Vertiv Liebert XDC User Manual

Symptom Possible Cause Check or Remedy
Unstable pump
operation
R-134a pump loop is overcharged
While pump is running R-134a receiver level must be within
recommended levels (see Checklist for LiebertXDC Startup on
page111).
Room becomes
too warm
Liebert XDC is off.
Check status of the Liebert XDC at the user interface. Turn system On
at I/O button if system is Off.
High dew point
Check temperature and relative humidity (RH) of room. Lower RH
setpoint if necessary to lower dew point. At normal room temperature of
68°F (20°C), the RH should be set to 50% or lower.
Liebert XD cooling modules are Off.
Check Liebert XD cooling modules to make sure that they are On before
starting the Liebert XDC.
Minimum room temperature setpoint is too
high.
Check the setpoint in the User Setpoints menu (see Figure 6.7 on
page70).
Incorrect location of temperature/humidity
senors
Place the sensor on the return air side of the primary air mover (i.e.,
Liebert DS). Do not install the sensor near unsealed doors, windows, and
similar areas.
Pipe rattle Loose pipe connections Check pipe connections.
Actuator motors
(if applicable)
No 24VAC power to motor Check for 24VAC between P2-1 and P2-4.
No signal from control Check 24VAC at P22-1 (close) or P22-3 (close).
Motor not operating
Unplug P22 completely off of the board. Jumper P22-5 to P2-4 for
grounding, then jumper P22-1 to P2-1 to drive close. Remove jumper to
close, and then jumper P22-3 to P2-1 to drive open. If motor fails to work,
replace it.
Table 9.1 Liebert XDC troubleshooting (continued)
Vertiv | Liebert® XDC™ User Manual | 122

Vertiv Liebert XDC Specifications

General

Brand	Vertiv
Model	Liebert XDC
Category	Freezer
Language	English