Installation and operation manual
18
10T8Y1B
VRV-W IV System Air Conditioner
4P399208-1 – 2015.01
10.4. Leak test and vacuum drying
It is very important that all refrigerant piping work is done before the
units (outdoor or indoor) are powered on.
When the units are powered on, the expansion valves will initialize.
This means that they will close. Leak test and vacuum drying of field
piping and indoor units is impossible when this happens.
Therefore, there will be explained 2 methods for initial installation,
leak test and vacuum drying.
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 3 stop valves
to increase efficiency (refer to
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, 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
.
10.4.3
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
) 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, 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
Heat pump system (2-pipe)
Heat recovery system (3-pipe)
1
Pressure reducing valve
2
Nitrogen
3
Charge hose
4
Refrigerant R410A tank (siphon system)
5
Measuring instrument
6
Vacuum pump
7
Outdoor unit
8
Gas line stop valve (in case of heat pump system): HP/LP
9
Liquid line stop valve
10
HP/LP gas line stop valve
11
Suction gas line stop valve (in case of heat recovery
system)
12
Stop valve service port (in case of heat recovery system)
13
To indoor unit
14
To indoor unit/BS unit
15
Field piping
A
Valve A
B
Valve B
C
Valve C
D
Valve D
Refrigerant piping works are
finished?
No
Finish piping work
Yes
The indoor units and/or
outdoor unit were already
powered ON?
No
Use procedure
refrigerant piping, leak test,
.
Yes
Use procedure
refrigerant piping, leak test,
.
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 initialization
to apply setting [2-21].
1
8
2
4
5
R410A
6
13
7
7
9
12
15
A
B
C
3
1
2
4
5
R410A
10
6
7
7
14
9
11
12
15
A
B
C
D
