Dry Mode Of “I Feel Control”; Operation Time Chart; Heat Mode Of “I Feel Control” - Mitsubishi Electric MSH09TW Service Manual

—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.
By such controls, amount of air flow of indoor unit will be reduced in order to lower humidity without much room tempera-
ture drop.
1. Indoor fan speed control
Indoor fan operates at the set speed by FAN SPEED CONTROL button.
In AUTO fan operation, fan speed becomes Low.
2. The operation of the compressor and indoor/ outdoor fan (Refer to page 65 for MXZ30TN)
Compressor operates by room temperature control and time control.
Set temperature is controlled to fall 4˚F as initial set temperature.
Indoor fan and outdoor fan operate in the same cycle as the compressor.
• When the room temperature is 73˚F 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 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.

Operation time chart

Example: When the room temperature is 73˚F or over
OFF
Thermostat
Indoor fan
OFF
Outdoor fan
OFF
Compressor
3. 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, the speed becomes Low.
— HEAT mode of "I FEEL CONTROL" —
1. Indoor fan speed control
(1) In AUTO the fan speed is as follows.
Set temperature minus room temperature: 2 degrees or more ··········································High
Set temperature minus room temperature: Between 1 and 2 degrees· ·····························Med.
Set temperature minus room temperature: less than 1 degree··········································Low
(2) Cold air prevention control
<MSH09>
1 When the compressor is not operating,
(1) if the temperature of indoor coil thermistor RT12 is 64°F or less, the indoor fan stops.
(2) if the temperature of indoor coil thermistor RT12 is more than 64°F, the indoor fan operates at Very Low.
2 When the compressor is operating,
(1) if the temperature of RT12 is 72°F or more, the indoor fan operates at set speed.
(2) if the temperature of RT12 is less than 72°F and
(1) if the temperature of room temperature thermistor RT11 is 59°F or less, the indoor fan stops.
(2) if the temperature of room temperature thermistor RT11 is more than 59°F, the indoor fan operates at Very
Low.
ON
ON
ON
OFF
ON
ON
OFF
8 min.
3 min.
Initial temperature difference
OFF
ON
OFF
ON
OFF
4 min.
1 min.
57
ON
Difference between room
temperature and set
temperature during
Fan speed
operation
4 deg. 7 deg.
2 deg. 3 deg.