Existing Piping - Toshiba RAV-SM1104UT-E Data Book

Engineering Data
11

Existing Piping

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.
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)
Reference outside Wall thickness
diameter (mm)
12.7
15.9
22.2
28.6
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
• 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.
EN
Material
(mm)
0.8 —
1.0 —
1.0 Half hard
1.0 Half hard
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, double twin 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.
Placement location
Outdoors
Indoors
41
Term Curing manner
1 month or more
Less than 1 month
Pinching or taping
Every time
Pinching