To Connect The Refrigerant Piping To The Outdoor Unit; Checking The Refrigerant Piping; To Check For Leaks; To Perform Vacuum Drying - Daikin 2MXM40A2V1B9 Installation Manual

5 Piping installation
Reducer type
2
Connection example:
▪ Connecting a Ø9.5 mm pipe to a Ø12.7 mm gas pipe connection
port
a b
a Outdoor unit connection port
b Reducer type 1
c Reducer type 2
d Flare nut for Ø12.7 mm
e Inter-unit piping
Coat the threaded connection port of the outdoor unit where the flare
nut comes in with refrigeration oil.
Flare nut for (mm)
Ø12.7
NOTICE
Use an appropriate wrench to avoid damaging the
connection thread by overtightening the flare nut. Be
careful NOT to overtighten the nut, or the smaller pipe may
be damaged (about 2/3-1× the normal torque).
5.2.2 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 main unit.
▪ To prevent gas leakage, apply refrigeration oil only to
the inside of the flare. Use refrigeration oil for R32
(Example: 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
b
c
d
Installation manual
14
Connection
Ø12.7 mm → Ø9.5 mm
c d e
Tightening torque (N•m)
50~60
e
a Liquid stop valve (room A)
b Gas stop valve (room A)
c Liquid stop valve (room B)
d Gas stop valve (room B)
e 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 open the stop valves before the vacuum drying is
finished.
NOTICE
Connect the vacuum pump to both the service ports of the
gas stop valves.
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...
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:
Then...
There is no moisture in the
system. This procedure is
finished.
There is moisture in the
system. Go to the next step.
2MXM40+50A9
R32 Split series
3P600450-8T – 2022.09