Applicable Systems
FC-30
FC-51
FC-101
FC-202
FC-302
Symptoms
The drive trips. The display shows Alarm 12, indicating drive overtemperature. The internal temperature sensor has detected that the drive heatsink temperature exceeds the safe limit.
Possible Causes
- Drive cooling fan failed or airflow blocked
- Ambient temperature exceeds drive rating
- Drive installed in an inadequately ventilated enclosure
- Drive operating at high duty cycle without sufficient cooling
Troubleshooting Steps
- Step 1: Check the drive cooling fan for operation
Fan is running and airflow is unobstructed - Step 2: Measure the ambient temperature inside the enclosure
Ambient temperature is within the drive rated range - Step 3: Inspect the drive heatsink for dust or debris blocking airflow
Heatsink is clean and air can flow freely - Step 4: Improve enclosure ventilation or reduce drive load if ambient is high
Drive temperature stays within safe limits
How to Reset
To reset: 1) Allow the drive to cool. 2) Fix the cooling issue (replace fan, clean heatsink, improve ventilation). 3) Press RESET. Caution: Repeated overtemperature trips damage drive power components permanently.
Frequently Asked Questions
- Q: How do I clean a Danfoss drive heatsink?
Power down the drive and wait for capacitors to discharge. Use low-pressure compressed air (max 3 bar) to blow dust from the heatsink fins. Do not use solvents or liquids.
- Q: What is the maximum ambient temperature for Danfoss drives?
Most Danfoss FC series drives are rated for ambient temperatures up to +45 or +50 deg C. Above this, output derating is required. Check the design guide for the specific model.
Source: Danfoss VLT FC-101 Design Guide, 2023
Category: PLC & VFD