Shock vs. Overcurrent Protection
Both devices provide electrical safety protection for a home, but in different ways. A circuit breaker is designed to cut off the electricity to a circuit when the current flow (amperage) exceeds the rating for the wires it serves. High current flow through wires that don’t have a large enough cross-section to handle it will overheat and can start a fire. The breaker trips when the amps exceed the number printed on the switch. So breakers are primarily for fire protection.
Ground-Fault-Circuit-Interrupter receptacles provide shock protection for the occupants of a home and are required in the wet areas, such as kitchen, bathrooms, garage, and exterior locations. They measure the amount of current leaving the receptacle and compare it with the current flow returning. If some of the electricity is leaking out of the circuit (a ground fault), the GFCI device in the receptacle trips within 25 milli-seconds.
Although the current might leave the circuit through multiple different routes, it is also possible that it is flowing through a human body to the ground. Because water is an electrical conductor, and wet areas of the home have the highest likelihood of providing a connection to ground for someone in contact with an electrically “live” surface, they are where GFCIs are required.
There is also a device that looks like a GFCI receptacle, but without the slots to plug in a cord. One is shown at the left side of the photo at the top of the page. It’s called a “dead front GFCI.”
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Here’s links to a collection of our other blog posts about AFCI and GFCI RECEPTACLES AND CIRCUIT BREAKERS:
• Does a septic pump or sump pump require a GFCI-receptacle?
• How can I troubleshoot a dead receptacle outlet?
• What is the difference between what trips a GFCI (ground fault) receptacle and a circuit breaker?
• Are Ground Fault Circuit Interrupters (GFCIs) really necessary and worth the trouble?
• What is the code requirement for GFCI protection for receptacles near a wet bar sink?
• When was GFCI-protection for kitchen dishwasher receptacle outlet first required?
• When did arc fault circuit interrupter (AFCI) breakers first become required?
• Does a washing machine receptacle outlet require GFCI protection?
• My spa tub stopped working. What's wrong?
• How do I identify a combination AFCI (CAFCI) circuit breaker?
• What does "listed and labeled" mean for an electrical component?
• What electrical hazards does a Ground Fault Circuit Interrupter (GFCI) NOT protect against?
• What is the difference between GFCI and AFCI circuit breakers?
• Where are GFCI receptacle outlets required?
• When were GFCI receptacle outlets first required?
• What happens when you press the "TEST" button on a circuit breaker in an electric panel?
• What is the difference between the electric service to a mobile home and a site built home?
• Why is there a wall switch next to the furnace or indoor unit of the air conditioner in the garage?
• What is a Dual Function Circuit Interrupter (DFCI)?
• How I can tell if a receptacle outlet is tamper resistant?
• What is the difference between a Combination Arc Fault Circuit Interrupter (CAFCI) and an Arc Fault Circuit Interrupter (AFCI) circuit breaker?
• What is the difference between "grounded" and "grounding" electrical conductors?
• What does it mean when a wire is "overstripped" at a circuit breaker?
• Why is there a GFCI breaker in the electric panel for the bathroom shower light and exhaust fan?
• What is the switch on the wall with two pushbuttons?
• How far apart should kitchen counter receptacles be spaced?
• How far above a kitchen countertop do electrical outlets have to be?
• How is it possible to provide both GFCI (Ground Fault Circuit Interrupter) and CAFCI (Combination Arc Fault Circuit Interrupter) protection for kitchen and laundry circuits?
• My bathroom electric receptacle/outlet is dead and there are no tripped breakers in the electric panel. What's wrong?
• My GFCI reset button is hard to push and won't reset. What's wrong?
• Why do some breakers in my electric panel have a "TEST" button on them?
Visit our ELECTRICAL page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.