Event 401 or 404 — Grid fault, frequency fluctuation

What does 401, 404 mean?

The inverter has disconnected from the utility grid because it detected a stand-alone grid or a very large, short-term change in the power frequency. This is a protective measure to ensure grid stability and safety.

• Detection of a stand-alone grid (islanding).
• Significant short-term frequency fluctuations in the grid connection.

Click steps to track your progress.

1. 1

   Check the grid connection for any significant short-term frequency fluctuations.

2. 2

   If frequency fluctuations are observed frequently, contact your grid operator for assessment.

3. 3

   If the issue persists without clear grid frequency problems, contact SMA Service.