Mitsubishi Electric M Series Manual page 546

MULTI SYSTEM Inverter Heat Pump
MXZ-3B/4B/5B
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
4-time flash Overcurrent
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
C-544
LED indication
(Outdoor P.C. board) Condition
LED 1 LED 2
Lighting Lighting
Lighting Lighting Overcurrent protection stop is
continuously performed three times
within 1 minute after the compressor
gets started, or converter protection
stop or bus-bar voltage protection
stop is continuously performed
three 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
28A 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-3B68/4B71/4B80/5B100VA)
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.
The P.C. board temperature exceeds
4 times Goes
out 73°C (MXZ-3B54/3B68/4B71VA)/
87°C (MXZ-4B80/5B100VA)
during operation.
Lighting Lighting
Failure occurs continuously three
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 (COOL mode)/40°C (HEAT mode)
for more than 40 minutes.
Indoor/outdoor
unit failure mode
recall function
M series