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15
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4.12 Protective control function
(1)
Frost prevention control
(During cooling or dehumidifying)
(a)
Operating conditions
1)
Indoor heat exchanger temperature (Th2) is lower than 5ºC.
2)
5 minutes after reaching the inverter command speed except 0 rps.
(b)
Detail of anti-frost operation
5°C or lower
2.5°C or lower
Item
Lower limit speed
25 rps
0rps
Indoor fan
Depends on operation mode
Protects the fan tap just before
frost prevention control
Outdoor fan
Depends on operation mode
Depends on stop mode
4-way valve
OFF
(c)
Reset conditions:
When either of the following condition is satisfied.
1
The indoor heat exchanger temperature (Th2) is 8ºC or higher.
2
The inverter command speed is 0 rps.
Indoor heat exchanger
temperature
Indoor heat exchanger
temperature (
°
C)
2.5
5
8
0 rps
Lower
limit
speed
Inverter
command
speed
(2)
Cooling overload protective control
(a)
Operating conditions:
When the outdoor air temperature (Th5) is 41ºC or higher continues for 30 seconds while the
inverter command speed of other than 0 rps.
(b)
Detail of operation
1) The outdoor fan is stepped up by 3 speed step. (Upper limit 8th speed.)
2) The lower limit of inverter command speed is set to 30 rps and even if the calculated result becomes lower than that after
fuzzy calculation, the speed is kept to 30 rps. However, when the thermo becomes OFF, the speed is reduced to 0 rps.
(c)
Reset conditions:
When either of the following condition is satisfied.
1
The outdoor air temperature is lower than 40ºC.
2
The inverter command speed is 0 rps.
(3)
Cooling high pressure control
(a)
Purpose:
Prevents anomalous high pressure operation during cooling.
(b)
Detector:
Outdoor heat exchanger sensor (Th4)
(c)
Detail of operation:
53
58
63
Outdoor unit heat exchanger temperature (˚C)
6rps
(1)
6rps
(1)
0rps
After lapse of 30 sec. or over
(3)
After lapse of 30 sec. or over
(3)
After lapse of 30 sec. or over
(3)
lower limit
speed 30 rps
(Example) Fuzzy
Notes (1) When the outdoor heat exchanger temperature is in the range of 58~63 ºC, the speed is reduced by 6 rps at each 30 seconds.
(2) When the temperature is 63 ºC or higher, the compressor is stopped.
(3) When the outdoor heat exchanger temperature is in the range of 53~58 ºC, if the inverter command speed is been maintained and the operation has
continued for more than 30 seconds at the same speed, it returns to the normal cooling operation.
Notes (1) When the indoor heat exchanger temperature is in the range of 2.5~5 ºC, the speed is reduced by 4 rps at each 20 seconds.
(2) When the temperature is lower than 2.5 ºC, the compressor is stopped.
(3) When the indoor heat exchanger temperature is in the range of 5~8 ºC, the inverter command speed is been maintained.
