Mitsubishi Electric PKH18FK Technical & Service Manual page 39

(6) Indoor coil thermistor abnormality detection
An abnormality can be detected during compressor ON, except for the following.
For the first 30 minutes after the temperature difference between the indoor coil temperature and room temperature
enters the RANGE C.
When the temperature difference enters the RANGE C until it moves to the RANGE B.
(7) Defrosting operation
After the outdoor unit starts the defrosting operation, when the temperature difference between the indoor coil temperature
and room temperature gets out of RANGE A and into RANGE B, the indoor unit starts the defrosting mode. After the out-
door unit stops the defrosting operation, when the temperature difference returns to the RANGE A, the indoor unit stops
the defrosting mode. While the indoor unit is in the defrosting mode, the indoor fan and the booster heater stop.
w1 RANGE A : Indoor coil temperature is more than 9 degrees above room temperataure.
RANGE B : Indoor coil temperature is within 9 degrees either way of room temperature.
RANGE C : Indoor coil temperature is more than 9 below room temperature
Indoor coil temperature
minus room temperature
RANGE A
(degree)
+9
0 RANGE B
-9
RANGE C
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