6-6.Instructions For Re-Use Piping Of R22 Or R407C; 6-6-1.Basic Conditions Needed To Reuse The Existing Pipe; 6-6-2.Restricted Items To Use The Existing Pipes; 6-6-3.Branching Pipe For Simultaneous Operation System - Toshiba RAV-GP561ATW-E Service Manual

6-6. Instructions for Re-use Piping of R22 or R407C
Instruction of Works:
The existing R22 and R407C piping can be reused
for our digital inverter R32 products 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
R32 models.
6-6-1. Basic Conditions Needed to
Reuse the Existing Pipe
Check and observe three conditions of 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 is no refrigerant leak.)
6-6-2. Restricted Items to Use the
Existing Pipes
In the following cases, the existing pipes cannot 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 the
new pipes for the works.
(2) When the thickness of the existing pipe is thinner
than the specified "Pipe diameter and thickness" be
sure to use the new pipes for the works.
• The operating pressure of R32 is high. 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)
6.4
9.5
12.7
15.9
• In case that the pipe diameter is DIA 12.7 mm or
less and the thickness is less than 0.7 mm, be
sure to use the new pipes for 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 possibility that rain water or air including
moisture enters in the pipe.
(4) When refrigerant cannot be recovered using a
refrigerant recovery unit.
• There is possibility that a large quantity of poor oil
or moisture remains inside of the pipe.
(5) When a commercially available dryer is attached to
the existing pipes.
Material
(mm)
0.8 -
0.8 -
0.8 -
1.0 -
• There is possibility that copper green rust
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 like following.
• The refrigerator oil is copper rust green:
There is possibility that moisture is mixed with the
oil and rust generates inside of the pipe.
• There is discolored oil, a large quantity of the
remains, or bad smell.
• A large quantity of sparkle remained wear-out
powder is observed in the refrigerator oil.
(7) When the air conditioner has a history of the
compressor failing and being replaced.
• When discolored oil, a large quantity of residue,
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) When 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 of confirmation by
our company and they are views on our air
conditioners, but they do not guarantee the use of the
existing pipes of the air conditioner that adopted R32 or
R410A in other companies.
6-6-3. Branching Pipe for Simultaneous
Operation System
• In the concurrent twin system, when TOSHIBA-
specified branching pipe is used, it can be reused.
Branching pipe model name:
RBC-TWP30E2, RBC-TWP50E2
On the existing air conditioner for simultaneous
operation system (twin system), there is a case of
using branch pipe that has insufficient compressive
strength. In this case please change it to the branch
pipe for R32 or R410A.
6-6-4. Curing of Pipes
When removing and opening the indoor unit or outdoor
unit for a long time, cure the pipes as follows:
• Otherwise rust may generate when moisture or
foreign matter due to dewing enters in the pipes.
• The rust cannot be removed by cleaning, and a new
piping work is necessary.
Place position
Outdoors
Indoors
49
Term Curing manner
1 month or more Pinching
Less than 1 month
Pinching or taping
Every time