Most inverter error codes are performance issues — inconvenient, but not dangerous. An arc fault error is different. It’s a safety detection, built into your inverter specifically to catch a condition that can start an electrical fire. If your system has flagged an arc fault, it deserves a faster response than a typical production drop.

What an Arc Fault Actually Is

An arc fault occurs when electrical current jumps across a gap it isn’t supposed to — through a damaged wire, a loose or corroded connector, or degraded insulation — instead of flowing through the intended conductor path. That arc generates intense, localized heat, which is exactly the mechanism behind a large share of solar-related electrical fires. Since 2011, the National Electrical Code (NFPA 70, Article 690.11) has required arc-fault circuit interrupter (AFCI) protection on rooftop DC PV circuits specifically because of this risk.

What Causes Arc Faults in Solar Systems

  • Damaged or chafed wiring — insulation worn through by rubbing against a roof surface, mounting hardware, or conduit edge
  • Loose or corroded connectors at panel, junction box, or combiner connections
  • Rodent damage to cabling in attics or under panels
  • UV degradation of exposed cable insulation over many years
  • Improperly seated MC4 connectors from installation or previous service work

Notably, wiring that runs across or touches the roof surface directly is a common contributor — the constant friction, heat cycling, and UV exposure accelerate insulation wear in exactly the way that leads to arcing. We cover this specific issue in detail in Wires Touching Your Roof: Fire Risk & Fix Options.

Why an Arc Fault Code Should Not Be Ignored

Unlike a communication fault or a grid voltage code, which are inconveniences, an arc fault has already been detected by the system’s built-in AFCI protection — meaning a genuine arc condition existed at some point. Continuing to operate the system without inspection risks:

  • Recurrence of the same fault, potentially without the inverter safely detecting and clearing it next time
  • Progressive wire damage that eventually causes a permanent fault or fire
  • In rare but documented cases, rooftop fires originating from DC-side PV wiring faults

What to Do If You See an Arc Fault Code

  1. Note the exact code and when it appeared — this helps a technician isolate the likely location
  2. Don’t reset and ignore it repeatedly — a fault that clears and returns is not resolved, it’s recurring
  3. Schedule a diagnostic inspection — a technician will trace the DC circuit, inspect connectors and cable runs, and identify the exact fault location, often using specialized arc fault locating equipment
  4. Address the root cause, not just the symptom — replacing a connector without checking for compromised wiring elsewhere on the same string risks a repeat fault

Related Reading

Get an Arc Fault Diagnosed Promptly

ElectriCare treats arc fault codes as priority service calls. Our technicians locate the fault, inspect the full circuit for related damage, and repair or replace affected wiring and connectors to code.

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Sources & Further Reading