Troubleshooting Check Table - Mitsubishi Electric Mr. Slim MUZ-D30NA Service Manual

10-3. TROUBLESHOOTING CHECK TABLE

MUZ-D30NA MUZ-D36NA MUY-D30NA MUY-D36NA
Indication
No. Symptom
LED1 LED2
(Red) (Yellow)
1 Lightning Twice
2 Lightning 3 times
3 Lightning 4 times
Outdoor
unit does
not oper-
4 Lightning 5 times
ate.
5 Lightning 6 times
6 Lightning 7 times
7 Lightning 8 times
8 Lightning 11 times
9 Lightning 12 times
10 Twice Goes out
11 3 times Goes out
12 4 times Goes out
'Outdoor
13 5 times Goes out High-pressure protection
unit stops
and restarts
3 minutes
14 8 times Goes out Converter protection
later' is
repeated.
15 9 times Goes out
16 13 times Goes out Outdoor fan motor
17 Lighting 8 times
18 Lighting 11 times
19 Lighting 12 times
NOTE 1. The location of LED is illustrated at the right figure. Refer to 10-6.1.
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
IPM protection stop or lock protection stop is continuously
performed three times within 1 minute after the compressor
Outdoor power system gets started, or converter protection stop or bus-bar voltage
protection stop is continuously performed 3 times within 3
minutes after start-up.
A short circuit is detected in the thermistor during opera-
Discharge temperature therm-
tion, or an open circuit is detected in the thermistor after 10
istor
minutes of compressor start-up.
Fin temperature thermistor
A short or open circuit is detected in the thermistor during
P.C. board temperature therm-
operation.
istor
Ambient temperature thermis- A short or open circuit is detected in the thermistor during
tor operation.
A short circuit is detected in the thermistor during operation,
Outdoor heat exchanger or an open circuit is detected in the thermistor after 5 minutes
temperature thermistor (in cooling) and 10 minutes (in heating (MUZ)) of compressor
start-up.
A short circuit is detected in the thermistor during operation,
Defrost thermistor (MUZ) or an open circuit is detected in the thermistor after 5 minutes
of compressor start-up.
The communication fails between the indoor and outdoor unit
Serial signal
for 3 minutes.
Nonvolatile memory data The nonvolatile memory data cannot be read properly.
Current sensor protection stop is continuously performed
Current sensor
twice.
Communication error between The communication protection stop between boards is con-
P.C. boards tinuously performed twice.
The protection stop of the zero cross detecting circuit is
Zero cross detecting circuit
continuously performed 10 times.
Overcurrent is detected after 30 minutes of compressor start-
IPM protection
up.
Overcurrent is detected within 30 minutes of compressor
Lock protection
start-up
Temperature of discharge temperature thermistor exceeds
Discharge temperature protec- 241°F (116°C), compressor stops. Compressor can restart
tion if discharge temperature thermistor reads 212°F (100°C) or
less 3 minutes later.
Fin temperature protection The fi n temperature exceeds 189°F (87°C) during operation.
P.C. board temperature pro- The P.C. board temperature exceeds 158°F (70°C) during
tection operation.
The outdoor heat exchanger temperature exceeds 158°F (70
°C) during cooling or indoor gas pipe temperature exceeds
158°F (70°C) during heating (MUZ).
A failure is detected in the operation of the converter during
operation.
The bus-bar voltage exceeds 400 V or falls to 200 V or below
Bus-bar voltage protection (1)
during compressor operating.
The bus-bar voltage exceeds 400 V or falls to 50 V or below
Bus-bar voltage protection (2)
during compressor operating.
Failure occurs continuously three times within 30 seconds
after the fan gets started.
A short or open circuit is detected in the current sensor during
Current sensor protection
compressor operating.
Communication error occurs between the outdoor electronic
Communication between P.C.
control P.C. board and power board for more than 10 sec-
boards protection
onds.
Zero cross detecting circuit Zero cross signal cannot be detected while the compressor is
protection operating.
0.5-second ON
2.5-second OFF
Condition
Outdoor electronic control P.C. board (Parts side)
0.5-second ON
27
Correspondence
• Check the connection of the compressor connect-
ing wire.
• Refer to 10-5. "How to check inverter/compres-
sor".
• Refer to 10-5. "Check of compressor start failure".
• Check the stop valve.
• Refer to 10-5. "Check of outdoor thermistor".
• Refer to 10-5. "Check of outdoor thermistor".
• Replace the outdoor electronic control P.C. board.
• Refer to 10-5. "Check of outdoor thermistor".
• Refer to 10-5. "How to check miswiring and serial
signal error.
• Replace the outdoor electronic control P.C. board.
• Replace the power board.
• Check the connecting wire between outdoor elec-
tronic control P.C. board and power board.
• Check the connecting wire among outdoor elec-
tronic control P.C. board, noise fi lter P.C. board and
power board.
• Reconnect compressor connector.
• Refer to 10-5. "How to check inverter/compres-
sor".
• Refer to 10-5. "Check of compressor start failure".
• Check the stop valve.
• Check the power module (PAM module).
• Check the amount of gas and refrigerant circuit.
• Refer to 10-5. "Check of LEV".
• Check around outdoor unit.
• Check outdoor unit air passage.
• Refer to 10-5. "Check of outdoor fan motor".
• Check around of gas and the refrigerant circuit.
• Check of stop valve.
• Replace the power board.
• Check the voltage of power supply.
• Replace the power board or the outdoor electronic
control P.C. board.
• Refer to 10-5. "Check of bus-bar voltage".
• Refer to 10-5. "Check of outdoor fan motor".
• Replace the power board.
• Check the connecting wire between outdoor elec-
tronic control P.C. board and power board.
• Check the connecting wire among outdoor elec-
tronic control P.C. board, noise fi lter P.C. board and
power board.
LED2 LED1
→
Lighting