Troubleshooting Check Table - Mitsubishi Electric MXZ-2A30VA - E1 Service Manual

13-4. TROUBLESHOOTING CHECK TABLE

MXZ-2A
Indication
Symptom
No.
LED1(Red) LED2(Yellow)
Outdoor unit
1 Lighting Once
does not
operate.
2 Lighting Twice
3
Lighting 3 times
4
Lighting 4 times
5
Lighting 5 times
6 Lighting 7 times
7 Lighting 11 times
'Outdoor
unit stops
Twice Goes out
and restarts
8
3 minutes
later' is
repeated.
3 times Goes out
9
10 4 times Goes out
11 5 times Goes out
12 9 times Goes out
13 13 times Goes out
14 8 times Goes out
10 times Goes out
15
Outdoor unit
operates.
16 Once
Lighting
Twice Lighting
17
18 3 times
Lighting
19
4 times Lighting
Abnormal point / Condition
The indoor unit detects any abnormality in the LEV for drain.
LEV for drain
Overcurrent protection stop is continuously performed three times
within 1 minute after the compressor gets started.
Outdoor power system
A short circuit is detected in the thermistor during operation, or when an
Discharge temperature
open circuit is detected in the thermistor after 10 minutes of compressor
thermistor
start-up.
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 when
Outdoor heat exchanger
an open circuit is detected in the thermistor after 5 minutes (in cooling)
temperature thermistor
and 10 minutes (in heating) of compressor start-up.
A short circuit is detected in the thermistor during operation, or when an
Defrost thermistor open circuit is detected in the thermistor after 5 minutes of compressor
start-up.
The nonvolatile memory data cannot be read properly.
Nonvolatile memory data
Closed valve is detected by compressor current.
Stop valve
Closed valve (MXZ-2A30VA, MXZ-2A40VA -
23 A (MXZ-2A30VA-
Overcurrent
30VA- )current flows into intelligent power module.
E2
Discharge temperature Discharge temperature exceeds 116°C during operation. Compressor can
restart if discharge temperature thermistor reads 100°C or less 3 minutes
protection
later.
Fin temperature
The fin temperature exceeds 90°C during operation.
protection
P.C. board temperature
The P.C. board temperature exceeds 78°C during operation.
protection
The outdoor heat exchanger temperature exceeds 70°C during cooling
High-pressure
or indoor gas pipe temperature exceeds 70°C during heating.
protection
Bus-bar voltage The bus-bar voltage exceeds 430 V or falls to 50 V or below during
compressor operating.
protection
Failure occurs continuously three 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 during
protection
compressor operating.
The compressor doesn't synchronize
Compressor
with the operating power.
Primary current protection
The input current exceeds 8 A (MXZ-2A30VA)/ 10 A (MXZ-2A40VA,
MXZ-2A52VA).
Secondary current protection
The current of the compressor exceeds 17 A.
High-pressure protection
The indoor gas pipe temperature exceeds 45°C during heating.
Defrosting in cooling
The indoor gas pipe temperature falls 3°C or below during cooling.
The discharge temperature exceeds 100°C during operation.
Discharge temperature
protection
The frequency of the compressor is kept 80 Hz or more and the discharge
Low discharge
temperature is kept under 50°C (COOL mode)/40°C (HEAT mode) for
temperature protection
more than 40 minutes.
Condition
)
E2
E1 , MXZ-2A40VA, MXZ-2A52VA)/ 14 A (MXZ-2A
125
Correspondence
• Refer to 13-6 "Check of LEV".
• Check the drain pump of the indoor unit.
• Check the connection of the compressor connecting
wire.
• Refer to 13-6. "How to check inverter/compressor".
• Check the stop valve.
• Refer to 13-6. "Check of outdoor thermistors".
• Refer to 13-6. "Check of outdoor thermistors".
• Replace the outdoor electronic control P.C. board.
• Refer to 13-6. "Check of outdoor thermistors".
• Replace the outdoor electronic control P.C. board.
• Check the stop valve.
• Reconnect compressor connector.
• Refer to 13-6. "How to check inverter/compressor".
• Check the stop valve.
• Check the amount of gas and refrigerant circuit.
• Refer to 13-6. "Check of LEV".
• Check refrigerant circuit and refrigerant amount.
• Refer to 13-6. "Check of outdoor fan motor".
• Check the amount of gas and the refrigerant circuit.
• Check the stop valve.
• Replace the power board.
• Refer to 13-6. "Check of outdoor fan motor".
• Replace the power board.
• Reconnect compressor connector.
• Refer to 13-6. "How to check inverter/compressor".
• Check the stop valve.
These symptoms do not mean any abnormality of the
product, but check the following points.
• Check if indoor filters are clogged.
• Check if refrigerant is short.
• Check if indoor/outdoor unit air circulation is short cycled.
• Check refrigerant circuit and refrigerant amount.
• Refer to 13-6. "Check of LEV".
• Refer to 13-6. "Check of outdoor thermistors".
• Refer to 13-6. "Check of LEV".
• Check refrigerant circuit and refrigerant amount.