Fujitsu AOYG09KHCAN, Service Manual

Page: 65 / 128

3-2. Outdoor unit—No power
Forecast of cause
Power supply failure
External cause
Electrical components defective
Check point 1. Check installation condition
• Isn’t the breaker down?
• 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" .
+
-
↓
• 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
- (03-29) -
3. Troubleshooting without error code
TROUBLESHOOTING TROUBLESHOOTING