Mitsubishi Electric MXZ-2B30VA Service Manual page 66

3. Outdoor unit failure mode table
MXZ-2B
Upper or left lamp of
Abnormal point
OPERATION INDICATOR
(Failure mode / protection)
lamp (Indoor unit)
None (Normal)
OFF
Outdoor power system
2-time flash
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
Compressor
5-time flash Discharge temperature
6-time flash High pressure
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).
OBH554D
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.
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 14 A (MXZ-2B30VA)/18 A (MXZ-2B
40VA, MXZ-2B52VA) current flows into
intelligent power module.
The possibility of intercepting the
Twice
Goes
overcurrent by the compressor lock is
out
high.
9 times Goes The compressor does not synchronize
out with the operating power.
Discharge temperature exceeds 116°C
Lighting Lighting
during operation.
Compressor can restart if discharge
temperature thermistor reads 100°C or
less 3 minutes later.
Lighting Lighting
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 90°C
out
during operation.
4 times Goes The P.C. board temperature exceeds
out 78°C 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.
The frequency of the compressor is
Lighting Lighting
kept 68 Hz (MXZ-2B30VA, MXZ-
2B40VA)/80Hz (MXZ-2B52VA) or
more and the discharge
temperature is kept under
50°C (COOL mode)/40°C (HEAT mode)
for more than 40 minutes.
66
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 the connection of
the compressor
connecting wire.
• Refer to 11-6. "How to
check inverter/
compressor".
• 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".