Fujitsu ACUH09LUAS1, Service Manual

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3-2. Outdoor unit—No power
Forecast of cause
Power supply failure
External cause
Electrical components defective
Check point 1. Check installation condition
• Is the circuit breaker on or off?
• Check loose or removed connection cable.
If abnormal condition is found, correct it by referring to the installation manual or the “DESIGN &
TECHNICAL MANUAL”.
Check point 2. 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 in the power sup-
ply circuit.
• 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.
Check point 3. Check electrical components
Check the voltage of power supply.
Check if AC 187 to 253 V appears at outdoor unit terminal L — N
If no, go to "Check point 1" and "Check point 2" .
+
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• Check fuse in main PCB.
If fuse is open, check if the wiring between terminal and main PCB is loose, and replace fuse.
• Check varistor in main PCB.
If varistor is defective, there is a possibility of an abnormal power supply. Check the correct
power supply and replace varistor.
Upon checking the normal power supply, replace varistor.
Check point 4. Replace main PCB
If check point 1 to 3 do not improve the symptom, change main PCB.
End
3-2. Outdoor unit—No power
- (03-38) -
3. Troubleshooting without error code
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