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8. PIPE INSTALLATION II
Fig. A: Connection diagram
Pressure
gauge
Outdoor unit
Indoor
Indoor
Vacuum
unit
unit
pump
Tightening torque [N·m (kgf·cm)]
Liquid valve
Model
3-way valve
Blank cap
5.4 to 6.6
13.5 to 16.5
072
(55 to 67)
(138 to 168)
090/108/
8.1 to 9.9
18.0 to 22.0
126/144/
(83 to 101)
(184 to 224)
162
8.1. Sealing test
Use only nitrogen gas.
Never use refrigerant gas, oxygen, in flammable gas or poisonous gas to pressurize the
system. (If oxygen is used, there is the danger of an explosion.)
Do not apply shock during sealing test.
It can rupture the pipes and cause serious injury.
Do not turn on the power unless all operations are complete.
Do not block the walls and the ceiling until the sealing test and the charging of the
refrigerant gas have been completed.
After connecting the pipes, perform a sealing test.
Recheck that the 3-way valve are closed before performing a sealing test. (Fig. B)
Pour nitrogen gas through both the liquid pipe and the gas pipe.
Pressurize nitrogen gas to 4.2 MPa to perform the sealing test.
Check all flare connection areas and brazed areas.
Then, check that the pressure has not decreased.
Compare the pressures after pressurizing and letting it stand for 24 hours, and check that
the pressure has not decreased.
* When the outdoor temperature changes 5 °C, the test pressure changes 0.05 MPa.
If the pressure has dropped, the pipe joints may be leaking.
If a leakage is found, immediately repair it and perform a sealing test again.
* Decrease the pressure of nitrogen gas before blazing
After completing the sealing test, release the nitrogen gas from both valves.
Release the nitrogen gas slowly.
8.2. Vacuum process
Do not turn on the power unless all operations are complete.
If the system is not evacuated sufficiently, its performance will drop.
Be sure to evacuate the refrigerant system using a vacuum pump.
The refrigerant pressure may sometimes not rise when a closed valve is opened after
the system is evacuated using a vacuum pump. This is caused by the closure of the
refrigerant system of the outdoor unit by the electronic expansion valve. This will not
affect the operation of the unit.
Use a clean gauge manifold and charging hose that were designed specifically for use
with R410A. Using the same vacuum equipment for different refrigerants may damage
the vacuum pump or the unit.
Do not purge the air with refrigerants, but use a vacuum pump to evacuate the system.
• If moisture might enter the piping, follow below. (i.e., if doing work during the rainy
season, if the actual work takes long enough that condensation may form on the
inside of the pipes, if rain might enter the pipes during work, etc.)
• After operating the vacuum pump for 2 hours, pressurize to 0.05 MPa (i.e., vacuum
breakdown) with nitrogen gas, then depressurize down to -100.7 kPa (-755 mmHg) for
an hour using the vacuum pump (vacuum process).
• If the pressure does not reach -100.7 kPa (-755 mmHg) even after depressurizing for
at least 2 hours, repeat the vacuum breakdown - vacuum process.
After vacuum process, maintain the vacuum for an hour and make sure the pressure
does not rise by monitoring with a vacuum gauge.
En-15
Fig. B
Service hose
Pressure regu-
with valve core
lating valve
Charging
port
Nitrogen
Blank cap
Scale
Hexagon wrench
Liquid valve: size 4 mm
Gas valve: size 8 mm.
Gas valve
3-way valve
Blank cap
27.0 to 33.0
22.5 to 27.5
(275 to 337)
(229 to 280)
CAUTION
CAUTION
Evacuation procedure
(1) Remove the blank caps of the gas pipe and liquid pipe and check that the valves are
closed.
(2) Remove the charging port cap.
(3) Connect a vacuum pump and a pressure gauge to a charging hose and connect it to
the charging port.
(4) Activate the vacuum pump and vacuum the indoor unit and connection piping until
Charging
the pressure gauge becomes -100.7 kPa (-755mm Hg).
port cap
Evacuate from both the gas pipe and the liquid pipe.
(5) Continue evacuating the system for 1 hour after the pressure gauge reads -100.7
kPa (-755mm Hg).
3-way
(6) Remove the charging hose and reinstall the charging port cap.
valve
8.3. Additional charging
Connecting
pipe
Do not turn on the power unless all operations are complete.
After evacuating the system, add refrigerant.
Do not charge the system with a refrigerant other than R410A.
Always keep to the limit on the total amount of refrigerant. Exceeding the limit on the
total amount of refrigerant will lead to malfunction during charging of refrigerant.
Charging
Do not reuse recovered refrigerant.
port cap
Use an electronic scale to measure the charging amount of refrigerant.
Adding more refrigerant than the specified amount will cause a malfunction.
11.4 to 14.0
Charge refrigerant using the liquid pipe.
(116 to 143)
Adding refrigerant through the gas pipe will cause a malfunction.
Add refrigerant by charging the system with the refrigerant in the liquid state. If the
refrigerant cylinder is equipped with a siphon, it is not necessary to place the cylinder
upright.
Check if the steel cylinder has a siphon installed or not before filling. (There is an indica-
tion "with siphon for filling liquid" on the steel cylinder.)
Filling method
for cylinder with
siphon
Filling method for
other cylinders
Be sure to use the special tools for R410A for pressure resistance and to avoid mixing
of impure substances.
If the units are further apart than the maximum pipe length, correct operation cannot be
guaranteed.
Make sure to back closing valve after refrigerant charging. Otherwise, the compressor
may fail.
Minimize refrigerant release to the air. Excessive release is prohibited under the Freon
Collection and Destruction Law.
8.3.1 Procedure for charging the system with refrigerant
(1) Remove the charging port cap from the liquid pipe.
(2) Attach a charging hose to the refrigerant cylinder, and connect it to the charging port.
(3) Add refrigerant by calculating the additional refrigerant volume in accordance with
the calculation formula indicated below.
(4) Remove the charging hose and install the charging port cap.
(5) Remove the blank caps (gas pipe and liquid pipe) and open the valves.
(6) Close the blank caps.
(7) After adding refrigerant, indicate the added charging volume on the unit.
* Tighten the blank caps and charging port caps to the torque values specified in the
Table A. To open and close the valves, use a specified hexagon wrench.
8.3.2 Checking total amount of refrigerant and calculating the
amount of refrigerant charge to be added
• The amount of refrigerant charge to be added is the total value of the basic refrigerant
charge amount and the value calculated from the length of the liquid pipe.
• Round up the value to 2 decimal places.
Model
AJ*072LELBH
AJ*090LELBH
AJ*108LELBH
AJ*126LELBH
AJ*144LELBH
AJ*162LELBH
CAUTION
Set the cylinder vertical and fill with
R410A
Gas
the liquid.
(Liquid can be filled without turning
bottom up with the siphon inside.)
Liquid
Turn bottom up and fill with liquid.
R410A
Gas
(Be careful to avoid turning over the
cylinder.)
Liquid
"B"
Diameter of liquid
Factory charged
pipe (mm)
amount (kg)
7.0
Ø 6.35
7.5
Ø 9.52
7.5
Ø 12.70
11.0
11.0
11.8
"a"
Additional amount
for pipe length (kg/m)
0.021
0.058
0.114
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