Mitsubishi Electric PCH-2GKHA Service Manual page 36

(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 beetween 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 outdoor 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 5 degrees above room temperataure.
RANGE B : Indoor coil temperature is within 5 degrees either way of room temperature.
RANGE C : Indoor coil temperature is more than 5 degrees below room temperature
36
Indoor coil temperature
minus room temperature
RANGE A
(degree)
+5
0 RANGE B
-5
RANGE C