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How Does a Ground Fault Circuit Breaker Work? – Explanation

Written by Edwin Jones / Fact checked by Andrew Wright

how does a ground fault circuit breaker work

If you were thinking, “How does a ground fault circuit breaker work?” maybe learning about them would help you know whether to upgrade your current circuit.

GFCI breakers protect the user from the risk of electrocution. However, switching to a GFCI circuit breaker is quite expensive. Alternatively, you can consider using a GFCI outlet to replace the traditional receptacle for additional safety.

Continue reading this article to learn about the different types of GFCI devices and how they work.

How Does a GFCI Work?


The GFCI circuit breaker works as a standard circuit breaker in your panel. It compares the power sent to and from appliances to detect any differences and reacts quickly to circuit overloads. However, this type of circuit breaker also has advanced features designed to detect a ground fault.

A ground fault occurs when a hot wire touches the ground wire and interacts with water or any sort of debris. In the event of a ground fault, the GFCI will immediately trip. This is the primary purpose of GFCI circuit breakers and GFCI outlets; they are there for a user’s protection.

In addition, installing a GFCI circuit and receptacles are now required by the NEC. It is important to keep in mind that local electrical codes also have requirements to follow to pass an electrical inspection, and this may include ground fault protection.

Always look for an electrical diagram when installing a GFCI circuit or hire a professional.

What are GFCI Devices?

Ground Fault Circuit Interrupter, often referred to as GFCI, is a device used to detect a ground fault that can cause electrocution or electrical shock. The GFCI is mainly installed in the bathroom, kitchen, or even garage. Usually, it is installed where the circuit can come in contact with water.

There are three types of GFCI devices: a circuit breaker, an outlet, and a portable GFCI. Though they’re used in different applications or installations, their function is all the same. Here is a short overview to learn more about these three types of GFCI.

1. GFCI Circuit Breaker Definition

A Ground Fault Breaker or GFCI circuit breaker is a special circuit breaker that protects the entire circuit. It means that all the receptacles currently linked to the circuit with the GFCI breaker have its protection.

However, its effectiveness comes at a cost—it is more expensive than a typical circuit breaker currently used in most residential places.

Aside from GFCI circuit breakers, there are also combined GFCI and AFCI circuit breakers. This breaker has the dual protection of GFCI operation and AFCI operation. This means it has the ability to detect both ground faults and arc faults somewhere in the electrical system.

Tips: You can use a GFCI outlet as an alternative for GFCI breakers if you want the same protection at a lower cost.

2. GFCI Outlet

A GFCI outlet is like an outlet that has a built-in circuit breaker inside. It is commonly used to replace a typical receptacle for additional protection. Unlike the GFCI circuit breaker that protects the entire circuit, the GFCI outlet protection is limited to a single area.

However, compared to resetting a GFCI circuit breaker, resetting a GFCI is more straightforward. With the GFCI outlet, it is a simple matter of pushing the reset button. For the GFCI circuit breaker, however, you need to go to the breaker box to reset it.

Tip: You can use multiple-location wiring to extend your GFCI features to other outlets. This video by Terry Peterman will explain how this works.

3. Portable GFCI

The Portable GFCI has the same feature as the GFCI outlet and circuit breaker. Many contractors use it as GFCI protection on their working sites.

It is quite affordable and can be plugged into an outlet or handheld equipment like saws. For outdoor use, there are portable GFCI products that are waterproof.


Now that you know how does a ground fault circuit breaker work, it will change how you look at your electrical system. You may want to change or upgrade your circuit breaker for additional safety.

Though it does provide excellent protection, upgrading your breaker or changing the receptacle to GFCI only makes sense when the circuit is near or associated with water.

Is there anything in the article that you’d like to know more about? Let me know what you think in the comments section below.

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