Fujitsu ASU7RLF1 Service Instructions Manual page 37

Trouble shooting 2
INDOOR UNIT Error Method:
Serial Communication Error
(Serial Forward Transfer Error)
Detective Actuators:
Indoor unit Controller PCB
Forecast of Cause:
1. Connection failure
Check Point 1-1 : Reset the power and operate
Does error indication reappear?
YES
Check Point 2 : Check connection
Check any loose or removed connection line of
between indoor unit and outdoor unit.
>> If there is an abnormal condition, correct it by
referring to Installation Manual or Data &
Technical Manual.
Check connection condition in control unit.
(If there is loose connector, open cable or miss-wiring)
OK
Check Point 3 : Check the voltage of power supply
Check the voltage of power supply
>> Check if AC187V(AC208V-10%) - 253V(AC230V+10%) appears
at outdoor unit terminal L1 - L2.
OK
Check Point 4 : Check serial signal (Forward transfer signal)
Check Serial Signal (Forward Transfer Signal)
>> Check if Indicated value swings between AC30V and AC130V at Outdoor Unit Terminal 2 - 3.
>> If it is abnormal, replace Controller PCB.
>> If it is abnormal, Check Indoor unit fan motor. (PARTS INFORMATION 4)
>> If Indoor unit fan motor is abnormal, replace Indoor unit fan motor and Controller PCB.
BLACK
1
2
WHITE
RED
3
Indicate or Display:
Outdoor Unit : No indication
Indoor Unit
ERROR CODE : [E : 11]
Detective details:
When the outdoor unit cannot properly receive the serial signal from
indoor unit for 15 seconds or more.
2. External cause 3. Controller PCB failure
NO
+
-
: Operation lamp: 1 time Flash, Timer lamp: 1 time Flash
Economy lamp: Continuous flash.
Check Point 1-2 : Check external cause such as noise
Check if the ground connection is proper.
Check if there is any equipment that causes harmonic wave
near the power cable (Neon light bulb or any electronic
equipment which causes harmonic wave).
02-05