Mitsubishi Heavy Industries SRK100VNXWZRF Service Manual page 128

Indoor display
Error code
Outdoor unit
Remote control:
E49
Outdoor unit
inverter PCB
1. Applicable model
Models FDC100VN(S)X-W,
100VN(S)A-W, 200VSA-W
2. Error detection method
Detected by low pressure drop
and suction superheat
3. Condition of error displayed
➀ When the low pressure sensor
detects 0.079MPa or lower
for 15 seconds continuously,
compressor stops and it
restarts automatically after
3-minute delay, but if this
anomaly occurs 5 times
within 60 minutes.
➁ 10 minutes after the
compressor starts, if the
low pressure sensor detects
0.15MPa or lower for 60
seconds continuously and
compressor suction superheat
is detected 30degC or higher
for 60 seconds continuously,
but if this anomaly occurs 5
times within 60 minutes.
➂ If low pressure sensor
detects 0.079MPa or lower
for 5 minutes continuously
(Including the compressor
stop status)
4. Presumable cause
• Defective outdoor unit control
PCB
• Defective low pressure sensor
connector
• Defective low pressure sensor
• Defective suction pipe
temperature sensor connector
• Defective suction pipe
temperature sensor
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.
RUN light
–
Green LED
control PCB
Keeps flashing
Yellow LED
Keeps flashing
5. Troubleshooting
Check the low pressure value during
following state from the remote control.
ΠCompressor is stopping
 Compressor is operating
NO
Check the insulation resistance of pressure sensor.
insulation resistance more than 100MΩ
After connecting the gauge manifold on the low pressure
line, measure at the state Πabove. Compare the result
with the value indicated on the remote control.
To checking of refrigerant
amount, refrigerant circuit,
etc.
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TIMER light
Content
–
Red LED
(Models FDC100VN(S)X-W, 100VN(S)A-W,
1-time flash
Diagnosis
Is the low
pressure sensor connection OK
(at PCB side)?
YES
During
both Œ and  state low
pressure detected at around 0MPa
without any
fluctuation.
YES
Is the
at DC500V?
YES
*
Is the
pressure difference less than
0.2MPa?
Connect the pressure sensor of
YES
spare part to outdoor unit control
PCB in the condition open to
atmosphere.
Is the pressure
0MPa displayed on the remote
control?
127
- -
'22 • PAC-SM-422
Low pressure error or
low pressure sensor anomaly (1/2)
200VSA-W only)
Countermeasure
Correct connector.
NO
Replace low pressure
NO
sensor.
NO
Defective outdoor unit
NO
control PCB➞Replace.
Replace low pressure
YES
sensor.