Traction Motor - Toro Workman GTX Electric & Lithium Service Manual

Traction Motor

The traction motor stator winding, thermistor (tempera-
ture) and encoder (speed sensor) can be tested with the
motor attached to the transaxle. Test connection points
for the traction motor are shown in Fig. 33.
If a traction motor component is faulty, there should like-
ly be a fault code displayed on the controller LED and the
status indicator light. Before disconnecting electrical
connections on the motor, check for existing fault codes
that suggest a problem with the motor. See Controller in
this section for additional information regarding faults.
Before disconnecting any electrical connections from
the traction motor, open the vehicle battery circuit by dis-
connecting the conductors between the battery pack
and vehicle components (see Opening Battery Circuit in
the General Information section of this chapter). When
installing cables to motor terminals, torque jam nuts at
terminals from 72 to 88 in- -lb (8 to 9 N- -m) (Fig. 37). Ap-
ply Toro battery terminal protector (see Special Tools) to
motor connections after tightening nuts.
Refer to Traction Motor and Traction Motor Service in
the Service and Repairs section of this chapter for trac-
tion motor removal, installation, disassembly and as-
sembly information.
Stator Winding Testing
Use a multimeter to measure resistance (ohms) be-
tween motor terminals (U, V and W). There should be
very low (not zero) resistance between pairs of termi-
nals (U and V, V and W and U and W). Also, measure
resistance between each terminal and the motor drive
end bracket. There should be infinite resistance be-
tween each terminal and the drive end bracket.
If resistance between terminals is either very high or ze-
ro, the stator is damaged. The stator is also faulty if re-
sistance between any terminal and the drive end
bracket is not infinite. If stator is damaged, replacement
of the traction motor is necessary.
Thermistor (Thermally Sensitive Resistor) Testing
Use a multimeter to measure resistance (ohms) be-
tween the pins in the thermistor connector. The mea-
sured resistance at 77F (25
should be approximately 600 ohms. If resistance test-
ing determines a short circuit (low resistance) or an
open circuit (infinite resistance), the thermistor or ther-
mistor wiring is damaged and the motor must be re-
placed. The thermistor is an integral component of the
traction motor stator.
Workman GTX Electric
o
) (motor temperature)
Page 3A - - 23
Encoder (Speed Sensor) Testing
If encoder problems exist, the vehicle controller should
determine that a problem exists and a fault code should
be displayed on the controller LED and the status indica-
tor light. See Controller in this section for additional infor-
mation regarding encoder faults.
NOTE: If a traction motor armature problem exists in
the motor (e.g. worn bearing in rear end bracket, miss-
ing retaining ring on rear of armature shaft, loose or
damaged tone ring on armature), an encoder fault could
be generated due to the armature issue.
2
6
7
Figure 33
1. Thermistor connector
2. Terminal U
3. Terminal V
4. Terminal W
3
4
1
5
5. Drive end bracket
6. Encoder
7. Armature tone ring
Electrical System