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[ VIII Control ]
(3) Stopping the defrost operation
The defrost cycle ends when 12 minutes have passed since the beginning of the cycle, or when the pipe temperature (TH3),
in the following table, or above has been continuously detected for 4 minutes (when SW3-4 is set to OFF) or 2 minutes (when
SW3-4 is set to ON) that exceeds the values in the table below.
The defrost cycle will not end for two minutes once started unless one of the following conditions is met : Pipe temperature
reaches 25°C [77°F] and SW3-4 is set to OFF OR
*1 5°C [41°F]
25°C [77°F]
In the multiple system, defrosting is stopped on all units at the same time.
Model
250 model
350 model
400 model
(4) Problems during defrost operation
If a problem is detected during defrost operation, the operation will be stopped, and the defrost prohibition time based on the
integrated compressor operation time will be set to 20 minutes.
(5) Change in the number of operating indoor units during defrost operation
Even when there is a change in the number of operating indoor units during defrost operation, the operation will continue, and
an adjustment will be made after the completion of the defrost operation.
Defrost operation will be continued, even if the indoor units stop or under the Thermo-OFF conditions until it has run its course.
-8- Refrigerant Recovery Control
Recovery of refrigerant is performed during heating operation to prevent the refrigerant from accumulating inside the unit while
it is stopped (unit in fan mode), or inside the indoor unit that is in cooling mode or in heating mode with thermo off. It is also
performed during cooling operation to prevent an excessive amount of refrigerant from accumulating in the outdoor heat ex-
changer.
It is also performed during cooling operation to prevent an excessive amount of refrigerant from accumulating in the outdoor
heat exchanger.
(1) During heating operation
Starting refrigerant recovery mode
The refrigerant recovery mode in heating starts when all of the following three conditions are met:
15 minutes have passed since the completion of previous refrigerant recovery.
TH4 > 115°C [239°F]
Frequencies below 50 Hz
Refrigerant recovery
1) Refrigerant is recovered with the LEV on the applicable indoor unit (unit under stopping mode, fan mode, cooling, heating with
thermo off) being opened for 30 seconds.
2) Periodic capacity control of the outdoor units and periodic LEV control of the indoor units will be suspended during refrigerant
recovery operation; they will be performed after the recovery has been completed.
(2) During cooling operation
Starting refrigerant recovery mode
The refrigerant recovery mode starts when all the following conditions are met:
30 minutes have passed since the completion of previous refrigerant recovery.
When the unit keeps running for 3 minutes in a row or more with high discharge temperature
TH4 > 105°C [221°F] or 63HS1 > 3.43 MPa [497 psi] (35 kg/cm
Refrigerant recovery
The opening of LEV1 is increased and periodic control begins again.
HWE10190
*1
SW3 - 4 OFF
10°C [50°F]
7°C [45°F]
7°C [45°F]
Opening of LEV during refrigerant recovery
Opening of indoor unit LEV: 400 pulses
Initial opening of LEV
=25°C+TH7°C [77°F+TH7°F] and SW3-4 is set to ON.
TH3
SW3 - 4 ON
5°C [41°F]
5°C [41°F]
5°C [41°F]
30 seconds
Start
Finish
2
G) and SC0 > 10°C [18°F]
- 96 -
GB
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