7. Installing refrigerant piping
Table 1
(mm (in))
Copper pipe O.D.
Flare dimensions
øA dimensions
ø6.35 (1/4) 8.7-9.1 (11/32-23/64)
ø9.52 (3/8) 12.8-13.2 (1/2-33/64)
ø12.7 (1/2) 16.2-16.6 (41/64-21/32)
ø15.88 (5/8) 19.3-19.7 (49/64-25/32)
(in)
► Connect the liquid and gas pipes of each indoor unit to the same end
connection numbers as indicated on the indoor unit flare connection
section of each Branch Box. If connected to wrong end connection
numbers, it doesn’t work normally.
► When connecting indoor units, make sure to connect refrigerant pipes
and connection wires to the appropriate connection ports marked with
matching alphabets. (Ex. A, B, C, D, E) If connected to wrong end con-
nection numbers, it doesn't work normally.
Note:
Be sure to mark all the local refrigerant piping (liquid pipes, gas pipes, etc.)
for each indoor unit designating clearly which room it belongs in. (Ex. A, B,
C, D, E)
► List indoor unit model names in the name plate of Branch Box (for iden-
tification purposes).
• Conductsucientanti-condensationandinsulationworktopreventwaterdrip-
ping from the refrigerant piping. (liquid pipe/gas pipe)
• Increase insulation depending on the environment where the refrigerant piping is
installed, or condensation may occur on the surface of the insulation material.
(Insulation material Heat-resistant temperature: 120 °C [248 °F], Thickness:
15 mm [19/32 in] or more)
* When the refrigerant piping is used in locations subject to high temperature
and humidity such as in the attic, further addition of insulation may be re-
quired.
• Insulate the liquid and gas pipes of the branch box by attaching the heat-resis-
tant polyethylene foam tightly around them. (Fig. 7-3)
Otherwise, a burn during pipe connection work or water leakage due to con-
densation on pipes may result. If connected to wrong end connection numbers,
it doesn't work normally.
► When using commercially available refrigerant piping, ensure that both
liquid and gas piping are wrapped with commercially available thermal
insulation materials (insulation materials at least 1/2 in (12 mm) thick
and able to withstand temperatures in excess of 100ºC [212°F]).
► Refer to the installation manual of the outdoor unit when creating a
vacuum and opening or closing valves.
7.1. Piping connection procedure
(1)Removethearednutsandcapsfromthebranchbox.
(2) Flare the end of the liquid and gas pipes as shown in Fig. 7-1.
(3)Applyrefrigerantoilonthearedseat.(Fig.7-2)
Usethearenutremovedfromthebranchbox.Useofano-the-shelfnut
may lead to a crack in the nut.
Forconnection,rstalignthecenter,thentightentherst3to4turnsofare
nut by hand.
(4)Connecttherefrigerantpipingimmediately.Alwaystightenthearednutsto
thetorquespeciedintheTable2usingatorquewrenchanddoublespan-
ner.
Fig. 7-1
Table 2 (mm (in))
Copper pipe O.D.
(mm (in))
Flare nut O.D.
(mm (in))
Tightening torque
(N•m (ft•lbs))
ø6.35 (1/4) 17 (43/64) 14-18 (10-13)
ø6.35 (1/4) 22 (7/8) 34-42 (25-30)
ø9.52 (3/8) 22 (7/8) 34-42 (25-30)
ø9.52 (3/8) 26 (1-3/64) 49-61 (35-44)
ø12.7 (1/2) 26 (1-3/64) 49-61 (35-44)
ø12.7 (1/2) 29 (1-9/64) 68-82 (49-59)
ø15.88 (5/8) 29 (1-9/64) 68-82 (49-59)
ø15.88 (5/8) 36 (1-27/64) 100-120 (71-87)
Flare cutting dimensions
Caution:
• Tighten the are nut with a torque wrench in the specied method.
Overtightening will cause the are nut to crack and it will cause refrigerant
leakage over a period of time.
• Follow the instructions below to prevent abrasive components contained in
sandpaper and cutting tools from entering the refrigerant circuit because
those components can cause failures of the compressor and valves.
- To deburr pipes, use a reamer or other deburring tools, not sandpaper.
- To cut pipes, use a pipe cutter, not a grinder or other tools that use abrasive
materials.
- When cutting or deburring pipes, do not allow cutting chips or other foreign
matters to enter the pipes.
- Ifcuttingchipsorotherforeignmattersenterpipes,wipethemotheinsideof
the pipes.
øA
45°±2°
R1/64 to R1/32
90° ± 0.5°
Flare nut tightening torque
Apply refrigerant oil
Fig. 7-2
en
8
WG79B826H01_01en.indd 8 2023/01/13 13:42:50
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