Mitsubishi Electric MXZ-2A20NA-1 Service Manual page 43

11-4. Troubleshooting check table
Indication
Symptom
No.
LED1(Red) LED2(Yellow)
Outdoor unit
1 does not Lighting Once
operate.
2 Lighting Twice
3
Lighting 3 times
4
Lighting 4 times
5
Lighting 5 times
6
Lighting 7 times
7
Lighting 8 times
8 Lighting 10 times
9
Lighting 11 times
10
Lighting 12 times
'Outdoor unit
stops and
restarts 3
Twice Goes out
11
minutes
later' is
repeated.
3 times Goes out
12
13 4 times Goes out
14 5 times Goes out
15 8 times Goes out
16 9 times Goes out
17 13 times Goes out
18
Lighting 8 times
19 Lighting 11 times
Lighting 12 times
20
NOTE 1. The location of LED is illustrated at the right figure. Refer to 11-7.1.
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
When the indoor unit detects any abnormality in the LEV for drain.
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.
Nonvolatile memory data When the nonvolatile memory data cannot be read properly.
Current sensor Current sensor protection stop is continuously performed twice.
Gas pipe temperature
When a short or open circuit is detected in the thermistor during
thermistor A
cooling.
Gas pipe temperature
(A,B : MXZ-2A20NA, MXZ-3A30NA)
thermistor B
(C : MXZ-3A30NA)
Gas pipe temperature
thermistor C
When the communication protection stop between boards is
Communication error
continuously performed twice.
between P.C. boards
The protection stop of the zero cross detecting circuit is continuously
Zero cross detecting
performed 10 times.
circuit
When overcurrent is detected after 30 minutes of compressor start-up.
IPM protection
When overcurrent is detected within 30 minutes of compressor
Lock protection
start-up
Discharge temperature When discharge temperature exceeds 240.8˚F during operation. Compressor
protection
can restart if discharge temperature thermistor reads 212˚F or less 3
minutes later.
Fin temperature
When the fin temperature exceeds 188.6˚F during operation.
protection
P.C. board temperature
When the P.C. board temperature exceeds 158˚F during operation.
protection
High-pressure
When high-pressure is detected with the high-pressure switch (HPS)
protection
during operation.(MXZ-3A30)
When the outdoor heat exchanger temperature exceeds 158˚F
during cooling or when indoor gas pipe temperature exceeds 158˚F
during heating.
Converter protection When a failure is detected in the operation of the converter during
operation.
Bus-bar voltage When the bus-bar voltage exceeds 400V or falls to 200V or below
protection (1) during compressor operating.
When the bus-bar voltage exceeds 400V or falls to 50V or below
Bus-bar voltage
protection (2) during compressor operating.
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.
Communication error occurs between the outdoor electronic control P.C.
Communication between P.C.
board and power board for more than 10 seconds.
boards protection
When zero cross signal cannot be detected while the compressor is
Zero cross detecting circuit
operating.
protection
Condition
0.5-second ON
2.5-second OFF
43
Correspondence
D
• Refer to 11-6. "Check of LEV".
• Check the drain pump of the indoor unit.
• Check the connection of the compressor connecting
wire.
E
• Refer to 11-6. "How to check inverter/compressor".
• Check the stop valve.
F
• Refer to 11-6. "Check of outdoor thermistors".
F
• Refer to 11-6. "Check of outdoor thermistors".
• Replace the outdoor electronic control P.C. board.
F
• Refer to 11-6. "Check of outdoor thermistors".
• Replace the outdoor electronic control P.C. board.
• Replace the power board.
F
• Refer to 11-6. "Check of outdoor thermistors".
• Check the connecting wire between outdoor electronic control
P.C. board and power board.
• Check the connecting wire among outdoor electronic control
P.C. board, noise filter P.C. board and power board.
• Reconnect compressor connector.
E
• 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.
D
• Refer to 11-6. "Check of LEV".
•Check refrigerant circuit and refrigerant amount.
G
•Refer to 11-6. "Check of outdoor fan motor".
• Check around of gas and the refrigerant circuit.
• Check of stop valve.
• Replace the power board.
• Replace the power board.
G
• Refer to 11-6. "Check of outdoor fan motor".
• Replace the power board.
• Check the connecting wire between outdoor electronic control
P.C. board and power board.
• Check the connecting wire among outdoor electronic control
P.C. board, noise filter P.C. board and power board.
Outdoor electronic control P.C. board(Parts side)
Lighting
0.5-second ON
LED2 LED1