Error Display E37; Error Display E38; Defective Outdoor Unit Heat Exchanger Thermistor; Defective Outdoor Air Temperature Thermistor - Mitsubishi Heavy Industries FDCA Series Technical Manual

e37
Error display :
7
Indoor unit
Red LED
Green LED Keeps flashing
Is the outdoor
unit heat exchanger
thermistor connector
OK?
NO
Repair
● Display conditions
If the temperature sensed by the thermistor is – 30 ( – 50) ºC or lower
continuously for 5 seconds between 2 minutes and 2 minutes 20 sec-
onds after the compressor goes ON, the compressor stops. After a 3
minute delay, the compressor restarts. If this state is detected 3 times
in 60 (40) minutes.
Note (1) Values in ( ) show for the case of the FDCA801, 1001 models.
e38
Error display :
8
Indoor unit
Red LED
Green LED Keeps flashing
Is the outdoor
air temperature thermistor
connector connection
OK?
NO
Repair
● Display conditions
If the temperature sensed by the thermistor is – 30ºC or lower continu-
ously for 5 seconds between 2 minutes and 2 minutes 20 seconds after
the compressor goes ON, the compressor stops. After a 3 minute delay,
the compressor restarts. If this state is detected 3 times in 60 (40) min-
utes.
Note (1) Values in ( ) show for the case of the FDCA801, 1001 models.

[Defective outdoor unit heat exchanger thermistor]

Stays OFF Red LED
Green LED
Are the outdoor unit
YES
heat exchanger thermistor
characteristics OK, is there
any broken wire?
Defective outdoor unit
heat exchanger
thermistor

[Defective outdoor air temperature thermistor]

Stays OFF Red LED
Green LED
Is the outdoor
YES
air temperature thermistor
characteristics OK, is there
no broken wire?
Defective outdoor air
temperature thermistor
Replacement
Outdoor unit
1 time flash
Keeps flashing
YES
NO
Replacement
Outdoor unit
1 time flash
Keeps flashing
YES
NO
400
300
200
100
---50
149
- -
Defective outdoor unit control
PCB Replacement (Defective
outdoor unit heat exchanger
thermistor input circuit)
Outdoor unit heat exchanger
thermistor (Th
Resistance temperature characteristics
15
10
5
0 10
Temperature (°C)
Defective outdoor unit control PCB
Replacement (Defective outdoor air
temperature thermistor input circuit)
Temperature-resistance
characteristics of outdoor air
temperature thermistor (Th
T < 0°C
T > 0°C
0
0
Temperature [T](°C)
R)
O-
5kΩ at 25°C
20 30 40 50
A)
O-
40
30
20
10
0
50