4 Installation
Installation manual
7
(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…
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.
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
When
Charging additional refrigerant
When the total liquid piping
length is more than specified
(see later).
Completely recharging refrigerant
Example:
▪ When relocating the system.
▪ After a leak.
Charging additional refrigerant
Before charging additional refrigerant, make sure the outdoor unit's
external
refrigerant piping is checked (leak test, vacuum drying).
INFORMATION
Depending on the units and/or the installation conditions, it
might be necessary to connect electrical wiring before you
can charge refrigerant.
Typical workflow – Charging additional refrigerant typically consists
of the following stages:
1 Determining if and how much you have to charge additionally.
2 If necessary, charging additional refrigerant.
3 Filling in the fluorinated greenhouse gases label, and fixing it to
the inside of the outdoor unit.
Completely recharging refrigerant
Before completely recharging refrigerant, make sure the following is
done:
1 All refrigerant is recovered from the system.
2 The outdoor unit's
external
refrigerant piping is checked (leak
test, vacuum drying).
3 Vacuum drying on the outdoor unit's
internal
refrigerant piping is
performed.
NOTICE
Before completely recharging, perform vacuum drying on
the outdoor unit's
internal
refrigerant piping as well.
Typical workflow – Completely recharging refrigerant typically
consists of the following stages:
1 Determining how much refrigerant to charge.
2 Charging refrigerant.
3 Filling in the fluorinated greenhouse gases label, and fixing it to
the inside of the outdoor unit.
4.5.2
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
In Europe, the
greenhouse gas emissions
of the total
refrigerant charge in the system (expressed as tonnes CO
2
equivalent) is used to determine the maintenance intervals.
Follow the applicable legislation.
Formula to calculate the greenhouse gas emissions:
GWP value of the refrigerant × Total refrigerant charge [in
kg] / 1000
Please contact your installer for more information.
WARNING: FLAMMABLE MATERIAL
The refrigerant inside this unit is mildly flammable.
WARNING
The appliance shall be stored in a room without
continuously operating ignition sources (example: open
flames, an operating gas appliance or an operating electric
heater).
