Low Pressure Error Or Low Pressure Sensor Anomaly - Mitsubishi Electric FDF100VSXVD Technical Manual

Error code
E49
Remote controller:
1. Applicable model
All models
2. Error detection method
Detected by low pressure drop
and suction superheat
3. Condition of Error displayed
When the low pressure sensor
detects 0.079MPa or lower
for 15 seconds continuously,
compressor stops and it
restarts automatically after
3-minutes delay. And if this
anomaly occurs 3 times
within 60 minutes,
10 minutes after the
compressor starts, if the
low pressure sensor detects
0.15MPa or lower for 60
minutes continuously and
compressor suction superheat
is detected 30°C or higher
for 60 minutes continuously.
And if this anomaly occurs 3
times within 60 minutes,
If low pressure sensor
detects 0.079MPa or lower
for 5 minutes continuously
(including the compressor
stop status),
4. Presumable cause
• Defective outdoor control
PCB
• Defective low pressure sensor
connector
• Defective low pressure sensor
• Defective suction pipe
temperature thermistor
connector
• Defective suction pipe
temperature thermistor
Note:
* Connect the gauge manifold to the service valve check joint during cooling, or connect it to the check joint at internal
piping of outdoor unit during heating.
LED Green Red
Indoor Keeps flashing Stays OFF
Outdoor Keeps flashing 1 time flash
5. Troubleshooting
Diagnosis
Is the low
pressure sensor connection OK
(at PCB side)?
Check the low pressure value during
following state from the remote controller
Compressor is stopping
Compressor is operating
both
pressure detected at around 0MPa
NO
without any
fluctuation.
Check the insulation resistance of pressure sensor.
insulation resistance more than 100 ?
at DC500V?
After connecting the gauge manifold on the low pressure
line, measure at the state
with the value indicated on the remote controller.
pressure difference less than
0.2MPa?
YES
To checking of refrigerant
amount, refrigerant circuit,
etc. (next page)
0MPa displayed on the remote
187
–
Content Low pressure error or
low pressure sensor anomaly (1/2)
NO
YES
During
and state low
YES
Is the
NO
YES
*
above. Compare the result
Is the
NO
Connect the pressure sensor of
spare part to outdoor control
PCB in the condition open to
atmosphere.
Is the pressure
controller?
YES
–
'11 • PAC-T-160
Countermeasure
Correct.
Replace low pressure
sensor.
Defective outdoor control
NO
PCB Replace.
Replace low pressure
sensor.