Table of Contents
Advertisement
Curing of pipes
When removing and opening the indoor or outdoor unit
for a long time, cure the pipes as follows:
Otherwise rust may be generated when moisture or
foreign matter due to condensation enters the pipes.
The rust cannot be removed by cleaning, and new
pipes are necessary.
Placement
Term
Curing manner
location
1 month or more
Pinching
Outdoors
Less than 1 month
Pinching or taping
Indoors
Every time
41-EN
– 21 –
Are there scratches or dents on the existing pipes?
NO
Is it possible to operate the existing air conditioner?
YES
After the existing air conditioner is operated in
cooling mode for approx. 30 minutes or longer,*
recover the refrigerant.
Refer to "13 Refrigerant recovery".
For cleaning the pipes and recovering oil
Refrigerant recovery: Pump down method
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.
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.)
NO
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.
In case that the gas pipe Ø19 mm is used for the
outdoor unit of GV80 (3 HP) or higher : (Our R32
model 3 to 6 HP gas pipe size is Ø15.9 mm)
See page 19 "Existing piping".
(Airtight test), Vacuum dry, Refrigerant charge, Gas
leak check
Test run
YES
Existing pipes: Cannot be used.
Use new pipes.
NO
Nitrogen gas pressure 0.5 MPa
(If there is discharge of remains, it is judged that a
large quantity of remains are present.)
YES
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
Copper
pipe outer
Ø6.4
Ø9.5
Ø12.7 Ø15.9 Ø19.0
diameter
For R32,
17
22
26
29
R410A
Same
H
Same as
For R22
24
27
above
above
2) Flare machining size: A
Copper
pipe outer
Ø6.4
Ø9.5
Ø12.7 Ø15.9 Ø19.0
A
diameter
For R32,
9.1
13.2
16.6
19.7
24.0
R410A
For R22
9.0
13.0
16.2
19.4
23.3
Becomes a little larger for R32/R410A
Do not apply refrigerator oil to the flare surface.
(mm)
36
as
(mm)
42-EN
Advertisement
Table of Contents
