Great Plains 3N-4025P Operator Manual - Manual (Page 135)

Great Plains Manufacturing, Inc. Table of Contents Index Troubleshooting 131
2014-01-29 Table of Contents Index 196-538M
bearings, misaligned chains. Install pressure
gauge at motor inlet. Pressure should be
1000-1500 psi. If pressure is above 2000 psi,
significant torque problems are present.
5. Check Speed signal (if drive rotates in calibration
mode but not when planting)
Rapid drive rotation may occur causing serious injury.
a. No signal from speed sensor - check connection
at sensor and at drive controller.
b. Use Speed Simulator (p/n 27858) to
troubleshoot speed loop. Leave tractor
stationary and drive hydraulics do not need to be
engaged.
c. Test speed sensor and hall effect sensor;
replace sensor if simulated speed appears on
cab console.
d. Test speed cable between speed sensor and hall
effect module; replace cable if simulated speed
appears on cab console.
e. Test hall effect module and cable to external
controller; replace module and cable if simulated
speed appears on cab console. If speed does
not appear, external controller or chip may need
replacement. Call Service Department.
Drive rotates but not at desired speed:
6. Drive (out rate) fluctuating erratically:
a. If indicated field speed on drive is also
fluctuating erratically, troubleshoot speed signal
loop.
b. If field speed is steady, check for loose set
screws on motor encoder, contamination of
proportional valve, or mechanical binding of
chains.
7. Indicated speed fluctuating erratically:
a. Use speed simulator to troubleshoot speed loop.
Leave tractor stationary and drive hydraulics do
not need to be engaged. If steady speed
between 4-10 mph appears on cab console
using speed simulator, troubleshoot radar and
hall effect module. If steady speed does not
appear, external controller may need
replacement. Call Service Department.
b. Check radar gun angle.
c. Check power to system. Less than 12 Vdc power
will cause drive to behave erratically - often
problem manifests itself in speed loop.
8. Drive shuts off while planting:
a. If it occurs after 20 seconds of not planting, such
as turning on headlands, operation is normal
safety shutoff (on units with radar speed signal).
b. Check setting of speed signal interrupter switch -
reposition as necessary to keep actuator from
disengaging while planting.
c. 1.5 second delay shutting off drive - causes:
chain binding, inadequate hydraulics.
d. Drive will not achieve desired rate:
e. Recheck calibration number and rerun
calibration procedure if necessary.
f. Check to make sure that your desired rate is
within the range of the meter that is installed.
g. Inadequate hydraulic flow. Adjust flow control to
higher position. Check with flow meter if flow is
suspect.
h. Field speed too high. Check maximum planting
rate in seed chart for rate that you are planting.
i. Check speed shown on cab console against
other speedometer - tractor, planter monitor. If
drive speed is significantly lower, re-calibrate
speed on drive.
9. Drive plants significantly higher than desired rate:
a. Recheck calibration number and re-run
calibration procedure if necessary.
b. Check speed shown on cab console against
other speedometer. If drive speed is significantly
higher, re-calibrate speed on drive.
10. Drive continues to rotate after tractor has stopped:
a. Contamination or wear in proportional valve (p/n
19798). Remove and inspect. Blow out with
compressed air. Check o-rings and reinstall.
Replace if necessary.
11. Fluid weeping from motor shaft seal:
a. Excessive back pressure in return hose. Check
quick coupler connection. Use motor control port
for return if available.