10 Troubleshooting
Checking procedure for main parts
SMGB0091 rev.2 - 11/2015
275
10
10.4.3 Fault diagnosis of fan motor
Some alarms may have been caused due to faulty fan motor. Therefore, check the fan motor as explained below:
!
C A U T I O N
• Turn OFF main power before start working.
• Working and checking with the power ON may disturb correct diagnosis and may result in failure.
Procedure in case of error diagnosis
1
Disconnect the fan motor connectors from the CN35 connector and remove the propeller fan. Then, turn the fan
motor shaft by hand.
Normal
Fan motor shaft turns smoothly
Faulty
No continuous rotary torque movement felt when turning the motor by hand. This occurs because the
internal magnet of the fan motor breaks the movement when the internal electronic circuit of the fan
motor has a short-circuit fault.
2
Measure the fan motor resistance:
Measurement procedure
1
Ensure that the fan motor connector CN35 has been correctly disconnected as explained above.
2
Connect the tester between each pair of wires of the fan motor and measure if the coil resistance values are close
to the normal values in the table below.
Results
Normal
Observed values are close to the normal values in the table below.
Faulty
Observed values are deviated from the normal values in the table below. (Generally, an open-circuit
fault shows ∞, and a short-circuit fault shows several Ω - kΩ).
Internal electronic circuit fault of the fan motor including short-circuit and breakage can be checked.
Model
Motor model
Coil resistance
U-V (Brown-Black)
V-W (Black-Grey)
W-U (Grey-Brown)
RASC-(4-6)HNPE
CBM-10/10 350
32 Ω
32 Ω
32 Ω
RASC-(8/10)HNPE
CBM-12/12 550
15 Ω
15 Ω
15 Ω
Values are shown for referential purpose. While actual values may vary depending on the type of the tester, any tester
can be used to determine any short-circuit or breakage based on ∞ or several Ω or 0 Ω or ∞.