14 Piping installation
Installation and operation manual
26
RWEYQ8~14T9Y1B
VRV IV water-cooled system air conditioner
4P452190-1D – 2020.10
NOTICE
Before starting charging procedures, check if the
7‑segment display indication of the outdoor unit A1P PCB
is as normal (see
"16.1.4 To access mode 1 or 2"
If a malfunction code is present, see
problems based on error codes"
36].
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.
14.5.2
About charging refrigerant
The outdoor unit is factory charged with refrigerant, but depending
on the field piping you have to charge additional refrigerant.
Make sure the outdoor unit's external refrigerant piping is checked
(leak test, vacuum drying).
Charging additional refrigerant typically consists of the following
stages:
1
Determining how much you have to charge additionally.
2
Charging additional refrigerant (pre-charging and/or charging).
3
Filling in the fluorinated greenhouse gases label, and fixing it to
the inside of the outdoor unit.
14.5.3
To determine the additional refrigerant
amount
INFORMATION
For final charge adjustment in the test laboratory, please
contact your local dealer.
NOTICE
The refrigerant charge of the system must be less than
100 kg. This means that in case the calculated total
refrigerant charge is equal to or more than 95 kg you must
divide your multiple outdoor system into smaller
independent systems, each containing less than 95 kg
refrigerant charge. For factory charge, refer to the unit
name plate.
In case of heat pump system
Formula:
R=[(X
1
×
Ø22.2
)×0.37+(X
2
×
Ø19.1
)×0.26+(X
3
×
Ø15.9
)×0.18+
(X
4
×
Ø12.7
)×0.12+(X
5
×
Ø9.5
)×0.059+(X
6
×
Ø6.4
)×0.022]+A
R
Additional refrigerant to be charged [in kg and rounded off
to 1 decimal place]
X
1...6
Total length [m] of liquid piping size at
Øa
A
Parameter A
Parameter A.
If the total indoor unit capacity connection ratio
(CR)>100%, charge an additional 0.5 kg of refrigerant per outdoor
unit.
In case of heat recovery system
Formula:
R=[(X
1
×
Ø22.2
)×0.37+(X
2
×
Ø19.1
)×0.26+(X
3
×
Ø15.9
)×0.18+
(X
4
×
Ø12.7
)×0.12+(X
5
×
Ø9.5
)×0.059+(X
6
×
Ø6.4
)×0.022]×1.04+A+C
R
Additional refrigerant to be charged [in kg and rounded off
to 1 decimal place]
X
1...6
Total length [m] of liquid piping size at
Øa
A
Parameter A
C
Parameter C
Parameter A.
If the total indoor unit capacity connection ratio
(CR)>100%, charge an additional 0.5 kg of refrigerant per outdoor
unit.
Parameter C.
When using more than one multi BS unit, add the sum
of the individual BS unit charge factors.
Model
C
BS1Q10
0.05 kg
BS1Q16
0.1 kg
BS1Q25
0.2 kg
BS4Q
0.3 kg
BS6Q
0.4 kg
BS8Q
0.5 kg
BS10Q
0.7 kg
BS12Q
0.8 kg
BS16Q
1.1 kg
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
Ø16 mm
0.18
Ø19.1 mm
0.26
Ø18 mm
0.24
Ø22.2 mm
0.37
Ø22 mm
0.35
14.5.4
To charge refrigerant
Follow the steps as described below.
Pre-charging refrigerant
1
Calculate the additional amount of refrigerant to be added using
the formula mentioned in
"14.5.3 To determine the additional
2
The first 10 kg of additional refrigerant can be pre-charged
without outdoor unit operation:
If
Then
The additional refrigerant amount
is smaller than 10 kg
Perform steps 3~4.
The additional refrigerant charge
is larger than 10 kg
Perform steps 3~6.
3
Pre-charging can be done without compressor operation, by
connecting the refrigerant bottle to the service port of the liquid
stop valve (open valve B). Make sure that all outdoor unit stop
valves, as well as valves A, C, and D are closed.
NOTICE
During pre-charging, the refrigerant is charged through the
liquid line only. Close valves C, D, and A and disconnect
the manifold from the gas line and the high pressure/low
pressure gas line.
p< p>
R410A
N2
C
(1)
D
b
c
e
a
g
h
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
