16
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
no
t use
the
flare
nut
of
the
existing
pipe.)
•
Re-machine
the
flare
m
achining
size
to
size
for
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
In 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 pressure of R32 is high (1.6 t
imes
that of R22). If there is a scratch or dent on the pipe
or
a
thinner
pipe
is
used,
the
pressure
stren
gth
may
be
inad
equate,
which
may
cause
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 ge
nerated.
6.
When the existing air conditioner is removed after
refrigeran
t has been recovered.
Check
if
the
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
oil,
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-insulation
of
the
compressor
m
ay
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 remains inside the pipes.
W
ARNING
NOTE
Is it possible to operate the existing air conditioner?
•
Remove the existing a
ir conditioner from the piping
and
carry
out
flushing
(nitrogen
pressure
0.5
MPa)
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
NO
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 cleaning the pipes
and recovering oil
•
Refrigerant 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
9.1
13.2
16.6
For R22
9.0
13.0
16.2
Copper pipe outer diameter
Ø6.4
Ø9.5
Ø12.7
For
R32,
R410A
17
22
26
For R22
Same as above
24
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