2. ABOUT THE UNIT
2.1. Precautions for using R410A refrigerant
The basic installation work procedures are the same
as conventional refrigerant (R22) models.
However, pay careful attention to the following points:
• Since the working pressure is 1.6 times higher than that of
conventional refrigerant (R22) models, some of the piping
and installation and service tools are special. (See the
Especially, when replacing a conventional refrigerant (R22)
model with a new refrigerant R410A model, always replace
the conventional piping and À are nuts with the R410A piping
and À are nuts.
• Models that use refrigerant R410A have a different
charging port thread diameter to prevent erroneous
charging with conventional refrigerant (R22) and for safety.
Therefore, check beforehand. [The charging port thread
diameter for R410A is 1/2 inch.]
• Be more careful that foreign matter (oil, water, etc.) does
not enter the piping than with refrigerant (R22) models.
Also, when storing the piping ,securely seal the opening
by pinching, taping, etc.
• When charging the refrigerant, take into account the slight
change in the composition of the gas and liquid phases.
And always charge from the liquid phase where refrigerant
composition is stable.
2.2. Special tools for R410A
Pressure is high and cannot be measured
with a conventional (R22) gauge. To pre-
vent erroneous mixing of other refriger-
ants, the diameter of each port has been
It is recommended the gauge with seals
-0.1 to 5.3 MPa (30 in.Hg to 768 psi) for
-0.1 to 3.8 MPa (30 in.Hg to 551 psi) for
To increase pressure resistance, the hose
material and base size were changed.
A conventional vacuum pump can be used
by installing a vacuum pump adapter.
Special gas leakage detector for HFC re-
It is necessary to use seamless copper pipes and it is desirable
that the amount of residual oil is less than 0.004 oz/100ft.
Do not use copper pipes having a collapsed, deformed
or discolored portion (especially on the interior surface).
Otherwise, the expansion value 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.
Contents of change
• Do not use the existing (for R22) piping and À are nuts.
If the existing materials are used, the pressure inside the
refrigerant cycle will rise and cause failure, injury, etc. (Use
the special R410A materials.)
• When installing and relocating the air conditioner, do not
mix gases other than the speci¿ ed refrigerant (R410A) to
enter the refrigerant cycle.
If air or other gas enters the refrigerant cycle, the pressure
inside the cycle will rise to an abnormally high value and
cause failure, injury, etc.
2.3. For authorized service personnel only.
• For the air conditioner to operate satisfactorily, install it as
outlined in this installation manual.
• Connect the indoor unit and outdoor unit or branch box
with the air conditioner piping and cables available from
your local distributor. This installation manual describes
the correct connections using the installation set available
from your local distributor.
• Installation work must be performed in accordance with
national wiring standards by authorized personnel only.
• Do not turn on the power until all installation work is
This installation manual describes how to install the indoor
To install the outdoor unit or branch box, refer to the installation
manual included with the outdoor unit or branch box.
• Be careful not to scratch the air conditioner when handling it.
• After installation, explain correct operation to the customer,
using the operating manual.
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9/8/2010 9:56:05 AM