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2. Indoor fan speed control
Indoor fan operates continuously at the set speed by FAN SPEED CONTROL button
regardless of the thermostat’s OFF-ON.
In AUTO the fan speed is as follows.
Room temperature minus set temperature : 1.7
:
or more ········································High
Room temperature minus set temperature : Between 1 and 1.7
:
··································Med.
Room temperature minus set temperature : less than 1
:
········································Low
1.7
:
3
:
1
:
Initial temperature difference
Difference between room
temperature and set tempera-
ture during operation (
T)
Fan speed
Temperature of indoor coil thermistor
10°C or more
6°C to 8°C
3°C to 6°C
3°C or less
Operation frequency
Normal (variable)
8°C to 10°C
Raise 6Hz
Fixed
Lower 3Hz
Lower 6Hz
Compressor is turned OFF for 5 minutes when temperature of
indoor coil thermistor continues 3°C or less for 5 minutes or more.
The indoor fan maintains the actual speed of the moment.
3. Coil frost prevention
Temperature control
When indoor coil thermistor detects following temperature for 90 seconds, operational frequency
of compressor is controlled according to the following table.
-1.0
:
-0.7
:
1. Thermostat control
Thermostat is ON or OFF by difference between room temperature and set temperature
Initial temperature difference Thermostat
Room temperature minus set temperature : -1.0
:
or more··············································ON
Room temperature minus set temperature : less than -1.0
:
············································OFF
Set temperature
Difference between room
temperature and set temper-
ature during operation.
2-1. COOL (
) OPERATION
(1) Press OPERATE/STOP(ON/OFF) button.
OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone.
(2) Select COOL mode with OPERATION SELECT button.
(3) Press TEMPERATURE buttons (TOO WARM or TOO COOL button)to select the desired temperature.
The setting range is 16 ~ 31°C
4. Low outside temperature operation
MSZ-GA25
MSZ-GA35
If the outside temperature falls to 18°C or less during operation in COOL mode, the unit enters the low outside temperature
operation mode.
<Operation>
(1) If the unit enters the low outside temperature operation mode, the outside fan rotation speed gets slow down.
(2) Even when the unit is in the "thermostat-off" status under the low outside temperature operation mode, the outside fan
rotation does not stop.
(3) In this mode to detect the exact outside temperature the compressor turns OFF with the outdoor fan ON for 3 minutes
once 1 hour; if the outside temperature rises over 18°C, the unit goes back to the normal COOL mode, and if the
outside temperature is still 18°C or less, the unit stays in the low outside temperature operation mode.
(4) Dew drop prevention
When the ambient temperature thermistor RT65 reads -12
:
or less, as coil frost or dew drop from indoor unit may
occur, the compressor turns OFF with the outdoor fan ON for prevention of them.
W
Other protections work as well as in the normal COOL mode.
When the ambient temperature thermistor RT65 reads 17
:
or less, the operation mode moves to cool operation in low out-
side temperature from normal cool operation.
Each outdoor actuators (compressor/ fan/ solenoid valve) are operated in the exclusive control, which is different from one
of normal cool operation.
Especially fan motor doesn’t operates continuously to maintain sufficient cooling capacity.
(1) Outdoor fan control
Outdoor unit (compressor) operates with outdoor fan OFF basically.
But any of following conditions is satisfied, the outdoor fan turns ON for about 5 seconds.
a). the defrost thermistor RT61 reads 50
:
or more.
b). the fin temperature thermistor RT64 reads 60
:
or more.
(2) Solenoid valve control
In low outside temperature operation solenoid valve coil is energized and solenoid valve is open.
(3) Dew drop prevention
When the ambient temperature thermistor RT65 reads -12
:
or less, as coil frost or dew drop from indoor unit may
occur, the compressor turns OFF with the outdoor fan ON for prevention of them.
NOTE: This control can be released by cut of the jumper line JG on the outdoor inverter P.C. board.
Be sure to cut it since user accepts that maker can’t be responsible for coil frost or dew drop from indoor unit.
(4) Outside temperature detecting control
In this mode to detect the exact outside temperature the compressor turns OFF with the outdoor fan ON for 3 minutes
once 1 hour.
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