Fujitsu AB F18LAT Series Service Instruction page 53

Trouble shooting 20
OUTDOOR UNIT Error Method:
Excessive high pressure protection
Detective Actuators:
Outdoor Unit Main PCB Circuit
Outdoor Fan Motor
Heat Exchanger Temp. Thermistor (Middle)
Outdoor unit Electronic Expansion Valve
Forecast of Cause :
1. Defective connection of electric components 2. Outdoor Fan Operation failure
3. Outdoor Heat Exchanger clogged
Check Point 1 : 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 2 : Check Outdoor Fan, Heat Exchanger
Is there anything obstructing the air distribution circuit?
Is there any clogging of Outdoor Heat Exchanger?
Is the Fan rotating by hand when operation is off ?
>> If the Fan Motor is locked, replace it.
OK
Check Point 3 : Check Outdoor Fan
Check Outdoor Fan Motor. (Refer to Trouble shooting 17)
>> If the Fan Motor is failure, replace it.
OK OK
Check Point 4 : Check Thermistor (middle)
Check Thermistor (middle). (Refer to Trouble shooting 24)
>> If the Thermistor (middle) is failure, replace it.
OK OK
Check Point 5 : Check Electronic Expansion Valve
Check EEV. (PARTS INFORMATION 3)
OK OK
Check Point 6 : Replace Main PCB
If Check Point 1 5 do not improve the symptom, change Main PCB.
Indicate or Display:
Outdoor Unit : No indication
ERROR CODE : E : 24
on cooling
Detective details:
Excessive high pressure protection on cooling mode has been
activated.
4. Thermistor failure
is loose.
5. EEV failure
02-22
6. Main PCB failure