Mitsubishi Electric MXZ-2C30VA Service Manual page 90

MXZ-3C/4C/5C
Symptom Indication
No.
LED1(Red) LED2(Yellow)
Outdoor unit
Lighted Once
does not
1
operate.
2 Lighted Twice
3
Lighted 3 times
4
Lighted 4 times
5
Lighted 5 times
6
Lighted 7 times
7
Lighted 8 times
8
Lighted 11 times
9
Lighted 12 times
'Outdoor unit
stops and
Twice Not lighted
restarts 3
10
minutes
later' is
repeated.
11 3 times Not lighted
12 4 times Not lighted
13 5 times Not lighted
14 8 times Not lighted
15
9 times Not lighted
16
13 times Not lighted
17
Lighted 8 times
18 Lighted 11 times
Lighted 12 times
19
OBH584E
Abnormal point / Condition
The indoor unit detects an abnormality in the LEV and drain pump.
LEV and drain pump
Overcurrent protection cut-out operates 3 consecutive times
within 1 minute after the compressor gets started, or converter protection
Outdoor power system
or bus-bar voltage protection cut-out operates 3 consecutive 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 10 minutes after 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 5 minutes (in cooling) and 10
temperature thermistor
minutes (in heating) after compressor start-up.
A short circuit is detected in the thermistor during operation, or an open
Defrost thermistor
circuit is detected in the thermistor 5 minutes after compressor start-up.
Nonvolatile memory data The nonvolatile memory data cannot be read properly.
Current sensor Current sensor protection cut-out operates 2 consecutive times.
Communication error occurs twice between the electronic control
Communication error
P.C. board and power board for more than 10 seconds.
between P.C. boards
Zero cross detecting
The protection cut-out of the zero cross detecting circuit operates 10
circuit
consecutive times.
IPM protection Overcurrent is detected 30 seconds after compressor start-up.
Overcurrent is detected within 30 seconds after 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 73°C (MXZ-3C54/3C68/4C71VA)/
87°C (MXZ-4C80/5C100VA, 4C80/5C100VA2) during operation.
protection
High-pressure High-pressure is detected with the high-pressure switch (HPS) during
protection operation. (MXZ-3C68/4C71/4C80/5C100VA, 4C80/5C100VA2)
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-3C54/3C68/4C71VA)/
protection (2)
430 V (MXZ-4C80/5C100VA, 4C80/5C100VA2) or falls to 50 V or below
while the compressor is operating.
Failure occurs 3 consecutive 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 while the
protection compressor is operating.
Communication protection Communication error occurs between the electronic control P.C. 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
90
Remedy
• Refer to 11-6. "Check of LEV".
• Check the drain pump of the indoor unit.
• 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".
• Refer to 11-6. "Check of outdoor thermistors".
• Replace the electronic control P.C. board.
• Refer to 11-6. "Check of outdoor thermistors".
• Replace the electronic control P.C. board.
• Replace the power board.
• Check the connecting wire between electronic control
P.C. board and power board.
• Check the connecting wire between electronic control
P.C. board, noise filter P.C. board and power board.
• Reconnect compressor connector.
• Refer to 11-6. "How to check inverter/compressor".
• Check the stop valve.
• Check the power module (PAM module).
• Check the amount of gas and refrigerant circuit.
• Refer to 11-6. "Check of LEV".
•Check refrigerant circuit and refrigerant amount.
•Refer to 11-6. "Check of outdoor fan motor".
• Check the amount of gas and the refrigerant circuit.
• Check the stop valve.
• Replace the power board.
• Check the voltage of power supply.
• Replace the power board or the electronic
control P.C. board.
• Refer to 11-6. "Check of bus-bar voltage".
• Refer to 11-6. "Check of outdoor fan motor".
• Replace the power board.
• Check the connecting wire between electronic
control P.C. board and power board.
• Check the connecting wire between electronic control
P.C. board, noise filter P.C. board and power board.