TROUBLESHOOTING

PROCEDURE 2

 

MOTOR BRUSH INSPECTION

ELECTRO-MECHANICAL PARKING

 

(FIGURE 4)

BRAKE TEST (FIGURE 5)

There are two (2) contact 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.

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.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”. Thisisaccomplishedbyrunningthemotorforonehour 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.

1.On the four-pin motor connector, locate the side by side connectors in the black housings.

2.Set the digital multimeter to read ohms ().

3.Measure the resistance between the two (2) brake contacts. A normal reading is 100 ohms (). A reading of 0 ohms (W) 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.

CAUTION

Ashorted electro-mechanical brake will damage the brake output section in the controller. DO NOT connect a shorted electro-mechanical brake to a good controller module. A shorted brake MUST be replaced.

NOTE: A bad motor can damage the controller module but a bad controller should NOT damage a motor.

Cap Motor

T R O U B L E S H O O T I N G

Cap

Motor

 

4 Pin Motor Connector

Ohmmeter

4 Pin Motor Connector

FIGURE 4 - MOTOR BRUSH INSPECTION

FIGURE 5 - ELECTRO-MECHANICAL

PARKING BRAKE TEST

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Invacare P9000 service manual Cap Motor, Pin Motor Connector Ohmmeter