User manual

Start the Liebert XDP with iCOM
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5.2 Starting the Liebert XDP with iCOM Controller
The Liebert XDP is started, stopped and controlled through the Liebert iCOM controller. Figure 24
shows the Liebert iCOM keypad.
1. Turn On the fans of all the connected Liebert XD cooling modules.
2. Switch on power to the Liebert XDP with the main disconnect switch on the upper left corner of
the unit.
3. Turn the On Liebert iCOM controller by pressing it’s I/O switch (see (Figure 24).
Allow the system to attempt to start for at least 5 minutes.
If the Liebert XDP pump cannot maintain flow and continues to switch over due to starting diffi-
culties, refer to 8.0 - Troubleshooting. After remedying the problem, proceed to Step 4.
4. If constant flow is established, wait until the Liebert XDP has been operating for 10-15 minutes,
then verify that the refrigerant level in the receiver sight glass is between the second and third
level (see
Figure 30). Add or remove charge, if necessary.
5. Check pressure differential functionality:
The Liebert XDP system should be On. If it is Off:
a. Turn On the Liebert XD cooling module fans
b. Turn the Liebert XDP On with its I/O button.
If there is no “Loss of Flow” alarm present—This suggests that there is flow. Test the
pressure differential by closing the ball valve on either the suction line or discharge line to
stop the flow.
This should prompt an alarm for “loss of flow on P1.” This alarm confirms that the switch has
opened on low pressure (below 6 psi; 41kPa; 0.41 bars).
If there is a “Loss of Flow” alarm present—This suggests that there is no flow. Verify
that this is correctly annunciated by looking at the sight glass in the receiver. If a true no-flow
condition exists, the level will not move.
However, if there is flow, but the differential reading is faulty, the level will slowly
drop, indicating flow, while the loss of flow alarm is annunciated.
Check the pressure differential physically by making sure that the electrical connections are
properly connected. Then check the pressure differential electrically by making sure that the
unit has 24VAC across it.
Figure 30 System R-134a liquid level at 160kW load
Operation above sight glass #3 can
make the system operate erratically
and reduce cooling capacity. Reduce
charge to recommended level.
Recommended operating level
Acceptable operating level
Operation below sight glass #1 may
cause loss of flow or cooling. Add
charge to reach recommended level.
For lightly loaded systems,
the recommended operating
level is sight glass #2.
Sight Glasses 1, 2 & 3