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6. REFRIGERANT R32
This air conditioner adopts the R32 refrigerant which
does not damage the ozone layer.
The working pressure of the new refrigerant R32 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.
6-1. Safety During Installation/Servicing
As R32’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 R32, it is necessary to carry out
installation/servicing safely while taking the following
precautions into consideration.
1. Never use refrigerant other than R32 in an air
conditioner which is designed to operate with R32.
If other refrigerant than R32 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 R32.
The refrigerant name R32 is indicated on the
visible place of the outdoor unit of the air
conditioner using R32 as refrigerant.
A diameter of the charge port for R32 is the same
as that for the R410A’s. Be careful not to charge
the refrigerant by mistake.
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.
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 may result in water leakage,
electric shock and fire, etc.
6-2. Refrigerant Piping Installation
6-2-1. 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 R32 incurs pressure
higher than when using R22, it is necessary to
choose adequate materials.
Thicknesses of copper pipes used with R32 are as
shown in Table 6-2-1. Never use copper pipes
thinner than 0.8mm even when it is available on
the market.
NOTE
Refer to the “
6-6. Instructions for Re-use Piping of
R22 or R407C
”.
