Troubleshooting
51
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 by following instructions in 5.3.2 -
SETPOINTS.
Incorrect location of temperature-
humidity senors
Place the sensor on the return air side of the primary air
mover (I.e., Liebert Deluxe System 3). 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.
Motor burnout
Check control panel for welded
contactor contacts or welded
overload contacts
Replace defective components.
Main 24VAC
fuse trips
Shorts or loose connections Check the wiring connections of the 24VAC circuit.
Faulty circuit board Replace the circuit board.
Unstable pump
operation R-134a pump loop is overcharged While pump is running R-134a receiver level must be within
recommended levels (see Figure 31).
Table 24 Liebert XDC troubleshooting (continued)Symptom Possible Cause Check or Remedy