18
|
Piping installation
Installer and user reference guide
93
RWEYQ8~14T9Y1B
VRV IV water-cooled system air conditioner
4P452191-1B – 2020.10
NOTICE
Do NOT purge the air with refrigerants. Use a vacuum pump to evacuate the
installation.
18.4.3 Checking refrigerant piping: Setup
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
h
High pressure/low pressure gas line stop valve
A
Valve A
B
Valve B
C
Valve C
(1)
D
Valve D
(1) Only for heat recovery system.
NOTICE
Do not connect the vacuum pump to the suction gas stop valve if the unit is intended
to run as a heat pump system. This will increase the risk of unit failure.
Valve
State of valve
Valve A
Open
Valve B
Open
Valve C
Open
Valve D
Open
Liquid line stop valve
Close
Gas line stop valve
Close
High pressure/low pressure gas line
stop valve
Close
NOTICE
The connections to the indoor units and all indoor units should also be leak and
vacuum tested. Keep any possible (field supplied) field piping valves open as well.
Refer to the indoor unit installation manual for more details. Leak test and vacuum
drying should be done before the power supply is set to the unit. If not, see also the
flow chart earlier described in this chapter (see
18.4.4 To perform a leak test
The leak test must satisfy the specifications of EN378‑2.