Gree GMV-1015WM/G-U, Service Manual

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Gree GMV6 DC Inverter VRF Units Service Manual
282
2. Weld the
connector of the
oil separator
1. Place the oil
separator in the
correct position
3. Fix the bolt
4. Weld the oil
return pipe
assembly
Step 13: System leakage inspection
1) Check each welding joints. Firstly, observe whether the welding joints are smooth and
whether there are obvious welding holes and other abnormal conditions.
2) Then, charge the unit system with high-pressure nitrogen for leak inspection. If it is only for
ODU maintenance, and it can be confirmed that there is no abnormality in the IDU system, only
charge the ODU with high-pressure nitrogen for leak inspection. Note that it is necessary to
simultaneously charge nitrogen from the high and low pressure sides. It is recommended to charge
the nitrogen valve at the same time with nitrogen. The nitrogen pressure should be greater than
20kgf. Use soapy water to check whether the unit system leaks, and focus on checking the service
joints.
3) Finally, charge the system with high-pressure nitrogen to keep the system pressure at
above 25kgf. Close the large and small unit valves and hold the pressure of the IDUs and ODU for
more than 12 hours. If the pressure does not change, start vacuuming. Otherwise, repeat the
aforementioned procedure until the leaking point is located.
When checking whether there is any change in the pressure of the system, it is necessary to
eliminate the temperature influence as the temperature changes by 1°C, and the pressure changes by
about 0.01 MPa. For example, when the temperature of nitrogen is 30°C, the pressure is 2.5 MPa. After
the pressure is held for more than 12 hours, the temperature becomes 25°C, the unit passes the test if
the pressure is above 2.43 MPa.