Cooling Low Outdoor Air Temperature Protective Control - Mitsubishi Heavy Industries FDT40ZSXW1VH Service Manual

(a) Operating conditions
When the outdoor air temperature (TH2) has become continuously for 30 seconds at 41°C or more, or
When the outdoor air temperature (TH2) has become continuously for 30 seconds at 41°C or more, or
47ºC or more with the compressor running, the lower limit speed of compressor is brought up.
47ºC or more with the compressor running, the lower limit speed of compressor is brought up.
Outdoor air temperature
Outdoor air temperature
Lower limit speed
Lower limit speed
(b) Detail of operation
(b) Detail of operation
1) The outdoor fan is stepped up by 3 speed step. [Upper limit 8 th speed.]
1) The outdoor fan is stepped up by 3 speed step. [Upper limit 8 th speed.]
2) The lower limit of compressor speed is set to 30 or 40 rps.
2) The lower limit of compressor speed is set to 30 or 40 rps.
However, when the thermo OFF, the speed is reduced to 0 rps.
However, when the thermo OFF, the speed is reduced to 0 rps.
(c) Reset conditions
(c) Reset conditions
1)
1)
2)
2)
(a) Purpose
(a) Purpose
Prevents anomalous high pressure operation during cooling
Prevents anomalous high pressure operation during cooling
(b) Detector
(b) Detector
Outdoor heat exchanger sensor (Models SRK40, 50, 60 : TH1)
Outdoor heat exchanger sensor (Models SRK40, 50, 60 : TH1)
(c) Detail of operation
(c) Detail of operation
(Example) Compressor speed
(Example) Compressor speed
After lapse of 30 sec. or over
After lapse of 30 sec. or over
After lapse of 30 sec. or ove
P1
P1
Outdoor heat exchanger temperature (°C)
Outdoor heat exchanger temperature (°C)
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.
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
(2) When the temperature is P3
(3) When the outdoor heat exchanger temperature is in the range of P1-P2
(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. more than 20 seconds at the same speed, it returns to the normal cooling operation.

(4) Cooling low outdoor air temperature protective control

(4) Cooling low outdoor air temperature protective control
(a) Operating conditions
(a) Operating conditions
When the outdoor air temperature (TH2) is 22°C or lower continues for 20 seconds while the compressor speed is other than 0 rps. When the outdoor air temperature (TH2) is 22°C or lower continues for 20 seconds while the compressor speed is other than 0 rps.
(b) Detail of operation
(b) Detail of operation
1) It controls the upper and lower limit values for the compressor speed according to the following table.
1) It controls the upper and lower limit values for the compressor speed according to the following table.
2) It checks the outdoor temperature (TH2) once every hour to judge the operation range.
2) It checks the outdoor temperature (TH2) once every hour to judge the operation range.
Compressor speed: Upper/lower limit (rps)
Compressor speed: Upper/lower limit (rps)
Lower 1
Lower 1
Range B Range A
Range B Range A
35 Release
35 Release
Upper 2
ON
Upper 2
ON
Lower 2
Lower 2
9 11
9
40°C.
40°C.
After lapse of 30 sec. or over (3)
(3)
After lapse of 30 sec. or over (3)
(3)
After lapse of 30 sec. or ove r (3)
r (3)
P2
or higher, the compressor is stopped.
or higher, the compressor is stopped.
Upper 1 Lower 2 Upper 2
Upper 1 Lower 2 Upper 2
75 45 60
75 45 60
Upper 1
ON
Upper 1
ON
Lower 1
Lower 1
OFF
OFF
22 25
11 22 25
8rps (1)
8rps (1)
8rps (1)
8rps (1)
lower limit
lower limit
speed 30rps
speed 30rps
0rps
0rps
P2 P3
P3
Range B
Range B
Range A
Range A
25 26
25 26
Outdoor air tamperature(
Outdoor air tamperature(
, if the compressor speed is been maintained and the operation has continued for
, if the compressor speed is been maintained and the operation has continued for
Range A
Range A
Range B
Range B
24 26
24 26
Outdoor air temperature (
Outdoor air temperature (
28
- -
'19 • PAC-SM-302
Range C
Range C
31 32
31 32
)
)