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Piping installation
Installer and user reference guide
85
R R8T7V1B
VRV IV heat pump for indoor installation
4P499898-1A – 2020.10
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17.2.9 To connect the refrigerant branching kit
17.3 Checking the refrigerant piping
17.3.1 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
110]). 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.
