Daikin VRV IV Series Installation Manual page 9

• For information regarding the piping allowable maximum length, allowable height difference, and allow-
able length after a branch, refer to the installation manual that came with the outdoor unit or Engineering
Data Book.
• The refrigerant branch kit (sold separately) is required for piping branches. For information on how to
select a refrigerant branch kit, refer to the installation manual that came with the outdoor unit or Engi-
neering Data Book.
5-2 Protection against contamination when installing pipes
Protect the piping to prevent moisture, dirt, dust, etc. from entering the piping.
Place Installation period
More than a month
Outdoor
Less than a month
Indoor Regardless of the period
NOTE
Exercise special caution to prevent dirt or dust when passing piping through holes in walls and when pass-
ing pipe edges to the exterior.
5-3 Pipe connection work precautions
• When brazing refrigerant piping, begin working after replacing the nitrogen (*1) or perform brazing while
nitrogen is flowing in the refrigerant piping (*2) (refer to Fig. 5).
(*1) For details on nitrogen replacement, see the "VRV Installation Manual" (available at any Daikin
dealer).
(*2) The pressure regulator for the nitrogen released when doing the brazing should be set to about
2.9 psi (0.02 MPa) (enough to feel a slight breeze on your cheek).
NOTE
• Do not use an anti-oxidizing agent when brazing the piping. Residual debris could clog the piping or
cause parts to malfunction.
• Do not use a flux when brazing the refrigerant pipe joints.
Using a chlorine flux may cause the pipes to corrode, and if it contains fluoride it may cause the refriger-
ant lubricant to deteriorate, adversely affecting the refrigerant piping system.
Use phosphor copper brazing (B-Cu93P-710/795: ISO 3677) which does not require flux.
5-4 Pipe size selection
From Example of connection 1 and 2 below and Table 3, 4 and 5 select the piping size between the out-
door unit (refrigerant branch kit) and Branch Selector unit, and between the Branch Selector unit and the
indoor unit (refrigerant branch kit).
3P405106-10 English
Pressure-reducing valve
Part to be brazed Taping
Nitrogen
Refrigerant piping
Fig. 5
Protection method
Pinch the pipe
Pinch or tape the pipe
Nitrogen
Valve
6