Troubleshooting The Lift System; Lift System Description; Procedure - Precor Energy Series Service Manual

Troubleshooting the Lift System

Lift System Description:

The lift system on these units consists of an AC line voltage driven lift motor (120 VAC), and an
internal 10 K ohms potentiometer for lift position identification. The lift motor contains two motor
windings, one to operate the motor in an "upward" direction and the other to operate the motor in a
"downward" direction. As the lift motor is operated, the motor also rotates the potentiometer via an
internal gear system. Therefore, the position of the lift system can be determined by monitoring
the value of the internal potentiometer. The lift motor is initially set at a known starting position
(calibration, See Procedure 4.1), subsequent motor movement is tracked via the potentiometer
resistance reading.
Note: All resistance measurements must be performed with power removed from the treadmill. Performing
resistance measurements with voltage applied may damage your ohmmeter.

Procedure

1. If the lift motor operates briefly and creates a lift error (error 40) go to step 13. If the lift motor
will not move continue with the next step.
2. Set the treadmill on/off switch in the "off" position and remove the AC power cord from the AC
outlet.
3. Remove the hood from the treadmill.
4. Insert the AC power cord in the AC outlet and set the on/off switch in the "on" position. Set the
treadmill to operate in the manual program. Connect an AC voltmeter between terminal of 1
(red wire) and terminal 2 (white wire) of the JK4 connector on the lower PCA. Press the
INCLINE UP key. The UP LED should illuminate and the AC voltmeter should read AC line
voltage (105 to 120 VAC). If the incline operated normally in the upward direction go to step 8.
5. If the display indicated that the incline should be moving upwards and the UP LED did not
illuminate the problem is probably in the data cable between the upper and lower PCA.
Replace the data cable.
6. If the UP LED illuminated and the AC voltage reading in step 4 was absent or significantly low,
©2014 Precor Incorporated, Unauthorized Reproduction and Distribution Prohibited by Law
Page
Page 18
of 5418
Page 18