Vertiv Liebert XDC User Manual

9 TROUBLESHOOTING
Symptom Possible Cause Check or Remedy
Pump/compressor
will not energize
No main power Check L1, L2, and L3 for rated voltage.
Loose electrical connections Tighten connections.
Overloads tripped Allow pump to cool. Check amp draw.
Tripped circuit breaker Check circuit breaker to pump(s).
Incorrect phase wiring See Checklistfor LiebertXDC Startup on page111.
Pump will not run
Isolation valve(s) on pump suction and/or
discharge is closed.
Open all isolation valves completely during normal operation.
Liebert XD cooling modules are Off.
Check Liebert XD cooling modules to make sure that they are ON prior
to starting the Liebert XDC
Low Refrigerant Temperature
(high dew point)
Check alarm(s) history on Liebert XDC. The Liebert XDC was operating
below the dew point for a significant amount of time. Check humidity in
conditioned space; lower humidity if necessary to allow Liebert XDC to
operate at a lower temperature. (Disconnect must be switched to Off
then back to On to allow Liebert XDC to reset.)
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.
Pressure switch not making contact
Check both differential pressure settings. If not within 6psi, ±1 psi (41
kPa, ±7kPa; 0.41 bars, ±0.07 bars) then manually change accordingly.
Not enough charge See Filling the Direct Expansion (DX) Circuit—R-407C on page55.
Pump noisy
Cavitation due to vapor in pump
Check for adequate charge in system, refer to the user manual. Filling
the Direct Expansion (DX) Circuit—R-407C on page55
Pump is rotating in reverse See Checklist for LiebertXDC Startup on page111.
Worn motor bearings Replace pump
Liebert XDC (Pump)
suddenly stops
Low Refrigerant Temperature
(high dew point)
Check humidity of room along with location of remote sensors. Make
sure that the sensors are not located in a cold area where there is a lack
of sufficient air flow.
Loss of power When power is restored, the Liebert XDC will automatically restart.
Clogged filter/dryer and/or impeller Clean out debris.
Leak in system - loss of charge
Check the entire system for leaks with a refrigerant sniffer. Repair as
necessary.
Room becomes
too cold
Lack of load in the room If there is no cooling required, turn the Liebert XDC off at the I/O button.
Minimum room temperature setpoint is too
low.
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 Deluxe System 3). Do not install the sensor near unsealed doors,
windows, and similar areas.
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.
Table 9.1
Liebert XDC troubleshooting
Vertiv | Liebert® XDC™ User Manual | 121

Vertiv Liebert XDC Specifications

General

Brand	Vertiv
Model	Liebert XDC
Category	Freezer
Language	English