Mitsubishi Electric SEZ-M-DA Series, Service Manual

Page: 102 / 130

102
Operation start
Check the outdoor unit
LED indicator.
Refer to 12-6.
"Check of power supply".
• Indoor unit
serial signal
error
Refer to 12-6.
"How to
check
miswiring and
serial signal
error".
• COOL or
HEAT
operation only
Refer to 12-6.
"Check of
R.V. coil".
• When cooling,
room does not
cool.
Refer to 12-6.
"How to check
inverter/
compressor".
• When cooling, heat
exchanger of
non-operating indoor
unit frosts.
• When heating, non-
operating indoor unit
gets warm.
Refer to 12-6.
"Check of LEV".
• When heating,
room does not get
warm.
Refer to 12-6.
"How to check
inverter/compressor".
Check mispiping,
shortage of capacity.
• When cooling
dew drops in the
non-operating
indoor unit.
Check of
mispiping.
Refer to 12-4.
"Troubleshooting check table".
Both LED1 and
LED2 are OFF.
Both LED1 and
LED2 light.
LED1 or LED2
has blinked.
12-3. INSTRUCTION OF TROUBLESHOOTING
• Check the indoor unit referring to the indoor unit service manual, and confirm that there is any problem in the indoor unit.
Then, check the outdoor unit with referring to this page.
The left lamp of
OPERATION IN-
DICATOR lamp
(Indoor unit)
Abnormal point
(Failure mode/protection)
LED indication
(Outdoor P.C.
board)
Condition Remedy
Indoor/
outdoor unit
failure mode
recall function
LED1 LED2
14-time blink Refrigerant leakage
(Sensor detection)
Lit Lit The refrigerant sensor mounted on the
indoor unit does not work.
The refrigerant sensor is not connected
properly or the wire is broken.
• Connect the connector of the refrig-
erant sensor properly.
• Replace the refrigerant sensor.
○
Incompatible unit combination Lit 11 times The indoor unit which is not compatible
with the outdoor unit is connected.
• Replace the indoor unit with the
one which is compatible with the
outdoor unit.
○
15-time blink LEV and drain pump Lit Lit The indoor unit detects an abnormality in
the LEV and drain pump.
• Refer to 12-6. "Check of LEV".
• Check the drain pump of the indoor
unit.
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OBH790D