Mitsubishi Electric MS-A•WA Service Technical Manual page 4

1. Thermostat control
Thermostat is ON or OFF by difference between room temperature and set temperature.
Room temperature minus set temperature : -1.8 degrees or more·····································ON
Room temperature minus set temperature : less than -1.8 degrees···································OFF
2. Indoor fan speed control
Indoor fan operates at the set speed by FAN SPEED CONTROL button.
When thermostat OFF (compressor OFF) fan speed becomes Very Low.
In AUTO the fan speed is as follows.
Room temperature minus set temperature : 3.1 degrees or more ·······························High
Room temperature minus set temperature : Between 1.8 degrees and 3.1 degrees···Med.
Room temperature minus set temperature : less than 1.8 degrees ·····························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 4°F from initial room 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
OFF
Thermostat
OFF
Indoor fan
OFF
Outdoor fan
Compressor
4. Coil frost prevention
Coil frost prevention is as same as COOL mode. (2-1.3.)
The indoor fan maintains the actual speed of the moment. However ,when coil frost prevention works while the compressor
is not operating it's speed becomes the set speed.
Initial temperature difference
Initial temperature difference
ON
ON
ON
OFF
ON
ON
OFF
8 minutes
3 minutes
Fan speed
OFF
ON
OFF
ON
OFF
4 minutes 1 minute
4
Difference between room
temperature and set temper-
ature during operation
Thermostat
Set temperature
-1.8 deg. -1.3 deg.
Difference between room
temperature and set temper-
ature during operation (
1.8 deg. 3.1 deg.
ON
T)
4.5 deg.