Mitsubishi Electric MUZ-AY25VG Service Manual page 45

12-4. TROUBLESHOOTING CRITERION OF MAIN PARTS
Part name
Defrost thermistor (RT61)
Fin temperature
thermistor (RT64)
Ambient temperature
thermistor (RT65)
Outdoor heat exchanger
temperature thermistor
(RT68)
Discharge temperature
thermistor (RT62)
Compressor (MC)
Outdoor fan motor (MF)
R. V. coil (21S4)
Expansion valve coil
(LEV)
Defrost heater
MUZ-AY•VGH
OBH931
Check method and criterion
Measure the resistance with a multimeter.
Refer to 12-6. "Test point diagram and voltage", 1. "Inverter P.C. board", for
the chart of thermistor.
Measure the resistance with a multimeter. Before measurement, hold the
thermistor with your hands to warm it up.
Refer to 12-6. "Test point diagram and voltage", 1. "Inverter P.C. board", for
the chart of thermistor.
Measure the resistance between terminals using a multimeter.
(Temperature: -10 to 40°C)
MUZ-AY25/35VG
MUZ-AY25/35VGH
U-V
U-W 2.21 - 2.99
V-W
Measure the resistance between lead wires using a multimeter.
(Temperature: -10 to 40°C)
Color of lead
MUZ-AY25/35/42VG
wire
MUZ-AY25/35/42VGH
RED – BLK
BLK – WHT
31 - 42
WHT – RED
Measure the resistance using a multimeter. (Temperature: -10 - 40°C)
Normal (kΩ)
1.41 - 2.00
Measure the resistance using a multimeter. (Temperature: -10 to 40°C)
Normal (Ω)
Color of lead wire
RED – ORN
RED – WHT
RED – BLU
RED – YLW
MUZ-AY25/35/42VGH
802 - 980
Normal (Ω)
MUZ-AY42/50VG
MUZ-AY42/50VGH
0.82 - 1.11
Normal (Ω)
MUZ-AY50VG
MUZ-AY50VGH
15 - 20
37 - 54
Normal (Ω)
MUZ-AY50VGH
370 - 428
45
Figure
WHT RED BLK
W
V
U
WHT RED BLK
W
V
U
WHT
LEV
ORN
RED
(+12V)