Funcitions And Control; Main Functions And Control Specification Of Indoor Unit; Automatic Operation - Haier 2HUM18HC03/R2 Service Manual

5.Funcitions and Control

5.1 Main functions and control specification of indoor unit

5.1.1 Automatic operation

When the system is under the automatic operation option, the appropriate operation mode will be
decided according to the differences between the preset temperature and the indoor temperature
after the system starts up. Then, the system will operate according to the chosen mode. In the
following conditions, Tr stands for indoor temperature and Ts stands for outdoor temperature.
The system will choose the operation mode according to the following conditions when entering
into the automatic operation option for the first time.
Tr Ts-3
Tr Ts-3
Under the automatic option, the system will switch between the cooling and warming modes
according to the change of the indoor temperature. If the air conditionic is under the cooling
mode, when the preset temperature for stopping the compressor is reached, the compressor will
be stopped. The indoor temperature will be tested again 15 minutes after the stop of the
compressor. At the moment, if the tested temperature is under the Tr Ts-3
system will be switched into the warming mode. If not, the system will remain in the cooling mode.
If the air conditionic is under the warming mode, when the preset temperature for stopping the
compressor is reached, the compressor will be stopped. The indoor temperature will be tested
again 15 minutes after the stop of the compressor. At the moment, if the tested temperature is
under the Tr Ts+3
system will remain in the warming mode.
5.1.2 Cooling operation mode
Temperature control range: 16 ---30
Temperature difference: 1
* Control features: When Tr input airflow >Ts set temperature
opened,the indoor fan will operate at the set speed and the mode signal will be sent to the
outdoor system. When Tr input airflow
opened,the indoor fan will operate at the set speed and the mode signal will be sent to the
outdoor system. The system will keep the original status if Tr= Ts.
Airflow speed control: (temperature difference 1 )
Automatic: When Tr>=Ts+3 , high speed.
When the airflow speed has no delay from the high to low switching, the speed should be
delayed for 3 minutes (remain at high speed for 3 minutes.) before the next switch.
2HUM18HC03/R2(DB)-SM
Choose the cooling mode
Choose the warming mode
condition, the system will be switched into the cooling mode. If not, the
When Ts+1 =<Tr<Ts+3 , medium speed
When Tr<Ts+1 , low speed
When the sensor is off, low speed
14
Ts set temperature
Wiring diagrams
condition, the
, the compressor will be
, the compressor will be
Domestic air conditioner