Operation
10.8Backup Ventilation System
The XDF is equipped with a backup ventilation system that circulates ambient air through the XDF should any component of the cooling system fail or if power is lost. The backup ventilation system begins operating only after the internal temperature exceeds the ambient external temperature.
If powered by a UPS, evaporator fans circulate ambient air until the XDF returns to normal opera- tion.
Figure 35 Airflow pattern, backup ventilation operation
Heated air returns
Evaporator Fans |
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| Backup Ventilation Air | |
circulate cooling air |
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if powered by a UPS |
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| Exhaust Vent | |
Backup Ventilation Air | ||||
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Intake Vent
10.9XDF Compressor
The iCOM automatically adjusts the cooling capacity of the digital scroll compressor depending on the heat load in the cabinet.
Sensors near the evaporator fans monitor the cooling airflow and send the data to the iCOM. These sensors have setpoints that may be adjusted with the iCOM control unit to raise or lower the internal cabinet temperature. For information on changing the setpoints, refer to 10.6 - Changing the XDF’s Default Operating Temperature or call
If the return air temperature drops below the setpoint, iCOM reduces the compressor’s cooling output accordingly. The evaporator fans will continue to circulate internal cabinet air throughout the enclo- sure.
10.10 Uninterruptible Power Supply
The XDF may be supplied with any of several Liebert UPS units or with no UPS. For inte- grated/matched models, the UPS and the equipment installed in the XDF are sized with matched capacities. A larger UPS, with more battery time, can be obtained, but the connected electronics load should not exceed the XDF’s cooling capacity.
For XDF units equipped with a UPS, refer to the UPS manual for UPS operation and specifications.
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