Great Plains 2525P Operator Manual - Manual (Page 98)

2525P and 2520P
118-915M 4/23/2010
96
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 ap-
pears on cab console.
f. 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 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 val-
ue, 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 simu-
lator, troubleshoot radar, wheel pickup sensor, hall effect module. If steady speed does not appear with
speed simulator, 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
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 dis-
engaging 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 procedure if necessary.
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 sus-
pect.
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).
Rapid drive rotation may occur and
cause serious injury.