Defective Suction Pipe Thermistor; Defective Low Pressure And High Pressure Sensor; Error Display E53; Error Display E54 - Mitsubishi Heavy Industries FDCA Series Technical Manual

e53
Error display :
13
Indoor unit
Red LED
Green LED Keeps flashing
Is the suction pipe
thermistor connector
OK?
NO
Repair
● Display conditions
If the temperature sensed by the thermistor is –50ºC or lower con-
tinuously for 5 seconds between 10 minutes and 10 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 40 minutes.
e54
Error display :
14
Indoor unit
Red LED
Green LED Keeps flashing
connection of the
low pressure sensor connector
and high pressure sensor
Do the pressure
(actual measurement)
and remote controller's
display value match?
Is the refrigerant level appropriate?
Is there any abnormality in the
refrigeration circuit?
● Display conditions
If the voltage detected by the sensor is OV or lower or 3.49 V or higher continuously 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 condition is detected 3 times withhin 40 minutes.
[Defective suction pipe thermistor] (Only case of FDCA801, 1001 type)
Stays OFF Red LED
Green LED
Are the suction pipe thermistor
YES
characteristics OK, is there
Defective suction pipe
thermistor

[Defective low pressure and high pressure sensor]

(Only case of FDCA801, 1001 type)
Stays OFF Red LED
Green LED
Is the
NO
connector OK?
YES
NO
YES
Note (1) See page 155 concerning the methods of displaying operating data with the remote controller.
Outdoor unit
1 time flash
Keeps flashing
any broken wire?
NO
Replacement
Outdoor unit
1 time flash
Keeps flashing
Change of outdoor
unit control PCB
152
- -
Defective outdoor unit control
YES
PCB Replacement (Defective
suction pipe thermistor input circuit)
Suction pipe thermistor (Th
Resistance temperature characteristics
15
10
5
0 10
Correction
Replacement low pressure
or high pressure sensor
NO Did it rerun
to normal?
S)
O-
5kΩ at 25°C
20 30 40 50
Temperature (°C)