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19
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4.12 Protective control function
(1)
Frost prevention for indoor heat exchanger
(During cooling or dehumidifying)
(a)
Operating conditions
1)
Indoor heat exchanger temperature (detected with Th2) is lower than 5ºC.
2)
10 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
20, 25 type : 44 rps
Upper limit speed
35 type : 70 rps
0rps
50 type : 76 rps
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:
The indoor heat exchanger temperature (Th2) is 8ºC or higher after 5 minutes of operation following
control of the inverter command speed upper limit.
Indoor heat exchanger
temperature
Indoor heat exchanger
temperature (
°
C)
2.5
5
8
0 rps
Upper
limit
speed
Inverter
command
speed
(2)
Cooling overload protective control
(a)
Operating conditions:
When the outdoor unit is operating with the outdoor unit speed of other than 0 rps, and when the
outdoor air temperature sensor (Th5) becomes 41ºC or over for 30 seconds continuously.
(b)
Detail of operation
1) Outdoor fan is stepped up by 3 speed step. (Upper limit speed is 7th speed.)
2) The lower limit of control 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
When the outdoor air temperature becomes 40ºC or less.
2
When the inverter command speed is 0rps.
(3)
Cooling low outdoor temperature protective control
◆
<
I
>
(a)
Operating conditions:
When the outdoor air temperature sensor (Th5) is 22ºC or lower continues for 30 seconds while
outdoor speed is other than 0rps.
(b)
Detail of operation:
After the outdoor fan operates at A speed for 60 seconds; the corresponding outdoor heat
exchanger temperature shall implement the following controls.
1
Outdoor heat exchanger temperature =
<
21ºC
After the outdoor fan speed drops (down) to one speed for 60 seconds; if the outdoor heat exchanger temperature is
lower than 21
°
C, gradually reduce the outdoor fan speed by 1 speed. (Lower limit speed is 1st speed)
2
21ºC < Outdoor heat exchanger temperature =
<
38ºC
After the outdoor fan speed maintains at A speed for 20 seconds; if the outdoor heat exchanger temperature is 21
°
C~
38
°
C, maintain outdoor fan speed.
3
Outdoor heat exchanger tempeature > 38ºC
After the outdoor fan speed rises (up) to 1 speed for 60 seconds; if the outdoor heat exchanger temperature is
higher than 38
°
C, gradually increase outdoor fan speed by 1 speed. (Upper limit speed is 3rd speed)
(c)
Reset conditions:
When the either of the following conditions is satisfied
1
When the outdoor air temperature sensor (Th5) becomes 25ºC or higher.
2
When the inverter command speed is 0rps.
Outdoor temperature > 10˚C
Outdoor temperature
≤
_ 10˚C
2nd speed
Outdoor fan
1st speed
¡
Value of A