Great Plains 3N-4025P Operator Manual - Manual (Page 127)

4/23/2010 196-286M
125 Veris Drive Operating Instructions
f. Excessive torque in drive system. Disconnect main drive chain to check for rotation under zero load.
Check for a problem with the mechanical portion of drive, such as foreign material wedged in meter, frozen
bearings, misaligned chains, or swelled grain in meter. 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):
a. No signal from speed sensor - check connection at sensor and at drive controller.
b. Excessive gap between wheel sensor and sensor plate - re-
adjust to .030.
c. Use speed simulator (PN 27858) to troubleshoot speed loop.
Leave tractor stationary and drive hydraulics do not need to
be engaged.
d. Test speed sensor and hall effect sensor; replace sensor if
simulated speed appears on cab console.
e. Test speed cable between speed sensor and hall effect module; replace cable if simulated speed appears
on cab console.
f. Test hall effect module and cable to external controller; replace module and cable if simulated speed ap-
pears on cab console. If speed does not appear with speed simulator, 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 chain on row unit.
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, trou-
bleshoot radar, wheel pickup sensor, hall effect module. If steady speed does not appear with speed sim-
ulator, external controller may need replacement. Call Service Department.
b. Check radar gun angle.
c. Check gap between wheel sensor and pickup plate.
d. Check power to system < 12 volt power will cause drive to behave erratically - often problem manifests it-
self 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 shut-
off (on units with radar speed signal).
b. Check setting of speed signal interrupter switch - reposition as necessary to keep actuator from disengag-
ing while planting.
c. 1.5 second delay shutting off drive - causes: chain binding, inadequate hydraulics.
9. Drive will not achieve desired rate:
a. Recheck calibration number, and rerun calibration process.
b. Check to make sure that your desired rate is within the range of the meter that is installed.
c. Inadequate hydraulic flow. Adjust flow control to higher position. Check with flow meter if flow is suspect.
d. Field speed too high. Check maximum planting rate in seed chart for rate that you are planting.
e. Check sprocket combinations; see Assembly and Parts Manuals for the planter you are operating (30P
and 40P models).
f. Check speed shown on cab console against other speedometer - tractor, planter monitor. If drive speed is
significantly lower, recalibrate speed on drive.
Rapid drive rotation may occur and
cause serious injury.