Liebert XDP 5.4 System Shutdown Causes

Alarm Descriptions and Solutions

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

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.

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.

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.

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.