43
MUZ-A09/12/15/17NA MUY-A15/17NA
No. Symptom LED indication
Abnormal point / Condition
Condition Correspondence
1
Outdoor unit
does not operate.
1-time fl ash every
2.5 seconds
Outdoor power system
Overcurrent protection stop is continuously performed 3 times
within 1 minute after the compressor gets started.
• Reconnect connector of compressor.
•
Refer to 10-5. "How to check in-
verter/compressor".
•
Check stop valve.
2
Outdoor thermistors Discharge temperature thermistor, fi n temperature thermistor,
defrost thermistor (MUZ), P.C. board temperature thermistor or
ambient temperature thermistor shorts or opens during compressor running.
•
Refer to 10-5. "Check of outdoor
thermistors".
3
Outdoor control system
Nonvolatile memory data cannot be read properly. Replace inverter P.C. board.
4
6-time fl ash
2.5 seconds OFF
Serial signal The communication fails between the indoor and outdoor unit
for 3 minutes.
•
Refer to 10-5. "How to check
miswiring and serial signal error".
5
14-time fl ash
2.5 seconds OFF
Outdoor unit
(Other abnormality)
Outdoor unit is defective. Refer to 10-2.2. "Flow chart of the
detailed outdoor unit failure mode
recall function".
6
'Outdoor unit
stops and
restarts 3 minutes later' is
repeated.
2-time fl ash
2.5 seconds OFF
Overcurrent protection
24 A (09/12) / 26.5 A (15/17) current fl ows into intelligent power
module.
• Reconnect connector of compressor.
•
Refer to 10-5. "How to check in-
verter/compressor"
•
Check stop valve.
7
3-time fl ash
2.5 seconds OFF
Discharge temperature overheat protection
Temperature of discharge temperature thermistor exceeds 241
°F (116°C) compressor stops. Compressor can restart if discharge temperature thermistor reads 212°F (100°C) or less 3
minutes later.
•
Check refrigerant circuit and refrig-
erant amount.
•
Refer to 10-5. "Check of LEV".
8
4-timefl ash
2.5 seconds OFF
Fin temperature /
P.C. board temperature thermistor overheat protection
Temperature of fi n temperature thermistor on the heat sink
exceeds 180°F (82°C) (09/12) / 188°F (86.5°C) (15/17) or temperature of P.C. board temperature thermistor on the inverter
P.C. board exceeds 176°F (80°C).
•
Check around outdoor unit.
•
Check outdoor unit air passage.
•
Refer to 10-5. "Check of outdoor
fan motor".
9
5-time fl ash
2.5 seconds OFF
High pressure protection
Indoor coil thermistor exceeds 158°F (70°C) in HEAT mode.
(MUZ)
Defrost thermistor exceeds 158°F (70°C) in COOL mode.
•
Check refrigerant circuit and refrig-
erant amount.
•
Check stop valve.
10
8-time fl ash
2.5 seconds OFF
Compressor synchronous abnormality
The waveform of compressor current is distorted.
•
Reconnect connector of compressor.
•
Refer to 10-5. "How to check in-
verter/compressor"
11
10-time fl ash
2.5 seconds OFF
Outdoor fan motor Outdoor fan has stopped 3 times in a row within 30 seconds
after outdoor fan start-up.
•
Refer to 10-5. "Check of outdoor
fan motor".
•
Refer to 10-5. "Check of inverter
P.C. board".
12
12-timefl ash
2.5 seconds OFF
Each phase current
of compressor
Each phase current of compressor cannot be detected normally.
• Refer to 10-5.
"How to check
inverter/compressor"
13
13-time fl ash
2.5 seconds OFF
DC voltage DC voltage of inverter cannot be detected normally.
•
Refer to 10-5. "How to check in-
verter/compressor".
14
Outdoor unit
operates.
1-time fl ash
2.5 seconds OFF
Frequency drop by
current protection
Current from power outlet exceeds 9.2 A (09/12) / 11.1 A
(15/17) compressor frequency lowers.
The unit is normal, but check the following.
•
Check if indoor fi lters are clogged.
•
Check if refrigerant is short.
•
Check if indoor/outdoor unit air cir-
culation is short cycled.
15
3-time fl ash
2.5 seconds OFF
Frequency drop by high
pressure protection
Temperature of indoor coil thermistor exceeds 131°F (55°C) in
HEAT mode (MUZ), compressor frequency lowers.
Frequency drop by defrosting in COOL mode
Indoor coil thermistor reads 46°F (8°C) or less in COOL mode,
compressor frequency lowers.
16
4-time fl ash
2.5 seconds OFF
Frequency drop by
discharge temperature protection
Temperature of discharge temperature thermistor exceeds 232
°F (111°C), compressor frequency lowers.
•
Check refrigerant circuit and refrig-
erant amount.
•
Refer to 10-5. "Check of LEV".
•
Refer to 10-5. "Check of outdoor
thermistors".
17
Outdoor unit
operates.
7-time fl ash
2.5 seconds OFF
Low discharge temperature protection
Temperature of discharge temperature thermistor has been
122°F (50°C) or less for 20 minutes.
•
Refer to 10-5. "Check of LEV".
•
Check refrigerant circuit and refrig-
erant amount.
18
8-time fl ash
2.5 seconds OFF
PAM protection
PAM :
Pulse
Amplitude
Modulation
The overcurrent fl ows into IGBT (Insulated Gate Bipolar tran-
sistor: TR821) or when the bus-bar voltage reaches 320 V or
more, PAM stops and restarts.
This is not malfunction.
PAM protection will be activated in
the following cases:
lnstantaneous power voltage drop
(Short time power failure)
When the power supply voltage is high.
19
9-time fl ash
2.5 seconds OFF
Inverter check mode The connector of compressor is disconnected, inverter check
mode starts.
Check if the connector of the compressor is correctly connected.
Refer to 10-5. "How to check inverter/compressor".
NOTE: 1. The location of LED is illustrated at the right fi gure. Refer to 10-6.1.
2. LED is lighted during normal operation.
The fl ashing frequency shows the number of times the LED blinks after every 2.5-second OFF.
(Example) When the fl ashing frequency is "2".
Inverter P.C. board (Parts side)
LED
Flashing
ON
OFF
2.5-second OFF
2.5-second OFF
0.5-second ON 0.5-second ON
10-3. TROUBLESHOOTING CHECK TABLE