Checking Refrigerant Piping: Setup; To Perform A Leak Test - Daikin VRV IV Installer And User Reference Manual

18 | Piping installation

18.3.3 Checking refrigerant piping: Setup

18.3.4 To perform a leak test

To check for leaks: Vacuum leak test
To check for leaks: Pressure leak test
Installer and user reference guide
92
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
A Valve A
B Valve B
C Valve C
Valve
Valve A
Valve B
Valve C
Liquid line stop valve
Gas line stop valve
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
4
piping" [ 90]).
The leak test must satisfy the specifications of EN378‑2.
1 Evacuate the system from the liquid and gas piping to –⁠ 1 00.7 kPa (–⁠ 1 .007 bar)
(5 Torr absolute) for more than 2 hours.
2 Once reached, turn off the vacuum pump and check that the pressure does
not rise for at least 1 minute.
3 Should the pressure rise, the system may either contain moisture (see vacuum
drying below) or have leaks.
1 Test for leaks by applying a bubble test solution to all piping connections.
2 Discharge all nitrogen gas.
3 Break the vacuum by pressurising with nitrogen gas to a minimum gauge
pressure of 0.2 MPa (2 bar). Never set the gauge pressure higher than the
maximum operation pressure of the unit, i.e. 4.0 MPa (40 bar).
g
f
C
Open
Open
Open
Close
Close
State of valve
"About checking the refrigerant
RXMLQ8 + RXYLQ10~14T7Y1B*
VRV IV system air conditioner
4P543427-1A – 2020.10