GFCI vs. AFCI: Differences and Uses

Electrical systems power nearly everything around us, but they also carry risks.

Fires and shocks can happen in seconds if circuits aren’t protected. That’s why codes often require devices like GFCIs and AFCIs.

If you’re exploring a career in the electrical industry, understanding the differences between GFCI vs. AFCI systems is key to developing an in-demand skill set. These devices help save lives, prevent damage and are a must-know for anyone training to enter the field.

For anyone preparing for the electrical field, understanding GFCI vs. AFCI is critical since these devices are required for safety. You can practice working with them in any of the programs within the electrical training suite at Universal Technical Institute (UTI), where you can build an in-demand career skillset from the ground up.¹³⁰

Stick with us to learn the differences, why they matter and how you can train to become an electrical pro yourself.

What Is a GFCI?

A ground fault circuit interrupter (GFCI) is designed to protect people from shock. It quickly shuts off power when it detects an imbalance between incoming and outgoing current.

Ground-fault protection and uses

When to use GFCI protection is easy to remember — anywhere water and electricity might meet. Bathrooms, kitchens, outdoor outlets and garages all require them. If current leaks through a person or water instead of the circuit, the GFCI trips instantly.

Testing and resetting

GFCIs have built-in “test” and “reset” buttons. Technicians learn to press the test button monthly to make sure it trips. If it doesn’t, it should be replaced. Resetting restores normal power after a trip.

Read: Fuse vs. Circuit Breaker: What’s the Difference?

What Is an AFCI?

An arc fault circuit interrupter (AFCI) prevents fires by detecting dangerous electrical arcs. Arcs are sparks that happen when wires or connections are damaged.

Arc-fault detection and uses

When to use AFCI protection is usually in living spaces like bedrooms, family rooms and hallways. Code requires them to keep cords, outlets and wires from overheating or sparking fires.

Combination breakers and outlets

Some devices combine arc fault protection with other features. Combination AFCIs can be installed in breaker panels or as outlets, offering flexible protection.

Read: Troubleshooting Electrical Systems: A Technician’s Guide

GFCI vs. AFCI: Side-by-Side Comparison

So what’s the real difference between GFCI and AFCI? Both protect people and property, but in different ways.

Protection type

GFCI:

A ground fault circuit interrupter (GFCI) protects people from electric shock by cutting power when current leaks outside the intended path. It reacts within milliseconds, making it ideal for protecting against hazards around water.

AFCI:

An arc fault circuit interrupter (AFCI) protects wiring and equipment from dangerous arcs that can spark fires. It doesn’t stop shocks directly but reduces the risk of electrical fires inside walls or outlets.

Typical locations

GFCI:

GFCIs are required by code in areas where water and electricity may meet. You can find them in kitchens, bathrooms, garages, basements, laundry rooms and outdoor outlets.

AFCI:

AFCIs are common in living spaces where wiring runs behind walls. They’re required in bedrooms, family rooms and other habitable areas to reduce the chance of hidden arc faults starting fires.

Installation tips

GFCI:

• Check polarity: Ensure line and load connections aren’t reversed.
• Test regularly: Use the test button monthly to confirm operation.
• Use proper enclosures: Outdoor GFCIs need weatherproof covers.
• Follow code: Verify placement matches NEC requirements.

AFCI:

• Use compatible panels: Confirm your breaker box supports AFCI breakers.
• Don’t mix neutrals: Each AFCI circuit must have a dedicated neutral.
• Label circuits clearly: Helps with troubleshooting later.
• Test after install: Use an AFCI tester to verify proper function.

Troubleshooting

GFCI:

• No reset after trip: Check for reversed line/load wiring.
• Repeated tripping: Look for moisture, damaged cords or faulty appliances.
• Test button doesn’t work: Device may be worn out and need replacement.
• Outlet has no power: Verify upstream GFCI isn’t tripped.

AFCI:

• Nuisance tripping: Often caused by vacuum cleaners, treadmills or older electronics.
• Breaker won’t reset: Inspect for shared neutrals or wiring errors.
• Multiple trips in short time: Could indicate damaged wires or poor connections.
• Tester shows failure: Replace faulty breaker or confirm with manufacturer guidance.

Common mistakes

GFCI:

• Mixing up line and load terminals: Causes the device to fail.
• Not using weatherproof covers outdoors: Leads to water damage and false trips.
• Failing to test monthly: Can mask a non-working device until it’s too late.
• Overloading downstream outlets: Creates confusion about which outlet controls what.

AFCI:

• Tying neutrals together: Interferes with proper operation.
• Installing in incompatible panels: Not all panels accept AFCI breakers.
• Ignoring code updates: AFCI requirements expand with each NEC cycle.
• Skipping a proper test: Relying only on reset function without using a tester.

Read: Series vs. Parallel Circuits: What Future Electrical Technicians Need to Know

Code Basics Every Pro Should Know

Staying code-compliant is essential for protecting people and equipment. It also prepares you to get qualified and meet industry safety standards.

Residential spaces

GFCI:

Homes often require GFCI protection in kitchens, bathrooms, laundry areas, garages, basements and outdoor outlets. These rules help reduce the risk of shock where water is likely to be present.

AFCI:

AFCIs are required in most living spaces such as bedrooms, family rooms and dens. They provide fire protection in places where wiring runs behind walls and could otherwise arc unnoticed.

Permits

GFCI:

Installing or replacing GFCI outlets often requires a permit. Local codes ensure devices are installed safely and by qualified professionals.

AFCI:

AFCI installations may also need permits, especially when adding breakers to panels. Permit rules verify compatibility with current code requirements.

Inspections

GFCI:

Inspectors test GFCIs to confirm proper wiring and tripping function. Outdoor installations are checked for weatherproof covers and labeling.

AFCI:

AFCI inspections confirm breakers function with an approved tester. Inspectors also check that wiring layouts follow NEC rules and panel standards.

Staying current

GFCI:

NEC updates often expand where GFCIs are required. Keeping up with changes ensures compliance and safer installations.

AFCI:

AFCI coverage grows with each code cycle, adding more room types. Staying informed helps avoid costly corrections after inspections.

Read: How to Read Electrical Schematics: A Technician’s Guide

Learning About GFCI vs. AFCI Systems

At Universal Technical Institute, students in any of the programs within the electrical training suite learn by doing. While enrolled, you can learn in-demand industry skills, including how to work with GFCI and AFCI devices.

Installation and testing

Hands-on electrical training gives students the chance to install and test real systems in a lab setting. By practicing on equipment used in the field, they can learn how to apply safety standards and confirm that devices work the way they should.

Career prep in one year or less

You can choose between four electrical training options — wind energy, robotics and automation, industrial maintenance or electronics.

Whichever field you decide to train for, you can practice this skill set in real lab settings and be ready for a career in one year or less.¹³⁰  Employers look for pros who can hit the ground running — and that’s what UTI prepares you to do after graduation.

Train To Learn About GFCI vs. AFCI systems!

Whether it’s learning the differences between GFCI vs. AFCI systems or wiring full panels, hands-on training can help you practice in-demand career skills. Choose from four electrical skills programs to start preparing to become the pro industries need today.

Ready to move forward? Enroll now. Click the button below or call 1-800-834-7308 to request more information.