Mitsubishi Electric M-SERIES, Manual

Page: 546 / 586

M series MULTI SYSTEM Inverter Heat Pump
MUL
TI
SYSTEMS
TROUBLESHOOTING
C-544
MXZ-3B/4B/5B
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.
Abnormal point
(Failure mode / protection)
Condition
Indoor/outdoor
unit failure mode
recall function
LED indication
(Outdoor P.C. board)
LED 1 LED 2
OFF
2-time flash
3-time flash
4-time flash
5-time flash
6-time flash
7-time flash
8-time flash
Lighting Lighting
Lighting Lighting
Lighting Once
Lighting Once
Lighting Twice
Lighting 3 times
Lighting 4 times
Lighting 9 times
Once Goes out
Lighting Lighting
Lighting Lighting
3 times Goes
out
4 times Goes
out
Lighting Lighting
Lighting Lighting
Lighting 5 times
9-time flash
10-time flash
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.
Thermistor shorts or opens during
compressor running.
28A current flows into intelligent power
module.
Discharge temperature exceeds 116°C
during operation.
Compressor can restart if discharge
temperature thermistor reads 100°C or
less 3 minutes later.
High-pressure is detected with the
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.
The fin temperature exceeds 89°C
during operation.
The P.C. board temperature exceeds
73°C ( MXZ-3B54/3B68/4B71VA )/
87°C ( MXZ-4B80/5B100VA )
during operation.
Failure occurs continuously three
times within 30 seconds after the
fan gets started.
Nonvolatile memory data cannot be
read properly.
Outdoor power system
Discharge temperature
thermistor
Defrost thermistor
Ambient temperature thermistor
Fin temperature thermistor
P.C. board temperature
thermistor
Overcurrent
Discharge temperature
High pressure
Fin temperature
P.C. board temperature
Outdoor fan motor
Nonvolatile memory data
Discharge temperature
None (Normal)
Upper or left lamp of
OPERATION INDICATOR
lamp (Indoor unit)
Outdoor heat exchanger
temperature thermistor