU to MPU (2.5 -7.0 VAC)
(Terruinal block #3 and #4)
This voltage ;pread is the result of the distance tlle MPtJ is
positioned from the flat of tlle flywheel ring gear tootll.
The closer to the tootll, tlle higher the AC signal. The
further away, the lower tlle AC signal.
Engines & Generators
51