309

DC input voltage MPPT 1 too high

Fronius · Symo Advanced Manual

What does 309 mean?

The DC input voltage on Maximum Power Point (MPP) tracker 1 has exceeded its maximum permissible limit. This indicates an overvoltage condition on the specific solar string connected to MPPT1.

Common Causes

  • Overvoltage from the solar array connected to MPPT1
  • Incorrect sizing or configuration of the solar string for MPPT1

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    If this status code keeps recurring, contact your system engineer for diagnosis.

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Verified technical data. Last updated: March 2026

Related Faults

307DC low DC input voltage too low for feeding energy into the grid102AC voltage too high401No communication possible with the power stage set
Source: Fronius Symo Advanced Manual
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Fronius Error 309: DC input voltage MPPT 1 too high — Troubleshooting Guide | ErrorLib