Mitsubishi SRK20ZSX-W Technical Manual page 78

(e) Cooling low outdoor air temperature protective control
(i) Operating conditions
When the outdoor air temperature (models SRK20, 25, 35 : TH3 ; models SRK50, 60 : TH2) is 22°C or lower continues
for 20 seconds while the compressor speed is other than 0 rps.
(ii) Detail of operation
1) It controls the upper and lower limit values for the compressor speed according to the following table.
2) It checks the outdoor temperature (models SRK20, 25, 35 : TH3 ; models SRK50, 60 : TH2) once every hour to
judge the operation range.
Compressor speed: Upper/lower limit (rps)
Range B
SRK20, 25, 35
SRK50, 60
Upper 2
ON
Lower 2
A B
Outdoor air temperature (°C)
(iii) Reset conditions
When either of the following condition is satisfied.
1) The outdoor air temperature (models SRK20, 25, 35 : TH3 ; models SRK50, 60 : TH2) is D°C or higher.
2) The compressor speed is 0 rps.
(f ) Heating high pressure control
(i) Purpose
(ii) Detector
(iii) Detail of operation
(Example)
Compressor
speed
When the indoor heat exchanger temperature is in the range of A-B °C, if the compressor speed is been maintained and the operation has continued for more
than 20 seconds at the same speed, it returns to the normal heating operation.
fan
Temperature list
SRK20, 25, 35
RPSmin < 50
< =
50 RPSmin < 115
115 < =
RPSmin < 120
120 < =
RPSmin
SRK50, 60
RPSmin < 50
50 < =
RPSmin < 115
115 < =
RPSmin < 120
120 < = RPSmin
Lower 1
Upper 1 Lower 2 Upper 2
Range A
20 Release 70 30
35 Release 75 45
Upper 1
ON
Lower 1
OFF
C D
After lapse of 20 sec. or over
After lapse of 20 sec. or over
After lapse of 20 sec. or over
A
Indoor heat exchanger temperature(°C)
speed
A
44
44
44 - 42 51 - 49
42
A
45
45
45 - 43 52 - 50
43
-
Range B
60
24
60
Outdoor air temperature ( )
Outdoor air temperature (˚C)
A
SRK20, 25, 35 0
9
SRK50, 60
4rps 8rps
(3) (1)
4rps
(1)
(3)
lower limit
(3)
speed 35 rps
B C
B - C
C - D
fan
B C
53.5
51
51 56
56 - 54
49 54
B C
52 54.5
52 57
57 - 55
50 55
76
-
'09•SRK-DB-087D
'18 • SRK-T-234
Range A
26
B C D
3 22 25
11 22 25
(2)
8rps
(2)
0rps
D
10
10
D
60
60
60 - 58
58
D
58
60
60 - 58
58