Haier AS25THMHRA-C, Service Manual

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Functions and control
16
Domestic air conditioner
When refrigerating, it is needed to satisfy
F-MIN-d(compressor’s Min_hz)< F<F-MAX-d(compressor’s Max_hz)
When heating, it is needed to satisfy
F-MIN-r (compressor’s Min_hz)< F<F-MAX-r (compressor’s Max_hz)
PID control :
The innital frequency Sn is determined by Pn . We can calculate Hzoutf according to the value of Kp ,Ki ,Kd,
Out_gain,Pn.Then , Fn = Sn + Hzoutf. The value of Fn is calculated in each sample time (60 seconds),and Fn is
adujusted according to previous frequency of Sn and filtered output of Hzoutf.
7.1.2 The outdoor fan control (Exchange fan)
When the fan is changed among every airflow speed (including stop blowing), in order to avoid the
airflow speed from skipping frequently, it must be kept under each mode for over 30 seconds, and then
it can be changed to another mode (when refrigerating, the time is changed to 15 seconds).
7.1.2.1 The outdoor fan control
Within three minutes of compressor starting, the compressor is controled according to the ambient temperature.
Tao
（℃）
Tao <22
●
℃
22
℃
< Tao <28
℃
Tao
≥
29
℃
Refrigeration/dehumidification 2nd level /2nd level 3rd level /4th level 5th level /6th level
Tao
（℃）
Tao <<10
℃
10
℃
< Tao <17
℃
Tao
≥
17
℃
Heating 5th level /6th level 3th level /5th level 3rd level /2nd level
After 3 minutes, the compressor is controled according to the ambient temperature and the frequency of the
compressor.
Refrigeration/dehumidification
frequency
（
Hz
）
<40 Hz 40 Hz-60 Hz
≥
60 Hz
Tao
（℃）
≤
22 2nd level 3rd level 5 th level(6 th)
22-28 3rd level 5 th level 7 th level(6 th)
≥
28
7 th level
Heating frequency
（
Hz
）
(18K/24K)
<51 Hz 51-70 Hz
≥
70 Hz
Tao
（℃）
≤
10 5nd level(3rd) 6rd level 7 th level
10-17 3rd level(2nd)
●
4 th level 5 th level(6 th)
≥
17 2nd level
●
7
●
.1.3 The control of the outdoor Electronic expansion valve (EEV)
In cooling mode, the EEV opening range is 90~480 steps. The EEV opening is 90 steps when unit is
off.
In heating mode, the EEV opening range is 60~480 steps. The EEV opening is 60
●
steps when unit is
off.
After outdoor unit is off, the EEV opening keep the current on for 5 s, then open the EEV completely for
2 minutes, then become 90 steps (cooling) or 60 steps (heating).
The EEV opening will increase if SH (superheat degree) >0 while decrease if SH<0.
Adjust frequency:
If |SH|=0, 60s/ 1 step