Airwell Multi Split DUO 50 DCI, Service Manual

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APPENDIX A
SM DLF 1-A.1 GB
CAUTION R410A Air Conditioner Installation
THIS AIR CONDITIONER ADOPTS THE
NEW HFC REFRIGERANT (R410A)
WHICH DOES NOT DESTROY OZONE
LAYER. R410A refrigerant is apt to be
affected by impurities such as water,
oxidizing membrane, and oils because the
working pressure of R410A refrigerant is
approx. 1.6 times of refrigerant R22.
Accompanied with the adoption of the new
refrigerant, the refrigeration machine oil has
also been changed. Therefore, during
installation work, be sure that water, dust,
former refrigerant, or refrigeration machine
oil does not enter into the new type
refrigerant R410A air conditioner circuit. To
prevent mixing of refrigerant or refrigerating
machine oil, the sizes of connecting
sections of charging port on main unit and
installation tools are different from those
used for the conventional refrigerant units.
Accordingly, special tools are required for
the new refrigerant (R410A) units. For
connecting pipes, use new and clean piping
materials with high pressure fittings made
for R410A only. Moreover, do not use the existing piping
because there are some problems with
pressure fittings and possible impurities
in existing piping.
Changes in the product and
components
In air conditioners using R410A, in order
to prevent any other refrigerant from
being accidentally charged, the service
port diameter size of the outdoor unit
control valve (3 way valve) has been
changed. (1/2 UNF 20 threads per inch).
In order to increase the pressure
resisting strength of the refrigerant
piping, flare processing diameter and
opposing flare nuts sizes have been
changed. (for copper pipes with nominal
dimensions 1/2 and 5/8).
In case of pipes welding please make
sure to use dry Nitrogen inside the
pipes.
Use copper tube of special thickness for
R410A:
1/4”-1/2” 0.8 mm
5/8”-3/4” 1 mm
Do not vent R410A into atmosphere: R410A is a fluorinated greenhouse gas, covered by
Kyoto Protocol, with a Global Warming Potential (GWP) = 1730