Refrigerant R410A - Toshiba RAS-M10PKVP-E Service Manual

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 air
conditioner 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. Confi rm 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 fi re,
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 fi re in the fan-driven heater,
space heater, etc., a poisonous gas may occur.
3.

REFRIGERANT R410A

6. When an air conditioning system charged with a
7. Be sure to carry out installation or removal
8. Unauthorized modifi cations to the air conditioner
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
– 9 –
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.
according to the installation manual.
Improper installation may cause refrigeration
trouble, water leakage, electric shock, fi re, etc.
may be dangerous.
If a breakdown occurs please call a qualifi ed air
conditioner technician or electrician.
Improper repair may result in water leakage,
electric shock and fi re, etc.
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.