5 Installation
Installation manual
13
RZAG71~Y1
Sky Air Alpha-series
4P695306-1 – 2022.05
WARNING
Provide adequate measures to prevent that the unit can be
used as a shelter by small animals. Small animals that
make contact with electrical parts can cause malfunctions,
smoke or fire.
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.
5.3
Checking the refrigerant piping
5.3.1
Checking refrigerant piping: Setup
a
c
f
c
f
b
d
e h
g
i
a
b
A
B
d
e
R32
R32
A
Setup in case of pair
B
Setup in case of twin
a
Pressure gauge
b
Nitrogen
c
Refrigerant
d
Weighing scale
e
Vacuum pump
f
Stop valve
g
Main piping
h
Refrigerant branch kit
i
Branch piping
5.3.2
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.
5.3.3
To perform vacuum drying
NOTICE
▪ Connect the vacuum pump to
both
the service port of
the gas stop valve and the service port of the liquid
stop valve to increase efficiency.
▪ Make sure that the gas stop valve and liquid stop valve
are firmly closed before performing the leak test or
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.
5.4
Charging refrigerant
5.4.1
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.
