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5.3. Connecting the piping
BENDING PIPES
(1) When bending the pipe, be careful not to crush it.
(2) To prevent breaking of the pipe, avoid sharp
bends.
Bend the pipe with a radius of curvature of
150 mm or over.
(3) If the copper pipe is bend the pipe or pulled
to often, it will become stiff. Do not bend the
pipes more than three times at one place.
FLARING
(1) Cut the connection pipe to the necessary
length with a pipe cutter.
(2) Hold the pipe downward so that cuttings will
not enter the pipe and remove the burrs.
(3) Insert the flare nut onto the pipe and flare
the pipe with a fl aring tool.
Insert the flare nut (always use the flare nut
attached to the indoor and outdoor units respectively) onto the pipe and perform the fl are
processing with a fl are tool.
Use the special R410A fl are tool, or the conventional (for R22) fl are tool.
When using the conventional fl are tool, always use an allowance adjustment gauge and
secure the A dimension shown in Table 2.
ADAPTER
12 type only
Connection ports of outdoor unit
• When using the ADAPTER, be careful not to overtighten the nut, or the smaller pipe
may be damaged.
• Apply a coat of refrigeration oil to the threaded connection port of the outdoor unit
where the fl are nut comes in.
• Use appropriate wrenches to avoid damaging the connection thread by overtightening
the fl are nut.
• Apply wrenches on both of fl are nut (local part), and ADAPTER to tighten them.
Adapter tightening torque
Adapter type [mm]
ø12.7 → ø9.52
CONNECTION
(1) Install the outdoor unit wall cap (supplied with the optional installation set or pro-
cured at the site) to the wall pipe.
(2) Connect the outdoor unit and indoor unit piping.
(3) After matching the center of the fl are surface and tightening the nut hand tight,
tighten the nut to the specifi ed tightening torque with a torque wrench. (Table 1)
Tighten with two wrenches.
Wrench (fi xed)
Flare nut
Torque
wrench
Connection
Indoor unit pipe
Table 1
Flare nut size and tightening torque
Flare nut [mm (in.)]
6.35 (1/4) dia.
9.52 (3/8) dia.
12.70 (1/2) dia.
15.88 (5/8) dia.
19.05 (3/4) dia.
Table 2
Pipe outside diameter
Pipe outside diameter
[mm (in.)]
6.35 (1/4)
9.52 (3/8)
12.70 (1/2)
15.88 (5/8)
19.05 (3/4)
Fasten a fl are nut with a torque wrench as instructed in this manual. If fastened too
tight, the fl are nut may be broken after a long period of time and cause a leakage of
refrigerant.
During installation, make sure that the refrigerant pipe is attached fi rmly before you run
the compressor. Do not operate the compressor under the condition of refrigerant piping
not attached properly with 2-way or 3-way valve open. This may cause abnormal pres-
sure in the refrigeration cycle that leads to breakage and even injury.
En-5
Check if [L] is fl ared uniformly and
is not cracked or scratched.
Die
Tightening torque
49 to 61 [N·m] (490 to 610 kgf·cm)
To prevent gas leakage, coat the fl are
pipe
surface with refrigerator oil.
Tightening torque [N•m (kgf•cm)]
16 to 18 (160 to 180)
32 to 42 (320 to 420)
49 to 61 (490 to 610)
63 to 75 (630 to 750)
90 to 110 (900 to 1100)
Dimension A [mm]
Flare tool for R410A, clutch type
0 to 0.5
CAUTION
5.4. Air purge
Always use a vacuum pump to purge the air.
Refrigerant for purging the air is not charged in the outdoor unit at the factory.
Close the high pressure side valve of the gauge manifold fully and do not operate it during
the following work.
Refrigerant must not be discharged into atmosphere.
After connecting the piping, check the joints for gas leakage with gas leak detector.
Gas leak checks are performed using either vacuum or nitrogen gas, so select the proper
one depending on the situation.
Checking gas leaks with vacuum:
(1) Check if the piping connections are secure.
(2) Remove the cap of 3-way valve, and connect the gauge manifold charge hoses to the
A
charging port of the 3-way valve.
(3) Open the valve of the gauge manifold fully.
Pipe
(4) Operate the vacuum pump and start pump down.
(5) Check that the compound pressure gauge reads -0.1 MPa (76 cmHg), operate the
vacuum pump for at least 1 hour.
(6) At the end of pump down, close the valve of the gauge manifold fully and stop the
vacuum pump.
(It checks that leave as it is for about 10 minutes, and a needle does not return.)
(7) Disconnect the charge hose from the 3-way valve charging port.
(8) Remove the blank caps, and fully open the spindles of the 2-way and 3-way valves
with a hexagon wrench.
[torque: 6 to 7 N·m (60 to 70 kgf·cm)].
(9) Tighten the blank caps and charging port cap of the 2-way valve and 3-way valve to
the specifi ed torque.
Checking gas leaks with nitrogen gas:
(1) Check if the piping connections are secure.
(2) Remove the cap of 3-way valve, and connect the gauge manifold charge hoses to
the charging port of the 3-way valve.
(3) Pressurize with nitrogen gas using the 3-way valve charging port.
(4) Do not pressurize up to the specifi ed pressure all at once but do so gradually.
1 Increase the pressure up to 0.5 MPa (5 kgf/cm
and then check for any decrease in pressure.
2 Increase the pressure up to 1.5 MPa (15 kgf/cm
and then check for any decrease in pressure.
3 Increase the pressure up to the specifi ed pressure (the pressure designed for the
product) and then make a note of it.
(5) Let it sit at the specifi ed pressure and if there is no decrease in pressure then it is
satisfactory. If a pressure decrease is confi rmed, there is a leak, so it is necessary to
specify the leak location and make minor adjustments.
(6) Discharge the nitrogen gas and starting removing the gas with a vacuum pump.
(7) Open the valve of the gauge manifold fully.
(8) Operate the vacuum pump and start pump down.
(9) Check that the compound pressure gauge reads -0.1 MPa (76 cmHg), operate the
vacuum pump for at least 1 hour.
(10) At the end of pump down, close the valve of the gauge manifold fully and stop the
vacuum pump.
(11) Disconnect the charge hose from the 3-way valve charging port.
(12) Remove the blank caps, and fully open the spindles of the 2-way and 3-way valves
with a hexagon wrench.
[torque: 6 to 7 N·m (60 to 70 kgf·cm)].
(13) Tighten the blank caps and charging port cap of the 2-way valve and 3-way valve to
the specifi ed torque.
3-way valve
Charging port cap
Blank cap
Charging port cap
CAUTION
Compound pressure gauge
-0.1 MPa
-
2
way valve
(-76 cmHg
Flare nut
-1 bar)
Low pressure
side valve
Valve stem
Blank cap
Charging port
Tightening torque
6.35 mm (1/4 in)
20 to 25 N·m (200 to 250 kgf·cm)
9.52 mm (3/8 in.)
20 to 25 N·m (200 to 250 kgf·cm)
12.70 mm (1/2 in.)
28 to 32 N·m (280 to 320 kgf·cm)
15.88 mm (5/8 in.)
30 to 35 N·m (300 to 350 kgf·cm)
19.05 mm (3/4 in.)
35 to 40 N·m (350 to 400 kgf·cm)
12.5 to 16 N·m (125 to 160 kgf·cm)
2
), let it sit for about fi ve minutes
2
), let it sit for about fi ve minutes
Gauge manifold
Pressure gauge
High
pressure
side valve
(closed)
Charge
hose
Charge hose
Vacuum pump
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