– 19 –
About refrigerant R410A
This air conditioner adopts a HFC type refrigerant (R410A) which does not deplete the ozone layer.
1. Safety Caution Concerned to R410A Refrigerant
The pressure of R410A is 1.6 times higher than that of the former refrigerant (R22).
Accompanied with change of refrigerant, the refrigerating oil has been also changed.
Therefore, be sure that water, dust, the former refrigerant or the former refrigerating oil is not mixed into the
refrigerating cycle of the air conditioner with R410A refrigerant during installation work or service work.
If an incorrect work or incorrect service is performed, there is a possibility to cause a serious accident.
Use the tools and materials exclusive to R410A to purpose a safe work.
2. Cautions on Installation/Service
<Piping>
The pipe thickness, flare-finishing size, flare nut and others differ according to a refrigerant type.
When using a long copper pipe for R410A, it is recommended to select “Copper or copper-base pipe without
seam” and one with bonded oil amount 40mg/10m or less.
Also do not use crushed, deformed, discolored (especially inside) pipes.
(Impurities cause clogging of expansion valves and capillary tubes.)
<Flare nut>
Use the flare nuts which are attached to the air conditioner unit.
1) Do not mix the other refrigerant or refrigerating oil.
For the tools exclusive to R410A, shapes of all the joints including the service port differ from those of
the former refrigerant in order to prevent mixture of them.
2) As the use pressure of the R410A refrigerant is high, use material thickness of the pipe and tools which
are specified for R410A.
3) In the installation time, use clean pipe materials and work with great attention so that water and others
do not mix in because pipes are affected by impurities such as water, oxide scales, oil, etc.
Use the clean pipes.
Be sure to braze while flowing nitrogen gas. (Never use gas other than nitrogen gas.)
4) For the earth protection, use a vacuum pump for air purge.
5) R410A refrigerant is azeotropic mixture type refrigerant.
Therefore use liquid type to charge the refrigerant. (If using gas for charging, composition of the
refrigerant changes and then characteristics of the air conditioner change.)
3. Pipe Materials
For the refrigerant pipes, copper pipe and joints are mainly used.
It is necessary to select the most appropriate pipes to conform to the standard.
Use clean pipes or joints to which little impurities adhere.
1) Copper pipe
2) Joint
The flare joint and socket joint are used for joints of the copper pipe.
The joints are rarely used for installation of the air conditioner. However clear impurities when using
them.
