Fronius Inverters Shut Down and Restart

Fronius Primo/Symo Series

Restarting your inverter can often resolve WiFi dropouts, communication issues, or minor system faults. It’s important to follow the correct shutdown and start-up sequence to keep your system safe and operating properly.

Before you begin

• Make sure it’s daytime — the inverter needs sunlight from the panels to power up correctly.
• If your system includes a battery or backup unit (such as a GEN24 Plus), confirm that no backup operation is currently running.
• Avoid restarting the system during lightning storms or if any components appear damaged.

1. Turn off the AC supply

• Find the Solar Inverter Main Switch or AC isolator (usually near your switchboard) and switch it OFF.

2. Turn off the DC isolator(s)

• These are located beside or below the inverter and labelled PV Array DC Isolator.
• Switch them OFF.

3. Wait 1–2 minutes

• Allow the inverter to fully power down — the display and all lights should go out.

4. Turn the DC isolator(s) back ON

• Switch the DC isolator(s) to the ON position.

5. Turn the AC supply back ON

• Switch the Solar Inverter Main Switch or AC isolator back ON.

6. Allow the inverter to restart

• The display should show normal startup messages, and the green LED will illuminate once the system is generating.
• If your inverter uses WiFi, a solid blue light indicates a successful connection.

Fronius GEN24 and GEN24 Plus Series

1. Turn off the AC power

• Locate the inverter’s AC isolator or main switch near your switchboard and switch it OFF.

2. Turn off the DC isolator

• Find the DC isolator beneath or beside the inverter and turn it OFF.

3. Wait 1–2 minutes

• Allow the inverter to shut down fully — the LED ring and display should go completely dark.

4. Turn the DC isolator back ON

• Switch the DC isolator ON and wait a few seconds.

5. Turn the AC isolator back ON

• Switch the AC isolator ON.

6. Let the inverter reboot

• The LEDs will flash while the unit starts up.
• A solid green light means it’s operating normally, and a solid blue light confirms the WiFi connection is established.

7. Check Solar.web monitoring

• Log in to Solar.web to ensure system data is updating as expected.

Fronius Tips

• After a firmware update or communication changes, give the inverter up to 5 minutes to reconnect to Solar.web.
• If a fault code appears after restarting, take note of the error before attempting another power cycle.
• If you need to restart the inverter repeatedly, it may indicate a deeper issue — contact your installer or Fronius Support for help.