Daikin VRV-WIII, Installation Manual

Page: 14 / 22

9 English
9. REFRIGERANT PIPING
Caution
After completing installation, be sure to open the valve.
(See
9-9 Additional refrigerant charge for details) (Operating
the unit with the valve shut will break the compressor.)
Use R410A to add refrigerant.
All field piping must be installed by a licensed refrigeration techni-
cian and must comply with relevant local and national regulations.
CAUTION TO BE TAKEN WHEN BRAZING REFRIGERANT
PIPING
Do not use flux when brazing copper-to copper refrigerant pip-
ing. (Particularly for the HFC refrigerant piping) Therefore, use
the phosphor copper brazing filler metal (BCuP-2: JIS Z 3264,
B-Cu93P-710/795: ISO 3677) which does not require flux.
(Flux has extremely harmful influence on refrigerant piping sys-
tems. For instance, if the chlorine based flux is used, it will cause
pipe corrosion or, in particular, if the flux contains fluorine, it will
damage the refrigerant oil.)
Note
• Installation tools:
Gauge manifold, charge hose, etc.
Make sure to use installation tools that are exclusively used for
R410A installations to withstand the pressure and to prevent
foreign materials (e.g. mineral oils such as SUNISO and mois-
ture) from mixing into the system.
(The screw specifications differ for R410A and R407C.)
Vacuum pump
1.
Use a 2-stage vacuum pump with a non-return valve.
2.
Make sure the pump oil does not flow oppositely into the sys-
tem while the pump is not working.
3.
Use a vacuum pump which can evacuate to –100.7 kPa (5Torr,
–755mmHg).
9-1 Selection of piping material
1.
Foreign materials inside pipes (including oils for fabrication) must
be 30mg/10m or less.
2.
Use the following items for the refrigerant piping.
Material : Jointless phosphor-deoxidized copper pipe
Size : See “Example of connection” to determine the correct
size.
Thickness : Select a thickness for the refrigerant piping which
complies with national and local laws.
For R410A, the design pressure is 4.0 MPa (40-bar).
The minimum thickness of piping according to Japan’s High-
Pressure Gas Safety Law (as of January 2003) is shown
below.
Temper grade (O type, 1/2H type) in the table indicate the
material types specified in JIS H 3300.
(unit : mm)
(unit : mm)
3.
Make sure to use the particular branches of piping that have been
selected referring to chapter “Example of connection”.
4.
Refer to chapter “Shutoff valve operation procedure” in 9-10 about
the shutoff valve operation procedure.
5.
Make sure to perform the piping installation within the range of the
maximum allowable pipe length, allowable level difference and
allowable length after branching as indicated in chapter “Example
of connection”
6.
For installation of the refrigerant branching kit, refer to the instal-
lation manual delivered with the kit.
And follow the conditions listed below.
• Mount the REFNET joint so that it branches either horizontally
or vertically.
• Mount the REFNET header so that it branches horizontally.
(Refer to figure 22)
1. Horizontal surface
2. With in 30° against horizontal surface
3. Horizontal surface
7.
The outside unit multi connection piping kit that is sold separately
as an option (BHFP22MA56·84, BHFP26MA56·84) is necessary
for the multi installation of outside units. See the installation man-
ual attached to the kit with attention to the following restrictions
when installing.
Restriction for the installation of the outside unit multi connec-
tion piping kit
• Install the joint horizontally within a lean of ±15°with caution
nameplate on top. Refer to figure 23 (Fig. A)
Do not connect it vertically. Refer to figure 23 (Fig. B)
• Reserve the straight part of 500mm or more to the branch pipe
and do not bend the local pipe in that area.Straight part of 500mm
or more can be reserved if a local pipe (straight pipe) of 120mm or
more is connected to the joint. Refer to figure 23 (Fig. C)
• Incorrect installation may cause breakage of outside unit.
(Refer to figure 23)
1. Caution nameplate
2. Horizontal line
3. Ground
4. Straight part of 500mm or more
5. Local pipe
(120mm length or more)
9-2 Protection against contamination when
installing pipes
• Take measures to prevent foreign materials like moisture and
contamination from mixing into the system.
• Great caution is needed when passing copper tubes through
walls.
9-3 Pipe connection
• Only use the flare nuts included with the unit.
Using different flare nuts may cause the refrigerant to leak.
• Be sure to perform a nitrogen blow when brazing.
(Brazing without performing nitrogen replacement or releasing
nitrogen into the piping will create large quantities of oxidized
film on the inside of the pipes, adversely affecting valves and
compressors in the refrigerating system and preventing nor-
mal operation.)
Caution
Do not use anti-oxidants when brazing the pipe joints.
Residue can clog pipes and break equipment.
Note
• For nitrogen replacement method,
see the “Installation Manual” (contact your dealer).
• The pressure regulator for the nitrogen released when doing the
brazing should be set to 0.02 MPa(0.2kg/cm 2 ) or less.
(Refer to figure 18)
1. Refrigerant pipe
2. Location to be brazed
3. Nitrogen
4. Taping
5. Manual valve
6. Regulator
Precautions when connecting pipes
• See the following table for flare part machining dimensions.
• When connecting the flare nuts, apply refrigerant oil to the inside
and outside of the flares and screw them in by hand three or four
times at first.
(Use ester oil or ether oil.)
• See the following table for tightening torque.
(Applying too much torque may cause the flares to crack.)
• After all the piping has been connected, check the gas leak with
nitrogen.
Temper grade O type
outer diameter
φ
6.4
φ
9.5
φ
12.7
φ
15.9
smallest thickness 0.80 0.80 0.80 0.99
Temper grade 1/2H type
outer diameter
φ
19.1
φ
22.2
φ
25.4
φ
28.6
φ
31.8
φ
34.9
φ
38.1
φ
41.3
smallest thickness 0.80 0.80 0.88 0.99 1.10 1.21 1.32 1.43
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
pipe size
tightening
torque (N · m)
A (mm) flare shape
φ
9.5
32.7 - 39.9 12.8 - 13.2
φ
12.7
49.5 - 60.3 16.2 - 16.6
φ
15.9
61.8 - 75.4 19.3 - 19.7
R=0.4~0.8
45˚±2
90˚±2
A
01_EN_3P153897-8L.fm Page 9 Friday, July 11, 2008 5:04 PM