Polarity of DC strings reversed

What does 311 mean?

This code indicates that the polarity of one or more DC strings connected to the inverter has been reversed. This is a critical wiring error that causes a short-term interruption in energy feeding, preventing proper operation and potentially damaging the inverter.

• Incorrect wiring of the DC input from the PV modules, reversing positive and negative terminals.
• Misconnection of PV strings during installation or maintenance.

Click steps to track your progress.

1. 1

   If the status code is displayed continuously, notify a Fronius-trained service engineer.

2. 2

   Carefully check the polarity of all DC strings connected to the inverter and correct any reversed connections.

3. 3

   Before reconnecting, verify DC string polarity using a multimeter.