33
4.8.4 SYSTEM TROUBLESHOOTING
SYSTEM INOPERATIVE
If the engine governing system does not function, the fault may be determined by performing the voltage
tests described in Steps 1,2,3, and 4. (+) and (-) refer to meter polarity. Should normal values be indicated
as a result of following the trouble shooting steps, the fault may be with the actuator or the wiring to the
actuator. See the actuator publication for testing details.
STEP TERMINALS NORMAL READING PROBABLE CAUSE OF ABNORMAL READING
1. F(+) & E(-) Battery Supply Voltage 1. DC battery power not connected. Check for blown
(12 or 24 VDC) fuse.
2. Low battery voltage.
3. Wiring error.
2. C&D 1.0 VAC RMS min., 1. Gap between speed sensor and gear teeth too
while cranking great. Check gap.
2. Improper or defective wiring to the speed sensor.
Resistance between terminals C and D should be
30 to 1200ohms.
3. Defective speed sensor.
3. P(+) & G(-) 10 VDC, Internal Supply 1. Short on terminal P. (This will cause a defective unit.)
2. Defective Speed Control.
4. F(+) & A(-) 1.0 - 2.0 VDC while 1. SPEED adjustment set too low.
cranking 2. Short/open in actuator wiring.
3. Defective speed control.
4. Defective actuator. See Actuator Troubleshooting.
UNSATISFACTORY PERFORMANCE
If the governing system functions poorly, perform the following tests.
SYMPTOM TEST PROBABLE FAULT
Engine overspeeds 1. Do not crank. Apply DC power to 1. Actuator goes to full fuel. Then,
governor system disconnect sensor at Terminals A (-) &
speed sensor at Terminals C&D. If actuator still at full fuel - speed control
unit defective. If actuator at minimum fuel
position - erroneous speed signal. Check
speed sensor data.
2. Manually hold the engine at the 1. If the voltage reading is 1.0 to 2.0 VDC,
desired running speed. Measure the a) SPEED adjustment set above
DC voltage between Terminals A (-) desired speed.
& F(+) on the speed control unit. b) Defective speed control unit.
2. If the voltage reading is above 2.0 VDC,
a) Actuator or linkage binding.
3. If the voltage reading is below 1.0 VDC,
a) Defective speed control unit.
4. Gain set too low.
To Next Page
Loading...
Need help?
General
