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ESD2100 Electronic Speed Control Unit
10.14.16
PIB 1022
D
If unsuccessful in solving issue, contact GAC for assistance.
[email protected] or call: 1-413-233-1888
UNSATISFACTORY PERFORMANCE
SYMPTOM
NORMAL READING
PROBABLE CAUSE OF
ABNORMAL READING
Engine Overspeeds
1.
Do Not Crank. Apply DC power to the governor
system.
1.
2.
After the actuator goes to full fuel, disconnect the speed sensor at
Terminal C & D. If the actuator is still at full fuel-speed then the speed
control unit is defective.
If the actuator is at minimum fuel position and there exists an
erroneous position signal, then check speed sensor cable.
2.
Manually hold the engine at the desired running
speed. Measure the DC voltage between Termi-
nals H(-) & E(+) on the speed control unit.
1.
2.
3.
4.
If the voltage reading is
1.0 to 1.5 VDC:
a. SPEED adjustment is set
above desired speed
b. Defective speed control unit
If voltage reading is above 1.5 VDC then check for:
a. actuator binding
b. linkage binding
Set point of overspeed shutdown set too low.
If the voltage reading is
below 0.8 VDC:
a. Defective speed control unit
Actuator does not energize
fully
1.
Measure voltage between Terminals H(-) & E(+)
on the speed control unit. Should be 0.8 to 1.5
volts.
1.
2.
3.
Replace the battery if weak or undersized.
Actuator wiring incorrect.
If the voltage is less than 1.5V:
a. SPEED set too low.
2.
Momentarily connect Terminals E to H. The
actuator should move to the full fuel position.
1.
2.
3.
Actuator or battery wiring in error
Actuator or linkage binding
Defective actuator
Engine remains below de-
sired governed speed
1.
Measure the actuator output, Terminals G & H,
while running under governor control.
1.
2.
If voltage measurement is within
1.5 VDC of the battery supply voltage
level, then fuel control is restricted from reaching full fuel position,
possibly due to mechanical governor, carburetor spring, or linkage
interference.
If not, increase speed setting.
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SYSTEM TROUBLESHOOTING
If the engine governing system does not function, the fault may be determined by performing the voltage tests described in Steps 1 through 4. Positive (+) and nega-
tive (-) refer to meter polarity. Should normal values be indicated during troubleshooting steps, and then the fault may be with the actuator or the wiring to the actuator.
Tests are performed with battery power on and the engine off, except
where noted. See actuator publication for testing procedure on the actuator.
SYSTEM INOPERATIVE
STEP
WIRES
NORMAL READING
PROBABLE CAUSE OF
ABNORMAL READING
1
E(+) & F(-)
Battery Supply
Voltage
(12, 24, or 32 VDC)
1.
2.
3.
DC battery power not connected. Check for blown fuse.
Low battery voltage
Wiring error
2
A(+) & B(-)
0-3.9 with speed trim. 7.1-7.9 with-
out speed trim.
1.
2.
Speed trim shorted or miswired.
Defective unit.
3
C(+) & D(-)
1.0 VAC minimum while cranking
1.
2.
3.
Gap between speed sensor and gear teeth too great.
Improper or defective wiring to the speed sensor. Resistance should be between 30 to 1200
ohms.
Defective speed sensor.
4
H(-) & E(+)
0.8-1.5 V while cranking
1.
2.
3.
Wiring error to actuator.
Defective speed control unit.
Defective actuator.
