Motor Brush Inspection; Electro-Mechanical Parking Brake Testing - Invacare Arrow RWD Service Manual

Motor Brush Inspection

NOTE: For this procedure, refer to FIGURE 6.3.
NOTE: This procedure should only be performed on wheelchairs with conventional motor/gearbox
assembly.
There are two contact brushes on STORM 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.
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.
Once the motor brush caps have been removed, pull the brushes out of the motor. The end
of the brushes should be smooth and shiny and the spring should not be damaged or
discolored. If one or both of the brushes are damaged, only the damaged or worn brushes
need be replaced. It is very important that any time a brush is replaced, it must be "burned
in". This is accomplished by running the motor for one hour in each direction with a half
hour break in-between. This should also be done with little or no load on the motor, i.e.,
put the wheelchair up on blocks so the drive (large) wheels do not contact the ground and
run the wheelchair. 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.

Electro-Mechanical Parking Brake Testing

NOTE: For this procedure, refer to FIGURE 6.4 on page 56.
NOTE: This procedure should only be performed on wheelchairs with conventional motor/gearbox
assembly.
1. On the four-pin motor connector, locate the side by side connectors in the black
housings.
2. Set the digital multi-meter to read ohms (Ω).
3. Measure the resistance between the two brake contacts. A normal reading is 100 ohms
(Ω). A reading of 0 ohms (Ω) or a very high reading; i.e., MEG ohms or O.L. (out of
limit) indicates a shorted brake or an open connection respectively. If either condition
exists, send the motor to Invacare Technical Service for inspection/repair.
Part No. 1104849
Cap
4-Pin Motor Connector
FIGURE 6.3 Motor Brush Inspection
55
SECTION 6—TROUBLESHOOTING
Motor
3G Storm Series® Wheelchairs