10
Standard Controller Operation
The chiller includes a controller to perform all
control functions directly from the front panel. When
Control Power is applied, the controller initiates a
diagnostic test of each indicating light and display
segment by briefly lighting each sequentially. As part
of this initial diagnostic test, the revision level of the
control program displays for a moment. After the
initial diagnostic sequence is completed, the
controller is ready for operation.
Changing Temperature Display Scale
The chiller is able to display temperatures in either °F
or °C. To determine which temperature is in use and
to change the temperature scale used stop the unit
and press the Power button to turn off the
controller. Press and hold the Stop Button and then
press the Power Button. When the controller
illuminates, release both buttons. The To Process
display will read "Unt". The Set Point display will
show either "F" or "C" depending on the current
display units selected. If "F" is displayed the
temperature display is in °F mode. If "C" is displayed
the temperature display is in °C mode. To change
from °F to °C press the Lower Set Point Temperature
button (down arrow). To change from °C to °F press
the Raise Set Point Temperature button (up arrow).
After changing to the desired temperature scale the
Set Point display shows the desired display units.
Press and release the Start button to store the new
selection into the controller memory then press and
release the Power button to exit the function. Press
and release the Power button again to restore
controller power. The unit is now ready for
operation.
Table 6 -Temperature Displays
Display
Description of Operation
Set Point
The Set Point display shows the set point temperature. This display also shows alarm codes and programming
information.
To Process
The To Process display normally shows supply temperature. If the return temperature display option is purchased this
display is also used for the return fluid temperature. To toggle this display between supply and return temperatures,
depress and hold down the Down and Up button at the same time. The return temperature shows as long as the Down
and Up button are depressed. Release the Down and Up buttons to return the display to show the supply temperature.
