Installation of refrigerant piping, leak test, vacuuming before
electrical installation is done (regular installation method)
When all piping work is complete, it is necessary to:
check for any leakages in the refrigerant piping and
to perform vacuum drying to remove all moisture in the
refrigerant piping.
If there is a possibility of moisture being present in the refrigerant
piping (for example, rainwater may have entered the piping), carry
out the vacuum drying procedure below until all moisture has been
removed and consider the installation of a liquid dryer.
All piping inside the unit has been factory tested for leaks.
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 indoor unit stop valves are OPEN (no
outdoor unit stop valves!) before you start leak test and
vacuuming.
See "Set-up" on page 17, "Leak test" on page 17, and "Vacuum
drying" on page 18.
Installation of refrigerant piping, leak test, vacuuming after
electrical installation is done on any indoor or outdoor unit
Apply outdoor unit setting 2-21=1 (see page 29) before starting leak
test and vacuuming. This setting will open all field expansion valves
and solenoid valves to guarantee a R410A piping pathway.
NOTICE
Make sure that ALL indoor unit stop valves are OPEN
(no outdoor unit stop valves!) before you start leak
test and vacuuming.
Make sure that ALL indoor units connected to the
outdoor unit are powered on.
Wait untill the outdoor unit has finished the
initialisation.
When all piping work is complete, it is necessary to:
check for any leakages in the refrigerant piping and
to perform vacuum drying to remove all moisture in the
refrigerant piping.
If there is a possibility of moisture being present in the refrigerant
piping (for example, rainwater may have entered the piping), first
carry out the vacuum drying procedure below until all moisture has
been removed and consider the installation of a liquid dryer.
All piping inside the unit has been factory tested for leaks.
Only field installed refrigerant piping needs to be checked. Therefore,
make sure that all the stop valves are firmly closed before performing
leak test or vacuum drying.
See "Set-up" on page 17, "Leak test" on page 17, and "Vacuum
drying" on page 18.
Installation manual
17
Set-up
7
8
11
1
3
2
4
5
1 Pressure reducing valve
2 Nitrogen
3 Refrigerant R410A tank (siphon system)
4 Measuring instrument
5 Vacuum pump
6 Suction pipe stop valve
7 Outdoor unit
8 Liquid pipe stop valve
9 Indoor unit HXHD125
10 Charge hose
11 Refrigerant charge port
12 HP/LP gas pipe stop valve
13 Other indoor unit
BS Branch selector box
Valve
Stop valve service port
NOTICE
The connections to the indoor units and all indoor units
should also be leak and vacuum tested. Keep the stop
valves of the indoor units 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. See also the flow chart
earlier described in this chapter.
Leak test
The leak test must satisfy specification EN 378-2.
1
Vacuum leak test
1.1 Evacuate the system from the liquid, gas and high pressure
piping to –100.7 kPa (5 Torr) for more than 2 hours.
1.2 Once reached, turn off the vacuum pump and check that
the pressure does not rise for at least 1 minute.
1.3 Should the pressure rise, the system may either contain
moisture (see vacuum drying below) or have leaks.
2
Pressure leak test
2.1 Break the vacuum by pressurizing 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).
2.2 Test for leaks by applying a bubble test solution to all piping
connections.
NOTICE
Make sure to use a recommended bubble test
solution from your wholesaler.
Do not use soap water, which may cause cracking of
flare nuts (soap water may contain salt, which
absorbs moisture that will freeze when the piping gets
cold), and/or lead to corrosion of flared joints (soap
water may contain ammonia which causes a corrosive
effect between the brass flare nut and the copper
flare).
2.3 Discharge all nitrogen gas.
6
12
12
13
13
9
BS
BS
8
REYAQ10~16P7Y1B
VRVIII system outdoor unit
4PW62582-1A – 08.2011