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6-6-5. Final Installation Checks
Do not apply the refrigerator oil to the flare surface.
Existing pipe: NO * Use a new pipes.
Clean the pipes or use the new pipes.
Trial run
Is it possible to operate the existing air conditioner?
Was not largely discolored oil or
a large quantity of remains discharged?
(When the oil deteriorates, the color of the
oil changes to muddy and black color.)
∗ After the existing air conditioner operated in cooling mode
for approx. 30 minutes or longer*, recover the refrigerant.
∗ For cooling the pipes and recovering of oil
• Refrigerant recovery: Pump down method
∗ Remove the existing air conditioner from the piping and
carry out flashing (nitrogen pressure 0.5 Mpa) to remove
the remains inside of the pipe.
Note] In case of twin, also be sure to flash the
branching pipe.
Connect the indoor/outdoor units to the existing pipe.
• Use a flare nut attached to the main unit for the
indoor/outdoor units.
(Do not use the flare nut of the existing pipe.)
• Re-machine the flare machining size to size for R410A.
∗ (Airtight test), Vacuum dry, Refrigerant charge,
Gas leak check
When using a Ø19.1 mm pipe for the gas pipe of the first
branching pipe machining size due to pipe compression.
→ Turn the existing pipe switch on the cycle control
P.C. board of the outdoor unit to ON side.
At shipment from factory OFF → ON for existing pipe
(Refer to the table below.)
(Be sure to set the contents in the table below in order
to restrict the refrigerating cycle pressure of the
equipment in the pipe standard.)
Existing pipe SW
Nitrogen gas pressure 0.5 Mpa
H
A
(If there is discharge of remains,
it is judged that there is a large quantity of remains.)
If you are in trouble of
pipe cleaning, please contact us.
Piping necessary to change the flare nut/
machining size due to pipe compression.
1) Flare nut width: H
2) Flare machining size: A
(mm)
36
Ø19.1
29
Ø15.9
26
2724
Ø12.7
22
Ø9.5
17
Ø6.4
Same
as above
Copper pipe
outer dia.
For R22
For R410A
Same as above
(mm)
24.0
Ø19.1
19.7
Ø15.9
16.6
Ø12.7
13.2
Ø9.5
9.1
23.319.416.213.09.0
Ø6.4
Copper pipe
outer dia.
For R22
For R410A
Becomes large a little for R410A
Switch
Bit 3 of SW802 → ON
Is there no scratch or dent on the existing pipes?
YES
YES
NO
NO