Carrier 40GRQB12B-3 - Malfunction of Blocked Protection of IDU Fan Motor H6

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2. Malfunction of Blocked Protection of IDU Fan Motor H6
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Turn the fan blades
by hand under
power-off condition
Do the fan blades rotate
smoothly with little to no
resistance
Adjust the motor and blade
assembly so the rotor can run
smoothly.
Under power-off condition,
check whether the wiring terminal
between
indoor fan and main
board is loose.
Turn unit on
to check whether the
malfunction is
eliminated.
Turn unit on
to check whether the
malfunction is
eliminated.
Reinsert the wiring
terminal of indoor fan.
It's the malfunction of main board.
Replace a new main board that is
of the same model.
It's the malfunction of main board.
Replace a new main board that is
of the same model.
Replace a new board of the same
model.
It's the malfunction of main board.
Then check whether the voltage
between terminal 2 and terminal 3
of the motor interface is 15VDC.
Connect power and restart the unit.
Test whether the voltage between terminal 1 and terminal 2
of motor interface is within 280~310VDC.
Then check whether there is voltage
between terminal 2 and terminal 4
of the motor interface.
It's the malfunction of motor.
Replace a new motor that is
of the same model.
Start
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Fig. 26 – Troubleshooting