Troubleshooting Check Table - Mitsubishi Electric MXZ-2A40VA Service Manual

13-4. Troubleshooting check table

MXZ-2A
Indication
Symptom
No.
LED1(Red) LED2(Yellow)
Outdoor unit
Lightning Once
does not
1
operate.
2
Lightning Twice
3
Lightning 3 times
4
Lightning 4 times
5 Lightning 5 times
6
Lightning 7 times
'Outdoor unit
stops and
restarts 3
Twice Goes out
7
minutes
later' is
repeated.
3 times Goes out
8
9 4 times Goes out
10
5 times Goes out
11 9 times Goes out
12 13 times Goes out
13 8 times Goes out
10 times Goes out
14
Outdoor unit
Once Lighting
15
operates.
Twice Lighting
16
3 times
17
Lighting
4 times
18 Lighting
NOTE 1. The location of LED is illustrated at the right figure. Refer to 13-7.1.
2. LED is lighted during normal operation.
The flashing frequency shows the number of times the LED blinks after every 2.5-second OFF.
(Example) When the flashing frequency is "2".
ON
2.5-second OFF
OFF
Abnormal point / Condition
LEV for drain When the indoor unit detects any abnormality in the LEV for drain.
When over current protection stop is continuously performed three times
within 1 minute after the compressor gets started, or when converter
Outdoor power system
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
Discharge temperature
when an open circuit is detected in the thermistor after 10 minutes
thermistor
of compressor start-up.
Fin temperature
thermistor
When a short or open circuit is detected in the thermistor during
operation.
P.C board temperature
thermistor
Ambient temperature When a short or open circuit is detected in the thermistor during
thermistor operation.
When a short circuit is detected in the thermistor during operation, or
Outdoor heat exchanger
when an open circuit is detected in the thermistor after 5 minutes (in
temperature thermistor
cooling) and 10 minutes (in heating) of compressor start-up.
When a short circuit is detected in the thermistor during operation, or
Defrost thermistor
when an open circuit is detected in the thermistor after 5 minutes of
compressor start-up.
When the nonvolatile memory data cannot be read properly.
Nonvolatile memory data
When 28A current flow into intelligent power module.
Over current
Discharge temperature When discharge temperature exceeds 116:
can restart if discharge temperature thermistor reads 100: or less 3
protection
minutes later.
Fin temperature
When the fin temperature exceeds 87: during operation.
protection
P.C. board temperature
When the P.C. board temperature exceeds 70: during operation.
protection
High-pressure
When the outdoor heat exchanger temperature exceeds 70:
protection
during cooling or when indoor gas pipe temperature exceeds 70:
during heating.
When the bus-bar voltage exceeds 430V or falls to 50V or below
Bus-bar voltage
during compressor operating.
protection
When failure occurs continuously three times within 30 seconds after
Outdoor fan motor
the fan gets started.
Current sensor
When a short or open circuit is detected in the current sensor during
protection
compressor operating.
The compressor doesn't synchronize
Compreesor
with the operating power.
Primary current protection When the input current exceeds 15A.
When the current of the compressor exceeds 15A.
Secondary current protection
High-pressure protection
When the indoor gas pipe temperature exceeds 45: during heating.
Defrosting in cooling When the indoor gas pipe temperature falls 3: or below during cooling.
When the frequency of the compressor is kept 80Hz or more and
Discharge temperature
the discharge temperature is kept under 50:(COOL mode)
protection
/40:(HEAT mode) for more than 40 minutes.
When the frequency of the compressor is kept 80Hz or more and
Low discharge
the discharge temperature is kept under 39: for more than 20
temperature protection
minutes.
Condition
during operation. Compressor
0.5-second ON
2.5-second OFF
58
Correspondence
• Refer to 13-6.D "Check of LEV".
• Check the drain pump of the indoor unit.
• Check the connection of the compressor connecting
wire.
• Refer to 13-6.E "How to check inverter/compressor".
• Check the stop valve.
• Refer to 13-6.F "Check of outdoor thirmistors".
• Refer to 13-6.F "Check of outdoor thirmistors".
• Replace the outdoor electronic control P.C. board.
• Refer to 13-6.F "Check of outdoor thirmistors".
• Replace the outdoor electronic control P.C. board.
• Reconnect compressor connector.
• Refer to 13-6.E "How to check inverter/compressor".
• Check the stop valve.
• Check the amount of gas and refrigerant circuit.
• Refer to 13-6.D "Check of LEV".
•Check refrigerant circuit and refrigerant amount.
•Refer to 13-6.G "Check of outdoor fan motor".
• Check around of gas and the refrigerant circuit.
• Check of stop valve.
• Replace the power board.
• Refer to 13-6.G "Check of outdoor fan motor".
• Replace the power board.
• Reconnect compressor connector.
• Refer to 13-6.E "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.D "Check of LEV".
• Refer to 13-6.F "Check of outdoor thermistors".
• Refer to 13-6.D "Check of LEV".
• Check refrigerant circuit and refrigerant amount.
Outdoor electronic control P.C. board(Parts side)
Lighting
0.5-second ON
LED2 LED1