Mitsubishi Heavy Industries SRK60ZJX-S, Technical Manual

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(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 (Model 50: 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 (model 50 : 8th) speed.)
b) The lower limit of compressor command speed is set to 30 or 40 (model 50 : 30) rps and even if the calculated result
becomes lower than that after fuzzy calculation, the speed is kept to 30 or 40 (model 50 : 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.
(c) Cooling high pressure control
1) Purpose:
Prevents anomalous high pressure operation during cooling.
2) Detector:
Outdoor heat exchanger sensor (TH1)
3) 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 compressor 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.
Model
Item
SRF25, 35ZJX-S SRF50ZJX-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
(11) 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
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 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 : 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