22
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Maintenance and service
Installer and user reference guide
135
RWEYQ8~14T9Y1B
VRV IV water-cooled system air conditioner
4P452191-1B – 2020.10
22.3 About service mode operation
Refrigerant recovery operation/vacuuming operation is possible by applying setting
[2‑21]. Refer to
116] for details how to set mode 2.
When vacuuming/recovery mode is used, check very carefully what should be
vacuumed/recovered before starting. See installation manual of the indoor unit for
more information about vacuuming and recovery.
22.3.1 To use vacuum mode
1
When the unit is at standstill, set the unit in [2‑21]=1.
Result:
When confirmed, the indoor and outdoor unit expansion valves will
fully open. At that moment the 7‑segment display indication=
and the user
interface of all indoor units indicate TEST (test operation) and
(external
control) and the operation will be prohibited.
2
Evacuate the system with a vacuum pump.
3
Press BS3 to stop vacuuming mode.
22.3.2 To recover refrigerant
This should be done with a refrigerant recovery unit. Follow the same procedure as
for vacuuming method.
DANGER: RISK OF EXPLOSION
Pump down – Refrigerant leakage.
If you want to pump down the system, and there
is a leak in the refrigerant circuit:
▪
Do NOT use the unit's automatic pump down function, with which you can collect
all refrigerant from the system into the outdoor unit.
Possible consequence:
Self-
combustion and explosion of the compressor because of air going into the
operating compressor.
▪
Use a separate recovery system so that the unit's compressor does NOT have to
operate.
NOTICE
Make sure to NOT recover any oil while recovering refrigerant.
Example:
By using an
oil separator.
