GMV DC Inverter VRF 
39 
Total refrigerant charging amount R = 5+0=5kg. 
Modular combination of outdoor unit subjects to combinations that is currently available. 
3.7.2 Refrigerant-charging Method   
Refrigerant charging for multi VRF unit includes two parts: pre-charging and start-up charging. 
(1)  Pre-charging of refrigerant. 
Step 1: Connect the pipe of high pressure gauge of the pressure gauge to the detection port of 
liquid pipe, the pipe of low pressure gauge to the detection port of gas pipe valve, and the pipe of 
intermediate pressure gauge to the vacuum pump. Put through the power for the vacuum pump to 
conduct the vacuum drying work. 
Step 2: Once vacuum drying is completed, close the high pressure gauge valve and the low 
pressure gauge valve. Disassemble the intermediate gauge pipe and the vacuum pump connection 
end, and then connect the refrigerant tank. 
Step 3: Properly loosen the pipe of intermediate gauge and the connection end of pressure 
gauge, slightly open the refrigerant tank valve, and empty the pipe of intermediate gauge. After that, 
retighten the joint and open the refrigerant tank valve. 
Step 4: If the refrigerant tank itself does not have a siphon, then the refrigerant tank needs to be 
inverted and placed on the electronic scale to record the current weight of m1; if the refrigerant tank 
itself has a siphon, the refrigerant tank should be kept in an upright state, and record the current 
weight of m1.   
   
Fig. 3.7.1