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11-3. TROUBLESHOOTING CHECK TABLE
No. Symptom LED indication
Abnormal point/
Condition
Condition Remedy
16
Outdoor unit
operates.
1-time fl ash
2.5 seconds OFF
Frequency drop by
current protection
Current from power outlet is nearing breaker capacity. The unit is normal, but check the
following.
Check if the indoor fi lters are
clogged.
Check if the refrigerant is short.
Check if the indoor/outdoor unit air
circulation is short cycled.
•
•
•
17
3-time fl ash
2.5 seconds OFF
Frequency drop by
high pressure pro-
tection
Temperature of indoor coil thermistor exceeds 55°C in HEAT
mode, compressor frequency lowers.
Frequency drop by
defrosting in COOL
mode
Indoor coil thermistor reads 8°C or less in COOL mode, com-
pressor frequency lowers.
18
4-time fl ash
2.5 seconds OFF
Frequency drop by
discharge tempera-
ture protection
Temperature of discharge temperature thermistor exceeds
111°C, compressor frequency lowers.
Check the refrigerant circuit and
the refrigerant amount.
Refer to 11-5.
"Check of LEV".
Refer to 11-5. "Check of outdoor
thermistors".
•
•
•
19
Outdoor unit
operates.
7-time fl ash
2.5 seconds OFF
Low discharge tem-
perature protection
Temperature of discharge temperature thermistor has been
50°C or less for 20 minutes.
Refer to 11-5. "Check of LEV".
Check the refrigerant circuit and
the refrigerant amount.
•
•
20
8-time fl ash
2.5 seconds OFF
MUZ-GE25/33/35/42/50
PAM protection PAM:
Pulse Amplitude Modu-
lation
The overcurrent fl ows into IGBT (Insulated Gate Bipolar tran-
sistor: TR821) or the bus-bar voltage reaches 320 V or more,
PAM stops and restarts.
This is not malfunction. PAM pro-
tection will be activated in the fol-
lowing cases:
1 Instantaneous power voltage
drop. (Short time power failure)
2 When the power supply voltage
is high.
MUZ-GE60/71/80
Zero cross detecting
circuit
Zero cross signal cannot be detected.
21
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 com-
pressor is correctly connected.
Refer to 11-5. "How to check
inverter/compressor".
•
NOTE: 1. The location of LED is illustrated at the right fi gure. Refer to 11-6.1.
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”.
ON
OFF
2.5-second OFF
2.5-second OFF
0.5-second ON
0.5-second ON
LED
Flashing →
Inverter P.C. board
LED
MUZ-GE
25/33/35/
42/50
MUZ-GE
60/71/80
→
Flashing
OBH532E