Mitsubishi Electric MR. Slim PEAD-M50JA Service Manual page 44

9-6. TROUBLE CRITERION OF MAIN PARTS
Part name
Room temperature
thermistor
(TH1)
Pipe temperature
thermistor/liquid
(TH2)
Condenser/evaporator
temperature thermistor
(TH5)
Wiring diagram
9-7. Thermistor
<Thermistor Characteristic graph>
Thermistor for
lower temperature
Thermistor R =15k" ± 3%
0
Fixed number of B=3480k" ± 2%
Rt=15exp { 3480(
273+t
0: 15k"
10: 9.6k"
20: 6.3k"
25: 5.2k"
30: 4.3k"
40: 3.0k"
Measure the resistance with a tester.
(Part temperature 10°C ~ 30°C)
Normal
4.3kΩ~9.6kΩ
Vm (Power supply for motor)
Vcc (Power supply for control)
Vsp (Speed command voltage)
PG (Pulse output for rotation)
Room temperature thermistor (TH1)
Pipe temperature thermistor (TH2)
Condenser/evaporator temperature
thermistor (TH5)
1 1
) }
273
Check method and criterion
Abnormal
Opened or short-circuited
Board with build-in motor
Regulator Hall IC
GND
44
Motor
Motor winding
Power Pre
device driver
Current detecting resistor
< Thermistor for lower temperature >
50
40
30
20
10
0
-20 -10 0 10 20 30 40 50
Temperature (:)