6 Charging refrigerant
Installation manual
9
RXA-A8
R32 Split system air conditioners
3P748894-1A – 2023.09
5.2
Connecting the refrigerant piping
DANGER: RISK OF BURNING/SCALDING
CAUTION
▪ No brazing or welding on site for units with R32
refrigerant charge during shipment.
▪ During installation of the refrigeration system, joining of
parts with at least one part charged shall be performed
taking into account the following requirements: inside
occupied spaces non-permanent joints are NOT
allowed for R32 refrigerant except for site made joints
directly connecting the indoor unit to piping. Site made
joints directly connecting piping to indoor units shall be
of non-permanent type.
5.2.1
To connect the refrigerant piping to the
outdoor unit
▪
Piping length.
Keep field piping as short as possible.
▪
Piping protection.
Protect the field piping against physical
damage.
WARNING
Connect the refrigerant piping securely before running the
compressor. If the refrigerant piping is NOT connected and
the stop valve is open when the compressor is run, air will
be sucked in. This will cause abnormal pressure in the
refrigeration cycle, which may result in equipment damage
and even injury.
NOTICE
▪ Use the flare nut fixed to the unit.
▪ To prevent gas leakage, apply refrigeration oil ONLY to
the inside of the flare. Use refrigeration oil for R32
(FW68DA).
▪ Do NOT reuse joints.
1
Connect the liquid refrigerant connection from the indoor unit to
the liquid stop valve of the outdoor unit.
a
c b
a
Liquid stop valve
b
Gas stop valve
c
Service port
2
Connect the gas refrigerant connection from the indoor unit to
the gas stop valve of the outdoor unit.
NOTICE
It is recommended that the refrigerant piping between
indoor and outdoor unit is installed in a ducting or the
refrigerant piping is wrapped with finishing tape.
5.3
Checking the refrigerant piping
5.3.1
To check for leaks
NOTICE
Do NOT exceed the unit's maximum working pressure (see
"PS High" on the unit name plate).
1
Charge the system with nitrogen gas up to a gauge pressure of
at least 200 kPa (2 bar). It is recommended to pressurize to
3000 kPa (30 bar) in order to detect small leaks.
2
Check for leaks by applying the bubble test solution to all
connections.
NOTICE
ALWAYS use a recommended bubble test solution from
your wholesaler.
NEVER use soap water:
▪ Soap water may cause cracking of components, such
as flare nuts or stop valve caps.
▪ Soap water may contain salt, which absorbs moisture
that will freeze when the piping gets cold.
▪ Soap water contains ammonia which may lead to
corrosion of flared joints (between the brass flare nut
and the copper flare).
3
Discharge all nitrogen gas.
5.3.2
To perform vacuum drying
DANGER: RISK OF EXPLOSION
Do NOT open the stop valves before the vacuum drying is
finished.
1
Vacuum the system until the pressure on the manifold indicates
−0.1 MPa (−1 bar).
2
Leave as is for 4-5 minutes and check the pressure:
If the pressure…
Then…
Does not change
There is no moisture in the
system. This procedure is
finished.
Increases
There is moisture in the
system. Go to the next step.
3
Vacuum the system for at least 2 hours to a manifold pressure
of −0.1 MPa (−1 bar).
4
After turning the pump OFF, check the pressure for at least
1 hour.
5
If you do NOT reach the target vacuum or CANNOT maintain
the vacuum for 1 hour, do the following:
▪ Check for leaks again.
▪ Perform vacuum drying again.
NOTICE
Make sure to open the stop valves after installing the
refrigerant piping and performing vacuum drying. Running
the system with the stop valves closed may break the
compressor.
6
Charging refrigerant
6.1
About the refrigerant
This product contains fluorinated greenhouse gases. Do NOT vent
gases into the atmosphere.
Refrigerant type: R32
Global warming potential (GWP) value: 675
Periodical inspections for refrigerant leaks may be required
depending on the applicable legislation. Contact your installer for
more information.
