Mitsubishi SRK20ZSX-W Technical Manual page 77

Indoor heat exchanger
(iii) Reset conditions
Item
Lower limit of compressor command speed
1)
Indoor fan
2)
Outdoor fan
4-way valve
(c) Cooling overload protective control
(i) Operating conditions
When the outdoor air temperature (models SRK20, 25, 35 : TH3 ; models SRK50, 60 : TH2) has become continuously
for 30 seconds at 38°C or more, or 41°C or more, or 47ºC or more with the compressor running, the lower limit speed
(iii) Reset conditions
of compressor is brought up.
1)
Item
2)
Outdoor air temperature
Lower limit speed
(c) Cooling overload protective control
(ii) Detail of operation
SRK20, 25, 35
(i) Operating conditions
1) The outdoor fan is stepped up by 3 speed step. [Upper limit 8 th speed.]
When the outdoor air temperature (models SRK20, 25, 35 : TH3 ; models SRK50, 60 : TH2) has become continuously
2) The lower limit of compressor speed is set to 25 or 30 or 40rps.
for 30 seconds at 38°C or more, or 41°C or more, or 47ºC or more with the compressor running, the lower limit speed
However, when the thermo OFF, the speed is reduced to 0 rps.
ON1
of compressor is brought up.
(iii) Reset conditions
OFF
Item
37 38 40 41
1)
Outdoor air temperature (°C) Outdoor air temperature
2)
Lower limit speed
(ii) Detail of operation
(d) Cooling high pressure control
The outdoor fan is stepped up by 3 speed step. [Upper limit 8 th speed.]
1)
(i) Purpose
2) The lower limit of compressor speed is set to 25 or 30 or 40rps.
Prevents anomalous high pressure operation during cooling.
However, when the thermo OFF, the speed is reduced to 0 rps.
(ii) Detector
(iii) Reset conditions Outdoor heat exchanger sensor (models SRK20, 25, 35 : TH2 ; models SRK50, 60 : TH1).
(iii) Detail of operation
(Example) Compressor speed
1)
2)
(d) Cooling high pressure control
(i) Purpose
Prevents anomalous high pressure operation during cooling.
(ii) Detector
P1
Outdoor heat exchanger sensor (models SRK20, 25, 35 : TH2 ; models SRK50, 60 : TH1).
Outdoor heat exchanger temperature (°C)
(iii) Detail of operation
(Example) Compressor speed
P1
Notes (1) When the outdoor heat exchanger temperature is in the range of P2-P3 , the speed is reduced by 8 rps at each 20 seconds.
Outdoor heat exchanger temperature (°C)
(2) When the temperature is P3
(3) When the outdoor heat exchanger temperature is in the range of P1-P2
more than 20 seconds at the same speed, it returns to the normal cooling operation.
Notes (1) When the outdoor heat exchanger temperature is in the range of P2-P3 , the speed is reduced by 8 rps at each 20 seconds.
(2) When the temperature is P3
(3) When the outdoor heat exchanger temperature is in the range of P1-P2
more than 20 seconds at the same speed, it returns to the normal cooling operation.
temperature 5°C or lower
Depends on compressor speed
Model
SRK20, 25, 35
38°C or more
25 rps
ON3
ON2
Model
SRK20, 25, 35
46 47
38°C or more
25 rps
After lapse of 30 sec. or over (3)
After lapse of 30 sec. or over (3)
After lapse of 30 sec. or ove r (3)
After lapse of 30 sec. or over (3)
After lapse of 30 sec. or over (3)
After lapse of 30 sec. or ove r
(3)
Outdoor air tamperature(
or higher, the compressor is stopped.
Outdoor air tamperature(
or higher, the compressor is stopped.
2.5°C or lower
Keep the fan speed before
frost prevention control
2.5–5
5–8
SRK50, 60
41°C or more
30 rps
SRK50, 60
ON2
ON1
OFF
SRK50, 60
40 41 46 47
37°C (models SRK50, 60 : 40°C).
Outdoor air temperature (°C) 41°C or more
30 rps
37°C (models SRK50, 60 : 40°C).
8rps (1)
8rps (1)
lower limit
speed 30rps
0rps
P3
P2
8rps (1)
8rps (1)
Range B
lower limit
speed 30rps
Range A
0rps
31 32
)
P2 P3
, if the compressor speed is been maintained and the operation has continued for
SRK20, 25, 35
Range B
Range A
31 32
)
, if the compressor speed is been maintained and the operation has continued for
75
- -
limit
speed
0 rps
'18 • SRK-T-234
2.5
Indoor heat exchanger
temperature (°C)
47°C or more
40 rps
47°C or more
40 rps
Range B
Range A
25 26 31
Outdoor air tamperature(
SRK50, 60
Range B
Range A
25 26 31
Outdoor air tamperature(
5 8
Range C
32
)
Range C
32
)