Installation Manual
– 53 –
53-EN
Are there scratches or dents on the existing pipes?
Is it possible to operate the existing air conditioner?
After the existing air conditioner is operated in cooling
mode for approx. 30 minutes or longer,* recover the
refrigerant.
For cleaning the pipes and recovering oil
Refrigerant recovery: Pump down method
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 R32.
(Airtight test), Vacuum dry, Refrigerant charge,
Gas leak check
Test run
Was largely discolored oil or a large quantity
of remains discharged? (When the oil deteriorates,
the color of the oil changes to a muddy or
black color.)
Existing pipes: Cannot be used.
Use new pipes.
Clean the pipes or use new pipes.
Piping necessary to change the flare nut /
machining size due to pipe compression
1) Flare nut width: H
H
(mm)
Copper pipe
outer diameter
Ø6.4 Ø9.5 Ø12.7 Ø15.9
For R32, R410A 17 22 26 29
For R22 Same as above 24 27
2) Flare machining size: A
A
(mm)
Copper pipe
outer diameter
Ø6.4 Ø9.5 Ø12.7 Ø15.9
For R32, R410A 9.1 13.2 16.6 19.7
For R22 9.0 13.0 16.2 19.4
Becomes a little larger for R32
Do not apply refrigerator oil to the flare surface.
(If there is discharge of remains, it is judged that a
large quantity of remains are present.)
YES
YES
NO
NO
NO
YES
Nitrogen gas pressure 0.5 MPa
Remove the existing air conditioner from the piping
and carry out flushing (nitrogen pressure 0.5 MPa) to
remove any remains inside of the pipe.
Note: In case of twin pipes, also be sure to fl ush the
branching pipe.
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