Checking The Refrigerant Piping; To Check For Leaks; To Perform Vacuum Drying; Charging Refrigerant - Daikin 3MXM40A2V1B Installation Manual

NOTICE
▪ Use the flare nut fixed to the main 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.
b
c
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).
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).
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.
3 Discharge all nitrogen gas.
5.3.2

To perform vacuum drying

DANGER: RISK OF EXPLOSION
Do NOT start the unit if it is vacuumed.
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:
2MXM-A, 3MXM-A, 4MXM-A, 5MXM-A
R32 Split series
3P600450-6M – 2021.12
If the pressure...
Does not change
Increases
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.
a
▪ Perform vacuum drying again.
c
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
NOTICE
Applicable legislation on fluorinated greenhouse gases
requires that the refrigerant charge of the unit is indicated
both in weight and CO
Formula to calculate the quantity in CO
tonnes: GWP value of the refrigerant × total refrigerant
charge [in kg] / 1000
Please contact your installer for more information.
WARNING: MILDLY FLAMMABLE MATERIAL
The refrigerant inside this unit is mildly flammable.
WARNING
The appliance shall be stored so as to prevent mechanical
damage and in a well-ventilated room without continuously
operating ignition sources (e.g. open flames, an operating
gas appliance, or an operating electric heater). The room
size shall be as specified in the General safety precaution.
WARNING
▪ Do NOT pierce or burn refrigerant cycle parts.
▪ Do NOT use cleaning materials or means to accelerate
the defrosting process other than those recommended
by the manufacturer.
▪ Be aware that the refrigerant inside the system is
odourless.
6 Charging refrigerant
Then...
There is no moisture in the
system. This procedure is
finished.
There is moisture in the
system. Go to the next step.
equivalent.
2
equivalent
2
Installation manual
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