Emerson Xtreme Density Manuel D’Utilisation
Designing a Liebert XD Solution
28
3.16.2 Calculating Refrigerant Charge—Example
Using Tables 7, 8, 9 and 10, calculate the refrigerant charge of the individual sections of your Liebert
XD system. Add the calculated charge amounts to determine the amount of R-134a refrigerant
required for one system combining a Liebert XDP with Liebert XD cooling modules (Liebert XDCF,
Liebert XDH, Liebert XDO and Liebert XDV). The example below combines one Liebert XDP with 20
Liebert XDV8 cooling modules.
Verify that the refrigerant volume of the Liebert XD system with the longest piping length is within
the allowable limit. If the allowable limit is exceeded, the Liebert XDP/Liebert XDC should be moved
closer to the cooling modules (refer to 3.12 - Liebert XD Refrigerant for limits and related details).
Another way to shorten the total pipe length is to reroute the pipe runs.
3.17 Liebert XDC DX R-407c Circuit Volume—Air Cooled Units
Weigh in the calculated charge based on Tables 13, 14 and 15.
Table 11
Calculating refrigerant charge—example
Components
Number of Units
or Piping Length, feet
Pounds Per Component
Total, lb.
Liebert XDP/Liebert XDC
1
157
157
Liebert XDV8 Cooling Modules
20
2.32
46.4
Supply Main, 1-1/8"
100
0.45
45
Return Main, 2-1/8"
100
0.28
28
Liebert XDV 1/2" supply Flex
Pipes
20
0.8
16
Liebert XDV 5/8" return Flex
Pipes
20
0.03
0.6
Total
293
Table 12
Worksheet to calculate refrigerant charge
Components
Number of Units
or Piping Length
Pounds Per Component
Total
Total
!
CAUTION
Risk of improper lubrication. May cause equipment damage.
Liebert XDCs with refrigerant R-407c charges over 35 lb. (15.9kg) require additional oil. Refer
Liebert XDCs with refrigerant R-407c charges over 35 lb. (15.9kg) require additional oil. Refer
to the Liebert XDC user manual, SL-16671, available at Liebert’s Web site,
Table 13
Indoor unit refrigerant charge—R-407c
Model 60/50 Hz
Charge/Circuit, lb. (kg)
Liebert XDC160
17.5 (8.0)