Charging Refrigerant And Adding Refrigerant Oil; Base/Side Panel Cutout Locations - Liebert DM User Manual

2.6.2 Charging refrigerant and adding refrigerant oil

1. Charging with refrigerant
The Liebert_DM 16kW air conditioner had been charged with 2bar nitrogen to keep pressure at the factory. In project
installation, see the unit nameplate for the initial charging capacity of Liebert_DM 16kW air conditioner.
If the connecting pipe between the indoor unit and the outdoor unit is longer than 10m, add refrigerant to the system in
order to ensure normal system operation.
The amount of the refrigerant is calculated through the following formula:
Refrigerant amount (kg) = unit length liquid pipe refrigerant amount (kg/m) × length of extended pipe (m)
See Table 2-8 for the unit length liquid pipe refrigerant amount.
Length of extended pipe (m) = Total length of liquid pipe (m) - 10m
Pipe OD (mm)
9.52
12.7
16
2. Adding POE refrigerant oil
The added refrigerant will dilute the POE refrigerant oil in the system, undermining the lubricating and cooling effects
of the POE refrigerant oil. Therefore more POE refrigerant oil should be added. See the formula below:
Amount of refrigerant oil to be added (ml) = amount of added refrigerant (kg) × 22.6

2.7 Base/Side Panel Cutout Locations

Base cutout locations
Figure 2-22 and Figure 2-23 show the base figures with the side panel removed, and the distance between the dashed
lines and the rear panels is 25 mm, where is the mounting place of inner side panel.
IRWI: Infrared humidifier water in
F: Unit set screw
WI/WO: Condenser water inlet and outlet (water-cooled
models)
Table 2-8 Unit length liquid pipe refrigerant amount of pipes with different ODs
Unit length liquid pipe refrigerant
amount (kg/m)
0.060
0.112
0.181
160
F
25
72.5
2-Φ 35
D
IRWI
F
45
Figure 2-22 Base cutout location of upflow models
Liebert_DM 16kW Air Conditioner User Manual
Chapter 2 Mechanical Installation
Pipe OD (mm)
19
22
28.6
530
4-Φ 13 Knock-out
F
25
Knock-out
72 109
Knock-out
2-Φ 64
P
WO/LL
K K
F
WI /DL
760 45
D: Drain P: Power cable entry (Φ30)
K: Knock-out LL/DL: Liquid line / discharge line (air-cooled models)
Unit length liquid pipe refrigerant
amount (kg/m)
0.261
0.362
0.618
2-Φ 40
Knock-out
17