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Piping installation
Installer and user reference guide
85
RXYSQ4~6T8V/YB
VRV IV-S system air conditioner
4P482277-1B – 2020.10
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
Connection ratio requirements.
When selecting indoor units, the connection ratio
must comply with the following requirements. For more information, see the
technical engineering data.
Indoor units
Total CR
(a)
CR per type
(b)
VRV DX
RA DX
VRV DX
50~130%
50~130%
—
RA DX
80~130%
—
80~130%
(a)
Total CR = Total indoor unit capacity connection ratio
(b)
CR per type = Allowable capacity connection ratio per indoor unit type
18.4.4 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: