Troubleshooting - Yale 524150797 Maintenance Manual

Troubleshooting

PROBLEM
Unusual noise from traction motor.
Truck moves slow or in a jerky mo-
tion.
Temperature sensor failure.
Stator shorting.
Stator open circuit.
8
Troubleshooting
POSSIBLE CAUSE
Parking brake not
damaged.
Drive unit internal damage.
Traction motor bearing damaged.
Encoder broken.
Encoder wire broken.
Temperature sensor wire dam-
aged.
Main wiring harness damaged.
Temperature sensor malfunction.
Loss of insulation in wire.
Broken coil windings.
PROCEDURE OR ACTION
releasing/ Troubleshoot the parking brakes.
Check that the drive unit rotates
smoothly.
Replace end head(s) and check
stator and rotor for damage. Re-
place damaged components or
traction motor if necessary.
Replace encoder bearing.
Check and repair encoder wire or
replace encoder bearing.
Measure resistance with ohmme-
ter. Resistance should be 530
ohms at 25 °C (77 °F). Inspect and
repair temperature sensor wire.
The temperature sensor wire can
be repaired, but the temperature
sensor must be replaced if faulty.
Test temperature sensor circuit
through main wiring harness from
connection at controller.
Measure resistance with ohmme-
ter. If wiring is ok, resistance
should be 530 ohms at 25 °C (77
°F). Replace the temperature sen-
sor.
Disconnect the battery and check
resistance between winding and
case. Resistance should be at
50,000 ohms or above.
Raise drive wheel off the floor and
verify voltage at motor terminals.
Disconnect the battery and check
resistance of windings.
0620 YRM 1513