Outdoor Fan Cooling Control At Low Outdoor Air Temperature; Outdoor Fan Heating Control - Mitsubishi Heavy Industries KX6 series Service Manual

(c) Outdoor fan cooling control at low outdoor air temperature.
(i) Start conditions
This control is performed when all of following conditions is established.
➀ When the ordinary outdoor fan control is performed
➁ Outdoor air temperature ≦ 10ºC (It is reset with the hysteresis of the outdoor air temperature > 15ºC.)
➂ Outdoor fan speed = 1st speed (200 rpm)
(ii) Control contents
➀ Initial fan speed is 200 rpm
➁ If the following high pressure is detected for 20 seconds continuously, fan speed will be changed
➂ Outdoor fan speed is in a range of 130 rpm – 300 rpm.
(iii) End conditions
When either one of following conditions is established
➀ When the ordinary outdoor unit fan cooling control ends
➁ Outdoor air temperature > 15ºC
➂ Outdoor unit fan speed ≧ 2th speed
(Note) This control range is not more than 300 rpm × 1 fan.
(d) Outdoor fan heating control
The fan speed control is performed based on the low pressure (detected with PSL) during heating operation.
(i) Initial fan speed is 6th speed.
(ii) Speed is changed depending on the low pressure value.
➀ When it is detected LP ≦ 0.75 MPa for 30 seconds continuously, the fan speed is raised by 1 tap.
➁ When it is 0.75 MPa < LP < 0.85 MPa, the present fan speed is maintained.
➂ When it is detected LP ≧ 0.85 MPa for 30 seconds continuously, the fan speed is dropped by 1 tap.
➃ Control range of fan speed is 1st – 8th speeds.
One tap up
(iii)  W hen states change from LP < 1.0 MPa to HP ≧ 1.0 MPa during this control, the fan speed is changed
preferentially to the following. (It returns to the normal control after the change.)
➀ It changes to 4th or lower speed.
➁ If the fan speed was lower than the above speed before the change of states, the fan speed does not change.
Valid
10
Outdoor air temperature
Maintained
−10 rpm
1.4
High pressure (MPa)
Maintained
0.75 0.85
Low pressure (MPa)
16
-
Invalid
15
+10 rpm
1.7
One tap down
-
'10 • KX-SM-148