14
Piping
necessary
to
change
the
flare
nut
/
machining
size due to pipe compression
1) Flare nut width: H
(mm)
2) Flare machining size:
A
(mm)
Becomes a little larger for R32
Do not apply refrigerator oil to the flare surface.
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-machin
e the flare machining size to size fo
r R32.
APPENDIX
APPENDIX
W
ork instructions
The existing R22 and R410A
piping can be reused for
inverter R32 product installations.
Confirming
the
existence
of
scratches
or
dents
on
the
existing
pipes
and
confirming
the
reliability
of
the pipe strength are conventionally referred to the local site.
If
the
specifled
conditions
can
be
cleared,
it
is
possible to update existing R22 and R410A
pipes
to those for R32 models.
Basic conditions needed to reuse existing pipes
Check and observe the presence of three conditions in the refrigerant piping works. 1.
Dry
(There is no moisture inside of the pipes.)
2.
Clean
(There is no dust inside of the pipes.)
3.
Tight
(There are no refrigeran
t leaks.)
Restrictions for use of existing pipes
I
n the following cases, the existing pipes should not be reused as they are. Clean the existing pipes or exchange them with new pipes.
1.
When a scratch or dent is heavy
, be sure to use new
pipe
s for the refrigera
nt piping works.
2.
When the existing pip
e thickness is thinner than the
specified “Pipe diame
ter and thickness,” be sure to
use new pipes for the refrigerant piping works.
•
The operating pres
sure of R32 is high (1.6
items
that of R22 and R4
10A). If there is a scratch or dent
on the pipe or a thin
ner pipe is used, the pr
essure
strength may be ina
dequate, which may ca
use the
pipe to break in the worst case.
*
Pipe
diameter
and
thickness
(mm)
5.
When a commercially
available dryer is attached to the
existing pipes.
•
There is the possibility that copper green ru
st has
been generated.
6.
When the existing air conditioner is removed after
refrigeran
t has been recovered.
Check if t
he oil is judg
ed to be clearly different from
normal oil.
•
The refrigerator oil
is copper rust green in c
olor:
There is the possibility that moisture has mi
xed with
the oil and rust has been generated inside t
he pipe.
•
There is discolored
oil, a large quantity of re
sidue,
or a bad smell.
•
A large quantity of shiny metal dust or other
wear
residue
can be seen in the refrigerant oil.
7.
When the air conditio
ner has a history of the
compressor failing an
d being replaced.
•
When discolored oi
l, a large quantity of resi
due,
shiny metal dust, or other wear residue or m
ixture of
foreign
matter is observed, trouble will occu
r.
8.
When temporary insta
llation and removal of the air
conditione
r are repea
ted such as when leased etc.
9.
If th
e type of refrigerator oil of the existing air
conditione
r is other than the following oil (Mineral oil),
Suniso, Freol-S, MS (Synthetic oil), alkyl benzene
(HAB, Barrel-freeze), ester series, PVE only of ether
series.
•
The win
ding-insula
tion of the compressor may
deteriorate.
The above descriptions are results have been confirmed
by our company and represent our views on our air conditioners, but do not guarantee the use of the existing pipes of air conditioners that have adopted R32 in other companies.
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 moistu
re or
foreign matter due to condensation enters the
pipes.
•
The rust cannot be rem
oved by cleaning, and n
ew
pipe
s are necessary
.
3.
When the outdoor uni
t was left with the pipes
disconnec
ted, or the gas leaked from the pipes and
the pipes were not repaired and refilled.
•
There is the possibility of rain water or air
, including
moisture, entering the pipe.
4.
When refrigerant cann
ot be recovered using a
refrigeran
t recovery unit.
•
There is the possibility that a large quantity
of dirty
oil or moisture rema
ins inside the pipes.
W
ARNING
NOTE
Is it possible to operate the existing air conditioner?
•
Remove the existing a
ir conditioner from the p
iping
and carry out flushing
(nitrogen pressure 0.5 M
Pa) to
remove any remains in
side of the pipe.
Note:
In case of twin pipes, also be sure to flush
the
branching pipe.
W
as 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
.)
Nitrogen gas pressure 0.5 MPa
Clean the pipes or use new pipes.
(If there is discharge of remains, it is judged that a large quantity of remains are present.)
NO
NO
YES
YES
YES
H
Existing pipes: Cannot be used. •
Use new pipes.
Are there scratches or dents on the existing pipes?
•
After the existing air co
nditioner is operated in
cooling
mode for approx. 30 minutes or longer
,* recover the
refrigerant.
•
For cleani
ng the pipes
and recovering oil
•
Refriger
ant recovery: Pump down method
Test run
•
(Airtight test), V
acuum dry
, Refrigerant charge, Gas
leak check
A
Pipe outer diameter
Ø6.4
Ø9.5
Ø12.7
Thickness
R32, R410A
0.8
0.8
0.8
R22
Placement location
Term
Curing manner
Outdoors
1 month or more
Pinching
Less than 1 month
Pinching or taping
Indoors
Every time
Copper pipe outer diameter
Ø6.4
Ø9.5
Ø12.7
For R32, R410A
17
22
26
For R22
Same as above
24
Copper pipe outer diameter
Ø6.4
Ø9.5
Ø12.7
For R32, R410A
9.1
13.2
16.6
For R22
9.0
13.0
16.2
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