Mitsubishi Electric Mr. Slim MUZ-GE15NA-1, Руководство по обслуживанию

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50
10-3. TROUBLESHOOTING CHECK TABLE
No. Symptom LED indication
Abnormal point/
Condition
Condition Remedy
19
Outdoor
unit oper-
ates.
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 refrigerant
amount.
•
•
20
8-time
fl
ash
2.5 seconds OFF
PAM protection PAM:
Pulse Amplitude
Modulation
The overcurrent
fl
ows into IGBT (Insulated Gate Bipolar transis-
tor: TR821) or 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:
1 Instantaneous power voltage drop
(Short time power failure)
2 When the power supply voltage is high.
Zero cross detecting
circuit
Zero cross signal for PAM control 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 compres-
sor is correctly connected. Refer to
10-5. "How to check inverter/compres-
sor".
•
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. Flashing
(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 →
LED
MUZ-GE24NA
MUY-GE24NA
MUZ-GE09/12/15
NA/NA2/NAH/
NAH2
MUY-GE09/12/15
NA/NA2
MUZ-18NA/NAH
MUY-18NA
Inverter
P.C. board
(Parts side)
OBH549F