Checking Refrigerant Piping: General Guidelines; Checking Refrigerant Piping: Setup - Daikin VRV IV+ Installer And User Reference Manual

6 | Installation

6.5.2 Checking refrigerant piping: General guidelines

6.5.3 Checking refrigerant piping: Setup

Installer and user reference guide
60
Only field installed refrigerant piping needs to be checked. Therefore, make sure
that all the outdoor unit stop valves are firmly closed before performing leak test
or vacuum drying.
NOTICE
Make sure that all (field supplied) field piping valves are OPEN (not outdoor unit stop
valves!) before you start leak test and vacuuming.
For more information on the state of the valves, refer to
refrigerant piping: Setup" [
Connect the vacuum pump through a manifold to the service port of all stop valves
to increase efficiency (refer to
NOTICE
Use a 2-stage vacuum pump with a non-return valve or a solenoid valve that can
evacuate to a gauge pressure of –⁠ 1 00.7 kPa (−⁠ 1 .007 bar)(5 Torr absolute).
NOTICE
Make sure the pump oil does not flow oppositely into the system while the pump is
not working.
NOTICE
Do not purge the air with refrigerants. Use a vacuum pump to evacuate the
installation.
p < p >
A B
a
d
N2 R410A
b c e
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 Equalising line stop valve (only for RYMQ)
A Valve A
B Valve B
C Valve C
D Valve D
Valve
Valve A
Valve B
Valve C
Valve D
4
60].
"6.5.3 Checking refrigerant piping:
h
g
f
D
C
Open
Open
Open
Open
"6.5.3 Checking
4
Setup" [ 60]).
State of valve
RYYQ+RYMQ+RXYQ8~20U7Y1B
VRV IV+ heat pump
4P546228-1A – 2019.10