FN
Fan fault
Mitsubishi Electric · A500 Inverter
What does FN mean?
For inverters equipped with a cooling fan, this alarm appears on the operation panel when the cooling fan stops due to a fault or operates inconsistently with the setting of Pr. 244 "cooling fan operation selection". This indicates a problem with the inverter's active cooling system.
Common Causes
- Indoor or outdoor unit fan motor failure or obstruction.
- Fan speed sensor not reporting correct RPM (P1-32).
- Loose fan belt or coupling.
- Fan motor overload or internal winding fault.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Visually inspect the cooling fan for obstructions, debris, or physical damage.
- 2
Verify the cooling fan's electrical connections are secure.
- 3
Check the setting of Pr. 244 (cooling fan operation selection) to ensure it is configured correctly for the application.
Verified technical data. Last updated: March 2026
Related Faults
Source: Mitsubishi Electric A500 Inverter