Pressure switch
High pressure cut out. The high pressure cut out switch will open at a preset pressure, shutting off power
to the compressor contactor. After the pressure has fallen to another preset level, the switch will re-close
and the contactor coil will be energized.
To Test High Pressure Switch:
A. Attach refrigeration gauge set to high side port.
B. Disconnect leads to fan motor.
C. Measure voltage at high pressure control.
D. Switch ice machine on, observe pressure that the pressure control opens at, compare to spec. Allow
system to equalize, observe the pressure that the pressure control closes at, compare to spec.
Transformer
Check secondary voltage, it must be between 10 and 15.5 AC volts. Replace if no voltage is output or if
above or below the acceptable voltage..
Controller
The controller’s software operation is confirmed if it is functioning. Execute the test to confirm its
operation of the loads. Illumination of a diagnostic code (other than E) is not an indication of controller
failure. Each code requires its own diagnosis.
November 2010
Page 30
C2648 Service Manual
Test Procedures - Loads
