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9-8. DC FAN MOTOR (FAN MOTOR / INV BOARD)
[1]
[2]
[3]
[4]
[5]
[6]
[7]
Error codes and symptoms
Check items
If the static pressure settings for the unit and the duct do not match, the fan motor may repeat start/stop.
a. If there are problems only with the fan motor, replace the fan motor only.
(Fan motor failure will cause an overcurrent to pass through the inverter, but the inverter is protected from
damage with the protection function that will stop the inverter when an overcurrent is detected.)
b. If the inverter fails, replace the failed components on the inverter.
c. If both the fan motor and inverter fail, replace the fan motor and all applicable parts on the inverter.
1. Inside the inverter is a large capacity electrolytic capacitor, and the residual voltage that remains after the main power is
turned off presents a risk of electric shock. Before checking the inverter-related parts, turn off the main power, keep it
turned off for at least 10 minutes, and check that the voltage at both ends of the main capacitor (C015, C016) has dropped
to a safe level.
*Measure the voltage at both ends of the electrolytic capacitor at the check point where "CHECK VOLTAGE" is written in
the left top area of the NF board.
2. The IPM on the inverter becomes damaged if there are loose screws or connectors. When a problem occurs after
replacing components, faulty wiring is often the cause of the problem. Check the wiring, screws, connectors, and Fasten
terminals for proper connection.
3. Do not plug or unplug the inverter connectors while the main power is turned on, as this will result in damage to the circuit
board.
4. Electric current sensor will break if a current is passed through the sensor without it being connected to the circuit board.
Connect the current sensor to the appropriate connectors on the circuit board before operating the inverter.
Inverter-related errors
Pb
Main power breaker is tripped.
The main earth leakage breaker is tripped.
The fan motor vibrates excessively or makes
abnormal sounds.
(1) Troubleshooting the inverter-related problems
Check the error code display on the remote controller to see if the error is an
inverter-related error.
Only the fan motor is inoperative.
Peripheral devices pick up electrical noise.
Accidental malfunction (due to external noise)
Check the display on the remote controller. If the fan is in operation, proceed to
section (2)-[2] and (2)-[3].
a. Check the breaker capacity.
c. If no problems are found with items a and b, see (3)-[1].
See (2)-[2] and (2)-[3].
e. Connect the unit to a different power supply circuit.
b. Check the electric circuits other than the inverter circuits for short-circuit and
ground fault.
a. Check the capacity and the sensitivity current of the earth leakage breaker.
c. If no problems are found with items a and b, see (3)-[1].
b. Insulation resistance failure of the electrical components other than the
inverter
a. Check that the power wire to the peripheral devices are not routed adjacent
to the power wire to the indoor unit.
b. Check that the inverter output wiring is not routed adjacent to the power wire
or transmission line.
c. Check that a shielded cable is used if required. Check that the shield is
properly grounded.
b. Check that a shielded cable is used if required. Check that the shield is
properly grounded.
c. Check that the transmission line or wiring to external devices are not routed
adjacent to the power wires or are placed in the same conduit with them.
d. Insulation resistance failure of the electrical components other than the
inverter
f. If the problem appeared suddenly, there is a possibility that the inverter
output line had a ground fault. See section (2)-[2] and (2)-[3].
*For problems other than the ones listed above, consult your dealer.
*For problems other than the ones listed above, consult your dealer.
a. Check that the unit is properly grounded.
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