Mitsubishi Heavy Industries SRK20ZIX-S Service Manual page 69

(16) Outdoor fan control at low outdoor temperature
Cooling
◆
(a) Operating conditions: When the outdoor air temperature (TH2) is 22ºC or lower continues for 30 seconds while the
(b) Detail of operation: After the outdoor fan operates at A speed for 60 seconds; the corresponding outdoor heat
Outdoor heat exchanger temperature = < 21ºC
1)
After the outdoor fan speed drops (down) to 1 speed for 60 seconds; if the outdoor heat exchanger temperature is
lower than 21ºC, gradually reduce the outdoor fan speed by 1 speed. (Lower limit 1st speed)
21ºC < Outdoor heat exchanger temperature = < 38ºC
2)
After the outdoor fan speed maintains at A speed for 20 seconds; if the outdoor heat exchanger temperature is 21ºC~
38ºC, maintain outdoor fan speed.
3) Outdoor heat exchanger tempeature > 38ºC
After the outdoor fan speed rises (up) to 1 speed for 60 seconds; if the outdoor heat exchanger temperature is higher
than 38ºC, gradually increase outdoor fan speed by 1 speed. (Upper limit 3rd speed)
(c) Reset conditions: When either of the following conditions is satisfied
1) The outdoor air temperature (TH2) is 25ºC or higher.
2) The compressor command speed is 0 rps.
Heating
◆
(a) Operating conditions: When the outdoor air temperature (TH2) is 4ºC or lower continues for 30 seconds while the
(b) Detail of operation: The outdoor fan is stepped up by 2 speed step at each 20 seconds. (Upper limit 8th speed)
(c) Reset conditions: When either of the following conditions is satisfied
1) The outdoor air temperature (TH2) is 6ºC or higher.
2) The compressor command speed is 0 rps.
compressor command speed is other than 0 rps.
exchanger temperature shall implement the following controls.
¡ Value of A
Outdoor temperature > 10˚C
Outdoor temperature < = 10˚C
compressor command speed is other than 0 rps.
Outdoor fan
2nd speed
1st speed
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