What is the purpose of an AFCI?

• A. To monitor GFCI operation.
• B. To detect arcing faults and interrupt to prevent electrical fires.
• C. To regulate power factor in circuits.
• D. To protect against short circuits by opening on overcurrent.

Answer: (B)

Arcing faults are a leading cause of electrical fires, so AFCIs are designed to prevent those fires by watching for the distinctive electrical signature an arc makes. An AFCI continuously monitors a circuit and, when it detects an arc—whether it’s a loose connection, damaged insulation, or worn conductors—it trips the breaker to interrupt power. This stops the heat generated by the arc from damaging wires and starting a fire.

This is different from a GFCI, which protects against shock by sensing ground faults, not arcing. It’s not about regulating power factor, which relates to how efficiently a circuit uses voltage and current. And while some AFCIs can provide overcurrent protection as part of their function, their primary purpose is arc-fault detection and interruption to improve fire safety.