Daikin VRV IV-S - To Determine the Additional Refrigerant Amount; To Charge Refrigerant

6 Installation
Installer and user reference guide
24
RXYSQ8~12TMY1B
VRV IV-S system air conditioner
4P404225-1B – 2016.03
6.7.3 To determine the additional refrigerant
amount
INFORMATION
For final charge adjustment in a test laboratory, contact
your dealer.
Additional refrigerant to be charged=R (kg). R should be rounded off
in units of 0.1 kg.
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]
X
1...4
=Total length (m) of liquid piping size at Øa
INFORMATION
Piping length is considered the distance from the outdoor
unit to the farthest indoor unit.
When using metric piping, please take into account following table
concerning the weight factor to be allocated. It should be substituted
in the formula for R.
Inch piping Metric piping
Size (Ø) (mm) Weight factor Size (Ø) (mm) Weight factor
6.4 0.022 6 0.018
9.5 0.059 10 0.065
12.7 0.12 12 0.097
15.9 0.18 15 0.16
When selecting indoor unit, following table with connection ratio
limitation has to be respected. More detailed information can be
found in technical engineering data.
Used indoor
units
Total capacity
CR
(a)
Allowable capacity connection
ratio
VRVDX RADX
VRVDX 50~130% 50~130% —
RADX 80~130% — 80~130%
(a) CR=Connection ratio.
6.7.4 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.
3 Pre‑charge refrigerant until the determined additional refrigerant
amount is reached or pre‑charging is not possible anymore, and
then close valves C and B.
4 Do one of the following:
If Then
The determined additional
refrigerant amount is reached
Disconnect the manifold from
the liquid line.
You do not have to perform the
"Charging refrigerant (in
manual additional refrigerant
charge mode)" instructions.
Too much refrigerant is
charged
Recover refrigerant.
Disconnect the manifold from
the liquid line.
You do not have to perform the
"Charging refrigerant (in
manual additional refrigerant
charge mode)" instructions.
The determined additional
refrigerant amount is not
reached yet
Disconnect the manifold from
the liquid line.
Continue with the "Charging
refrigerant (in manual
additional refrigerant charge
mode)" instructions.
Charging refrigerant (in manual additional refrigerant charge
mode)
The remaining additional refrigerant charge can be charged by
operating the outdoor unit by means of the manual additional
refrigerant charge mode.
5 Connect as shown. Make sure valve A is closed.
p
<
p
>
R410A
a c
d
b
A
d
d
8 HP 10+12 HP
a Weighing scales
b Refrigerant R410A tank (siphon system)
c Vacuum pump
d Refrigerant charge port
A Valve A
NOTICE
The refrigerant charging port is connected to the piping
inside the unit. The unit's internal piping is already factory
charged with refrigerant, so be careful when connecting
the charge hose.
6 Open all outdoor unit stop valves. At this point, valve A must
remain closed!
7 Take all the precautions mentioned in "7 Configuration" on
page29 and "8Commissioning"on page39 into account.
8 Turn on the power of the indoor units and outdoor unit.
9 Activate setting [2‑20] to start the manual additional refrigerant
charge mode. For details, see "7.2.8Mode 2: Field settings"on
page33.
Result: The unit will start operation.