LG S4-S5-SE Chassis, Service Manual

Page: 8 / 44

• While in compressor off, the indoor fan repeats low air flow speed and pause.
• While the intake air temp is between compressor on temp, and compressor off temp., 10-min dehumidification
operation and 4-min compressor off repeat.
Compressor ON Temp Setting Temp+0.5°C
Compressor OFF Temp Setting Temp-0.5°C
• In 10-min dehumidification operation, the indoor fan operates with the low airflow speed
Heating Mode Operation
• When the intake air temp r4°... above the setting temp, the compressor is turned off.When below the
setting temp +2°, the compressor is turned on.
• While in compressor on, the indoor fan is off when the indoor pipe temp.is below 20°C, when above 28°C, it ope-
rates with the low or setting airflow speed.When the indoor pipe temp is between 20°C and 28°C, it operates with
Super-Low (while in sleep mode , with the medium airflow speed).
• While in compressor off, the indoor fan is off when the indoor pipe temp is below 33°C, when above 35°C, it ope-
rates with the low airflow speed.
• If overloaded while in heating mode operation, in order to prevent the compressor from OLP operation, the outdoor
fan is turned on/off according to the indoor pipe temp.
• While in defrost control, both of the indoor and outdoor fans are turned off
Defrost Control
• While in heating mode operation in order to protect the evaporator pipe of the outdoor unit from freezing, reversed
to cooling cycle to defrost the evaporator pipe of the outdoor unit.
• After 40 min heating mode operation, at 4 min interval, whether to carry out defrost control or not and the time of
defrost control are determined according to the following conditions.
1) While in heating mode operation, the maximum of the indoor pipe temperature is measured and it is compared
with the present indoor pipe temperature to get the difference of the indoor pipe temperatures (=the maximum
temperature of indoor pipe - the present temperature of indoor pipe), according to wich, whether to carry out de-
frost control or not is determined.
2) According to the need of defrost control shown above and the elapsed time of heating mode operation at that
moment, the defrost control time is determined.
3) When the determined time of defrost control is below 7 min, heating mode operation continues without carrying
out defrost control.According to the procedure stated above, the determination is made again.When the defrost
control time is 7 min or longer, defrost control is then carried out.
• While in defrost control, the minimum temp of the indoor pipe is measured and it is compared with the present
temp of the indoor pipe to get the difference of the indoor pipe temperatures (=the present temperature of the in-
door pipe - the minimum temperature of the indoor pipe). When the difference is 5°C or higher, defrost control is
completed and heating mode operation is carried out.
• While in defrost control, if the defrost time determined before the start of defrost control is completed, defrost cont-
rol stops and heating mode operation is carried out regardless of the above condition.
• When the indoor pipe temp is 42°C or above, defrost control is not carried out even if the condition is one of the
defrost conditions above.
Fuzzy Operation (C/O Model)
• According to the temperature set by Fuzzy rule, when the intake air temp is 0.5°C or more below the setting temp,
the compressor is turned off.When 0.5°C or more above the setting temp, the compressor is turned on.
Compressor ON Temp
Setting Temp+0.5°C
Compressor ON Temp Setting Temp+0.5°C
• At the beginning of fuzzy mode operation, the setting temperature is automatically selected according to the intake
air temp at that time.
• When the fuzzy key (Temperature Control key) is input after the initial setting temperature is selected, the Fuzzy
key value and the intake air temperature at that time are compared to select he setting temperature automatically
according to the Fuzzy rule.
• While in Fuzzy operation, the airflow speed of the indoor fan is automatically selected according to the temperature
26°C Intake Air Temp 25°C
24°C Intake Air Temp < 26°C Intake Air Temp +1°C
22°C Intake Air Temp < 24°C Intake Air Temp +0,5°C
18°C Intake Air Temp < 22°C Intake Air Temp
Intake Air Temp < 18°C 18°C
Compressor ON Temp Setting Temp+2°C
Compressor OFF Temp Setting Temp+4°C
-8-