Emerson Xtreme Density manual Liebert XD Piping Slope, Bypass Flow Controllers, Refrigerant Pumped

Designing a Liebert XD Solution

Figure 24 Hydraulic diagram

Liebert XDC

or

Liebert XDP

Liebert XDC

or

Liebert XDP

AC

B

Pumped	D
Refrigerant	C
	D

AC

B

Pumped	D
Refrigerant	C
	D

XD Cooling

Module *

XD Cooling

Module *

XD Cooling

Module *

XD Cooling

Module *

Supply Lines

Return Lines

*XD CoolFrame, XDH, XDO or XDV

3.14Liebert XD Piping Slope

The main supply and return lines to and from the XDP/XDC must be sloped downward toward the XDP/XDC at a rate of 1-2" per 20 feet (25-51mm per 6m) of pipe run. Horizontal connector lines should also be sloped downward from the cooling modules toward the main supply and return lines.

3.15Bypass Flow Controllers

To ensure the XDP/XDC pumps operate within the optimum range, some installations require one or more bypass flow controller(s). These devices are added to the field piping, and simulate the flow of additional cooling modules.

Each bypass flow controller should be installed with one shutoff valve to allow the controller to be dis- abled when cooling modules are added to a Liebert XD system.

If bypass flow controllers are required, they 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 Figures 26 and 25 for piping details of the bypass flow controller.

Refer to Table 6 to determine the number of bypass flow controllers needed, based on the total nomi- nal cooling capacity of the cooling modules in each Liebert XD system.

Table 6	Bypass flow controllers for Liebert XDC- or Liebert XDP-based systems
Cooling Modules -		Required Number of Bypass Flow Controllers
Cumulative Model Size
		Liebert XDP	Liebert XDC
	32 to 63	3	N/A
	64 to 95	2	2
	96 to 127	1	1
	128 to 160	0	0

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