Fault Diagnosis Of Dc Fan Motor - Hitachi RAS-2-HVNP Service Manual

8. Troubleshooting
8.4.3 Fault diagnosis of DC fan motor.
When ISPM/DIP-IPM is faulty and Alarm 03, 04 or 53 appears, the fan motor may also be damaged. To prevent ISPM/DIP-
IPM damage which may result from operation combined with a faulty fan motor, check also if the fan motor is not damaged
when ISPM/DIP-IPM is replaced
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 Remove fan motor connectors for DC fan motor from the control PCB, ISPM or DIP-IPM and turn the fan motor shaft
by hand.
Normal
The fan motor shaft turns smoothly.
Normal
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
Faulty
has a short-circuit fault.
2 Measure the fan motor resistance:
1 Remove the fan motor connector from the control PCB, ISPM or DIP-IPM.
2 Connect the black test lead of the tester to the black wire pin of the fan motor connector.
3 Connect the red test lead to the wire connector pin to be checked.
Observed values will be close to the normal values in the table below.
Normal
Obbserved values will be deviated from the normal values in the table below. (Generally, an open-circuit
fault shows ∞, and a short-circuit fault shows several Ω - kΩ).
Faulty
Internal electronic circuit fault of the fan motor including short-circuit and breakage can be checked.
Model
RAS-(2-2.5)HVNP
RAS-3HVNC
RAS-(3-6)H(V)NPE (both)
RAS-(4-6)H(V)NCE
RAS-(8-10)HN(P/C)E (both)
RAS-12HN(P/C)
N O T E
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 ∞.
284
SMGB0079 rev.0 - 01/2013
Models with DC motor(s)
RAS-(2-2.5)HVNP
RAS-3HVNC
RAS-3HVNPE
RAS-(4-6)H(V)NCE
RAS-12HN(P/C)
RAS-(4-6)H(V)NPE
RAS-(8-10)HN(P/C)E
Fan motor shaft turns smoothly
Measurement procedure
Results
Motor model
Red-black
FPD10U40S-902
SIC-61FW-D858 1MΩ or greater
∞
EQDW04AHT
SIC-81FW-8183 1MΩ or greater
Nº of motors
1 Pieces
1 Pieces above
2 Pieces
Wire color for checking (Normal value)
White-black Yellow-black
1MΩ or greater
Blue-black
1MΩ or greater
1MΩ or greater
∞
1MΩ or greater