Daikin RXYMQ36PVJU [12/20] 2 selecting piping material

Daikin RXYMQ36PVJU [12/20] 2 selecting piping material
English 8
Vacuum pump
Use extreme caution to prevent pump oil from flowing backwards
through the system when the pump is stopped.
Use a vacuum pump which can evacuate to –14.6PSI.
7-2 Selecting piping material
Use pipes that have no contaminants adhered to their inner surfaces
(such as sulfur, iron oxide, dust, cutting chips, oil and moisture). (It is
desirable that adhered oil inside the piping is 0.002lb. (9mg) or less per
10ft.)
The wall thickness of the refrigerant piping should comply with local
laws and regulations. The design pressure for R410A is 478PSI.
Use the following material for the refrigerant piping.
Material: Jointless phosphor-deoxidized copper pipe.
Thickness and size: choose based on the piping size selection
method on the “7-8 Air tight test and vacuum drying”.
Make sure to use the separately sold refrigerant branch kit when
branching the piping.
Piping work should be done within the maximum length, height dif-
ference, and length after branches set out in “7-8 Air tight test and
vacuum drying”.
Install the refrigerant branch kit while observing the following condi-
tion and referring to the installation manual offered as an accessory
of the kit.
(Refer to figure 21)
1.
Install the REFNET joint so it splits horizontally or vertically.
2. Horizontal surface
3. A-arrow view
4. ±30° or less
5. Level
6. Vertical is also OK
7. Install the REFNET header so that it splits horizontally.
8. B-arrow view
7-3 Protection against contamination when install-
ing pipes
Wrap the piping to prevent moisture, dirt, dust, etc. from entering the
piping.
Exercise caution when passing copper piping through the through-
holes and when passing them out to the outside.
7-4 Pipe connection
See “Shutoff valve operation procedure” in7-8 Air tight test and
vacuum drying” regarding handling of the shutoff valve.
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 nitro-
gen 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 normal operation.)
NOTE
The nitrogen used when brazing while flowing the nitrogen should be
set to 2.9PSI (2.8PSI: just enough to feel a breeze on your cheek) with
the decompression valve.
Do not mix any refrigerant other than that specified into the refriger-
ant system.
Do not mix air into the refrigerant system.
CAUTION
Do not use a flux when brazing the refrigerant pipe joints.
Use phosphor copper brazing (BCuP-2/B-Cu93P-710/795) which
does not require flux.
(Using a chlorine flux may cause the pipes to corrode, and if it con-
tains fluoride it may cause the refrigerant lubricant to deteriorate,
adversely affecting the refrigerant piping system.)
(Refer to figure 22)
1. Refrigerant pipe
2. Location to be brazed
3. Regulator
4. Nitrogen
5. Manual valve
6. Taping
7-5 Connecting the refrigerant piping
The local interunit piping is connectable in four directions.
(Refer to figure 23)
1. Front panel
2. Pipe outlet panel
3. Backward
4. Sideways
5. Downward
6. Pipe outlet panel screw
7. Forward
8. Screw for front panel
When connecting the pipings downward, remove the knockout
by making four holes in the middle on the each side of the
knockout with a drill.
(Refer to figure 24)
1. Dril
2. Center area around knockout hole
3. Knockout hole
4. Slit
After knocking out the knock-out, it is recommended to apply repair
paint to the edge and the surrounding end surfaces to prevent rust-
ing.
(Refer to figure 25)
1. Bottom frame
2. Interunit piping
NOTE
Cutting out the two slits makes it possible to install as shown in figure 25.
(Use a metal saw to cut out the slits.)
<Precautions when connecting pipes>
Please refer to the Table 1 for the dimensions for processing flares.
When connecting the flare nut, coat the flare both inside and outside
with refrigerating machine oil and initially tighten by hand 3 or 4 turns
before tightening firmly.
Please refer to the Table 1 for the tightening torque. (Too much tight-
ening will end up in splitting of the flare.)
Ta ble 1
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 (ft·lbf)
A dimen-
sions for
processing
flares (in.)
Flare shape (in.)
φ
3/8”
(9.5mm)
24.1~29.4
0.504~0.520
(12.8~13.2mm)
φ
5/8”
(15.9mm)
45.6~55.6
0.760~0.776
(19.3~19.7mm)
A
45˚± 2˚
90˚± 2˚
R0.016~0.031
(0.4~0.8mm)
01_EN_3PN07193-6F.fm Page 8 Tuesday, September 1, 2009 4:13 PM

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