AFCI (Arc Fault Circuit Interrupter) event

What does 801 mean?

The Fronius Primo GEN24 208-240 inverter's Arc Fault Circuit Interrupter (AFCI) has detected a dangerous electrical arc in the PV array. This is a critical safety feature that shuts down the inverter to prevent fire hazards.

• AFCI event (arc fault).
• Loose connections in PV array.
• Damaged cables or connectors in PV array.
• Faulty PV module junction box.
• Rodent damage to PV cables.

Click steps to track your progress.

1. 1

   Immediately disconnect the PV arrays using the DC disconnector and the AC breaker, then perform a thorough visual inspection of the entire PV array wiring.

2. 2

   Systematically check all PV module connectors (MC4), string combiner box terminals, and DC cable connections for tightness, signs of arcing, melting, or corrosion.

3. 3

   Inspect all DC cables for physical damage, insulation breakdown, rodent damage, or pinched sections.

4. 4

   Examine the junction boxes on the back of each PV module for signs of internal arcing or moisture ingress.

5. 5

   If the fault location cannot be identified visually, use specialized arc fault detection equipment or systematically isolate strings/modules for testing. Contact qualified PV service personnel.