Refrigerant R410A And R32 - Toshiba RAS-M07G3DV-E Service Manual

Refrigerant R410A
This air conditioner adopts the new refrigerant HFC
(R410A) which does not damage the ozone layer.
The working pressure of the new refrigerant R410A is
1.6 times higher than conventional refrigerant (R22).
The refrigerating oil is also changed in accordance with
change of refrigerant, so be careful that water, dust,
and existing refrigerant or refrigerating oil are not
entered in the refrigerant cycle of the air conditioner
using the new refrigerant during installation work or
servicing time.
The next section describes the precautions for air
conditioner using the new refrigerant. Conforming to
contents of the next section together with the general
cautions included in this manual, perform the correct
and safe work.
3-1.Safety During Installation/Servicing
As R410A's pressure is about 1.6 times higher than
that of R22, improper installation/servicing may cause
a serious trouble. By using tools and materials
exclusive for R410A, it is necessary to carry out
installation/servicing safely while taking the following
precautions into consideration.
1. Never use refrigerant other than R410A in an airc
onditioner which is designed to operate with R410A.
If other refrigerant than R410A is mixed, pressure in
the refrigeration cycle becomes abnormally high,
and it may cause personal injury, etc. by a rupture.
2. Confirm the used refrigerant name, and use tools
and materials exclusive for the refrigerant R410A.
The refrigerant name R410A is indicated on the
visible place of the outdoor unit of the air conditioner
using R410A as refrigerant. To prevent mischarging,
the diameter of the service port differs from that of
R22.
3. If a refrigeration gas leakage occurs during
installation/servicing, be sure to ventilate fully.
If the refrigerant gas comes into contact with fire, a
poisonous gas may occur.
4. When installing or removing an air conditioner, do
not allow air or moisture to remain in the refrigeration
cycle. Otherwise, pressure in the refrigeration cycle
may become abnormally high so that a rupture or
personal injury may be caused.
5. After completion of installation work, check to make
sure that there is no refrigeration gas leakage.
If the refrigerant gas leaks into the room, coming into
contact with fire in the fan-driven heater, space
heater, etc., a poisonous gas may occur.
6. When an air conditioning system charged with a
large volume of refrigerant is installed in a small
room, it is necessary to exercise care so that, even
when refrigerant leaks, its concentration does not
exceed the marginal level.
If the refrigerant gas leakage occurs and its
concentration exceeds the marginal level, an oxygen
starvation accident may result.

3. REFRIGERANT R410A AND R32

7. Be sure to carry out installation or removal according
to the installation manual.
Improper installation may cause refrigeration trouble,
water leakage, electric shock, fire, etc.
8. Unauthorized modifications to the air conditioner
may be dangerous. If a breakdown occurs please
call a qualified air conditioner technician or
electrician.
Improper repair's may result in water leakage,
electric shock and fire, etc.
3-2. Refrigerant Piping Installation
3-2-1.Piping Materials and Joints Used
For the refrigerant piping installation, copper pipes and
joints are mainly used. Copper pipes and joints suitable
for the refrigerant must be chosen and installed.
Furthermore, it is necessary to use clean copper pipes
and joints whose interior surfaces are less affected by
contaminants.
1. Copper Pipes
It is necessary to use seamless copper pipes which
are made of either copper or copper alloy and it is
desirable that the amount of residual oil is less than
40 mg/10 m. Do not use copper pipes having a
collapsed, deformed or discolored portion (especially
on the interior surface).
Otherwise, the expansion valve or capillary tube may
become blocked with contaminants.
As an air conditioner using R410A incurs pressure
higher than when using R22, it is necessary to
choose adequate materials.
Thicknesses of copper pipes used with R410A are
as shown in Table 3-2-1. Never use copper pipes
thinner than 0.8 mm even when it is available on the
market.
Refrigerant R32
This air conditioner adopts a new HFC type refrigerant
(R32) which does not deplete the ozone layer.
1. Safety Caution Concerned to Refrigerant R32
Be sure that water, dust, the former refrigerant or the
former refrigerating oil is not mixed into the
refrigerating cycle of the air conditioner with
refrigerant R32 during installation work or service
work.
If an incorrect work or incorrect service is performed,
there is a possibility to cause a serious accident.
Use the tools and materials exclusive to R32 to
purpose a safe work.
– 12 –