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
Purge any obstructions from the cooling air openings of the PV DC module
- 2
Clean the heat sink of the PV DC module to improve cooling
Verified technical data. Last updated: March 2026
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Source: Fronius Solar Energy