Liebert Extreme Density Chiller XDC - Manual (Page 56)

Troubleshooting
50
7.0 T
ROUBLESHOOTING
Table 24 Liebert XDC 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 Table 18.
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 2.7 - Filling the Direct Expansion (DX) Circuit—R-
407c.
Pump noisy
Cavitation due to vapor in pump
Check for adequate charge in system, refer to the user
manual. 2.7 - Filling the Direct Expansion (DX) Circuit—R-
407c
Pump is rotating in reverse See Table 18
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 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.
Table continued on following page