Mitsumi electronic MU12NN Air Conditioner User Manual


 
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NOTE : Coil frost prevention during COOL mode of “I FEEL CONTROL”
There are two types of controls in coil frost prevention.
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Temperature control
<MS09NW> When the indoor coil thermistor RT12 reads 39°F or below for 5 minutes, the coil frost prevention mode starts.
<MS12/15/17NN> When the indoor coil thermistor RT12 reads 30°F or below, the coil frost prevention mode starts
immediately.
However, the coil frost prevention only works after 5 minutes from the compressor starts.
The compressor stops and the indoor fan operates at the set speed for 5 minutes.
After that, if RT12still reads below 39°F (MS09NW) or below 30°F (MS12/15/17NN) this mode is prolonged until the RT12
reads over 39°F (MS09NW) or 30°F (MS12/15/17NN) .
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Time control
When the three conditions below have been satisfied for 1 hour and 45 minutes, compressor stops for 3 minutes.
a. Compressor has been continuously operating.
b. Indoor fan speed is Lo or Me.
c. Room temperature is below 79°F.
When compressor stops, the accumulated time is cancelled and when compressor restarts, time counting starts
from the beginning.
Time counting also stops temporarily when the indoor fan speed becomes Hi or the room temperature exceeds
79°F. However, when two of the above conditions (b.and c.) are satisfied again.Time accumulation is resumed.
Indoor fan operates at the set speed by FAN SPEED CONTROL button.
Followings are the fan speed in AUTO.
Initial temperature difference
Room temperature minus set temperature : 4 degrees or more············································Hi
Room temperature minus set temperature : 2 degree or more and less than 2 degrees·····Me
Room temperature minus set temperature : less than 2 degree···········································Lo
—DRY mode of “I FEEL CONTROL”—
The system for dry operation uses the same refrigerant circuit as the cooling circuit.
The compressor and the indoor fan are controlled by the temperature and the microprocessor.
By such controls, indoor flow amounts will be reduced in order to lower humidity without much room temperature
decrease.
The operation of the compressor and indoor fan is as follows.
1. When the room temperature is 73°F or over:
Compressor operates by temperature control and time control.
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Set temperature is controlled to fall 4°F as initial set temperature.
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When the thermostat is ON, the compressor repeats 8 minutes ON and 3 minutes OFF.
When the thermostat is OFF, the compressor repeats 4 minutes OFF and 1 minute ON.
Indoor fan and outdoor fan operate in the same cycle as the compressor.
2. When the room temperature is under 73°F.
When the thermostat is ON, the compressor repeats 2 minutes ON and 3 minutes OFF.
When the thermostat is OFF, the compressor repeats 4 minutes OFF and 1 minute ON.
2 deg.
3 deg.
4 deg.
7 deg.
— COOL mode of “I FEEL CONTROL” —
Compressor and
outdoor fan motor
OFF
ON
Run continuously in cooling mode
Indoor fan motor
ON
ON
OFF
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