Instructions For Re-Use Piping Of R22 Or R407C; Basic Conditions Needed To Reuse The Existing Pipe; Restricted Items To Use The Existing Pipes; Branching Pipe For Simultaneous Operation System - Toshiba RAV-GM 801UT-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
diameter (mm)
6.4
9.5
12.7
15.9
• In case that the pipe diameter is Ø12.7 mm or
less and the thickness is less than 0.7 mm, be
sure to use the new pipes for works.
3. The pipes are left as coming out or gas leaks.
(Poor refrigerant)
• There is possibility that rain water or air including
moisture enters in the pipe.
4. Refrigerant recovery is impossible.
(Refrigerant recovery by the pump-down operation
on the existing air conditioner)
• There is possibility that a large quantity of poor
oil or moisture remains inside of the pipe.
Wall thickness
Material
(mm)
0.8 —
0.8 —
0.8 —
1.0 —
5. A dryer on the market is attached to the existing
pipes.
• There is possibility that copper green rust generated.
6. Check the oil when the existing air conditioner was
removed after refrigerant had been recovered.
In this case, if the oil is judged as clearly different
compared with normal oil
• 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. The air conditioner which compressor was
exchanged due to a faulty compressor.
When the discolored oil, a large quantity of the
remains, mixture of foreign matter, or a large
quantity of sparkle remained wear-out powder is
observed, the cause of trouble will occur.
8. Installation and removal of the air conditioner are
repeated with temporary installation by lease and etc.
9. In case that type of the 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.
• Winding-insulation of the compressor may
become inferior.
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
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-TWP30E, RBC-TWP50E
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
Less than 1 month
Indoors
– 46 –
Term Curing manner
1 month or more Pinching
Pinching or taping
Every time