Liebert Refrigerant Distribution Unit XDP - Manual (Page 28)

Microprocessor Control
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4.3.2 SETPOINTS
Selecting SETPOINTS from the Main Menu will reveal the following menu items:
MIN TEMP SP
Minimum Room Temperature Setpoint—This is used to keep the room temperature above the set-
point. The Liebert XDP can lower the room temperature too much depending on the room dew point
and load. This setpoint will back off the cooling to keep the room temperature above this temperature.
HIGH CW TEMP
High Chilled Water Temperature Setpoint—There could be many reasons that the chilled water tem-
perature is above this setpoint (e.g., chiller problem, control valve failure, etc.) This is the setpoint at
which the HIGH CW TEMP alarm will be activated.
HI AIR TEMP
High Room Air Temperature Setpoint—This is the setpoint at which the HIGH REMOTE TEMP and
HIGH LOCAL TEMP alarms will be activated.
LOW AIR TEMP
Low Room Air Temperature Setpoint—This is the setpoint at which the LOW REMOTE TEMP and
LOW LOCAL TEMP alarms will be activated.
4.3.3 STATUS
The user can check the status of the control valve, pump operation, and refrigerant and chilled water
temperature.
CONTROL VALVE—0-100%
PUMP 1—On/Off
PUMP 2—On/Off
REFRIG T—Refrigerant temperature 0-100° F
CW TEMP—Chilled Water temperature 0-100° F
4.3.4 ACTIVE ALARMS
This submenu allows the user to review any present alarms. If no alarms are present, the screen will read
“No Alarms Present.” If any alarms are occurring, the screen will display “Alarm XX of YY,” followed by
the alarm text (“XX” is the reference number of the alarm shown, “YY” is the total number of alarms).
If more than one alarm is present, use the Up or Down arrow keys to scroll through the alarms.
4.3.5 ALARM HISTORY
This submenu allows the user to review the 60 most-recent alarms. The first line of the screen will
show the alarm number—01 being the newest—and the name of the alarm. The second line of the
screen will show the most recent alarm’s date and the time in 24 hour format. Use the Up or Down
arrow key to scroll through the alarm history list.
Table 13 Setpoint functions, default values and allowable ranges
Menu Item Function Default, °F (°C) Range, °F (°C)
MIN TEMP SP Minimum room temperature setpoint 72 (22) 50-80 (10-27)
HI CW TEMP High chilled water temperature setpoint 55 (13) 35 to 95 (2-35)
HI AIR TEMP High room air temperature setpoint 80 (27) 35 to 95 (2-35)
LO AIR TEMP Low room air temperature setpoint 65 (18) 35 to 95 (2-35)
* For optimal cooling performance, the minimum temperature setpoint should be at least 1-2° below the expected temperature at
the remote sensor, which may require additional consideration of the remote sensor location or minimum temperature setting. If
the minimum temperature setpoint is set above the typical remote temperature sensor reading, this will reduce the Liebert XD
cooling output and, in extreme cases, cause erratic Liebert XD performance.
NOTE
This is not a true room temperature setpoint. The Liebert XDP has no heaters; it will try to cool
as much as possible. If it is able to cool the room to this setpoint, it will back off its cooling
capability to try to keep the room temperature at or above this setpoint.