Mitsubishi Electric MXZ-2D33VA Service Manual page 133

MXZ-3D/4D/5D
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.
3 times Not lighted
11
12 4 times Not lighted
5 times Not lighted
13
6 times Not lighted
14 Not lighted
8 times
15
9 times Not lighted
16 13 times Not lighted
17 Lighted 8 times
18 Lighted 11 times
Lighted 12 times
19
OBH626K
Abnormal point / Condition
LEV and drain pump The indoor unit detects an abnormality in the 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.
The nonvolatile memory data cannot be read properly.
Nonvolatile memory data
Current sensor protection cut-out operates 2 consecutive times.
Current sensor
Communication error Communication error occurs twice between the outdoor control
between P.C. boards P.C. board and the power P.C. board for more than 10 seconds.
Zero cross detecting
The protection cut-out of the zero cross detecting circuit operates 10
circuit
consecutive times.
Overcurrent is detected 30 seconds after compressor start-up.
IPM protection
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-3D54/3D68/4D72VA,
protection MXZ-3D54VA2)/87°C (MXZ-4D83/5D102VA) during operation.
High-pressure
High-pressure is detected with the high-pressure switch (HPS) during
protection
operation. (MXZ-3D68/4D72/4D83/5D102VA)
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 pre-heat.
Pre-heat protection
(MXZ-3D54/3D68/4D72VA, MXZ-3D54VA2)
Converter protection
A failure is detected in the operation of the converter during operation.
Bus-bar voltage
The bus-bar voltage falls to 200 V or below during compressor
protection (1)
operating.
Bus-bar voltage
The bus-bar voltage exceeds 400 V (MXZ-3D54/3D68/4D72VA,
protection (2)
MXZ-3D54VA2)/430 V (MXZ-4D83/5D102VA) 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 error occurs between the outdoor control P.C.
Communication protection
board and the power P.C. 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
133
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 outdoor control P.C. board.
• Refer to 11-6. "Check of outdoor thermistors".
• Replace the outdoor control P.C. board.
• Replace the power P.C. board.
• Check the connecting wire between the outdoor control
P.C. board and the power P.C. board.
• Check the connecting wire between the outdoor control P.C.
board, the noise filter P.C. board and the power P.C. 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 the refrigerant circuit.
• Refer to 11-6. "Check of LEV".
•Check the refrigerant circuit and the 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 P.C. board.
• Replace the power P.C. board.
• 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".
• Refer to 11-6. "Check of outdoor fan motor".
• Replace the power P.C. board.
• Check the connecting wire between the outdoor
control P.C. board and the power P.C. board.
• Check the connecting wire between the outdoor control P.C.
board, the noise filter P.C. board and the power P.C. board.