biodex 950-273, Installation & Operation Manual

Page: 24 / 44

3. Speed control signal on motor amplifier should measure .250 VDC per mill per hour E.G.
NOTE: Measurement taken at J1, PIN 1 to PIN 2 (ground)
1mph = .250 VDC
2mph = .500 VDC
4mph = 1.00 VDC
8mph = 2.00 VDC
If speed control signals are OK, proceed to step 4.
4. Check Amplifier Output. The Output Terminals are located on top of amplifier and are
designated “m+” and “m-”. The Output voltage should be:
1mph = 32 VAC, 2mph = 52 VAC
NOTE: Remember to use the volts A.C. selection on your meter. The Amplifier is pulse width
modulating, therefore, A.C. scale is required.
If amplifier output is OK, proceed to step 5.
5. Check Motor Resistance. The motor has a winding resistance of 1.3 to 3 Ohms. The
value is dependent on commutation position. If resistance reading is significantly higher
the windings or brush contacts are defective.
To measure resistance turn treadmill power OFF. Place meter lead across terminals
marked “m+” and “m-”. Set meter scale to the lowest resistance selection. Check resis
tance in several commutator positions by rotating motor shaft 9.0 degrees for every one
revolution.
CONTENTS
TROUBLE-SHOOTING — 24 —