LG multi V PLUS, Service Manual

Page: 168 / 373

168 Indoor Unit
Operation Details
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Heating Mode Operation
• When the intake air temp r3°…above the setting temp, the compressor is turned off. When below
the setting temp, the compressor is turned on.
Compressor ON Temp.
➲
Setting Temp.
Compressor OFF Temp.
➲
Setting Temp.+3°C
• While in compressor on, the indoor fan is off when the indoor pipe temp. is below 20°C, when above 28°C
, it operates 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 operates 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.
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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 com-
pared 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 which,
whether to carry out defrost 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 car-
rying 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 pre-
sent temp of the indoor pipe to get the difference of the indoor pipe temperatures (=the present temperature
of the indoor 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 control 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.
• While in defrost control, the compressor is on and the indoor fan, the outdoor fan, and the 4 way valve are
off.