Table 9 - Temperature Displays - Conair EP2 series User Manual

Table 8 – Operating Buttons (continued)
Button
Pump Test With the chiller stopped, pressing this button briefly engages the pump to test its operation. The pump will not run if
there are any active alarms. The pump shuts down by either pressing the Stop button or pressing the Pump Test button a
second time. The pump will shut down after one minute of operation.
Display/Program The Display/Program button will change the temperature displayed in the Process screen from Supply to Return. When
the display is set to supply temperature, there will be an orange indicating light in the lower right corner of the Process
temperature display. When the display is set to return temperature, there will be no orange indicating light in the lower
right corner of the Process temperature display. To toggle the process temperature display from supply to return
temperature, press and release the Display/Program button. The display will return to the default Supply temperature
automatically after 5 seconds without a button press. In addition to switching between the supply and return process
temperature displays, the Display/Program button will initiate and navigate through the program menu. See the Program
Menu section for more detail.
Up The Up button raises the set point temperature. Pressing the Up button and releasing it increases the set point
temperature by one degree. Pressing the Up button and holding it increases the set point temperature until reaching the
maximum allowable set point temperature. In addition to adjusting the set point temperature, the Up button adjusts
various alarms and set point values when the unit in the programming mode.
Down The Down button decreases the set point temperature. Pressing the Down button and releasing it decreases the set point
temperature by one degree. Pressing the Down button and holding it decreases the set point temperature until reaching
the minimum allowable set point temperature. In addition to adjusting the set point temperature, the Down button
adjusts various alarms and set point values when the unit is in the programming mode.

Table 9 - Temperature Displays

Display
Set Point The Set Point display normally shows the set point temperature. A decimal point in the lower right corner of this display
indicates the temperature unit of measure is set to °F, no decimal point indicates the temperature unit of measure is set to
°C. See the Program Menu section to change the temperature scale units of measure. This display also shows alarm codes
and programming information.
Process The Process Temperature display normally shows supply temperature. A decimal point in the lower right corner of the
display indicates the temperature displayed is the supply temperature, no decimal point indicates the temperature
displayed is the return temperature. To change the display from supply to return temperature, press and release the
Display/Program button. The display will return to the default Supply temperature automatically after 5 seconds without a
button press. This display also shows alarm codes and programming information.
Table 10 - Operating Lights
Light
Control Power The Control Power light is green when 24VDC control voltage is present.
Autostart Signal The Autostart Signal light is green when closed (run), yellow when open (stop), and unlit if this feature is disabled. This
feature allows starting and stopping of the unit by a remote contact closure. From the factory, the Autostart feature is
disabled. See the Program Menu section for instructions on how to enable or disable the Autostart feature. Do not
introduce any external voltage to the Autostart contacts, as this will result in damage to the controller.
Pump The Pump light is solid green when the pump is running and flashes red if the pump motor overload trips.
Hot Gas Bypass The Hot Gas Bypass light will pulse or light solidly when the chiller is operating at partial load and the hot gas bypass
valve opens. The light stays on for longer periods of time when the chiller is under smaller loads. If the light stays off the
chiller is under full load. If the light stays on the chiller is fully unloaded. If this condition persists, the To Process
temperature may begin to drop below the Set Point temperature, eventually cycling off compressor(s).
Compressor #1 The Compressor #1 light is solid green when Compressor #1 is running, flashes red if a compressor overload or fault
occurs, and is solid red if the controller is attempting to start the compressor before the anti-recycle timer has timed out.
Compressor #1 is enabled when the temperature of the coolant leaving the chiller rises above the Set Point by an amount
equal to the control parameter PS1 (Compressor #1 Positive Spread). PS1 is equal to 2 °F by default. The compressor is
disabled if the temperature of the coolant leaving the chiller drops below the Set Point by an amount equal to the control
parameter nS1 (Compressor #1 Negative Spread). The parameter nS1 is set to 4 °F by default. See the Program Menu
section for instructions on how to adjust PS1 and nS1.
Description of Operation
Description of Operation
Description of Operation
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