M-Series MUZ-GE Technical & Service Manual

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)
10-4. TROUBLE CRITERION OF MAIN PARTS
MUZ-GE09NA MUZ-GE12NA MUZ-GE15NA MUZ-GE18NA MUZ-GE24NA
MUZ-GE09NA2 MUZ-GE12NA2 MUZ-GE15NA2
MUZ-GE09NAH MUZ-GE12NAH MUZ-GE15NAH MUZ-GE18NAH
MUZ-GE09NAH2 MUZ-GE12NAH2 MUZ-GE15NAH2
MUY-GE09NA MUY-GE12NA MUY-GE15NA MUY-GE18NA MUY-GE24NA
MUY-GE09NA2 MUY-GE12NA2 MUY-GE15NA2
Part name Check method and criterion Figure
Defrost thermistor (RT61)
(MUZ)
Fin temperature
thermistor (RT64)
Ambient temperature
thermistor (RT65)
Outdoor heat exchanger
temperature thermistor
(RT68)
Measure the resistance with a tester.
Refer to 10-6. “Test point diagram and voltage”, 1. “Inverter P.C.
board”, for the chart of thermistor.
Discharge temperature
thermistor (RT62)
Measure the resistance with a tester. Before measurement, hold the
thermistor with your hands to warm it up.
Refer to 10-6. “Test point diagram and voltage”, 1. “Inverter P.C.
board”, for the chart of thermistor.
Compressor
Measure the resistance between terminals using a tester.
(Temperature: -4 ~ 104°F (-20 ~ 40°C))
Normal (Ω)
GE09 GE12 GE15/18 GE24
U-V
U-W
V-W
1.36 ~ 1.93 1.52 ~ 2.17 0.78 ~ 1.11 0.83 ~ 1.18
W
U
V
WHT
RED BLK
OBH549G