Precautions When Connecting The Refrigerant Piping; To Connect The Refrigerant Piping To The Outdoor Unit; Checking The Refrigerant Piping; To Check For Leaks - Daikin RXP20M5V1B Manuel D'installation

4.3.2 Precautions when connecting the
refrigerant piping
DANGER: RISK OF BURNING
CAUTION
▪ 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.
▪ Do NOT reuse joints.
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.
4.3.3 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.
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.
(A)RXP20~35M5V1B
R32 split series
3P519299-5B – 2018.12
4.4

Checking the refrigerant piping

4.4.1

To check for leaks

NOTICE
Do NOT exceed the unit's maximum working pressure (see
"PS High" on the unit name plate).
NOTICE
Make sure to use a recommended bubble test solution
from your wholesaler. Do not use soap water, which may
cause cracking of flare nuts (soap water may contain salt,
which absorbs moisture that will freeze when the piping
gets cold), and/or lead to corrosion of flared joints (soap
water may contain ammonia which causes a corrosive
effect 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.
4.4.2

To perform vacuum drying

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:
▪ 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.
4.5

Charging refrigerant

4.5.1

About charging refrigerant

The outdoor unit is factory charged with refrigerant, but in some
cases the following might be necessary:
What
Charging additional refrigerant
Completely recharging refrigerant Example:
4 Installation
Then...
There is no moisture in the
system. This procedure is
finished.
There is moisture in the
system. Go to the next step.
When
When the total liquid piping
length is more than specified
(see later).
▪ When relocating the system.
▪ After a leak.
Installation manual
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