Liebert Refrigerant Distribution Unit XDP - Manual (Page 34)

Alarm Descriptions and Solutions
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5.0 A
LARM
D
ESCRIPTIONS AND
S
OLUTIONS
5.1 Alarm Descriptions
• LOSS OF FLOW P1—Activated when Pump 1 is commanded to run and the differential pres-
sure switch does not sense differential pressure (set at 6 psi; 41kPa; 0.41 bars). After attempting
to start Pump 1 for 120 seconds (including time delays), the Liebert XDP will automatically
switch to the other pump to establish flow.
• LOSS OF FLOW P2—Activated when Pump 2 is commanded to run and the differential pres-
sure switch does not sense differential pressure (set at 6 psi; 41kPa; 0.41 bars). After attempting
to start Pump 2 for 120 seconds (including time delays), the Liebert XDP will automatically
switch to the other pump to establish flow.
• SHORT CYCLE—Activated when the Liebert XDP is trying to establish flow (differential pres-
sure), and it is unable to do it. The Liebert XDP will attempt to establish flow for 4 minutes on
each pump, for a total of 8 minutes. If this “cycling” occurs within 30 minutes and the Liebert
XDP still does not establish flow, a SHORT CYCLE alarm will be present. This alarm will shut
down the Liebert XDP. Main power (disconnect switch) must be turned Off, then back On to clear
this alarm. The cycling time for the SHORT CYCLE alarm can be adjusted from the default of 30
minutes; the range is from 10 minutes to 60 minutes.
• CONDENSATION!—Activated when water is detected at the Liebert XD cooling module (24VAC
is applied to the condensation input on the control). When this alarm is active, the control will
raise its refrigerant control point by 4°F (-16°C). Alarm will reset when the 24VAC signal ends or
main power is removed.
• VALVE FAILURE—Activated when the chilled water control valve has been commanded by the
control to open or close and no change is detected from the valve-position signal. The control will
close the valve and then try to control the control valve based on its travel time. Main power (dis-
connect switch) must be turned Off, then back On to clear this alarm.
• CUSTOMER ALRM—Activated when 24VAC signal is applied to the customer alarm input on
the control board. Alarm will reset when the 24VAC signal is taken away.
• HIGH CW TEMP—Activated when entering chilled water temperature exceeds the user speci-
fied setpoint. The alarm will reset itself when the entering chilled water temperature drops below
the setpoint.
• FAILED CW SENSOR—Activated when the control stops receiving a signal from the entering
chilled water temperature sensor. The alarm will reset itself when the temperature sensor signal
is re-established.
• HIGH REMOTE TEMP & HIGH LOCAL TEMP—Activated when the remote or local temper-
ature exceeds the user specified setpoint. The alarm will reset itself when the room temperature
drops below the setpoint.
• LOW REMOTE TEMP & LOW LOCAL TEMP—Activated when the remote or local tempera-
ture is below the user-specified setpoint. The alarm will reset itself when the room temperature
raises above the setpoint.
• REMOTE SENS PROB—Activated when no signal is present from the remote temperature or
humidity sensors. Alarm will reset when the temperature and humidity signals are re-estab-
lished.
• LOCAL SENS PROB—Activated when no signal is present from the local temperature or
humidity sensors or when communication with the display is lost. The alarm will reset when the
temperature and humidity signals are re-established.
• HIGH REFRIG TEMP—Activated when the refrigerant temperature exceeds the user-specified
setpoint. The alarm will reset itself when the refrigerant temperature drops below the setpoint.
• LOW REFRIG TEMP—Activated when the refrigerant temperature drops 1.5°F (1°C) below the
refrigerant temperature control point. The alarm will reset itself if the refrigerant temperature
rises before the control shuts down because of low refrigerant temperature.
NOTE
Alarms must be acknowledged before they can be reset. To acknowledge or silence an alarm,
press the ALARM SILENCE / ? key.