Invacare STORM Service Manual page 72

Testing drive motors
Only basic tests can be performed on the drive motors. Any further tests are only possible with special testing
instruments.
The following components of the drive motors can be tested by means of a multimeter:
– Motor coils for continuity
– Motor brakes for resistance
Testing hints:
If the following tests show no results, the drive motor should be sent in for testing. Any further measurements
can only be performed by the INVACARE Service Department.
Visual test of the plug contacts:
Test whether the contacts of the plug are not unduly bent up, pushed
back or oxidized.
Testing the electric circuit of the motor
• Set multimeter to continuity check.
• Measure the continuity of the motor’s electric circuit at the
plug contacts shown in the drawing to the right.

NOTE:
Instructions on the use of the multimeters can be found in the
User’s Manual.
Testing the magnetic brake
• Engage the motors.
• Set the multimeter to resistance measuring.
• Measure the resistance of the brake coils at the plug contacts
shown in the drawing to the right.
It must amount to between 20 ohms and 200 ohms.
Testing the free-wheel switch:
The free-wheel switch switches the motors to pushing operation,
putting the magnetic brake out of function.
• Disengage motors.
• Set multimeter to resistance measuring.
• Measure the resistance of the brake coils at the plug contacts
shown in the drawing to the right.
The resistance measured must amount to infinite.
Malfunction
No continuity of the electric
circuit of the motor.
Resistance being 0 ohms.
Resistance clearly > 200
ohms, but not infinite.
72
Cause
Parted cable in the motor.
Carbon brushes worn out.
Short circuit in magnetic brake.
Defective contact in the
magnetic brake. -
Plug Contacts
Motor Brake Contacts
Motor Contacts
Testing the Electric Circuit of the Motor
Testing Magnetic Brake
Resistance = 20 ohms - 200 ohms
Solution
Replace motor.
Check / replace carbon
brushes.
Replace motor.
Replace motor.
Chapter
13.4
13.2
13.4
15.4