Arc-fault, ground-fault, dual-function, and equipment-protection circuit breakers may look similar, but they are designed to respond to different electrical hazards. Choosing the right one starts with understanding what each device detects—and what it does not.
This guide explains the differences among AFCI, GFCI, dual-function AFCI/GFCI, and ground-fault equipment-protection breakers so you can narrow your selection before confirming the exact part number.
Quick comparison
| Breaker type | Primary purpose | What it detects | Important distinction |
|---|---|---|---|
| AFCI | Reduce the risk of electrical fires | Electrical arcing patterns | Does not replace required Class A GFCI protection |
| GFCI | Personnel protection from electric shock | Small differences between outgoing and returning current | Class A devices commonly trip around 5 mA |
| Dual function | Arc-fault and personnel ground-fault protection | Both arcing and low-level ground faults | Combines AFCI and GFCI functions in one breaker |
| Equipment protection / GFEP | Protect equipment from damaging ground faults | Ground-fault leakage at a higher threshold | Often 30 mA and not intended as personnel GFCI protection |
What is an arc-fault circuit interrupter?
An arc-fault circuit interrupter (AFCI) is designed to recognize electrical arcing patterns and de-energize the circuit. Arcing can develop from damaged insulation, loose connections, pinched conductors, worn cords, or other wiring problems. Some arcs may not draw enough current to trip a conventional thermal-magnetic breaker quickly, even though they can create dangerous heat.
AFCI breakers are primarily associated with reducing fire risk. They still provide standard overcurrent protection, but their electronic sensing adds protection against qualifying arc-fault conditions.
Common AFCI terminology
- Combination-type AFCI: Designed to detect both series and parallel arc-fault conditions within its listed performance requirements.
- Branch/feeder AFCI: An earlier form of AFCI protection with more limited arc-fault coverage than combination-type devices.
- Plug-on-neutral AFCI: Connects directly to a compatible neutral bar and typically eliminates the breaker’s neutral pigtail.
- Pigtail AFCI: Uses a factory-installed white neutral lead that connects to the panel neutral bar.
What is a ground-fault circuit interrupter?
A ground-fault circuit interrupter (GFCI) monitors the current leaving and returning through a circuit. If the difference reaches the device’s trip threshold, the breaker opens the circuit.
Class A GFCI protection is intended to reduce the risk of serious electric shock. These devices are commonly identified by a TEST button and are used where the applicable electrical code requires personnel ground-fault protection.
A GFCI breaker can protect the wiring and connected outlets downstream of the breaker, provided the circuit is wired correctly. A GFCI receptacle protects from its installation point downstream when its load terminals are used correctly. The right format depends on the circuit, panel, equipment, and installation requirements.
What is a dual-function breaker?
A dual-function circuit breaker combines combination-type AFCI protection and Class A GFCI protection in one device. It can respond to qualifying arc faults as well as low-level ground faults associated with shock hazards.
Dual-function breakers are useful when a circuit requires both forms of protection. Using one breaker can simplify the panel and avoid the need to combine an AFCI breaker with a separate GFCI receptacle. However, the breaker still must be listed for the panel and match the circuit’s electrical requirements.
Do not confuse “dual function” with a two-pole breaker. Dual function describes the two protective functions—AFCI and GFCI—not the number of poles.
What is an equipment-protection breaker?
A ground-fault equipment-protection breaker, often identified as GFEP or equipment ground-fault protection, is intended to protect equipment from damaging line-to-ground leakage. Many commonly encountered equipment-protection breakers have a 30 mA trip sensitivity, although the marked rating on the specific breaker controls.
GFEP breakers are used in applications such as heating equipment, de-icing and snow-melting systems, heat tracing, HVAC equipment, pumps, and other loads when equipment-level ground-fault protection is specified.
A 30 mA equipment-protection breaker is not a substitute for a Class A personnel-protection GFCI. The two devices have different intended uses and trip thresholds. Always read the breaker markings and the equipment requirements before selecting one.
How to choose the correct breaker
Protection type is only one part of the selection. Before ordering, confirm all of the following:
- Panel manufacturer and series: Breakers are not universally interchangeable. Use only a breaker listed or classified for the specific panel.
- Protection required: Choose AFCI, Class A GFCI, dual function, or equipment protection based on the circuit and applicable requirements.
- Amperage: Match the breaker rating to the conductor, load, and circuit design.
- Voltage: Confirm the system and breaker voltage ratings.
- Number of poles: Determine whether the circuit requires a one-pole or common-trip two-pole breaker.
- Interrupting rating: The breaker’s AIC rating must meet the available fault-current requirements.
- Neutral connection: Confirm whether the panel and breaker use a neutral pigtail or a compatible plug-on-neutral design.
- Catalog number: For replacements, compare the full catalog number—not just the brand, amperage, or appearance.
Why does an AFCI or GFCI breaker trip?
A trip does not automatically mean the breaker is defective. Possible causes include a legitimate arc or ground fault, damaged insulation, moisture, shared or incorrectly connected neutrals, neutral-to-ground contact downstream, loose wiring, appliance leakage, or an incompatible installation.
Repeatedly resetting a breaker without identifying the cause can leave a hazardous condition unresolved. A qualified electrician should inspect a circuit that continues to trip.
Testing electronic-protection breakers
AFCI, GFCI, dual-function, and many equipment-protection breakers include a TEST button. Follow the manufacturer’s instructions and the testing interval marked on the device. If the breaker does not trip during the prescribed test, will not reset, or indicates an internal fault, have the circuit and breaker evaluated.
Find the right replacement at Breakers Now
Breakers Now carries arc-fault, ground-fault, dual-function, and equipment-protection circuit breakers from leading manufacturers. To identify a replacement, send us the complete catalog number and clear photographs of the breaker label and panel nameplate.
Shop AFCI, GFCI & Dual-Function Circuit Breakers or contact our team for help narrowing the selection.
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This article is a general product-selection guide and is not a substitute for an electrical design, code analysis, or field inspection. Requirements vary by application and jurisdiction. Circuit breakers should be selected and installed by qualified electrical professionals in accordance with the equipment listing, manufacturer instructions, and applicable electrical codes.