Technical Specifications

Designing a Liebert XD Solution
27
Installing the Liebert XDR in a hot aisle/cold aisle configuration provides benefits such as increased
ride-through in the event of a failure. With the room-neutral cooling, the Liebert XDR can be used
where hot aisle/cold aisle setup is not feasible to address hot spots (see Figure 25).
Figure 25 Liebert XD modules not in hot aisle/cold aisle configuration
These methods can increase the redundancy of any Liebert XD system:
• Hot aisle/cold aisle design
• Interlacing the modules with different Liebert XDPs or Liebert XDCs
• Using multiple types of Liebert XD cooling modules
• Containment methods
3.13 Liebert XD Piping System Design
All piping must be ASTM (American Society for Testing and Materials) Type “ACR” copper pipe. The
typical maximum operating pressure in the system is 90 psi (620kPa).
Piping for the Liebert XD system is arranged in a manner similar to piping for a chilled water system.
Liebert XD cooling modules are connected in parallel between the main return and supply pipes going
to and from the Liebert XDP/Liebert XDC. Figure 26 represents a typical configuration. The
guidelines provided for pipe size must be strictly followed. Failure to size the main lines
and connection lines adequately may result in reduced cooling capacity. The critical aspects
of pipe sizing are related to refrigerant volume and pressure drop. Each must be minimized.
Figure 26 Piping for Liebert XDP/Liebert XDC used with Liebert XD cooling modules
Liebert XDP/
Liebert XDC
SLOPE—The main supply and return lines to and from the Liebert XDP/Liebert XDC
must be sloped downward toward the Liebert XDP/Liebert XDC at a rate of 1-2" per
20 feet (25.4-51mm per 6m) of pipe run. Horizontal connector lines should also be
sloped downward from the cooling modules toward the main supply and return lines.
Liebert XD Cooling
Modules
All supply and
return mains must
be level with or
above the top of all
Liebert XDP or
Liebert XDC units
9ft.
(2.7m)
max.
20ft.
(6.7m)
max.