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6
Refrigerant piping
CAUTION
When the refrigerant pipe is long, provide support
brackets at intervals of 8'2" to 9'8" (2.5 m to 3 m) to
clamp the refrigerant pipe. Otherwise, abnormal sound
may be generated.
Use the flare nut attached with the indoor unit or R410A
flare nut.
Permissible piping length
and height difference
They vary depending on the outdoor unit. For details,
refer to the Installation Manual attached to the outdoor
unit.
Pipe size
Model
SM182
SM242 to SM482
Gas side
1/2"(12.7)
5/8"(15.9)
Pipe size
(Dia. : in(mm))
Liquid side
1/4"(6.4)
Connecting refrigerant piping
Flaring
1. Cut the pipe with a pipe cutter.
Remove burrs completely.
(Remaining burrs may cause gas leakage.)
2. Insert a flare nut into the pipe, and flare the pipe.
Use the flare nut provided with the unit or the one
used for the R410A refrigerant. The flaring
dimensions for R410A are different from the ones
used for the conventional R22 refrigerant. A new
flare tool manufactured for use with the R410A
refrigerant is recommended, but the conventional
tool can still be used if the projection margin of the
copper pipe is adjusted to be as shown in the
following table.
25-EN
Projection margin in flaring: B (Unit: in (mm))
Outer dia. of
R410A tool used
copper pipe
1/4"(6.4), 3/8"(9.5)
0 to 0.04"(1.1)
1/2"(12.7), 5/8"(15.9)
Flaring diameter size: A (Unit: in (mm))
Outer dia. of copper pipe
1/4"(6.4)
3/8"(9.5)
1/2"(12.7)
5/8"(15.9)
3/8"(9.5)
* In case of flaring for R410A with the conventional
flare tool, pull it out approx. 0.02" (0.5 mm) more
than that for R22 to adjust to the specified flare size.
The copper pipe gauge is useful for adjusting
projection margin size.
• The sealed gas was sealed at the atmospheric
pressure so when the flare nut is removed, there will
no "whooshing" sound: This is normal and is not
indicative of trouble.
• Use two wrenches to connect the indoor unit pipe.
Work using double spanner
� 13 �
• Use the tightening torque levels as listed in the
following table.
Outer dia. of connecting
pipe (in (mm))
Conventional
1/4" (6.4)
tool used
3/8" (9.5)
0.04"(1.0) to
1/2" (12.7)
0.06"(1.5)
5/8" (15.9)
• Tightening torque of flare pipe connections.
Pressure of R410A is higher than that of R22.
(Approx. 1.6 times) Therefore, using a torque
wrench, tighten the flare pipe connecting sections
which connect the indoor and outdoor units of the
specified tightening torque.
Incorrect connections may cause not only a gas leak,
but also a trouble of the refrigeration cycle.
CAUTION
+0
A
�0.02(0.4)
Tightening with an excessive torque may crack the nut
0.35"(9.1)
depending on installation conditions.
0.52"(13.2)
0.65"(16.6)
0.78"(19.7)
Piping with outdoor unit
Shape of valve differs according to the outdoor unit.
For details of installation, refer to the Installation
Manual of the outdoor unit.
Airtight test / Air purge, etc.
For airtight test, air purge, addition of refrigerant, and
Tightening torque
gas leak check, refer to the Installation Manual
(ft•lbs (N•m))
attached to the outdoor unit.
10.1 to 13.0 (14 to 18)
REQUIREMENT
24.6 to 30.4 (34 to 42)
Do not supply power to the indoor unit until the airtight
35.4 to 44.1 (49 to 61)
test and vacuuming are completed. (If the indoor unit is
45.5 to 55.7 (63 to 77)
powered on, the pulse motor valve is fully closed, which
extends the time for vacuuming.)
Open the valve fully
Open the valve of the outdoor unit fully.
For details, refer to the Installation Manual attached to
the outdoor unit.
Heat insulation process
Apply heat insulation for the pipes separately at liquid
side and gas side.
For the heat insulation to the pipes at gas side, be sure
to use the material with heat-resisting temperature
248 °F (120 °C) or higher.
Using the attached heat insulation material, apply the
heat insulation to the pipe connecting section of the
indoor unit securely without gap.
REQUIREMENT
• Apply the heat insulation to the pipe connecting
section of the indoor unit securely up to the root
without exposure of the pipe. (The pipe exposed to
the outside causes water leak.)
• Wrap heat insulator with its slits facing up (ceiling
side).
Wrap the pipe with the attached heat insulator
without any gap between the indoor unit.
Indoor unit
Heat insulation
Union
pipe
(Accessory)
The seam must be faced upward
(ceiling side).
Flare nut
Heat insulator
of the pipe
Banding band
(Locally
procured)
26-EN
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