15 Charging refrigerant
Installation and operation manual
28
RXYSA4~6A7V/Y1B
VRV 5-S system air conditioner
4P600329-1E – 2023.02
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).
14.3.3
To perform vacuum drying
To remove all moisture from the system, proceed as follows:
1
Evacuate the system for at least 2 hours to a target vacuum of
–100.7 kPa (–1.007 bar)(5 Torr absolute).
2
Check that, with the vacuum pump turned off, the target
vacuum is maintained for at least 1 hour.
3
Should you fail to reach the target vacuum within 2 hours or
maintain the vacuum for 1 hour, the system may contain too
much moisture. In that case, break the vacuum by pressurising
with nitrogen gas to a gauge pressure of 0.05 MPa (0.5 bar)
and repeat steps 1 to 3 until all moisture has been removed.
4
Depending on whether you want to immediately charge
refrigerant through the refrigerant charge port or first pre-charge
a portion of refrigerant through the liquid line, either open the
outdoor unit stop valves, or keep them closed. See
14.3.4
To check for leaks after charging
refrigerant
After charging refrigerant in the system an additional leak test must
be performed. Refer to
"15.6 To check for refrigerant leaks after
30].
15
Charging refrigerant
15.1
Precautions when charging
refrigerant
WARNING
▪ Only use R32 as refrigerant. Other substances may
cause explosions and accidents.
▪ R32 contains fluorinated greenhouse gases. Its global
warming potential (GWP) value is 675. Do NOT vent
these gases into the atmosphere.
▪ When charging refrigerant, ALWAYS use protective
gloves and safety glasses.
NOTICE
If the power of some units is turned off, the charging
procedure cannot be finished properly.
NOTICE
Turn ON the power 6 hours before operation in order to
have power running to the crankcase heater and to protect
the compressor.
NOTICE
If operation is performed within 12 minutes after the indoor
and outdoor units are powered on, the compressor will not
operate before the communication is established in a
correct way between outdoor unit(s) and indoor units.
NOTICE
Before starting charging procedures, check if the
7‑segment display indication of the outdoor unit A1P PCB
is as normal (see
"18.1.4 To access mode 1 or 2"
If a malfunction code is present, see
problems based on error codes"
NOTICE
Make sure all connected indoor units are recognised
(setting [1‑10]).
NOTICE
Close the front panel before any refrigerant charge
operation is executed. Without the front panel attached the
unit cannot judge correctly whether it is operating properly
or not.
NOTICE
In case of maintenance and the system (outdoor unit+field
indoor units) does not contain any refrigerant any
more (e.g., after refrigerant reclaim operation), the unit has
to be charged with its original amount of refrigerant (refer
to the nameplate on the unit) and the determined additional
refrigerant amount.
NOTICE
▪ Ensure that contamination of different refrigerants does
not occur when using charging equipment.
▪ Charging hoses or lines shall be as short as possible to
minimise the amount of refrigerant contained in them.
▪ Cylinders shall be kept in an appropriate position
according to the instructions.
▪ Ensure that the refrigerating system is earthed prior to
charging the system with refrigerant. See
connect the electrical wiring to the outdoor unit"
31].
▪ Label the system when charging is complete.
▪ Extreme care shall be taken not to overfill the
refrigerating system.
NOTICE
Prior to charging the system, it shall be pressure tested
with the appropriate purging gas. The system shall be leak
tested
on
completion
of
charging
but
prior
to
commissioning. A follow up leak test shall be carried out
prior to leaving the site.
15.2
To determine the additional
refrigerant amount
WARNING
The maximum allowable total refrigerant amount is
determined based on the smallest room being served by
the system.
See
"12.2 System layout requirements"
17] to determine
the maximum allowable total refrigerant amount.
INFORMATION
For final charge adjustment in a test laboratory, contact
your dealer.
