Applicable Systems
MELSEC FX3U
MELSEC FX5U
FR-A800
FR-A700
MR-J4
iQ-R Motion Controller (R32MTCPU/R16MTCPU)
Symptoms
The drive trips and the panel displays E.FIN, indicating heatsink overheat. The temperature sensor on the power module heatsink has exceeded the thermal trip threshold, causing the drive to shut down to protect the IGBT modules.
Possible Causes
- Ambient temperature inside the panel exceeds the rated 40-50C
- Cooling fan is stopped or running at reduced speed due to failure or aging
- Heatsink fins are blocked by dust or debris reducing cooling efficiency
- Drive is operating at sustained high current near its rated limit
Troubleshooting Steps
- Step 1: Check the ambient temperature inside the electrical panel
Temperature should be below 45C; if above, improve ventilation or install air conditioning - Step 2: Verify the cooling fan is running at full speed
Fan should spin freely without noise; replace if seized, noisy, or running slow - Step 3: Clean the heatsink fins using compressed air or a brush
Fins should be clear of dust; shine a light through to verify airflow passage - Step 4: Measure the drive output current during operation
If current is consistently above 90% of rated, consider a larger drive or reduce the load
How to Reset
To reset: 1) Allow the drive to cool for at least 10 minutes. 2) Fix the cooling issue. 3) Press STOP/RESET. 4) Restart. Caution: Do not immediately reset without allowing the heatsink to cool, as the IGBT junction temperature may still be high.
Common Replacement Parts
- R60BZ-FAN: FR-A800 cooling fan assembly (Match to drive frame size; verify airflow direction before installation)
Frequently Asked Questions
- Q: How often should I clean the heatsink?
In a typical factory environment, inspect every 6 months and clean as needed. In dusty environments, inspect monthly. Clogged heatsinks are the leading cause of E.FIN and premature IGBT failure.
- Q: What is the E.FIN trip temperature?
The heatsink overheat trip occurs at approximately 110-120C (varies by model). A warning is issued at a lower threshold, typically around 90C, giving time to act before a trip.
Source: Mitsubishi FR-A800 Instruction Manual (Functions), 2024
Category: PLC & VFD