Mitsubishi Electric Mr.Slim MUZ-GC25NA - C1 Service Manual page 28

MUZ-GC50NA-
C1
The left lamp of
OPERATION Abnormal point
INDICATOR lamp (Failure mode / protection)
(Indoor unit)
OFF None (Normal)
2-time fl ash Outdoor power system
3-time fl ash Discharge temperature
thermistor
Defrost thermistor
Ambient temperature
thermistor
Fin temperature thermistor
P.C. board temperature
thermistor
Outdoor heat exchanger
temperature thermistor
4-time fl ash Over current
5-time fl ash Discharge temperature
6-time fl ash High pressure
7-time fl ash Fin temperature
P.C. board temperature
8-time fl ash Outdoor fan motor
9-time fl ash Nonvolatile memory data
10-time fl ash Discharge temperature
11-time fl ash Communication error between
P.C. boards
Current sensor
Zero cross detecting circuit
Converter
Bus-bar voltage (1)
Bus-bar voltage (2)
Even if this protection stop
is performed continuously 3
times, it does not mean the
abnormality in outdoor power
system.
NOTE : Blinking patterns of this mode differ from the ones of Troubleshooting check table (9-3.).
MUZ-GC60/71NA
LED indication
(Outdoor P.C. board)
LED 1 LED 2
— —
Lighting Lighting
Lighting Once
Lighting Once
Lighting Twice
Lighting 3 times
Lighting 4 times
Lighting 9 times
Once Goes out 28 A current fl ows into intelligent power module. • Reconnect compressor
Lighting Lighting
Lighting Lighting
3 times Goes out The fi n temperature exceeds 87°C during
4 times Goes out The P.C. board temperature exceeds 70°C
Lighting Lighting
Lighting 5 times
Lighting Lighting
Lighting 6 times
Lighting 7 times
5 times Goes out Zero cross signal cannot be detected while the
5 times Goes out A failure is detected in the operation of the
5 times Goes out The bus-bar voltage exceeds 400 V or falls to
6 times Goes out The bus-bar voltage exceeds 400 V or falls to 50
Condition
—
Overcurrent protection stop is continuously
performed 3 times within 1 minute after the
compressor gets started, or when converter
protection stop or bus-bar voltage protection
stop is continuously performed 3 times within 3
minutes after start-up.
Thermistor shorts or opens during compressor
running.
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.
The outdoor heat exchanger temperature
exceeds 70°C during cooling or the indoor gas
pipe temperature exceeds 70°C during heating.
operation.
during operation.
Failure occurs continuously 3 times within 30
seconds after the fan gets started.
Nonvolatile memory data cannot be read
properly.
The frequency of the compressor is kept 80 Hz
or more and the discharge temperature is kept
under 39°C for more than 20 minutes.
Communication error occurs between the
electronic control P.C. board and power board
for more than 10 seconds.
The communication between boards protection
stop is continuously performed twice.
A short or open circuit is detected in the current
sensor during compressor operating.
Current sensor protection stop is continuously
performed twice.
compressor is operating.
The protection stop of the zero cross detecting
circuit is continuously performed 10 times.
converter during operation.
200 V or below during compressor operating.
V or below during compressor operating.
28
Indoor/outdoor
unit failure
Correspondence
mode recall
—
• Check the connection of the
compressor connecting wire.
• Refer to 9-5. "How to check
inverter/compressor".
• Check the stop valve.
• Refer to 9-5. "Check of
outdoor thermistors".
• Replace the outdoor
electronic control P.C. board.
• Refer to 9-5. "Check of
outdoor thermistors".
connector.
• Refer to 9-5. "How to check
inverter/compressor."
• Check the stop valve.
• Check refrigerant circuit and
refrigerant amount. • Refer
to 9-5. "Check of LEV".
•Check refrigerant circuit and
refrigerant amount.
• Check the stop valve.
• Check around outdoor unit.
• Check outdoor unit air
passage.
• Refer to 9-5. "Check of
outdoor fan motor".
• Refer to 9-5. "Check of
outdoor fan motor".
• Replace the outdoor
electronic control P.C. board.
• Check refrigerant circuit and
refrigerant amount.
• Refer to 9-5. "Check of
LEV".
• Check the connecting wire
between outdoor electronic
control P.C. board and power
board.
• Replace the power board.
• Check the connecting wire
among electronic control P.C.
board, noise fi lter P.C. board
and power board.
• Replace the power board.
function
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