Mitsubishi Electric M Series Manual page 550

MULTI SYSTEM Inverter Heat Pump
MXZ-3B/4B/5B
Symptom Indication
No.
LED1(Red) LED2(Yellow)
Outdoor unit
Lighting Once
does not
1
operate.
2 Lighting Twice
3
Lighting 3 times
4
Lighting 4 times
5 Lighting 5 times
6
Lighting 7 times
7
Lighting 8 times
8
Lighting 11 times
9
Lighting 12 times
'Outdoor unit
stops and
Twice Goes out
restarts 3
10
minutes
later' is
repeated.
3 times Goes out
11
12 4 times Goes out
13 5 times Goes out
14 Goes out
8 times
15
9 times Goes out
16 13 times Goes out
17
Lighting 8 times
Lighting 11 times
18
Lighting 12 times
19
C-548
Abnormal point / Condition
LEV for drain The indoor unit detects any abnormality in the LEV for drain.
Overcurrent protection stop is continuously performed three times
within 1 minute after the compressor gets started, or converter protection
Outdoor power system
stop or bus-bar voltage protection stop is continuously performed three
times within 3 minutes after start-up.
A short circuit is detected in the thermistor during operation, or an open
Discharge temperature
circuit is detected in the thermistor after 10 minutes of compressor start-up.
thermistor
Fin temperature
thermistor
A short or open circuit is detected in the thermistor during operation.
P.C board temperature
thermistor
Ambient temperature
A short or open circuit is detected in the thermistor during operation.
thermistor
A short circuit is detected in the thermistor during operation, or an open
Outdoor heat exchanger
circuit is detected in the thermistor after 5 minutes (in cooling) and 10
temperature thermistor
minutes (in heating) of compressor start-up.
A short circuit is detected in the thermistor during operation, or an open
Defrost thermistor
circuit is detected in the thermistor after 5 minutes of compressor start-up.
Nonvolatile memory data The nonvolatile memory data cannot be read properly.
Current sensor protection stop is continuously performed twice.
Current sensor
Communication error occurs twice between the outdoor electronic control
Communication error
P.C. board and power board for more than 10 seconds.
between P.C. boards
Zero cross detecting
The protection stop of the zero cross detecting circuit is continuously
circuit
performed 10 times.
Overcurrent is detected after 30 minutes of compressor start-up.
IPM protection
Overcurrent is detected within 30 minutes of compressor start-up.
Lock protection
Discharge temperature Discharge temperature exceeds 116°C during operation. Compressor can
protection restart if discharge temperature thermistor reads 100°C or less 3 minutes
later.
Fin temperature
The fin temperature exceeds 89°C during operation.
protection
P.C. board temperature
The P.C. board temperature exceeds 87°C during operation.
protection
High-pressure
High-pressure is detected with the high-pressure switch (HPS) during
protection
operation. (MXZ-3B68/4B71/4B80/5B100VA)
The outdoor heat exchanger temperature exceeds 70°C during cooling
or indoor gas pipe temperature exceeds 70°C during heating.
Converter protection
A failure is detected in the operation of the converter during operation.
Bus-bar voltage
The bus-bar voltage exceeds 400 V or falls to 200 V or below during
protection (1)
compressor operating.
Bus-bar voltage
The bus-bar voltage exceeds 400 V (MXZ-3B54/3B68/4B71VA)/
protection (2)
430 V (MXZ-4B80/5B100VA) or falls to 50 V or below during
compressor operating.
Failure occurs continuously three times within 30 seconds after the fan
Outdoor fan motor
gets started.
Current sensor A short or open circuit is detected in the current sensor during compressor
protection
operating.
Communication error occurs between the outdoor electronic control P.C.
Communication protection
board and power board for more than 10 seconds.
between P.C. boards
Zero cross detecting circuit
Zero cross signal cannot be detected while the compressor is operating.
protection
Condition
M series