Liebert XDC 7.0 T

Troubleshooting

7.0 TROUBLESHOOTING

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 Expansio n (DX) Circuit—R-

407c

Pump is rotating in reverse See Table18

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