AFCI (Arc Fault Circuit Interrupter) event
Fronius · Primo GEN24
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.
Common Causes
- 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.
Repair Steps & Checklist
Click steps to track your progress.
- 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
Systematically check all PV module connectors (MC4), string combiner box terminals, and DC cable connections for tightness, signs of arcing, melting, or corrosion.
- 3
Inspect all DC cables for physical damage, insulation breakdown, rodent damage, or pinched sections.
- 4
Examine the junction boxes on the back of each PV module for signs of internal arcing or moisture ingress.
- 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.