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LED1(Red) LED2(Yellow)
Lightning Twice Outdoor power system
• Check the connection of the compressor connecting
wire.
• Refer to 10-6.A "How to check inverter/compressor".
• Check the stop valve.
Lightning 3 times
Discharge temperature
thermistor
• Refer to 10-6.B "Check of outdoor thirmistors".
• Refer to 10-6.B "Check of outdoor thirmistors".
Outdoor heat exchanger
temperature thermistor
Defrost thermistor
Lightning 7 times Nonvolatile memory data • Replace the outdoor electronic control P.C. board.
Lightning 8 times Current sensor • Replace the power board.
Lightning 11 times
Communication error
between P.C. boards
• Check the connecting wire between outdoor electronic control
P.C. board and power board.
Lightning 12 times
Zero cross detecting
circuit
• Check the connecting wire among outdoor electronic control
P.C. board, noise filter P.C. board and power board.
Abnormal point / Condition Correspondence
When a short circuit is detected in the thermistor during operation, or
when an open circuit is detected in the thermistor after 5 minutes (in
cooling) and 10 minutes (in heating) of compressor start-up.
When a short circuit is detected in the thermistor during operation, or
when an open circuit is detected in the thermistor after 5 minutes of
compressor start-up.
• Refer to 10-6.B "Check of outdoor thirmistors".
• Replace the outdoor electronic control P.C. board.
Indication
When over current protection stop is continuously
performed three times within 1 minute after the compressor gets
started, or when converter protection stop or bus-bar voltage
protection stop is continuously performed three times within 3
minutes after start-up.
When a short circuit is detected in the thermistor during operation, or
when an open circuit is detected in the thermistor after 10 minutes
of compressor start-up.
Condition
When the nonvolatile memory data cannot be read properly.
Lightning 6 times Serial signal
Fin temperature
thermistor
P.C board temperature
thermistor
Lightning 4 times
Ambient temperature
thermistor
Current sensor protection stop is continuously performed twice.
When the communication protection stop between boards is
continuously performed twice.
The protection stop of the zero cross detecting circuit is continuously
performed 10 times.
When a short or open circuit is detected in the thermistor during
operation.
When a short or open circuit is detected in the thermistor during
operation.
5 timesLightning
Outdoor electronic control P.C. board(Parts side)
Lighting
IPM protection
Lock protection
3 times Goes out
Discharge temperature
protection
• Check the amount of gas and refrigerant circuit.
• Refer to 10-6.G "Check of LEV".
Fin temperature
protection
P.C. board temperature
protection
High-pressure
protection
8 times Goes out
Converter protection
• Replace the power board.
Bus-bar voltage
protection (1)
• Replace the power board.
Bus-bar voltage
protection (2)
13 times Goes out Outdoor fan motor • Refer to 10-6.D "Check of outdoor fan motor".
Lighting 8 times
Current sensor
protection
• Replace the power board.
Lighting 11 times
Communication between P.C.
boards protection
• Check the connecting wire between outdoor electronic control
P.C. board and power board.
Lighting 12 times
Zero cross detecting circuit
protection
• Check the connecting wire among outdoor electronic control
P.C. board, noise filter P.C. board and power board.
•Check refrigerant circuit and refrigerant amount.
•Refer to 10-6.D "Check of outdoor fan motor".
• Check around of gas and the refrigerant circuit.
• Check of stop valve.
• Reconnect compressor connector.
• Refer to 10-6.A "How to check inverter/compressor".
• Check the stop valve.
• Check the power module (PAM module).
Twice Goes out
4 times Goes out
5 times Goes out
9 times Goes out
When over-current is detected after 30 minutes of compressor start-up.
When over-current is detected within 30 minutes of compressor
start-up
When the bus-bar voltage exceeds 400V or falls to 200V or below
during compressor operating.
When the bus-bar voltage exceeds 400V or falls to 50V or below
during compressor operating.
When discharge temperature exceeds 116:during operation.
compressor stops. Compressor can restart if discharge temperature
thermistor reads 100: or less 3 minutes later.
When the fin temperature exceeds 87: during operation.
When the P.C. board temperature exceeds 70: during operation.
When failure occurs continuously three times within 30 seconds after
the fan gets started.
When a short or open circuit is detected in the current sensor during
compressor operating.
Communication error occurs between the outdoor electronic control P.C.
board and power board for more than 10 seconds.
When zero cross signal cannot be detected while the compressor is
operating.
When the outdoor heat exchanger temperature exceeds 70:
during cooling or when indoor gas pipe temperature exceeds 70:
during heating.
When a failure is detected in the operation of the converter during
operation.
Outdoor unit
does not
operate.
LED2
LED1
• Refer to 10-6.H "How to check mis-wiring and serial signal
error.
When the communication fails between the indoor and outdoor
unit for 3 minutes.
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Symptom
'Outdoor unit
stops and
restarts 3
minutes
later' is
repeated.
MUZ-GB50VA
ON
OFF
2.5-second OFF
2.5-second OFF
The flashing frequency shows the number of times the LED blinks after every 2.5-second OFF.
(Example) When the flashing frequency is “2”.
0.5-second ON
0.5-second ON
NOTE 1. The location of LED is illustrated at the right figure. Refer to 10-7.1.
2. LED is lighted during normal operation.
10-4. Troubleshooting check table
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