Safety and work practicesQuestion 621 of 1506

What is the main job of an arc fault circuit interrupter (AFCI)?

To protect people from shock, in place of a GFCI
To open on arcing shorts that a normal breaker would miss
To limit the starting current of large motors
To open when the load is slightly above the breaker rating

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Correct answer: To open on arcing shorts that a normal breaker would miss

Arcing current can be too low to trip a standard breaker yet still start a fire. An AFCI does not protect against shock the way a GFCI does.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 3.8: Safe Circuit Design

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Questions last reviewed: 18 October 2026

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