303

DC module overtemperature (PV)

Fronius · Solar Energy

What does 303 mean?

An overtemperature condition has been detected in the DC module associated with the PV system. This causes a short-term interruption in grid feed-in as the inverter attempts to restart its operation.

Common Causes

  • Excessively high ambient temperatures around the PV DC module
  • Obstructed cooling air openings for the PV DC module
  • Accumulation of dirt or debris on the PV DC module's heat sink

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Purge any obstructions from the cooling air openings of the PV DC module

  2. 2

    Clean the heat sink of the PV DC module to improve cooling

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Verified technical data. Last updated: March 2026

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