Vertiv | Liebert® CRV4 | User Manual 48
Start-up Commissioning
5.2. Power-On Commissioning
5.2.1. Preparation Before Commissioning
• Mechanical part
1. Follow the instructions labeled on the valve to open all valves in the refrigerant loop.
2. The refrigerant piping system has cleared the pressure leakage test.
3. Ensure the refrigerant is properly charged in the system.
4. Ensure that the total system charge has been roughly accounted. If the charge is less than the base charge
allowed, additional lubricant oil should have been added into the system.
5. The water supply and drain pipes of the humidication system have been connected, the material
requirement is met and the leakage detection has been installed.
6. The crankcase heater of the compressor has been preheated for over 12hours.
7. The equipment room is above 18 °C with certain heat-load. Otherwise, warm up the equipment room with
any heating device, or by manual running the heaters of the unit (in this case, go through the following
procedures till the third step of Section 5.2.2 Commissioning Procedure) and of other equipment in the room.
Ensure suicient heat-load for the commissioning.
8. During low ambient conditions, it may be necessary to manually raise the condensing pressure up to 21 bar
by manually shielding some condensing area to limit the condensing air volume.
• Electrical part
1. Ensure that the voltage of the main power supply is within ±10% of the rated voltage, and the isolation switch
of the air-cooled condenser of the outdoor unit has been closed.
2. Ensure that all electrical or control connections are correct, and all electrical and control connectors are
tighten.
3. Ensure that the power cable and the low-voltage control cables are separately arranged.
4. Ensure that the high-water-level cables are correctly connected and the pump operates correctly.
5.2.2. Commissioning Procedures
1. Turn-O all the MCBs of various parts. Turn-On the isolation switches and control MCBs. Check and conrm
that the control voltage is 24 Vac ±10%.
2. Turn-On the fans’ MCBs to check if the fans run normally. Measure the operational phase-currents of the all
fans.
3. Vacuum in system loop: Connect the compound pressure gauge to the corresponding high and low pressure
schrader valves. Evacuate the cooling system vacuum to -30 in. Hg (-1.02 bar; pumping time: >3hr), and
hold the state for 4hr. The pressure should not rise, and the color of the sight glass is normal (to ensure the
cooling system vacuum and dry eect, evacuate the cooling system repeatedly at least three times). If there
is a hydraulic solenoid valve in the system, user needs to choose vacuum in manual mode, and then vacuum
after opening the solenoid valve.
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