Hisense ADM-24UX4SGKA Service Manual page 24

6 . C O N T R O L M O
6 . C O N T R O L M O
Switchover: When initially powered on for heating, the 4-way valve is activated
immediately.
In the change from cooling to heating, it needs an interval of 50 seconds for the 4-way
valve to change over from being interrupted to being activated.
4.3.7 Overload control
4.3.7.1 Conditions for the system to be interrupted on overload: When the indoor heat
exchanger temperature is higher than or equal to the Interrupting Temperature for
Overload Protection 65¡æ , and maintains for 10 s, the overload control is activated to
interrupt the system.
Action of the overload interruption: The compressor is interrupted, the outdoor fan
stops and the indoor fan keeps running or operates for cold air prevention.
Conditions for overload interruption left: When the indoor heat exchanger temperature
drops below the Temperature for Overload Protection Lift 47¡æ , the overload control
interruption is left.
4.3.8 Overcurrent protection in heating
Same as cooling.
4.3.9 The compressor discharge temperature too high protection
Same with the cooling-run mode.
4.3.10 Defrost
4.3.10.1 Conditions for the judgment for frosting
Condition 1: The compressor has been kept operating for a certain time (50 minutes)
Condition 2:
When T
outdoor ambient ¡Ý
When T
outdoor ambient £¼
minutes.
If both conditions set out above are met at the same time, then it is judged that frosting
has taken place.
4.3.10.2 Defrosting operation
The outdoor fan stops;
The compressor' s operating frequency drops , the 4-way valve is closed, and then
goes up at a certain frequency for operation.
4.3.10.3 Conditions for the Completion of Defrosting
The defrosting run lasts for more than a certain time(12 minutes)
The outdoor coils temperature ≥ 12
If either of the above conditions is met, it judges that frosts have been cleared off.
4.3.10.4 Operations to end defrosting
The compressor frequency goes down at a rate, and the compressor get interrupted;
50 s later the 4-way valve opens up, and 10 s more both the compressor and the
outdoor fan restarts in normal operation.
4.4 Dehumidifying mode
The dehumidifying mode is illustrated as follows:
D E L
D E L
3¡æ , T
outdoor condenser ¡Ü
3¡æ , T -T
outdoor ambient
0
C
A D M - 2
A D M - 2
-3¡æ , and maintains for 5 minutes.
8¡æ , and maintains for 5
outdoor condenser ¡Ý
21
4 U X 4 S G K A
4 U X 4 S G K A
.