14 Piping installation
Installation and operation manual
22
RXYTQ8~16U7YF
VRV IV+ heat pump for high ambient temperatures
4P546223-1B – 2020.10
NOTICE
If the power of some units is turned off, the charging
procedure cannot be finished properly.
NOTICE
In case of a multiple outdoor system, turn on the power of
all outdoor units.
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 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
29]). If a
malfunction code is present, see
NOTICE
Make sure all connected indoor units are recognised (see
[1‑10] in
30]).
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) by pre-charging before the
automatic charging function can be started.
14.4.2
About charging refrigerant
Once vacuum drying is finished, additional refrigerant charging can
start.
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.
This step is included in below procedure (see
24]). It can be skipped, but charging will take longer
then.
A flow chart is available which gives an overview of the possibilities
and actions to be taken (see
23]).
14.4.3
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.
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
(a)
Piping length
(b)
CR
A
8 HP
10+12 HP 14+16 HP
≤30 m
50%≤CR≤105%
0 kg
1 kg
105%<CR≤130%
0.5 kg
1.5 kg
>30 m
50%≤CR≤70%
0 kg
1 kg
70%<CR≤85%
0.3 kg
0.5 kg
1.5 kg
85%<CR≤105%
0.7 kg
1 kg
2 kg
105%<CR≤130%
1.2 kg
1.5 kg
(a)
In case of a multi-outdoor-unit system, add the sum of the
individual outdoor unit charge factors.
(b)
Piping length is considered the distance from the outdoor
unit to the farthest indoor unit
CR
Total indoor unit capacity connection ratio
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
