731 Initialization error – USB stick is not supported - Incompatible USB stick.

What does 731 mean?

A warning message indicates that the inserted USB stick is not supported by the inverter. This can happen if the USB stick's format or type is incompatible with the device.

• The USB stick is not formatted correctly.
• Uses an unsupported file system.
• Is not compatible with the inverter.

Click steps to track your progress.

1. 1

   Remove the current USB stick from the inverter.

2. 2

   Insert a different, known-compatible USB stick into the inverter.

3. 3

   Check the file system of the USB stick (e.g., FAT32 is common). If the code persists, contact a Fronius-trained service technician.