Fujitsu AUXB04GALH Service Manual page 109

Trouble shooting 31
OUTDOOR UNIT Error Method:
Auto Address Setting Error
Detective Actuators:
Outdoor unit Main PCB
1. Indoor unit power supply defective 2 Indoor unit overconnected
Forecast of Cause :
3.Communication line incorrect connection 4. Noise, momentary open
Check Point 1 : Check the indoor unit power supply
Check the indoor unit power supply
OK
Check Point 2 : Check the indoor unit number connection
Check if each indoor units are connected in a refrigerant circuit
OK
Check Point 3 : Check the communication line connection
Check if communication line is correctly connected
Is it uncoupled or cut halfway ?
Connecting terminal position is correct as the installation manual shows ?
OK
Check Point 4 : Check noise, momentary open, voltage drop
Check if power supply temporarily stops by outages or if strong noise is generated from
surrounding environment during auto address
E. 28. 1
Indicate or Display:
Outdoor Unit : E. 28. 1
Indoor Unit
Error Code
Detective details:
When none of the connected indoor units answers during auto address
And when abnormal answer signal is input.
: No Display
: 28
04-39