Underfrequency

What does LF mean?

This fault occurs when the frequency of the incoming mains power supply falls below the specified operating range. By default, this critical condition triggers a full TRIP, inhibiting all ignition pulses and resetting the Ready signal to prevent damage to the drive and motor that could result from operation at an incorrect frequency. Manual reset is required after the frequency stabilizes.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Check for overloaded generators: If the drive is powered by a local generator, ensure it is not overloaded or malfunctioning.

2. 4

   Inspect power distribution equipment: Check for issues in transformers or switchgear that could affect frequency.

3. 5

   Ensure frequency monitoring parameters are correctly set in the drive (if applicable).