Technical Specifications

Liebert XDC and Liebert XDP

5.0 LIEBERT XDC AND LIEBERT XDP

5.1 Liebert XDC Standard Features

• Compressors—Scroll with a suction gas cooled motor, vibration isolators, thermal overloads,

manual reset high-pressure switch and pump down low-pressure switch.

• Refrigeration System—Dual refrigeration circuits each including liquid line filter dryers,

refrigerant sight glass with moisture indicator, electronic control valve, adjustable externally

equalized expansion valves and liquid line solenoid valves.

• Heat Exchanger—Brazed plate design with interwoven circuiting constructed of stainless steel

plates, copper brazed.

• Pumps—Centrifugal type, end suction, canned rotor design.

• Liebert iCOM—The Liebert iCOM offers the highest capabilities in unit control, communication

and monitoring of Liebert Precision Cooling units. The Liebert iCOM is a factory-installed

assembly. Operating conditions and status are indicated on the unit display, which is mounted

either on the unit or on the wall, depending on application details (see the Liebert XDC user

manual, SL-16674, available at Liebert’s Web site: www.liebert.com). The control system also

monitors unit operation and activates an alarm when any of the specified factory preset

conditions are exceeded. The unit includes two temperature-humidity sensors to aid in effective

cooling.

• Liebert Lee-Temp

™

Refrigerant Control Air-Cooled Condenser—The Liebert Lee-Temp

head pressure control system is designed to maintain proper operating head pressures in outdoor

temperatures down to -30°F (-34.4°C). The condensers utilize head pressure control valves, extra

refrigerant and insulated refrigerant receivers with heater pads. It works by flooding the

condenser coil with liquid refrigerant to a level that balances the system condensing requirements

with the condenser coil surface available to reject the system heat. During the summer, the

system requires the entire condenser coil surface for heat rejection and most of the refrigerant is

stored in a receiver. In the winter, the same amount of heat can be rejected by only a fraction of

the coil surface. As head pressure begins to fall, the control valve restricts the flow of liquid

refrigerant exiting from the condenser. This extra liquid refrigerant reduces the effective

condenser surface area available for heat transfer. The head pressure control valve also bypasses

hot gas into the receiver to warm the liquid and maintain liquid pressure for proper operation of

the expansion valve. Condenser fan controls are either fan cycling on ambient temperature or

constant on.