Vertiv Liebert XDC User Manual

4.4.1 Piping Installation—R-134a Pumped Circuit
Vertiv recommends venting the relief pressure of the Liebert XDC (located at the top of the receiver)
outside of the conditioned space where it is open to the atmosphere.
4.4.2 Bypass Flow Controllers
Two bypass flow controllers are required to ensure the Liebert XDC pumps operate within the optimum
range. These devices are added to the field piping and simulate the flow of additional cooling modules.
Each bypass flow controller must be installed with one shutoff valve to allow the controller to be disabled
when cooling modules are added to a Liebert XD system.
Bypass flow controllers should be connected between the main supply and the main return lines of the
field piping. The connection points to the main supply and return lines should be in a convenient and
accessible location between the Liebert XDP/Liebert XDC and the first Liebert XD module in the circuit.
See Figure 4.2 below andFigure 4.3 on the next page for piping details of the bypass flow controller.
Refer to Table 4.2 below to determine the number of bypass flow controllers needed to be open to
provide proper refrigerant flow, based on the total nominal cooling capacity of the cooling modules in
each Liebert XD system.
System Load kW
Cumulative Module Model Size
Required Number of Open
Bypass Flow Controllers
Liebert XDC
32 to 63 N/A
64 to 95 2
96 to 127 1
128 to 160 0
Table 4.2
Bypass flow controllers for a Liebert XDC-based system
Figure 4.2 Bypass flow controller details, dimensions
Vertiv | Liebert® XDC™ User Manual | 39

Vertiv Liebert XDC Specifications

General

Brand	Vertiv
Model	Liebert XDC
Category	Freezer
Language	English