Mitsubishi Electric MSC-CA20VB Service Technical Manual page 108

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 High or the room temperature exceeds 26°C.
However, when two of the above conditions (b. and c.) are satisfied again, time accumulation is resumed.
Operation chart
Example
Compressor
Outdoor fan
Indoor fan
8-1-2. 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 room temperature.
By such controls, indoor air flow amounts will be reduced in order to lower humidity without much room temperature
decrease.
1. Thermostat control
Thermostat is ON or OFF by difference between room temperature and set temperature.
Room temperature minus set temperature : 0.3 : or more················································ON
Room temperature minus set temperature : less than -0.3 :············································OFF
2. Indoor fan speed control
Indoor fan operates at the set speed by FAN SPEED CONTROL button.
However, in AUTO fan operation, fan speed becomes Low.
3. The operation of the compressor and indoor/ outdoor fan
Compressor operates by room temperature control and time control.
Set temperature is controlled to fall 2°C from initial room temperature.
Indoor fan and outdoor fan operate in the same cycle as the compressor.
• When the room temperature is 23°C or over:
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.
• When the room temperature is under 23°C.
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.
Operation time chart
Example
OFF
Thermostat
Indoor fan OFF
Outdoor fan OFF
Compressor
4. Coil frost prevention
• The operation is as same as coil frost prevention during COOL mode of "I FEEL CONTROL".
• Indoor fan operates at the set speed and the compressor stops for 5 minutes, because protection (Coil frost
prevention) has the priority.
However, when coil frost prevention works while the compressor is not operating, its speed becomes Low.
8-1-3. HEAT mode of "I FEEL CONTROL"
1. Thermostat control
Thermostat is ON or OFF by difference between room temperature and set temperature.
Room temperature minus set temperature : less than -0.3 :··············································ON
Room temperature minus set temperature : 0.3 : or more·················································OFF
ON
OFF
(continuously at set speed)
ON
Initial temperature difference
ON
ON
ON
OFF
ON
ON
OFF
8 minutes
3 minutes
Initial temperature difference
OFF
OFF
ON
OFF
ON
OFF
1 minute
4 minutes
108
ON
Difference between room
temperature and set tem-
perature during operation
Thermostat
Set temperature
:
-0.3
ON
Difference between room
temperature and set tem-
perature during operation
Set temperature
Thermostat
-0.3 :
0.3 :
:
0.3