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EN-28 28
Super Digital Inverter
15
APPENDIX
Work instructions
The existing R22 and R407C piping can be reused for our
digital inverter R410A product installations.
WARNING
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 specified conditions can be cleared, it is possible
to update existing R22 and R407C pipes to those for
R410A 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 refrigerant 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
pipes for the refrigerant piping works.
2. When the existing pipe thickness is thinner than the
specified “Pipe diameter and thickness,” be sure to use
new pipes for the refrigerant piping works.
• The operating pressure of R410A is high (1.6 times
that of R22 and R407C). If there is a scratch or dent on
the pipe or a thinner pipe is used, the pressure strength
may be inadequate, which may cause the pipe to break
in the worst case.
* Pipe diameter and thickness (mm)
• In case the pipe diameter is Ø12.7 mm or less and the
thickness is less than 0.7 mm, be sure to use new
pipes for the refrigerant piping works.
3. When the outdoor unit was left with the pipes
disconnected, 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 cannot be recovered using a refrigerant
recovery unit.
• There is the possibility that a large quantity of dirty oil
or moisture remains inside the pipes.
5. When a commercially available dryer is attached to the
existing pipes.
• There is the possibility that copper green rust has been
generated.
6. When the existing air conditioner is removed after
refrigerant has been recovered.
Check if the oil is judged to be clearly different from
normal oil.
• The refrigerator oil is copper rust green in color:
There is the possibility that moisture has mixed with the
oil and rust has been generated inside the pipe.
• There is discolored oil, a large quantity of residue, 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 conditioner has a history of the compressor
failing and being replaced.
• When discolored oil, a large quantity of residue, shiny
metal dust, or other wear residue or mixture of foreign
matter is observed, trouble will occur.
8. When temporary installation and removal of the air
conditioner are repeated such as when leased etc.
9. If the type of refrigerator oil of the existing air conditioner
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 winding-insulation of the compressor may
deteriorate.
NOTE
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 R410A in other
companies.
Branching pipe for simultaneous operation system
• In the concurrent twin system, when TOSHIBA has
specified that branching pipe is to be used, it can be
reused.
Branching pipe model name:
RBC-TWP30E2, RBC-TWP50E2, RBC-TRP100E
On the existing air conditioner for simultaneous operation
system (twin, triple system), there are cases of branch
pipes being used that have insufficient compressive
strength.
In such case, please change the piping to a branch pipe
for R410A.
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.
Pipe outer diameter Ø6.4 Ø9.5 Ø12.7 Ø15.9Ø19.0
Thickness
R410A
0.8 0.8 0.8 1.0 1.0
R22
(R407C)
Placement location Term Curing manner
Outdoors
1 month or more Pinching
Less than 1 month
Pinching or taping
Indoors Every time
29 29-E
N
Super Digital Inverter
H
A
Nitrogen gas pressure 0.5 MPa
Existing pipes: Cannot be used.
• Use new pipes.
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 fl
are nut of the
existing pipe.)
• Re-machine the flare machining size to size for R410A.
In case that a gas pipe
Ø
19 mm or bigger is used for the
outdoor unit of SP80 (3 HP): (Our R410A model 3 to 6 HP
gas pipe size is
Ø
15.9 mm)
•
•
•
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
• (Airtight test), Vacuum dry, Refrigerant charge, Gas leak
check
• Remove the existing air conditioner from the piping and
carry out flushing (nitrogen pressure 0.5 MPa) to remove
any remains i
nside 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.)
(If there is discharge of
remains, it is judged that a
large quantity of remains are present.)
Piping necessary to change the flare nut/
machining size due to pipe compression
Clean the pipes or use new pipes.
In case of twin pipes, also be sure to flush the
branching pipe.
Note]
T
→
→
→
urn the existing pipe switch on the cycle control PC
board of the outdoor unit to ON side. At shipment from
factory O
FF 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
Test run
1) Flare nut width: H
2) Flare machining size: A
(mm)
(mm)
Becomes a little larger for R410A
For R410A
For R22
Copper pipe
outer
diameter
For R410A
For R22
Same as above
Same as
above
Do not apply refrigerator oil to the flare surface.
Bit 3 of SW802
ON
Switch
Ø6.4 Ø9.5 Ø12.7 Ø15.9 Ø19.0
17 22 26 29 36
24 27
Ø6.4 Ø9.5 Ø12.7 Ø15.9 Ø19.0
9.113.216.619.724.0
9.013.016.219.4 23.3
Copper pipe
outer
diameter
NO
YES
YES
YES
NO
NO
Are there scratches or dents on the existing pipes?
Is it possible to operate the existing air conditioner?