MITSUBISHI ELECTRIC MUZ-FD09NA- U1 - Manual (Page 21)

21
No. Symptom LED indication Abnormal point/
Condition
Condition Correspondence
18
Outdoor unit
operates.
7-time fl ash
2.5 seconds OFF
Low discharge tem-
perature 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.
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•
19
8-time fl ash
2.5 seconds OFF
PAM protection
PAM: Pulse Ampli-
tude Modulation
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 protec-
tion will be activated in the following
cases;
1 Instantaneous power voltage drop
(Short time power failure)
2 When the power supply voltage is
high.
20
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 10-5. "How to check in-
verter/compressor".
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