Mitsubishi Electric MXZ-3C54VA Service Manual page 55

2. Outdoor unit failure mode table
MXZ-3C/4C/5C
Upper or left lamp of
Abnormal point
OPERATION INDICATOR
(Failure mode/protection)
lamp (Indoor unit)
None (Normal)
OFF
2-time flash Outdoor power system
3-time flash Discharge temperature
thermistor
Defrost thermistor
Ambient temperature thermistor
Fin temperature thermistor
P.C. board temperature
thermistor
Outdoor heat exchanger
temperature thermistor
Overcurrent
4-time flash
5-time flash Discharge temperature
High pressure
6-time flash
Fin temperature
7-time flash
P.C. board temperature
8-time flash
Outdoor fan motor
9-time flash
Nonvolatile memory data
Discharge temperature
10-time flash
NOTE: Blinking patterns of this mode differ from the ones of Troubleshooting check table (11-4).
LED indication
(Outdoor P.C. board) Condition
LED 1 LED 2
Lighting Lighting
Lighting Lighting
Overcurrent protection cut-out operates
3 consecutive times within 1 minute after
the compressor gets started, or converter
protection or bus-bar voltage protection
cut-out operates 3 consecutive times
within 3 minutes after start-up.
Lighting Once Thermistor shorts or opens during
compressor running.
Lighting Once
Lighting Twice
Lighting 3 times
Lighting 4 times
Lighting 9 times
Once Goes out 28 A current flows into intelligent power
module.
Discharge temperature exceeds 116°C
Lighting Lighting
during operation.
Compressor can restart if discharge
temperature thermistor reads 100°C or
less 3 minutes later.
High-pressure is detected with the
Lighting Lighting
high-pressure switch (HPS)
during operation.
(MXZ-3C68/4C71/4C80/5C100VA)
The outdoor heat exchanger
temperature exceeds 70°C during
cooling or the indoor gas pipe
temperature exceeds 70°C during
heating.
3 times Goes
The fin temperature exceeds 89°C
out
during operation.
4 times Goes The P.C. board temperature exceeds
73°C (MXZ-3C54/3C68/4C71VA)/
out
87°C (MXZ-4C80/5C100VA)
during operation.
Lighting Lighting
Failure occurs 3 consecutive
times within 30 seconds after the
fan gets started.
Lighting 5 times
Nonvolatile memory data cannot be
read properly.
Lighting Lighting
The frequency of the compressor is
kept 80Hz or more and the discharge
temperature is kept under
50°C (cooling)/40°C (heating)
for more than 40 minutes.
55
Indoor/outdoor
Remedy
unit failure mode
recall function
• Check the connection
of the compressor
connecting wire.
• Refer to 11-6.
"How to check
inverter/compressor".
• Check the stop valve.
• Refer to 11-6. "Check
of outdoor thermistors".
• Replace the outdoor
electronic control
P.C. board.
• Refer to 11-6. "Check
of outdoor thermistors".
• Reconnect compressor
connector.
• Refer to 11-6. "How to
check inverter/
compressor".
• Check the stop valve.
• Check refrigerant circuit
and refrigerant amount.
• Refer to 11-6. "Check
of LEV".
• Check refrigerant circuit
and refrigerant amount.
• Check the stop valve.
• Check around outdoor
unit.
• Check outdoor unit air
passage.
• Refer to 11-6. "Check
of outdoor fan motor".
• Refer to 11-6. "Check
of outdoor fan motor".
• Replace the outdoor
electronic control
P.C. board.
• Check refrigerant circuit
and refrigerant amount.
• Refer to 11-6. "Check
of LEV".