Trouble Criterion Of Main Parts; Thermistor - Mitsubishi Electric Mr.SLIM SFZ Series Technical & Service Manual

[ IX TROUBLESHOOTING ]

6. Trouble criterion of main parts

Part name
Room temperature

thermistor

(TH1)
Pipe temperature
thermistor/liquid
(TH2)
Condenser/evaporator
temperature thermistor
(TH5)
Wiring diagram
7. Thermistor
<Thermistor Characteristic graph>
Thermistor for
lower temperature
Thermistor R =15kΩ ± 3%
0
Fixed number of B=3480kΩ ± 2%
Rt=15exp { 3480(
0°C 15kΩ
10°C 9.6kΩ
20°C 6.3kΩ
25°C 5.2kΩ
30°C 4.3kΩ
40°C 3.0kΩ
HWE1909A
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+t 273
Check method and criterion
Abnormal
Opened or short-circuited
Board with build-in motor
Regulator Hall IC
GND
- 42 -
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 (°C)
GB