Mitsubishi Heavy Industries SRK60ZJX-S, Technical Manual

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132
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'10 • SR-T-091
(12) Protective control function
(a) Frost prevention control
(During cooling or dehumidifying)
1) Operating conditions
a) Indoor heat exchanger temperature (Th2) is lower than 5ºC.
b) 5 minutes after reaching the compressor command speed except 0 rps.
2) Detail of anti-frost operation
3) Reset conditions:
When either of the following condition is satisfied.
a) The indoor heat exchanger temperature (Th2) is 8ºC or higher.
b) The compressor command speed is 0 rps.
Indoor heat exchanger
temperature (ºC)
2.5 5 8
0 rps
Lower
limit
speed
compressor
command
speed
(b) Cooling overload protective control
1) Operating conditions:
When the outdoor air temperature (TH2) has become continuously for 30 seconds at 41ºC or
more, or 47ºC or more (Models 50, 60: 41ºC or more) with the compressor running, the lower
limit speed of compressor is brought up.
2) Detail of operation
a) The outdoor fan is stepped up by 3 speed step. (Upper limit 7th (models 50, 60 : 8th) speed.)
b) The lower limit of compressor command speed is set to 30 or 40 (models 50, 60 : 30) rps and even if the calculated result
becomes lower than that after fuzzy calculation, the speed is kept to 30 or 40 (models 50, 60 : 30) rps. However, when the
thermo becomes OFF, the speed is reduced to 0 rps.
3) Reset conditions:
When either of the following condition is satisfied.
a) The outdoor air temperature is lower than 40ºC or 46ºC.
b) The compressor command speed is 0 rps.
Notes (1) When the indoor heat exchanger temperature is in the range of 2.5~5ºC, the speed is reduced by 4 rps at each 20 seconds.
(2) When the temperature is lower than 2.5ºC, the compressor is stopped.
(3) When the indoor heat exchanger temperature is in the range of 5~8ºC, the compressor command speed is been maintained.
Indoor heat exchanger
temperature
Item
5°C or lower 2.5°C or lower
Lower limit of compressor command speed
22 rps (model 50, 60 : 25 rps) 0 rps
Indoor fan
Depends on operation mode
Protects the fan tap just before
frost prevention control
Outdoor fan
Depends on command speed
Depends on stop mode
4-way valve
OFF
Item
SRK20~35ZJX-S SRK50, 60ZJX-S
Outdoor air temperature
41°C or more 47°C or more 41°C or more
Lower limit speed
30 rps 40 rps 30 rps
Model
(b)
The unit checks the temperature every hour after the start of operation and, if the result of check is not same as the previous
operation mode, changes the operation mode.
(c)
When the unit is started again within one hour after the stop of automatic operation or when the automatic operation is selected
during heating, cooling or dehumidifying operation, the unit is operated in the previous operation mode.
(d)
Setting temperature can be adjusted within the following range. There is the relationship as shown below between the signals
of the wireless remote controller and the setting temperature.
Signals of wireless remote controller (Display)
–6 –5 –4 –3 –2 –1
±
0 +1 +2 +3 +4 +5 +6
Setting
temperature
Cooling
18 19 20 21 22 23 24 25 26 27 28 29 30
Dehumidifying
19 20 21 22 23 24 25 26 27 28 29 30 31
Heating
20 21 22 23 24 25 26 27 28 29 30 31 32
Unit : ºC