Mitsubishi Electric M-SERIES, Manual

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CEILING CASSETTE Inverter Heat Pump M series
TROUBLESHOOTING
CEILING CASSETTE
C-284
MLZ-KA25VA MLZ-KA35VA MLZ-KA50VA
Troubleshooting check table
NOTE :
Before taking measures, make sure that the symptom reappears for accurate troubleshooting.
OPERATION INDICATOR
Not lighted
Blinking
Lighted
· Flashing of OPERATION INDICATOR lamp (left-hand side lamp)
indicates abnormalities.
No.
1
3
6
7
Symptom Operation indicator lamp Condition
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.
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.
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.
Left lamp flashes.
3-time flash
2.5-second OFF
When the rotational frequency feedback
signal is not emitted during the indoor fan
operation.
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.
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
9
10
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.
Outdoor
control
system
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.
2
Outdoor unit
does not
operate.
Left lamp lights up.
• Float sensor is open.
• Float sensor detects abnormal water level.
Indoor unit
and outdoor
unit do not
operate.
Left lamp flashes.
9-time flash
2.5-second OFF
Drain
pump
Left lamp flashes.
7-time flash
2.5-second OFF
Left lamp flashes.
14-time flash
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.