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6. Refrigerant recovery control
Refrigerant is recovered at each pipe-end connection of the BC controller to prevent the refrigerant from accu-
mulating in the indoor units in heating operation, stopping mode (fan mode), cooling mode and heating mode
with thermo off.
Refrigerant recovery is also performed during cooling operation to prevent an excessive accumulation of refriger-
ant in the outdoor heat exchanger (P200-P400 types only).
(1) Initiation of refrigerant recovery
[Cooling only, cooling main, heating only, heating main]
Refrigerant recovery operation begins when all of the following conditions are met:
1
[Cooling only, cooling main:5minutes, heating only, heating main: 15minutes] have past since the conclu-
sion of the last refrigerant recovery and the following conditions are met
P200
:Td >95˚C
P250~P400 :Td >105˚C
P450~P650 :Td1 >105˚C or Td2 >105˚C
2
The mode at the pipe-end connection is not in the 3-minute restart suspension mode.
(2) Refrigerant recovery operation
1
The mode at the pipe-end connection is in the mode other than heating with thermo on.
Turn on SV
C at the pipe-end connection for 30 seconds (The
corresponds to each pipe-end connec-
tion number.)
2
The LED1 and LED3 openings are increased.
7. Outdoor unit fan
(1) Control method
• The air volume of outdoor unit fan is controlled by the inverter control to maintain a constant evaporation
temperature (0˚C = 0.71 MPa) during cooling operation and constant condensing temperature
(49˚C = 2.88MPa) during heating operation, depending on the required capacity.
(2) Control
• Outdoor unit fan stops while the compressor is stopped (except when there is an input from snow sensor).
• The fan operates at full speed for 5 seconds after start up (except the units with high static pressure specifi-
cations).
• The outdoor unit fan stops during defrost operation.
