Fujitsu AMUG24LMAS Service Manual page 66

Troubleshooting 13
Indoor unit fan motor error
Detective actuators:
Indoor unit controller PCB
Indoor unit fan motor
Detective details:
When condition that actual frequency of
Indoor fan is below 1/3 of target frequency
is continued more than 56 seconds.
Forecast of cause:
1. Fan rotation failure
2. Fan motor winding open
3. Motor protection by surrounding temperature rise
4. Power supply PCB failure
5. Indoor unit fan motor failure
6. Wrong fan motor connected
Check Point 1 : Check rotation of Fan
Try rotating the fan by hand when the operation is off to see
if the shaft is caught or locked.
>>If Fan or Bearing is abnormal, replace it.
OK
Check Point 2 : Check for missing connectors and broken wires
Reinsert the connector. Or check the wiring continuity between the transformer
and fan motor and between the CN650 and controller PCB.
>>Replace the wire with connector or the wire.
OK
Check Point 3* : Check the resistance value between pins of CN650
*Check with the fan motor disconnected from the controller PCB and with the power off.
Is the resistance value between pin3 and 4 of CN650 of 5.7k 5% and a resistance
value between pin1 and 2 of 2.0k 5% ?
>>If it is not the specified resistance value, replace the controller PCB.
OK
Check Point 4 : 24V AC transformer check
Turn on the power and measure the voltage with a tester.
24V AC is OK.
>>If it is not 24V, replace the transformer.
OK
Replace fan motor
Indicate or Display:
Indoor unit
Operation lamp: 5 times Flash,
Timer lamp
Wired remote
Error code : [E : 51]
Outdoor unit (AOG36/48LMAS1)
Mode Error
2
: Light OFF
03-18
: 1 time Flash
A B C D E
15
5
: Light ON n : n times blinking
F