Great Plains Raven 440 - Manual (Page 53)

Manual No. 016-0159-822 49
Preventative Maintenance and Troubleshooting
7
Rate Control Issues
Issue Corrective Action
The RATE displays as “0000”.
1. Verify that the SPEED is registering correctly. If the speed is
zero, refer to the “The SPEED is inaccurate or unstable” issue
in the Console Issues section for the appropriate
troubleshooting steps.
2. Verify that the TOTAL VOLUME is registering flow. If not, refer
to the “Total volume does not register” issue in this section.
The RATE is inaccurate or unstable.
1. Verify that all values are entered into the console correctly.
2. Verify that the SPEED is registering accurately. If it is
inaccurate, refer to the “SPEED is inaccurate or unstable”
issue in the Console Issues section for the appropriate
troubleshooting steps.
3. In MAN (manual) operation, verify that the RATE display
(GPA) holds constant. If not, refer to the “Total volume
registers flow inaccurately” issue in this section.
4. In MAN operation, check the low end and high end pressure
range. If pressure cannot be adjusted manually, refer to the
“Total volume registers flow inaccurately” issue in this section.
5. If the problem persists, return the console to the dealer to
have the processor board assembly replaced.
Cannot vary the RATE in automatic or
manual operation.
1. Check the cabling to the motorized control valve for breaks in
the line.
2. Verify the cable connections are clean.
3. Verify that there is voltage to the valve connector.
a. Turn the Master switch ON.
b. Switch the RATE 1/RATE 2/MAN switch to MAN.
c. Turn the POWER switch ON.
d. Manually operate the INC/DEC switch to verify voltage.
4. Verify that the valve is turning. If not, replace the motorized
control valve.
The sprayer pressure is correct, but the
RATE is low.
1. Verify that the nozzle strainer screens and check valves are
not plugged.
2. Verify that the pressure at each boom is the same.
3. Verify that all nozzles are of the correct and same orifice size.
Refer to the Calculate the Rate 1 and Rate 2 Cal Values
section on page 8 for the proper method to determine nozzle
size.
TOTAL VOLUME does not register.
1. Check the flow meter cable for breaks and shorts. Refer to
the Testing Flow Meter Cables section on page 44.
2. Clean, adjust, and check the flow meter parts. Refer to the
Flow Meter Preventative Maintenance and Adjustment
section on page 43.
3. Replace the flow meter transducer.
TOTAL VOLUME registers the flow
inaccurately.
Verify that the arrow on the flow meter is pointing in the direction of the
flow. Refer to the Flow Meter Preventative Maintenance and Adjustment
section on page 43 and the Recalibrating the Flow Meter section on
page 45.