SECTION 3—SAFETY INSPECTION/TROUBLESHOOTING
32
4-Pole Motor Brush Inspection and/or Replacement
NOTE: For this procedure, refer to FIGURE 3.3 on page 33.
NOTE: There is one contact brush under each brush cap on the motor housing. There are four motor brushes on a 4 pole motor.
NOTE: It may be necessary to remove the motor to access all of the motor brushes. Refer to Removing/Installing the SSD Motor/Gearbox
Assembly on page 39.
NOTE: If the brush caps are hard to remove they are either overtightened or the motor has become very hot. Allow 30 minutes for motors
to cool. If brush caps still cannot be removed, contact Invacare Technical Phone Support.
1.
Turn the power off.
2.
Disengage the motors.
3.
Locate a brush cap on the 4 pole motor (four caps in all). See Detail “A” in FIGURE 3.3.
4.
Remove the brush cap with a very wide flat blade screwdriver.
5.
Pull the motor brush partially out of the brush holder. See Detail “B” in FIGURE 3.3.
NOTE: If not installing a new motor brush, it is very important to note which way the existing motor brush comes out of the motor. The
existing motor brush MUST be placed into the motor exactly the same way to ensure good contact with the commutator.
6.
Place a temporary mark on the motor casting and on the top of the motor brush to indicate the orientation.
7.
Remove the motor brush from the brush holder.
8.
Inspect the motor brush thoroughly for excessive wear or chips in the brush and any discoloration in the shunt wire.
9.
Perform one of the following:
•
If motor brush is in good condition, (i.e., the end of the brushes are smooth and shiny, the spring is not damaged or
discolored, and shunt wire is not discolored) perform the following:
i.
Install existing motor brush into brush holder exactly the same way it was pulled out using the marks as
reference points.
ii. Install motor brush cap.
NOTE: Tighten and loosen motor brush cap a couple times to ensure proper seating of the motor brush.
•
If motor brush is in bad condition (brush is worn or damaged) replace immediately by performing the following:
i.
Install new motor brush into brush holder.
ii. Install motor brush cap.
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: DO NOT leave the wheelchair unattended while performing this procedure - otherwise damage to wheelchair and/or property
may occur.
NOTE: This procedure MUST be performed with little or no load on the motor.
iii. Put the wheelchair on blocks so that the drive wheels do not contact the ground.
NOTE: For STEPS iv and vi, use a rubber 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.
iv. Run the motors forward for one hour.
v.
Turn motors off and allow 30 minutes for motors to cool off.
vi. Run the motors in reverse for one hour.
vii. When process is complete, remove wheelchair from blocks and test drive the wheelchair.
NOTE: If wheelchair still does not perform properly, call Invacare Technical Service at 1-800-832-4707.
