MXS Service Manual

Troubleshooting for RA Indoor Unit SiUS121736EA
155 Service Diagnosis
Troubleshooting
Check No.02
Refer to P.210
Note: The rotation pulse is the feedback signal from the indoor fan motor.
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Correct the power
supply.
NO
Check the power supply
voltage.
Turn off the power and
disconnect the fan motor
connector, then turn the
power on.
Check No.02
Check the output of the
fan motor connector.
YES
YES
NO
YES
YES
NO
NO
NO
Note: The motor may break when the
motor connector is disconnected
while the power is turned on.
(Be sure to turn off the power
before reconnecting the
connector.)
Replace the indoor
fan motor.
Replace the indoor
unit PCB (control
PCB).
Replace the indoor
unit PCB (control
PCB).
Does the fan
rotate smoothly?
Does the fan
rotate?
Motor
power supply
voltage 310 ~ 340
VDC?
Turn off the power and
rotate the fan by hand.
Turn on the power and
start operation.
Check No.02
Check the output of the
fan motor connector.
(R22444)
YES
NO
YES
NO
YES
NO
Replace the indoor
fan motor.
Replace the indoor
unit PCB (control
PCB).
Replace the indoor
unit PCB (control
PCB).
Replace the indoor
unit PCB (control
PCB).
Replace the indoor
fan motor.
Stop the fan motor.
YES
Is the
voltage
fluctuation
within ±10% from
the rated
value?
Motor
control voltage 15
VDC generated?
Rotation
command voltage
1 ~ 6.5 VDC?
Indoor fan
motor rotation pulse
generated?
Indoor fan
motor rotation pulse
generated?