Fujitsu AB F18LAT Series Service Instruction page 49

Trouble shooting 15
OUTDOOR UNIT Error Method:
CT error
Detective Actuators:
Outdoor Unit Main PCB Circuit
Outdoor Unit Filter PCB Circuit
(Input current sensor unit)
Forecast of Cause :
1. Defective connection of electric components 2. External cause 3. Main PCB failure
Check Point 1-1 : Reset Power Supply and operate
Does Error indication show again?
YES
Check Point 2 :
Check connections of Outdoor Unit Electrical Components
Check if
the terminal connection
Check if connector is removed.
Check erroneous connection.
Check if cable is open.
>>Upon correcting the removed connector or mis-wiring,
reset the power.
OK
Check Point 3 : Replace Main PCB
If Check Point 1, 2 do not improve the symptom, change Main PCB.
Indicate or Display:
Outdoor Unit : LED 2sec ON/ 2sec OFF
ERROR CODE : E : 18
Detective details:
When Input Current Sensor has detected 0A, while Inverter Compressor is
operating at higher than 56Hz, after 1minute upon starting the Compressor.
(Except during the defrost operation)
is loose.
NO
Check Point 1-2 :
Check external cause at Indoor and Outdoor
(Voltage drop or Noise)
Instant drop : Check if there is a large load electric
Momentary power failure : Check if there is a defective
Noise : Check if there is any equipment causing harmonic
wave near electric line.(Neon bulb or electric
equipment that may cause harmonic wave)
Check the complete insulation of grounding.
02-18
apparatus in the same circuit.
contact or leak current in the
power supply circuit.