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Alarm Descriptions and Solutions
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5.3.2 Increase or Decrease Alarm Time Delays
An alarm time delay is the time that the a condition must exist before the control activates an alarm
for that condition. This can be used as a filter to prevent nuisance alarms from transient events.
These alarms may have their time delays changed:
• CUSTOMER—customer alarm
• HIGH CW TEMP—high chilled water temperature alarm
• HI RMT TEMP—high remote temperature alarm
• LO RMT TEMP—low remote temperature alarm
• HI LCL TEMP—high local temperature alarm
• LO LCL TEMP—low local temperature alarm
• LOW REFRIG TEMP—low refrigerant temperature alarm
To view the time delay for an alarm:
1. Press the MENU key.
2. Use the Up and Down arrow keys to move to the ALARM TIME DELAY menu. Press the ENTER
key to enter into the menu. Use the Up and Down arrow keys to move through the menu and view
the alarm time delays.
To change the time delay for an alarm:
1. Press the ENTER key. (The control will ask for a service password if passwords are enabled. Use
the Up and Down arrow keys and ENTER key to enter the three-digit password when prompted.)
2. Press the ENTER key again on the alarm to select the alarm to be changed.
3. Use the Up and Down arrow keys to change the alarm time delay.
4. Press the ENTER key to record the change.
5. Press the ESC key two to three times to return to the main display.
5.4 System Shutdown Causes
Unit Is Off By Refrig Sens Fail
The control has lost its signal from the refrigerant temperature sensor. The control has no way of
controlling the refrigerant temperature, so the unit is shut off. Main power (disconnect switch)
must be turned Off, then back On to clear this alarm.
Unit Is Off By High CW Temp
The entering chilled water temperature is too high to keep the refrigerant pump(s) running nor-
mally. If there is a HIGH CW TEMP alarm and the refrigerant pump loses flow (differential pres-
sure), the Liebert XDP will immediately attempt to restart the pumps and re-establish flow. If
flow is still not established, then the Liebert XDP will go into a pre-chill mode. The Liebert XDP
can attempt to start again only if the entering chilled water temperature drops below the HIGH
CW TEMP setpoint.
Unit Is Off By Pump Short Cycle
The control was unable to get a pump started upon startup or after a loss of differential pressure.
The control looks at the SHORT CYCLE time delay. If it cannot establish differential pressure
within that amount of time, the unit is shut down. This time is adjustable through the SHORT
CYCLE alarm time delay. Main power (disconnect switch) must be turned Off, then back On to
clear this alarm.
Unit Is Off By Low Refrig Temp
The control was unable to raise the refrigerant temperature to the calculated refrigerant temper-
ature control point. The unit is shut down because if the control cannot raise the refrigerant tem-
perature to the calculated refrigerant temperature control point, water may condense on the
refrigerant piping and receiving coils. Main power (disconnect switch) must be turned Off, then
back On to clear this alarm.