En-5
4.
PIPE INSTALLATION
CAUTION
Be more careful that foreign matter (oil, water, etc.) does not enter the piping than with
refrigerant R410A models. Also, when storing the piping, securely seal the openings by
pinching, taping, etc.
While welding the pipes, be sure to blow dry nitrogen gas through them.
4.1. Selecting the pipe material
CAUTION
Do not use existing pipes from another refrigeration system or refrigerant.
Use pipes that have clean external and internal sides without any contamination which
may cause trouble during use, such as sulfur, oxide, dust, cutting waste, oil, or water.
It is necessary to use seamless copper pipes.
Material : Phosphor deoxidized seamless copper pipes
It is desirable that the amount of residual oil is less than 40 mg/10 m.
Do not use copper pipes that have a collapsed, deformed, or discolored portion
(especially on the interior surface). Otherwise, the expansion valve or capillary tube
may become blocked with contaminants.
Improper pipe selection will degrade performance. As an air conditioner using R410A
incurs pressure higher than when using conventional (R22) refrigerant, it is necessary
to choose adequate materials.
•
Thicknesses of copper pipes used with R410A are as shown in the table.
•
Never use copper pipes thinner than those indicated in the table even if they are
available on the market.
Thicknesses of Annealed Copper Pipes (R410A)
Pipe outside diameter [mm (in)]
Thickness [mm]
6.35 (1/4)
0.80
9.52 (3/8)
0.80
12.70 (1/2)
0.80
15.88 (5/8)
1.00
19.05 (3/4)
1.20
4.2. Pipe requirement
CAUTION
Refer to the Installation Manual of the outdoor unit for description of the length of
connecting pipe or for difference of its elevation.
• Use pipe with water-resistant heat insulation.
CAUTION
Install heat insulation around both the gas and liquid pipes. Failure to do so may cause
water leaks.
Use heat insulation with heat resistance above 120 °C. (Reverse cycle model only)
In addition, if the humidity level at the installation location of the refrigerant piping is
expected to exceed 70 %, install heat insulation around the refrigerant piping. If the
expected humidity level is 70 to 80 %, use heat insulation that is 15 mm or thicker and
if the expected humidity exceeds 80 %, use heat insulation that is 20 mm or thicker.
If heat insulation is used that is not as thick as speci
fi
ed, condensation may form on
the surface of the insulation. In addition, use heat insulation with heat conductivity of
0.045 W/(m·K) or less (at 20 °C).
3.3.4. Fix the unit
(1) Hang the unit
Hanger bolt
Nut A
(Locally purchased)
Nut B
(Locally
purchased)
Washer
(Accessories)
Hanger
Hanger bolt
Nut A
(Locally purchased)
Washer
(Accessories)
Nut B
(Locally purchased)
Unit
Hanger
20 mm
or less
20 mm
or less
If the length of hanger bolt is over 20 mm, it will be not convenient for following works:
• The opening and closing of control box cover
• Replacement of drain pump
(2) Leveling
Base horizontal direction leveling on top of the unit.
Ceiling
Level
GOOD
PROHIBITED
10 mm or less
Give a slight tilt to the side to which the drain hose is connected. The tilt should be in the
range of 0 mm to 10 mm.
Level
Air
GOOD
PROHIBITED
5 mm or less
CAUTION
Leave a space of 100 mm or more between the inlet port and the ceiling.
Fasten the unit securely with nuts A and B.
Drain hose
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