"Ex-e protection" fault Stop with inhibit
SEW Eurodrive · MCBSM
What does 110 mean?
The duration of operation below 5 Hz has been exceeded, which is critical for "Ex-e protection" compliance in hazardous environments. Prolonged operation at low frequencies can lead to motor overheating in certain certified motors, potentially creating an ignition risk.
Common Causes
- Drive parameter P5-25 (Minimum Motor Frequency) set below 5 Hz or not enabled for Ex-e protection mode.
- Motor operating profile frequently demands speeds below the 5 Hz Ex-e protection threshold for extended durations (e.g., >30 seconds).
- Inadequate cooling of the motor at low speeds, leading to hotspot formation not detectable by standard sensors.
- Drive control logic error causing the motor to dwell below 5 Hz for extended periods due to improper programming.
- Motor is not certified for Ex-e operation at low frequencies, or the application exceeds its thermal limits at these speeds.
Repair Steps & Checklist
Click steps to track your progress.
- 1
1. Verify parameter P5-25 (Minimum Motor Frequency) is set correctly to enforce a minimum of 5 Hz for Ex-e motor protection.
- 2
2. Analyze the machine's operation profile to identify if sustained low-speed operation (below 5 Hz) is inherent and modify the process.
- 3
3. Check the motor cooling fan for proper operation and ensure all ventilation paths are clear and unobstructed.
- 4
4. Measure the motor winding resistance (e.g., U-V, V-W, W-U) to detect any imbalances or hotspots, comparing to nameplate data.
- 5
5. If the operating profile absolutely requires low speeds, confirm the motor is rated for 'Ex-e' with appropriate additional cooling or specific protection measures.