Vertiv
™
| Liebert® XDC | User Manual
36
4 System Startup and Commissioning
This chapter introduces the system startup and commissioning, including the position of the MCB and the specific operation
steps for startup and commissioning the unit.
4.1. Startup and Commissioning
4.1.1. Preparation Before Commissioning
• Mechanical Part
1. According to the instruction label at the valve, ensure that all valves of the Vertiv™ Liebert® XDC unit and all cooling
terminals are open.
2. The refrigerant piping system has passed the air tightness test and confirmed that there is no leakage.
3. The drainage pipe system at the cooling terminal has been reliably connected and leak-checked in accordance with the
specified material requirements.
4. The compressor heating belt has been preheated for more than 12hours.
5. The temperature of the equipment room is above 20 °C and has a certain thermal load. If not available, other heating
devices should be used to preheat the environment of the equipment room to ensure the necessary thermal load for the
commissioning.
• Electrical Parts
1. Confirm that the input voltage of the main power supply is within the nominal range of rated voltage
380 V t0 415 V (-10% to +6%) V; the power isolation switch of the outdoor unit air-cooled condenser is closed.
2. Confirm that all electrical or control connections are correct, and firmly fixed all electrical and control connections.
3. Confirm that the power supply cables and low-voltage control cables are arranged separately.
4.1.2. Vacuuming
As Liebert XDC unit and the cooling terminal are connected and used together to form a system, both should be powered
on, started, and commissioned at the same time.
1. Release the pressure-holding nitrogen and open all the ball valves in the system
2. Ensure that the air switches of compressor 1 and compressor 2 of the unit are disconnected to prevent the starting of the
compressor by mistake
3. Power on the unit and all terminals at the same time, and keep them in ready state
4. Ensure that the unit enters the vacuuming mode and the electronic expansion valve at the terminal is open;
5. The positions of the schrader valve for vacuuming are schrader valve 3, schrader valve 4, as shown in
6. The #1 and #2 systems need to be vacuumed separately to ensure that the vacuum time of each system is more than
3hours and the vacuum degree reaches -1 bar.
Note: During the vacuuming process, if the unit exits the vacuuming mode, ensure that the system enters the vacuuming
mode again through the settings.
Note: If the vacuum cannot reach -1 bar, it is necessary to stop vacuuming and check the system for any sign of leakages.
Note: If it is not possible to ensure that the unit is powered on during vacuuming, ensure that the schrader valves 1, 2 and
the two schrader valves of the inlet and outlet pipes at the terminal are simultaneously vacuumed at the four positions.
