Internal Fault

What does EEF mean?

This fault indicates an internal hardware failure within the drive controller itself. It is a critical error preventing normal operation and typically points to a component malfunction that cannot be resolved through software or external adjustments.

• Failure of a critical internal component (e.g., power supply, ADC, CPU) due to aging or manufacturing defect.
• Persistent overheating causing degradation of electronic components over time.
• Damage from electrical transients (e.g., voltage spikes, lightning) bypassing input protection.
• Contamination (e.g., metal dust, moisture) causing short circuits on internal circuit boards.
• Corrupted non-volatile memory (EEPROM) preventing proper drive initialization.

Click steps to track your progress.

1. 1

   1. Cycle drive power (turn off, wait 30 seconds, turn on) to attempt to clear transient hardware states.

2. 2

   2. Visually inspect the drive's internal circuit boards for signs of burned components, swollen capacitors, or carbon tracking (power off).

3. 3

   3. Verify the integrity of the incoming line voltage (phases A, B, C to ground) for spikes or sags using a power quality analyzer.

4. 4

   4. Perform a factory reset (e.g., Parameter P9-01 = 1) to eliminate potential software-related issues or corrupted data.

5. 5

   5. Measure the internal DC bus voltage (if accessible and safe to do so) to confirm proper internal power supply operation.