Specifications

Installation and operation manual
20
RXYQQ8~20T7Y1B
VRV IV System Air Conditioner
4P345099-1 – 2013.04
10.4.1. General guidelines
 Use a 2-stage vacuum pump with a non-return valve which can
evacuate to a gauge pressure of –100.7 kPa (5 Torr absolute,
–755 mm Hg).
 Connect the vacuum pump to the service port of all stop valves
to increase efficiency (refer to "10.4.4. Setup" on page 20).
10.4.2. 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.
 Perform vacuum drying to remove all moisture, air or nitrogen 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.
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.
See "10.4.4. Setup" on page 20 and "10.4. Leak test and vacuum
drying" on page 19.
10.4.3. 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 (refer to "15.2. Monitoring function
and field settings" on page 37) before starting leak test and
vacuuming. This setting will open field expansion valves to guarantee
a R410A piping pathway.
When all piping work is complete, it is necessary to:
 Check for any leakages in the refrigerant piping.
 Perform vacuum drying to remove all moisture, air or nitrogen 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.
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 "10.4.4. Setup" on page 20 and "10.4. Leak test and vacuum
drying" on page 19.
10.4.4. Setup
1 Pressure reducing valve
2 Nitrogen
3 Measuring instrument
4 Refrigerant R410A tank (siphon system)
5 Vacuum pump
6 Charge hose
7 Refrigerant charge port
8 Gas line stop valve
9 Liquid line stop valve
10 Outdoor unit
11 To indoor unit
12 Stop valve
13 Field piping
14 Gas flow
15 Stop valve service port
A Valve A
B Valve B
C Valve C
10.4.5. Leak test
The leak test must satisfy the specifications of EN 378-2:
1 Vacuum leak test:
1.1 Evacuate the system from the liquid and gas 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 system, i.e. 3.3 MPa (33 bar).
2.2 Test for leaks by applying a bubble test solution to all piping
connections.
2.3 Discharge all nitrogen gas.
NOTICE
Do not purge the air with refrigerants. Use a vacuum pump
to evacuate the installation.
NOTICE
Make sure that all (field supplied) field piping valves are
OPEN (not outdoor unit stop valves!) before you start leak
test and vacuuming.
NOTICE
 Make sure that all (field supplied) field piping valves
are OPEN (not 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 until the outdoor unit has finished the initialisation
to apply setting [2-21].
Which valves? State of valves
State of the valves A, B, and C and
the stop valve
Performing the airtightness test and
vacuum drying (Valve A must always
be shut. Otherwise the refrigerant in
the unit will pour out.)
Valve A Close
Valve B Open
Valve C Open
Liquid side stop valve Close
Gas side 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 "10.4. Leak test
and vacuum drying" on page 19).
1
23
4
5
6
B
C
9
8
10 10 10
11
13
12
14
15
A
7