8
English
6-2 PROTECTION AGAINST CONTAMINATION WHEN INSTALLING PIPES
Protect the piping to prevent moisture, dirt, dust, etc. from entering the piping.
NOTE
Exercise special caution to prevent dirt or dust when passing piping through holes in walls and when passing
pipe edges to the exterior.
6-3 PIPING 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
), and at the end made the indoor unit and
BS unit flare or flange connections.
(*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
0.02 MPa (0.2kg/cm
2
:Enough to feel a slight breeze on your cheek).
NOTES
•
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 refrigerant
lubricant to deteriorate, adversely affecting the refrigerant piping system.
Use phosphor copper brazing (BCuP-2: JIS Z 3264/B-Cu93P-710/795: ISO 3677) which does not require
flux.
6-4 PIPING SIZE SELECTION
From
Example of connection 1
and
2
below and
Table 1
,
2
, select the piping size between the outdoor unit
(refrigerant branch kit) and BS unit, and between the BS unit and the indoor unit (refrigerant branch kit).
Example of connection 1: When 1 indoor unit is connected downstream from the BS unit
Place
Installation period
Protection method
Outdoor
More than a month
Pinch the pipe
Less than a month
Pinch or tape the pipe
Indoor
Regardless of the period
Refrigerant piping
Valve
Pressure-reducing valve
Part to be brazed
Taping
Nitrogen
Nitrogen
Fig. 5
To refrigerant branch
kit or outdoor unit
*
Suction gas pipe
<Upstream>
<Downstream>
Gas pipe
Indoor unit
Liquid pipe
HP/LP gas pipe
Liquid pipe
Determine using
Table 1
based
on the total capacity of the indoor
units connected downstream.
Select from
Table 2
depending
on the capacity type of the
indoor unit.
BS
unit
01_EN_3P194121-1E.fm Page 8 Thursday, September 4, 2008 5:33 PM
