Troubleshooting Check Table - Mitsubishi Electric MLZ-KP25VF Service Manual

11-4. TROUBLESHOOTING CHECK TABLE

OPERATION INDICATOR
NOTE: Before taking measures, make sure that the symptom reappears for accurate troubleshooting.
Self check table
Abnormal
No.
Operation indicator lamp
point
Left lamp flashes.
0.5-second ON
Miswiring
1 or serial
signal
0.5-second OFF
Indoor coil
Left lamp flashes.
thermistor
2-time flash
2
Room
temperat-
2.5-second OFF
ure
thermistor
Left lamp flashes.
3-time flash
Indoor fan
3
motor
2.5-second OFF
Left lamp flashes.
Indoor
4-time flash
4
control
system
2.5-second OFF
Left lamp flashes.
5-time flash
Outdoor
5 power
system
Left lamp flashes.
6-time flash
Outdoor
6
thermistors
Left lamp flashes.
7-time flash
Outdoor
7
control
system
Left lamp flashes.
9-time flash
Drain
8
pump
2.5-second OFF
Left lamp flashes.
14-time flash or more
Other
9
abnormality
2.5-second OFF
NOTE: When the indoor unit has started operation and the above failures are detected (the first detection after the power ON),
the indoor electronic control P.C. board turns OFF the indoor fan motor with OPERATION INDICATOR lamp flashing.
OBH801
· Flashing of OPERATION INDICATOR lamp (left-hand side lamp) indicates
Lit
abnormalities.
Blinking
Not lit
Symptom
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
Condition
When the serial signal from the outdoor unit is
not received for a maximum of 6 minutes.
When the indoor coil or the room temperature
thermistor is shorts or opens circuit.
signal is not emitted during the indoor fan
operation.
When it cannot properly read data in the
nonvolatile memory of the indoor electronic
control P.C. board.
The compressor stops 3 times consecutively
for over current protection or start-up failure
protection within 1 minute after start-up.
When the outdoor thermistors short or open
circuit during the compressor operation.
When it cannot properly read data in the
nonvolatile memory of the inverter P.C. board
or of the outdoor electronic control P.C. board.
An abnormality other than above mentioned is
detected.
29
Remedy
miswiring and serial signal
indoor coil thermistor, and the
room temperature thermistor
on 11-7.
control P.C. board.
Refer to outdoor unit service
manual.
Refer to outdoor unit service
manual.
board or the outdoor electronic
control P.C. board.
Refer to outdoor unit service
manual.
characteristics.
sensor and the drain pump.
detail using the failure mode
recall function.
Refer to outdoor unit service
manual.