GMV5 DC INVERTER VRF UNITS SERVICE MANUAL 
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Equip a pressure regulator valve to the nitrogen cylinder.   
The nitrogen flow is above 4-6 L/min (pressure of 0.02 to 0.05 MPa) and must be regulated based 
on the pipe caliber. 
3.6 Requirements on Manifold Installation 
Manifolds are used to divert refrigerant. Requirements on manifold installation are as follows: 
A. Ensure that the manifold is close to the IDU to reduce impact on refrigerant assignment by IDU 
branches. 
B. The manifold must be that specified by the manufacture and match with the devices. 
C. Ensure that the manifold model is correct. 
D. Manifolds can be laid in the following ways: 
D1.  Horizontal  installation:  The  three  ports  must  be  on  the  same  level.  The  shaping  size  and 
assembly angle cannot be changed.   
D2. Vertical installation: The direction can be upwards or downwards. Three ports must be on the 
same elevation without inclination. 
Within ±15°
Within ±15°
Diagram for direction A
Diagram for direction B
B
A
 
D3. The length of a straight pipe between two manifolds cannot be less than 500 mm. 
D4. The length of a straight pipe before the main pipe port of the manifold cannot be less than 500 
mm. 
D5. The length of a straight pipe between the branch of the manifold and the IDU cannot be less 
than 500 mm. 
 
E. Fixing of manifolds. 
There must be three fixing point for both horizontal and vertical installation of the Y-type manifold. 
Fixing point 1: 100 mm on the main inlet manifold from the welding point 
Fixing point 2: 200 mm on the main branched pipe from the welding point 
Fixing point 3: 250 mm on the branched pipe from the welding point