Unit installation

Special tools for R410A
This air conditioner uses new refrigerant HFC (R410A).
The basic installation work procedures are the same as conventional refrigerant models.
However, pay careful attention to the following points:
1 Since the working pressure is 1.6 times higher than that of conventional refrigerant models, some of the piping and
installation and service tools are special. (See the table below.)
Especially, when replacing a conventional refrigerant model with a new refrigerant R410A model, always replace the
conventional piping and flare nuts with the R410A piping and flare nuts.
2 Models that use refrigerant R410A have a different charging port thread diameter to prevent erroneous charging with
conventional refrigerant and for safety. Therefore, check beforehand. [The charging port thread diameter for R410A is
1/2 UNF 20 threads per inch.]
3 Be more careful that foreign matter (oil, water, etc.) does not enter the piping than with refrigerant models. Also, when
storing the piping, securely seal the openings by pinching, taping, etc.
4 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 side whose composition is stable.
Contents of change
Pressure is high and cannot be measured with a conventional gauge. To prevent erroneous mixing of other
refrigerants, the diameter of each port has been changed.
It is recommended the gauge with seals –0.1 to 5.3 MPa (–76 cmHg to 53 kgf/cm
2
) for high pressure. –0.1 to
3.8 MPa (–76 cmHg to 38 kgf/cm
2
) for low pressure.
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 refrigerant R410A.
Tool name
Gauge manifold
Charge hose
Vacuum pump
Gas leakage detector
Copper pipes
It is necessary to use seamless copper pipes 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
conventional refrigerant, it is necessary to choose adequate materials.
Thicknesses of copper pipes used with R410A are as shown in the table. Never
use copper pipes thinner than that in the table even when it is available on
the market.
Pipe outside diameter
6.35 mm (1/4 in.)
9.52 mm (3/8 in.)
12.70 mm (1/2 in.)
15.88 mm (5/8 in.)
19.05 mm (3/4 in.)
Thickness
0.80 mm (1/32 in.)
0.80 mm (1/32 in.)
0.80 mm (1/32 in.)
1.00 mm (5/128 in.)
1.20 mm (3/64 in.)
Thicknesses of Annealed Copper Pipes (R410A)