Mitsubishi Electric MXZ-2D33VA-E1, Service Manual

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75
MXZ-3D/4D/5D
LED1(Red) LED2(Yellow)
Lighted Twice Outdoor power system
Lighted 3 times
Discharge temperature
thermistor
• Refer to 11-6. "Check of outdoor thermistors".
Outdoor heat exchanger
temperature thermistor
Defrost thermistor
Lighted 7 times Nonvolatile memory data • Replace the outdoor control P.C. board.
Lighted 8 times Current sensor • Replace the power P.C. board.
Lighted 11 times
Communication error
between P.C. boards
• Check the connecting wire between the outdoor control
P.C. board and the power P.C. board.
Lighted 12 times
Zero cross detecting
circuit
• Check the connecting wire between the outdoor control P.C.
board, the noise filter P.C. board and the power P.C. board.
Abnormal point / Condition Remedy
A short circuit is detected in the thermistor during operation, or an open
circuit is detected in the thermistor 5 minutes (in cooling) and 10
minutes (in heating) after compressor start-up.
A short circuit is detected in the thermistor during operation, or an open
circuit is detected in the thermistor 5 minutes after compressor start-up.
• Replace the outdoor control P.C. board.
Indication
Overcurrent protection cut-out operates 3 consecutive times
within 1 minute after the compressor gets started, or converter protection
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
circuit is detected in the thermistor 10 minutes after compressor start-up.
Condition
The nonvolatile memory data cannot be read properly.
Fin temperature
thermistor
P.C board temperature
thermistor
Lighted 4 times
Ambient temperature
thermistor
Current sensor protection cut-out operates 2 consecutive times.
Communication error occurs twice between the outdoor control
P.C. board and the power P.C. board for more than 10 seconds.
The protection cut-out of the zero cross detecting circuit operates 10
consecutive times.
A short or open circuit is detected in the thermistor during operation.
A short or open circuit is detected in the thermistor during operation.
5 times Lighted
IPM protection
Lock protection
3 times Not lighted
Discharge temperature
protection
Fin temperature
protection
P.C. board temperature
protection
High-pressure
protection
8 times Not lighted
Converter protection
• Replace the power P.C. board.
Bus-bar voltage
protection (1)
• Check the voltage of power supply.
• Replace the power P.C. board or the outdoor
control P.C. board.
• Refer to 11-6. "Check of bus-bar voltage".
Bus-bar voltage
protection (2)
13 times Not lighted Outdoor fan motor • Refer to 11-6. "Check of outdoor fan motor".
Lighted 8 times
Current sensor
protection
• Replace the power P.C. board.
Lighted 11 times
Communication protection
between P.C. boards
• Check the connecting wire between the outdoor
control P.C. board and the power P.C. board.
Lighted 12 times
Zero cross detecting circuit
protection
• Check the connecting wire between the outdoor control P.C.
board, the noise filter P.C. board and the power P.C. board.
• Check the amount of gas and the refrigerant circuit.
• Check the stop valve.
• 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".
• Reconnect compressor connector.
• Refer to 11-6. "How to check inverter/compressor".
• Check the stop valve.
• Check the power module (PAM module).
Twice Not lighted
4 times Not lighted
5 times Not lighted
6 times Not lighted
9 times Not lighted
Overcurrent is detected 30 seconds after compressor start-up.
Overcurrent is detected within 30 seconds after compressor start-up.
The bus-bar voltage falls to 200 V or below during compressor
operating.
The bus-bar voltage exceeds 400 V
(MXZ-3D54/3D68/4D72VA) /
430 V (MXZ-4D83/5D102VA) or falls to 50 V or below while the
compressor is operating.
Discharge temperature exceeds 116°C during operation. Compressor can
restart if discharge temperature thermistor reads 100°C or less 3 minutes
later.
The fin temperature exceeds 89°C during operation.
The P.C. board temperature exceeds 73°C (
MXZ-3D54/3D68/4D72VA)
/
87°C (MXZ-4D83/5D102VA) during operation.
High-pressure is detected with the high-pressure switch (HPS) during
operation. (MXZ-3D68/4D72/4D83/5D102VA)
Pre-heat protection • Replace the power P.C. board.
A failure is detected in the operation of pre-heat.
(MXZ-3D54/3D68/4D72VA)
Failure occurs 3 consecutive times within 30 seconds after the fan
gets started.
A short or open circuit is detected in the current sensor while the
compressor is operating.
Communication error occurs between the outdoor control P.C.
board and the power P.C. board for more than 10 seconds.
Zero cross signal cannot be detected while the compressor is operating.
The outdoor heat exchanger temperature exceeds 70°C during cooling
or indoor gas pipe temperature exceeds 70°C during heating.
A failure is detected in the operation of the converter during operation.
Outdoor unit
does not
operate.
Lighted Once LEV and drain pump
• 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".
• Refer to 11-6. "Check of LEV".
• Check the drain pump of the indoor unit.
The indoor unit detects an abnormality in the LEV and drain pump.
No.
1
2
3
4
5
6
7
9
8
10
11
12
13
14
15
16
17
18
19
Symptom
'Outdoor unit
stops and
restarts 3
minutes
later' is
repeated.
OBH626B