SECTION 9—MOTORS
Pronto® M71™ 84 Part No 1118377
Inspecting/Replacing External Motor Brushes
NOTE: For this procedure, refer to FIGURE9.3 on page 83.
NOTE: It is very important to note which way the brush comes out of the motor. The brush MUST
be placed into the motor exactly the same way to ensure good contact with the commutator.
1. Turn power off.
2. Remove the motor. Refer to Removing/Installing the Motor on page80.
NOTE: There are two motor brushes on the motors located under the brush caps on the motor
housing. If these caps are hard to remove they are either overtightened or the motor has become very
hot. Let motors cool. If caps still cannot be removed, it is recommended that the motor be sent to
Invacare Technical Services for inspection/repair.
3. Remove the brush cap securing the motor brush into the motor housing.
4. Remove the motor brush and perform the following:
A. Inspect the commutator (not shown) for damage.
B. Inspect the motor brush thoroughly for excessive wear or chips in the brush and
perform one of the following:
• If motor brush is in good condition, (i.e., the end of the brushes are smooth and
shiny), reinstall existing brush.
• If motor brush is in bad condition, brush is worn or damaged, discard
immediately and install new brush.
5. Reinstall motor brush and brush cap into the motor housing.
6. Repeat STEPS 3-5 until all four motor brushes have been inspected/replaced.
7. Reinstall the motor. Refer to Removing/Installing the Motor on page80.
NOTE: Repeat STEPS 2-7 for the opposite motor.
8. If new motor brush was installed, perform the following process:
NOTE: This process, also called Brush Burn-in or Finger Printing Process, is necessary to seat
the brush to the commutator plates inside the motor for optimum performance of the motor.
NOTE: A motor with only one brush replaced will only carry a small percentage of its rated
load capacity until the new brush is burned in.
WARNING
DO NOT leave the wheelchair unattended while performing this procedure - other-
wise damage to wheelchair and/or property may occur.
NOTE: This procedure must be performed with little or no load on the motor.
A. Put the wheelchair on blocks so that the drive wheels do not contact the ground.
NOTE: For s teps B and D, use a rub ber band to hold the driver control in the direction needed
or program the chair for latched driving. Refer to the electronics manual for latched
programming instructions.