5 Installation
Installation and operation manual
10
RKXYQ5T7Y1B
VRV IV compressor unit for indoor installation
4P408443-1 – 2015.07
5.4
Checking the refrigerant piping
5.4.1
About checking the refrigerant piping
Refrigerant piping works are
finished?
The indoor units, compressor
unit and/or heat exchanger
unit were already powered
ON?
Use procedure:
"Method 2: After power ON".
Finish piping work.
Use procedure:
"Method 1: Before power ON
(regular method)".
Yes
No
No
Yes
It is very important that all refrigerant piping work is done before the
units (compressor unit, heat exchanger unit or indoor units) are
powered on.
When the units are powered on, the expansion valves will initialise.
This means that they will close. Leak test and vacuum drying of field
piping, heat exchanger unit and indoor units is impossible when this
happens.
Therefore, there will be explained 2 methods for initial installation,
leak test and vacuum drying.
Method 1: Before power ON
If the system has not yet been powered on, no special action is
required to perform the leak test and the vacuum drying.
Method 2: After power ON
If the system has already been powered on, activate setting [2‑21]
(refer to
"6.1.4 To access mode 1 or 2" on page 16
). This setting
will open field expansion valves to guarantee a R410A piping
pathway and make it possible to perform the leak test and the
vacuum drying.
NOTICE
Make sure that the heat exchanger unit and all indoor units
connected to the compressor unit are powered on.
NOTICE
Wait until the compressor unit has finished the initialisation
to apply setting [2‑21].
Leak test and vacuum drying
Checking the refrigerant piping involves:
▪ Checking for any leakages in the refrigerant piping.
▪ Performing 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, water 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 compressor unit stop valves are
firmly closed before performing leak test or vacuum drying.
NOTICE
Make sure that all (field supplied) field piping valves are
OPEN (not compressor unit stop valves!) before you start
leak test and vacuuming.
For more information on the state of the valves, refer to
"5.4.3 Checking refrigerant piping: Setup" on page 10
.
5.4.2
Checking refrigerant piping: General
guidelines
Connect the vacuum pump through a manifold to the service port of
all stop valves to increase efficiency (refer to
refrigerant piping: Setup" on page 10
).
NOTICE
Use a 2-stage vacuum pump with a non-return valve or a
solenoid valve that can evacuate to a gauge pressure of
–100.7 kPa (5 Torr absolute).
NOTICE
Make sure the pump oil does not flow oppositely into the
system while the pump is not working.
NOTICE
Do not purge the air with refrigerants. Use a vacuum pump
to evacuate the installation.
5.4.3
Checking refrigerant piping: Setup
The system contains 2 refrigerant circuits:
▪
Circuit 1:
Compressor unit → Heat exchanger unit
▪
Circuit 2:
Compressor unit → Indoor units
You have to check both circuits (leak test, vacuuming drying). How
to check depends on your available tools:
If you have a
manifold…
Then
With refrigerant line
splitters
You can check both circuits at once. To do
so, connect the manifold via the splitters to
both circuits, and check.
Without refrigerant
line splitters
(takes twice as long)
You have to check the circuits separately. To
do so:
▪ First connect the manifold to
circuit 1
,
and check.
▪ Then connect the manifold to
circuit 2
,
and check.
Possible connections:
Manifold
Connections
Compressor unit
p< p>
R410A
N2
b
c
e
a
d
B
A
Circuit 1 and 2
together
C
g
h
A
f
i
B
C
C
C
D
D
h
i
g
f
Only circuit 1
i
B
h
A
C
C
Only circuit 2
C
C
f
B
g
A
