Haier H2SM-(9+12)HEK03/R2 Service Manual page 16

5.2.1 Single-unit cooling operation
When the single unit's indoor unit gives a cooling signal, the corresponding outdoor compressor
carries out cooling operation. During the operation, the outdoor fan operates 1 second before the
compressor operates.
When changed from heating to cooling, the compressor stands by for 3 minutes, the outdoor fan
operates to blow off remaining heat and stops 30 seconds later.
a return difference of 2°C for the change between high and medium speed.
return difference of 2°C for the change between low and medium speed.
3 minute run. There is a return difference of 2°C for the change between low speed and run and stop.
Once the fan operates in a mode, it must operate for more than 45 seconds.
There is a temperature cut-off protection: when the indoor coil temperature higher than T_CPS
(68°C) and maintains for 10 seconds, both the compressor and outdoor fan stop. The compressor will not
restart in 3 minutes until the coil temperature lower than T_CP R(50°C). The indoor fan is controlled the
same as the thermostat is OFF.
5.2.2 Double-unit cooling operation
When the indoor unit gives out a double unit cooling signal, outdoor compressor A starts cooling
operation. During the operation, the outdoor fan runs 1 second before compressor A operates, 20
seconds later, outdoor compressor B starts cooling operation.
Once a compressor starts, the other compressor will not start in 20 seconds from the start.
When changed from heating to cooling, the compressor stands by for 3 minutes. When both
compressors are in the strand-by status, the outdoor fan stops. Otherwise, it operates. The status of the
fan depends on the number of the compressors that operate.
a return difference for the change between high and medium speed;
return difference for the change between low and medium speed;
3 minute run. There is a return difference of 2°C for the change between low speed and run and stop.
Once the fan operates in a mode, it must operate for more than 45 seconds.
There is a temperature cut-off protection: when a indoor coil temperature higher than T_CPS (68°C)
and maintains for 10 seconds, the corresponding compressor stops. The compressor will not restart in 3
minutes until the coil temperature lower than T_CPR(50°C). The indoor fan is controlled the same as the
thermostat is OFF.
In the case of double-unit cooling, one compressor stops and it changes to the single-unit
operation. The fan is controlled in the single-unit operation mode. It stops 30 after blowing off the
remaining heat only if both compressors turn off at the same time.
5.2.3 Single unit heating operation
When the single unit's indoor unit gives a heating signal, the corresponding outdoor compressor
carries out cooling operation. During the operation, the outdoor fan and 4-way valve operate 1 second
H2SM-(9+12)HEK03/R2
14
Funcitions and Control
Domestic Air Conditioner