Fujitsu General AOHG45KRTA, Service Manual, Page: 71 / 154

2-26. E: AC. Heat sink temperature error (Outdoor unit)
Indicator
Wired remote
controller
Error code E: AC
Detective actuator
Outdoor unit inverter PCB
Protection stop by heat sink temperature ≥ 80 °C during
heat sink operation generated 2 times within 24 hours.
Heat sink temperature thermistor
Forecast of cause
Foreign matter on heat sink, heat sink dirty
Foreign matter on heat exchanger, excessive ambient
temperature rise
Heat sink temp. thermistor defective
Check point 1. Check the heat sink state
Heat sink foreign matter, soiling check
↓
Check point 2. Check the foreign matter and ambient temperature of heat exchanger
• Heat exchange foreign matter check
• Ambient temperature not raised by effect of other heat sources?
• Discharged air not sucked in?
↓
Check point 3. Check the heat sink temperature thermistor
The heat sink temperature thermistor characteristics check. (Check by disconnecting thermistor
from PCB.)
NOTE: For the characteristics of the thermistor, refer to "Thermistor resistance values" on page
03-52.
↓
Check point 4. Replace inverter PCB
Replace inverter PCB
↓
End
2-26. E: AC. Heat sink temperature error (Outdoor unit)
- (03-35) -
2. Troubleshooting with error code
TROUBLESHOOTING TROUBLESHOOTING