Technical Specifications

Designing a Liebert XD Solution

Example

A space is 5,000 square feet, with an 18" raised floor and an 8' 6" suspended ceiling. Liebert XDOs

and a Liebert XDP are to be placed in this raised-floor area.

The volume of the space is (1.5 + 8.5) x 5,000 or 50,000 cubic feet.

The maximum amount of R-134a refrigerant that can be used in a single Liebert XDP/Liebert

XDC/Liebert XD module system within this space is 13 * (50000/1000) = 13 * 50 = 650 lb.

Multiple Liebert XD systems can be installed in this space, as long as the amount of R-134a

refrigerant in any one system does not exceed 650lb. (294.8kg).The maximum amount of

refrigerant is 650lb (294.8kg) per Liebert XD loop.

3.23 Determining Refrigerant Volume

After the preliminary system design is completed, Tables 15 through 20 may be used to determine

the amount of refrigerant required. Perform the calculation below for each Liebert XD system being

configured.

3.23.1 Liebert XDP/Liebert XDC Pumped R-134a Circuit Volume

This is the refrigerant circuit from the Liebert XDP/Liebert to the Liebert XD cooling module.

NOTE

Local codes might permit exceeding the maximum refrigerant limit above if a refrigerant

detector and an exhaust system are installed. Installing oxygen sensors may meet some local

codes.

NOTE

All lengths in Tables 15, 16, 17 and 18, are actual pipe lengths, not equivalent pipe lengths.

NOTE

System refrigerant volume calculations in Tables 15, 16, 17 and 18, are based on a fully

loaded system. Additional charge may be required for lightly loaded systems.

Table 15 System R-134a charge for a Liebert XDP/Liebert XDC with any model

Liebert XDH/Liebert XDO/Liebert XDV/Liebert XDCF

Refrigerant Charge,

lb (kg)

Per Liebert XD Unit

(Excludes Connector Lines to and from Liebert XD Cooling Module)

157 (71.2) Liebert XDP/Liebert XDC

3.55 (1.61) Liebert XDO

2.32 (1.05) Liebert XDV

2.66 (1.21) Liebert XDH (per circuit)

1.41 (0.64) Liebert XDCF

4 (1.81) Liebert XDR

Table 16 System refrigerant charge for the supply and return mains

Refrigerant Charge,

lb/foot (kg/m)

Supply/Return Main Length and Diameter

0.45 (0.67) Main supply actual length per 1-1/8" OD copper tubing

0.68 (1.01) Main supply actual length per 1-3/8" OD copper tubing

0.28 (0.42) Main return actual length per 2-1/8" OD copper tubing

0.43 (0.64) Main return actual length per 2-5/8" OD copper tubing