MITSUBISHI ELECTRIC Mitsubishi Split-Type - Manual (Page 15)

15
NOTE : When the indoor unit has started operation and the above detection method has detected an abnormality (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.
No.
1
3
6
7
Symptom Operation indicator lamp Detection method Check point
Left lamp flashes.
0.5-second ON
0.5-second OFF
Mis-Wiring
or serial
signal
Outdoor
power
system
Outdoor
thermistors
Outdoor
control
system
Indoor coil
thermistor
When the serial signal from the outdoor unit is
not received for a maximum of 6 minutes.
When it consecutively occurs 3 times that the
compressor stops for overcurrent 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 the outdoor electronic control P.C. board.
• Refer to "Check of outdoor
thermistor".
Refer to service manual
OB379 or OB377.
• Refer to "Check of inverter/
compressor".
Refer to service manual
OB379 or OB377.
Check the stop valve.
• Replace the inverter P.C.
board or the outdoor
electronic control P.C. board.
Refer to service manual
OB379 or OB377.
• Refer to 9-6. D "How to check
mis-wiring and serial signal
error".
4
Indoor fan
motor
8
Abnormal
point
Room
tempera-
ture
thermistor
Left lamp flashes.
2-time flash
2.5-second OFF
When the indoor coil or the room temperature
thermistor is shorts or opens circuit. • Refer to 9-7.the
characteristics of indoor coil
thermistor, and the room
temperature thermistor.
Left lamp flashes.
3-time flash
2.5-second OFF
When the rotational frequency feedback
signal is not emitted during the indoor fan
operation.
• Refer to 9-6. A "Check of
indoor fan motor".
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
Left lamp flashes.
5-time flash
2.5-second OFF
Left lamp flashes.
6-time flash
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
Other
abnormality An abnormality other than above mentioned is
detected.
• Confirm the abnormality in
detail using the failure mode
recall function.
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
9
5
Left lamp flashes.
4-time flash
2.5-second OFF
Indoor
control
system When it cannot properly read data in the
nonvolatile memory of the indoor electronic
control P.C. board.
Indoor unit
and outdoor
unit do not
operate.
• Replace the indoor electronic
control P.C. board.
Outdoor
control
system When it cannot properly read data in the
nonvolatile memory of the inverter P.C. board
or the outdoor electronic control P.C. board.
• Check the blinking pattern of
the LED on the inverter P.C.
board or the outdoor
electronic
control P.C. board.
2
Outdoor unit
does not
operate.
Left lamp lights up
Left lamp flashes.
7-time flash
2.5-second OFF
Left lamp flashes.
14-time flash
2.5-second OFF
9-4. Troubleshooting check table
NOTE : Before taking measures, make sure that the symptom reappears for accurate troubleshooting.
Self check table
Not lighted
Blinking
OPERATION INDICATOR
Lighted
· Flashing of OPERATION INDICATOR lamp (left-hand side lamp)
indicates abnormalities.
OB378_--1qxp 05.1.17 12:55 Page 15