5 Installation
Installation and operation manual
12
RXYSQ6TMYFK
VRV IV-S system air conditioner
4P524881-1 – 2018.02
▪ Use heat resistant polyethylene foam which can withstand a
temperature of 70°C for liquid piping and polyethylene foam which
can withstand a temperature of 120°C for gas piping.
▪ Reinforce the insulation on the refrigerant piping according to the
installation environment.
Ambient
temperature
Humidity
Minimum thickness
≤30°C
75% to 80% RH
15 mm
>30°C
≥80% RH
20 mm
Condensation might form on the surface of the insulation.
▪ If there is a possibility that condensation on the stop valve might
drip down into the indoor unit through gaps in the insulation and
piping because the outdoor unit is located higher than the indoor
unit, this must be prevented by sealing up the connections. See
below figure.
b
a
a
Insulation material
b
Caulking etc.
5.6
Charging refrigerant
5.6.1
Precautions when charging refrigerant
WARNING
▪ Only use R410A as refrigerant. Other substances may
cause explosions and accidents.
▪ R410A contains fluorinated greenhouse gases. Its
global warming potential (GWP) value is 2087.5. 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
Be sure to 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 turned 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 compressor unit A1P
PCB is as normal (see
"6.1.4 To access mode 1 or 2" on
). If a malfunction code is present, see
"8.1 Solving problems based on error codes" on page 21
.
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.
5.6.2
To determine the additional refrigerant
amount
INFORMATION
For final charge adjustment in a test laboratory, contact
your dealer.
Formula:
R=[(X
1
×
Ø15.9
)×0.18+(X
2
×
Ø12.7
)×0.12+(X
3
×
Ø9.5
)×0.059+
(X
4
×
Ø6.4
)×0.022]
R
Additional refrigerant to be charged [in kg and rounded off
to 1 decimal place]
X
1...4
Total length [m] of liquid piping size at
Øa
Metric piping.
When using metric piping, replace the weight factors
in the formula by the ones from the following table:
Inch piping
Metric piping
Piping
Weight factor
Piping
Weight factor
Ø6.4 mm
0.022
Ø6 mm
0.018
Ø9.5 mm
0.059
Ø10 mm
0.065
Ø12.7 mm
0.12
Ø12 mm
0.097
Ø15.9 mm
0.18
Ø15 mm
0.16
5.6.3
To charge refrigerant
To speed up the refrigerant charging process, it is in case of larger
systems recommended to first pre-charge a portion of refrigerant
through the liquid line before proceeding with the manual charging. It
can be skipped, but charging will take longer then.
Pre-charging refrigerant
Pre-charging can be done without compressor operation, by
connecting the refrigerant bottle to the service port of the liquid stop
valve.
1
Connect as shown. Make sure that all outdoor unit stop valves,
as well as valve A are closed.
p< p>
N2
C
b
c
e
a
g
f
d
A
B
a
Pressure reducing valve
b
Nitrogen
c
Weighing scales
d
Refrigerant R410A tank (siphon system)
e
Vacuum pump
f
Liquid line stop valve
g
Gas line stop valve
A
Valve A
B
Valve B
C
Valve C
2
Open valves C and B.
