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What’s a ground fault circuit interrupter?

October 11, 2022 | Terry Zank | how does that work, safety
A ground fault circuit interrupter on an electrical outlet in a kitchen.

What is it?

A ground fault circuit interrupter (GFCI) is a device installed in certain electrical sockets of homes and other buildings to prevent someone from receiving an electrical shock.

A GFCI outlet monitors the amount of electricity going to a device. If there is an interruption in the current – e.g., an appliance dropped in water – the GFCI detects the interruption in the current and the power is cut within 1/30th of a second.

Generally, the National Electric Code calls for GFCI’s to be installed in places where electricity could accidentally make contact with water.

Where are they?

In the home, that includes kitchens and bathrooms – near sinks, showers and bathtubs – as well as laundry rooms, unfinished basements, crawl spaces, garages and outdoors.

GFCI’s have a test button and a reset button. If a GFCI “trips” or interrupts power on a circuit, the reset button will pop out. When that happens, the homeowner should determine the cause, resolve the problem and then push the reset button.

Sometimes, you may need to bring in a licensed electrician to troubleshoot and repair the issue. This is important, because GFCI’s can prevent serious injuries and save lives.

According to the Energy Education Council, homeowners should test GFCI’s monthly to make sure they are working properly. Pushing the test button should cause the device to cut power to the circuit.

To test a GFCI, press the reset button, and then plug in a simple electrical device, such as a lamp. The device should turn on. Then press the test button. If the GFCI works, the device will turn off.

If the GFCI does not work, the device will remain on. In that instance, the GFCI may have been improperly installed or is malfunctioning. Thus, it will not protect you from shocks. In such cases, you should replace the GFCI or contact a licensed electrician.

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About Terry Zank

Terry Zank is a contributor to The Wire and senior digital channel specialist at OPPD, where he has worked for 30 years. He and his wife have three sons. Terry enjoys bike riding, playing racquetball, hiking, watching college football, watching great movies from years’ past, and citing quotes from those movies, much to his family’s chagrin.

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