Vertiv
™
| Liebert® XDC | User Manual
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2.8.5. Air Tightness Test
After completion of the brazing of piping, the nitrogen gas must be used for leak detection and to ensure that the system
does not have any sign of leakage. The system must strictly follow the segmented leak detection:
1. According to the valve labeling (refer
), close the suction and discharge ball valves of the two
Vertiv™ Liebert® XDC systems, a total of 4 Nos; open all the ball valves at theVertiv™ Liebert® XD cooling terminal.
Once all ball valves are open, each system is divided into two sections:
a) The inside of Liebert XDC is the low-pressure section. Check the pipeline for the sign of leakage which including
compressor, oil separator and connecting piping.
b) The outside of Liebert XDC is the high-pressure section. Check the pipeline for the sign of leakage, including the
condenser, all cooling terminals and connecting piping.
2. To detect the sign of leakages in the low pressure section, pressurize the schrader valve2 to 31 bar.
3. To detect the sign of leakages in the high pressure section, simultaneously pressurize schrader valve3 and schrader
valve4 to 40 bar.
4. At the mentioned pressure, if there is no leakage in the system, retain the pressure for 24 hours then the leak detection
process is completed; otherwise, fixed the leak point and repeat the Step 2, Step3 and Step 4.
5. After the leak detection is completed, release the nitrogen gas and add refrigerant oil.
Note: Ensure the pressure of the leak detection in the low pressure section must not exceed the value higher than
32.8 bar, otherwise the compressor will be damaged.
After the leak detection is completed, the nitrogen pressure must be released slowly and the pressure
must be released at the designated location to prevent the nitrogen from carrying out the lubricating
oil in the system.
2.8.6. Charging Refrigerant Oil
The Liebert XD system must be recharged with refrigerant oil as per the requirement before commissioning the unit for the
first time. The amount of refrigerant oil added must be according to the actual length of the connecting piping on site.
1. Select the correct type of refrigerant oil.
2. The addition of refrigerant oil must as per to the actual length of the liquid return piping, not the equivalent length.
3. When the actual length of the liquid return piping is less than or equal to 30 m, each system needs to be supplemented
with 1.5 Liters of refrigerant oil.
4. When the actual length of the liquid return piping is more than 30 m then calculate the amount of refrigerant oil to be
added according to the actual piping length and piping diameter, as provided in
.
5. Recharge the refrigerant oil for each system through the schrader valve reserved on the branch manifold, as shown in
.
Table 2-12 Additional Amount of Refrigerant Oil
Liebert XDC130
Actual Pipe Length < 30 m
Actual Pipe Length > 30 m
Each system must be supplemented
with refrigerant oil of 1.5 Liter
Each system:
Charged amount of refrigerant oil = 1.5 Liter + (the actual length of the liquid
return pipe - 30 m) * the amount of refrigerant charged per unit length x 6%
