To Perform A Leak Test - Daikin VRV 5 S Series Installer And User Manual

18 | Piping installation

18.3.4 To perform a leak test

Vacuum leak test
Pressure leak test
To check for leaks after charging refrigerant
Installer and user reference guide
94
B Valve B
C Valve C
Valve A
Valve B
Valve C
Liquid line stop valve
Gas line stop valve
NOTICE
Indoor units should also be leak and vacuum tested. Keep any possible (field
supplied) field piping valves open as well.
1 Evacuate the system from the liquid and gas piping to a gauge pressure of
–⁠ 1 00.7 kPa (–⁠ 1 .007 bar) 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 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 working pressure of the unit, i.e. 3.52 MPa (35.2 bar).
2 Test for leaks by applying a bubble test solution to all piping connections.
3 Discharge all nitrogen gas.
NOTICE
ALWAYS use a recommended bubble test solution from your wholesaler.
NEVER use soap water:
▪
Soap water may cause cracking of components, such as flare nuts or stop valve
caps.
▪
Soap water may contain salt, which absorbs moisture that will freeze when the
piping gets cold.
▪
Soap water contains ammonia which may lead to corrosion of flared joints
(between the brass flare nut and the copper flare).
After charging refrigerant in the system an additional leak test must be performed.
Refer to "19.8 To check for refrigerant leaks after
Valve Status
Open
Open
Open
Close
Close
4
charging" [ 103].
RXYSA4~6A7V/Y1B
VRV 5-S system air conditioner
4P600330-1D – 2023.02