set position
set speed
set position
set speed
Indoor fan
Compressor normal
Outdoor fan
R.V. coil
(21S4)
OFF (COOL)
OFF
Maximum frequency
horizontal
Horizontal vane
Very Low (temperature of indoor coil thermistor > 64 °F)
30
seconds
30
seconds
30
seconds
40
seconds
5 seconds 5 seconds
40
seconds
OFF
OFF
OFF
ON (HEAT)
ON ON
ON (HEAT)
horizontal (temperature of indoor coil thermistor
<
102 °F)
<Outdoor unit>
<Indoor unit>
10
Time chart of defrosting in HEAT mode (reverse type)
2-4. AUTO CHANGE OVER ··· AUTO MODE OPERATION (MSZ)
Once desired temperature is set, unit operation is switched automatically between COOL and HEAT operation.
1. Mode selection
(1) Initial mode
At first indoor unit operates only indoor fan with outdoor unit OFF for 3 minutes to detect present room temperature.
Following the conditions below, operation mode is selected.
If the room temperature thermistor reads more than set temperature, COOL mode is selected.
If the room temperature thermistor reads set temperature or less, HEAT mode is selected.
(2) Releasing conditions of defrosting
Defrosting is released when any of the following conditions is satisfied:
a) The defrost thermistor continues to read 50 °F or more (MUZ-A09/12 MUZ-D) / 41 °F or more (MUZ-A15/17 MUZ-FD) /
59 °F or more (MUZ-A24) for 30 seconds.
b) Defrosting time has exceeded 10 minutes.
c) Any other mode than HEAT mode is set during defrosting.