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8 backup ventilation system, 9 xdf compressor, 10 uninterruptible power supply – Emerson Liebert XDF User Manual

Page 53: Backup ventilation system, Xdf compressor

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Operation

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10.8 Backup 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

10.9 XDF 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 800-543-2778.
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.

Backup Ventilation Air

Exhaust Vent

Heated air returns

Evaporator Fans

circulate cooling air

if powered by a UPS

Backup Ventilation Air

Intake Vent

Self-contained, air cooled

XDF shown; vents and

operation apply to all XDF

models