Daikin RYYQ8U7Y1B, Installer And User Manual

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17 | Piping installation
Installer and user reference guide
93
RYYQ+RYMQ+RXYQ
VRV IV+ heat pump
4P546228-1C – 2021.11
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.
17.3.3 Checking refrigerant piping: Setup
p< p>
R410A N2
C
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 Equalising line stop valve (only for RYMQ)
A Valve A
B Valve B
C Valve C
D Valve D
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
Equalising 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
"17.3.1 About checking the
refrigerant piping" [
4
91]).
17.3.4 To perform a leak test
The leak test must satisfy the specifications of EN378‑2.
To check for leaks: Vacuum leak test
1 Evacuate the system from the liquid and gas piping to –⁠100.7 kPa (–⁠1.007 bar)
(5 Torr absolute) for more than 2 hours.