Modern electrical systems have features like circuit breakers that are designed to make the system much safer. While circuit breakers are extremely useful, they can protect only against electrical overloads, not another dangerous issue known as a ground fault. This is why having GFCI (ground fault circuit interrupter) outlets in some places in a home is also essential. Learn more about what a ground fault is and how it can improve your home’s safety.
What Is a Ground Fault?
A ground fault is a specific electrical issue that occurs due to electricity escaping an outlet or device and taking a different path — such as a person — that allows the current to flow to the ground. Electricity will always naturally try to flow to the ground through whatever path offers the least resistance.
This normally isn’t an issue, as any electrical circuit is a closed loop, so the current can’t escape. Instead, the current flows out of the electrical panel through the ground wire that supplies power to each outlet, light, or other device. The current then continues flowing back to the panel through the neutral wire.
A problem arises if you have something like a damaged, bare wire in an appliance, power tool or other electronic device that comes into contact with anything metal. When this happens, the current can then escape the circuit and flow into the metal object, electrifying it. This can also happen if water comes into contact with a live wire, as the water can then conduct the electricity into any metal objects nearby. If a person touched the metal object, the current would then flow through them since their body allowed it a direct, low-resistance path to the ground. That means they’d be severely shocked if not fatally electrocuted.
How a GFCI Protects Against Ground Faults
GFCI outlets have an internal breaker that can shut off the power to the outlet if a ground fault occurs. Consider the scenario we just discussed, in which you have a device with a damaged cord that touches something metal. When this happens, the metal essentially becomes part of the circuit. That means the amperage of the current flowing through the outlet’s live wire and the amperage flowing through the neutral wire remain the same. However, if someone then touched the metal and caused a ground fault, the amount of current flowing back out through the neutral wire would instantly decrease. That’s because at least some of the current flowing into the outlet would escape and flow through the person instead of back into the neutral wire.
GFCIs work by measuring the current flowing into and back out of the outlet. When there’s even a tiny drop in the current flowing back out, the internal breaker instantly trips and blocks the power from continuing to flow. The breaker in a GFCI outlet is so sensitive that it will trip when the outgoing current drops by 5 milliamps. It also takes less than 1/40th of a second from when the ground fault occurs until the breaker trips.
If 5 milliamps of electricity flow through a person, all they’ll feel is a minor shock. It usually takes at least 50 milliamps to fatally electrocute a person, which is why GFCIs are so effective at preventing electrocution. In fact, GFCIs work so well that there has been more than a 90% decrease in electrocutions from consumer electronic devices since they were first required.
Which Outlets in a Home Should Be GFCIs?
The National Electric Code requirement for GFCI outlets in homes has been updated numerous times since the outlets were first introduced in the 1970s. At first, they were required only in places that were within 5 feet of a source of water, in areas that could flood or in outlets that could potentially get wet. That meant they were mainly required in outlets next to kitchen and bathroom sinks along with all outlets in a basement or garage or outside. The most recent code requires GFCIs to be used in every outlet in a kitchen and bathroom. They’re also required for all outlets in a laundry room or utility room.
Unless you’re renovating any area where GFCI outlets are now required, there is no legal requirement for you to upgrade your old outlets with GFCIs. Nonetheless, it is well worth upgrading to GFCIs in all of these places since it will help keep everyone in your household much safer.
The other option is to install GFCI breakers for the circuits that supply power to your kitchen, bathroom, laundry room, etc. A GFCI breaker works just like a GFCI outlet. The only difference is that the breaker protects the entire circuit instead of just at an outlet. That means if a ground fault occurs in any part of the circuit, the power to the entire circuit will be shut off.
The Importance of Regularly Testing GFCI Outlets
As with most things, GFCI outlets aren’t failproof. The internal breaker in the outlet can end up breaking or getting stuck and no longer being able to trip in the event of a ground fault. That’s why you need to make sure you test each GFCI outlet in your home every month so that you can be certain they all still work like they’re supposed to. It shouldn’t take all that long to test all of your outlets, and it’s definitely worth taking the time to ensure that they’re safe.
All GFCI outlets and GFCI circuit breakers have a Test button and a Reset button on them. Pressing the test button trips the breaker and opens the circuit. The breaker should then close so power again starts flowing to the outlet when you press the reset button. It’s always best to test a GFCI outlet under load, meaning with something plugged into it. That way, you can make sure the breaker actually trips and shuts the power off when you press the test button. If the outlet still has power after you press the test button, it means the breaker isn’t working. If that happens, don’t use that outlet until an electrician replaces it.
Most GFCI outlets also have an LED light that is green when the outlet is on. If the outlet trips, or you trip it manually by pressing the test button, the light should either turn off or change to red. Most newer GFCI outlets have a self-test feature that tests the breaker a few times a minute. If the test fails, the LED will also usually turn to solid red or start flashing red. However, the self-test feature also doesn’t always work as it should. That means you still need to manually test the outlet each month.
Since 1996, John Henry's Plumbing, Heating, Air, and Electrical has been the company to trust for electrical, plumbing and HVAC services in Lincoln and Omaha, NE and the surrounding areas. Whether you need to install or replace any outlets in your home or are dealing with heating or AC issues, you can count on us to do the work correctly and for an honest price.
To schedule an appointment for whatever home service you need, including electrical inspection, contact our team at John Henry's Plumbing, Heating, Air, and Electrical today.
