Fujitsu AB F18LAT Series Service Instruction page 54

Trouble shooting 21
OUTDOOR UNIT Error Method:
INDOOR UNIT
PFC circuit error
Detective Actuators:
Outdoor Unit Main PCB Circuit
Forecast of Cause :
1. External cause 2. Connector connection failure 3. Main PCB failure
Check Point 1 : Check external cause at Indoor and Outdoor (Voltage drop or Noise)
Instant drop : Check if there is a large load electric apparatus in the same circuit.
Momentary power failure : Check if there is a defective contact or leak current
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.
OK OK
Check Point 2 : Check connection of Connector
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 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 : No indication
ERROR CODE : E : 25
Detective details:
When inverter output DC voltage is higher than 415V for over 3 seconds,
the compressor stops.
If the same operation is repeated 5 times, the compressor stops permanently.
in the power supply circuit.
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