E41
Inverter Power Transistor Overheat
Mitsubishi Electric · FR-D700 Inverter
What does E41 mean?
The power transistor for the inverter has overheated, indicating excessive heat generation, potentially due to a fault or overload condition. This poses a risk to the inverter module's longevity.
Common Causes
- Inverter power transistor (IGBT) has overheated.
- Insufficient cooling for the inverter module.
- Overcurrent condition causing excessive heat.
- Faulty heatsink or fan for the inverter.
- High ambient temperature impacting inverter operation.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Inspect the inverter unit's heatsink for dust accumulation and ensure proper ventilation clearances.
- 2
Verify the outdoor fan operation is providing adequate cooling to the inverter components, checking fan speed and direction.
- 3
Measure the current draw of the compressor and compare to specification, checking for overload conditions.
- 4
Check for loose electrical connections within the inverter module's power circuit.
Verified technical data. Last updated: March 2026
Related Faults
Source: Mitsubishi Electric FR-D700 Inverter