Haier 1U25YEPFRA-H Service Manual page 20

the compressor decreases at the speed of 0.1HZ/second.
During the starting process of the compressor, if the AC current is greater than 7.5A, the frequency of
the compressor increases at the prohibited speed.
During the starting process of the compressor, if the AC current is greater than 6.5A, the frequency of
the compressor increases at the speed of no faster than 0.1HZ/second.
Remarks: when the outdoor temperature is high, there's compensation for AC current protection.
(1) When the outdoor environment temperature is higher than 40℃, AC current protection value
decreases by 2A/1A(09K/12K).
(2) When the outdoor environment temperature is higher than 50℃, AC current protection value
decreases by 3A/2A(09K/12K).
7.1.5.5 Anti-freezing protection of the indoor heat exchanger
When refrigerating/heating, prevent freezing.
Tpg_indoor is the minimum value of the effective indoor unit (start it and it is in accord with the running
state).
ice_temp_3+3 9℃
ice_temp_3 7℃
ice_temp_2 5℃
ice_temp_1 3℃
1℃
When Tpg_indoor〈 ice_temp_1, the frequency of the compressor decreases at the speed of
1HZ/1second.
When Tpg_indoor〈 ice_temp_2, the frequency of the compressor decreases at the speed of
1HZ/10seconds.
When Tpg_indoor begins to rise again, and ice_temp_2≤Tpg_indoor≤ ice_temp_3, the frequency
of the compressor doesn't change.
When ice_temp_3〈Tpg_indoor〈ice_temp_3+3℃, the frequency of the compressor increases at the
speed of 1HZ/10seconds.
For example, Tpg_indoor≤0℃，last for 2 minutes, and then the outdoor unit will stop, and report
underload malfunction, but don't send malfunction report to the indoor.
The compressor stops for more than 3 minutes, Tpg_indoor> ice_temp_3+2℃, the compressor
recovers.
7.1.5.6 The frequency limitation of modification rate
In the field which is controlled by high frequency, if the modification rate is not high enough, the
control-driven chip will enter into weak magnetic control, this will help to relieve the problem of
11℃//ice_temp_3+5
Increasing slowly
8℃//ice_temp_3+2
Keeping the frequency
7℃
Decreasing slowly
Decreasing rapidly ice_temp_1
Stop
20
Functions and control
Domestic air conditioner