Thursday, March 14, 2013


                                                    Error 28 - Temperature Too High
Some treadmill motor controllers monitor the temperature of the motor controller output switching
device. Typically, these motor controllers use a fan to force cool the output devices heat sink.
This error indicates that the heat sink temperature has exceeded maximum.
Possible Causes
1. The lower PCA cooling fan is clogged.
2. The lower PCA cooling fan is inoperative.
3. The running belt and/or running bed is badly worn.
4. The lower PCA is defective.
5. A shorted or de-magnetized drive motor is causing the high power demand
Possible Remedies
1. Check the cooling fan mounted on the lower PCA to ensure that the fan is not clogged with
dust. Thoroughly clean the fan and ensure that it spins freely. Some lower PCA’s do not have
a cooling fan and some lower PCA’s have the fan mounted on the underside of the the lower
PCA and are not immediately visible.
2. The lower PCA is clean and unobstructed but the fan does not spin. Ensure that the fan
wiring is securely and correctly connected to the lower PCA. If the fan is unobstructed and
the fan wiring is good, replace the lower PCA.
3. A clamp-on A.C. ammeter must be used to determine the amount of A.C input current being
drawn by the treadmill under no load and loaded conditions. The current readings can be
used to determine the condition of the running belt and/or running bed. These same readings
should be taken on a similar unit with a known good running belt and running bed. Those
readings can then be used as a benchmark for future use. Replace the running belt and/or
running bed as required. Remember, many running beds are double sided and the bed can
be flipped over rather than being replaced.
4. Substitute a known good lower PCA to determine if the lower PCA is defective.
5. Substitute a known good drive motor to determine if the drive motor is defective.