38
HWE1305A
TROUBLESHOOTING
9-6. How to check the parts
Part name
Check method and criterion
Room temperature
thermistor
(TH1)
Measure the resistance with a tester.
(Part temperature 10°C ~ 30°C)
Normal
Abnormal
4.3kΩ~9.6kΩ
Opened or short-circuited
Pipe temperature
thermistor/liquid
(TH2)
Condenser/evaporator
temperature thermistor
(TH5)
Wiring diagram
Motor
Board with build-in motor
Current detecting resistor
Regulator
Hall IC
Motor winding
Power
device
Pre
driver
Vm (Power supply for motor)
Vcc (Power supply for control)
Vsp (Speed command voltage)
PG (Pulse output for rotation)
GND
9-6-1. Thermistor
(1) Thermistor Characteristic graph
Thermistor for lower temperature
•
Room temperature thermistor (TH1)
•
Pipe temperature thermistor (TH2)
•
Condenser/evaporator temperature thermistor (TH5)
Thermistor R
0
=15kΩ ± 3%
Fixed number of B=3480kΩ ± 2%
Rt=15exp { 3480(
1
‒
1
) }
273+t
273
0°C 15kΩ
10°C 9.6kΩ
20°C 6.3kΩ
25°C 5.2kΩ
30°C 4.3kΩ
40°C 3.0kΩ
0
10
20
30
40
50
-20 -10 0 10 20 30 40 50
< Thermistor for lower temperature >
Temperature (°C)
Resistance (KΩ)