Haier AS25THMHRA-C, Service Manual

Page: 45 / 537

Functions and control
14 Domestic air conditioner
7.Funcitions and control
7.1 Main functions and control specification
7.1.1 Automatic operation
When the running mode is turned to automation after starting the system, the system will first
determine the running mode according to the current room temperature and then will run according to
the determined mode. Tr in the following selection conditions means room temperature, Ts means
setting temperature, Tp means temperature of indoor coil pipe
Tr
ı
Ts-3
ć
Choose Cooling Mode
Tr
˘
Ts-3
ć
Choose Heating Mode
After turning to the automation mode, the running mode can be switched between cooling mode,
fan mode and heating mode according to the change of the indoor ambient temperature. But the
automatic conversion between cooling mode and heating mode must be conducted after 15 minutes.
7.1.2 Cooling operation mode
Temperature control range: 16 ć ---30 ć
Temperature difference:
r
1
ć
* Control features: When Tr ˄ input airflow ˅ >Ts ˄ set temperature ˅ + temperature Backlash A, the
compressor will be 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
˅
Ts
˄
set temperature
˅
temperature Backlash
B, the compressor will be shutted, 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
ć
)
Automatic: When Tr ” Ts+3 ć , high speed.
When Ts+1
ć ”
Tr<Ts+3
ć
, medium speed
When Tr<Ts+1
ć
, low speed
When the sensor is off, low 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.
Manus: When the system is operating, you can set the high, medium or low speed manually. (When
the sensor is on or off, the system will change the speed 2 seconds after receiving the signal.)
*Airgate location control: the location for the airgate can be set according to your needs.
*Defrosting function: preventing the frosting on the indoor heat exchanger (when cooling or
dehumidifying). When the compressor works continuously for 6 minutes and the temperature of the
indoor coils has been below one centigrade for 10 seconds, the compressor will be stopped and the
malfunction will be recorded in the malfunction list. The indoor system will continue to run. When the
temperature of the indoor coil is raised to 9
ć
, the compressor will be restarted again (the requirement
of 3 minutes’ delay should be satisfied.)
* timing system on/off function.
* Dormant control function.