Haier 1U18TR4ERA, Service Manual

Page: 22 / 72

Functions and control
20
Domestic air conditioner
decreases by 1A.
(2) When the outdoor environment temperature is higher than 50
℃
, AC current protection value
decreases by 2.5A.
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).
11 ℃ //ice5
ice3 9
℃
Increasing slowly
8 ℃ //ice2
Keeping the frequency
ice_temp_3 7 ℃ 7 ℃
ice_temp_2 5
℃
Decreasing slowly
ice_temp_1 3
℃
Decreasing rapidly ice_temp_1
0 ℃ Stop
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
〈
ice3
℃
, 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> ice2
℃ , 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
modification rate. If during the course of weak magnetic control, the modification rate is still not high
enough, enter into the control of decreasing frequency until the alarm of modification rate is relieved.
7.1.5.7 Temperature protection of the outdoor refrigerating coil
When the defrosting temperature and the sensor’s temperature are higher than 65 ℃ , the frequency of
the compressor decreases 1hz/10seconds. Keep the frequency until it decreases to the lowest
frequency. When the temperatures are lower than 65
℃
and higher than 60
℃
, keep the frequency of