Service manual

36
Compressor
Outdoor fan
OFF
ON
(continuously at set speed)
Indoor fan
ON
ON
OFF
Operation chart
Example
4. Discharge temperature protection <MS-30RV only>
The compressor is controlled by the temperature of discharge temperature thermistor RT62 for excess rise protection of
compressor discharge pressure.
• Compressor
When the temperature of discharge temperature thermistor RT62 goes to 120: or more, the compressor is turned OFF.
After 3 minutes since the compressor has been turned OFF, if the temperature of discharge temperature thermistor RT62
becomes 100: or less, the compressor is turned ON.
3. Outdoor fan speed control <MS-30RV only>
Outdoor fan speed is controlled according to the temperature of ambient temperature thermistor RT63.
Outdoor fan Low operation : When the outside temperature decreases to 23°C or less.
Until the outside temperature goes to 27°C or more.
Outdoor fan High operation : Until the outside temperature decreases to 23°C or less.
When the outside temperature goes to 27°C or more.
NOTE : When indoor fan speed is Low except FAN operation mode and the outside temperature is 29: or less,
the outdoor fan operates at Low.
Outdoor fan Low operation is cancelled according to the following conditions(
1 or 2):
1 When the operation is not changed and the outside temperature goes to 31: or more.
2 When the operation is changed. (Change to FAN operation mode / Change of the indoor fan speed)
2 Time control
When the three conditions as follows 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 Low or Med..
c. Room temperature is below 26°C.
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.
1. Indoor fan speed control
Indoor fan operates at the set speed by FAN SPEED CONTROL button.
In AUTO the fan speed is as follows.
Initial temperature difference
Room temperature minus set temperature : 3 degrees or more········································High
Room temperature minus set temperature : Between 1 and 1.7 degrees····························Med.
Room temperature minus set temperature : less than 1 degree······································· Low
2. Coil frost prevention
1 Temperature control
<MS-18/24RV>
When the indoor coil thermistor RT12 reads -1°C or below, the coil frost prevention mode starts immediately.
However, the coil frost prevention doesn’t work for 5 minutes since the compressor has started.
The indoor fan operates at the set speed and the compressor stops for 5 minutes.
After that, if RT12still reads below -1°C this mode is prolonged until the RT12 reads over -1°C.
<MS-30RV>
When the indoor coil thermistor RT12 or RT13 reads -1°C or below, the coil frost prevention mode starts immediately.
However the coil frost prevention doesn’t work for 5 minutes since the compressor has started.
The indoor fan operates at the set speed and the compressor stops for 5 minutes.
After that, if RT12 or RT13 still reads below -1°C this mode prolonged until the RT12 and RT13 reads over -1°C.
1 deg.
1.7 deg.
3 deg.
9-1-1. COOL mode of “I FEEL CONTROL”
Fan speed
Difference between room
temperature and set tem-
perature during operation
High
23:
27:
Low
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