Have you ever been using a blow dryer only to have the buttons on the dryer plug to trip, shutting off the dryer? You didn’t overload the circuit. The safety plug on your hair dryer protected you from an electric shock caused by a ground fault–electricity that escapes the confines of the wiring and seeks to ground elsewhere. Because water is an excellent conductor of electricity, ground faults are particularly dangerous in wet areas like the bathroom.
The buttons on your hair dryer plug are ground fault interrupters that cut power if/when it short circuits. To prevent shock from ground faults, some outlets also have ground fault interrupters.
In this blog, we discuss ground faults (which cause shock), arc faults (which cause fire), and the outlets and breakers that protect against them.
1. Ground Faults Cause Electric Shock
Ground faults are caused by loose or deteriorating wires, faulty appliances, or power tools. A ground fault is a short circuit that occurs when electric current travels outside electric wire and seeks a grounding path outside the established wiring. When electric current leaves the circuit, the pathway to ground is unrestricted, which causes sudden increase in current. The surge overloads the circuit breaker, which trips to cut the flow of current. Ground faults are dangerous because they can cause injuries and death from electric shock.
Because circuit breakers don’t cut power quickly enough to prevent shock, national electric code requires GFI or GFCI switch at either the outlet or the panel for all damp/wet areas which is where ground faults are most likely to occur
2. GFI and GFCI Protect Against Electric Shock
A ground fault circuit interrupter (GFCI) is a protective switch at the electric panel that protects multiple circuits. When a GFCI detects imbalances in electric current, it quickly cuts power to all the circuits it is protecting. A ground fault interrupter (GFI) is basically the same as a GFCI except that it protects an individual circuit at the outlet. If there is an imbalance in current, only that one circuit will lose power.
The terms GFI and GFCI are used interchangeably, although technically, a GFI is a switch on the electric outlet whereas a GFCI is a switch on the electric panel. (For simplicity, we will use the term GFI except where we are specifically referring to a GFCI at the electric panel.)
3. GFI Is Required by Electric Code
National electric code requires GFI for all outlets in damp/wet areas. This includes:
- Laundry rooms
- Wet bars
- Pool and spa areas
- Crawl spaces and unfinished basements
The GFI/GFCI can be installed for these circuits at the outlet or at the electric panel.
4. GFI Protects You and Your Property
- GFI outlets protect against electric shock.
The main risk of a ground fault is electric shock. During a ground fault electric current seeks the nearest path to ground. If someone is holding the wires or touching water or metal (which are great conductors), the person becomes the grounding path. It only takes a millisecond of electricity to stop a heart. A GFI decreases the risk of injury or death from electric shock.
- GFI switches protect appliances from damage caused by ground faults
When electric current leaves the circuit, it can ground through appliances or electronics.. Electric current can damage the appliance’s machinery and electronic elements. If the appliance has a metal shell, there is further danger of electric shock to humans. A GFI increases the life expectancy of appliances and electronics.
- GFI outlets protect against fire
Another risk of ground faults is fire. Electric current running through conductive materials creates heat that can cause burns or fire. While the main function of a GFI is to protect against electric shock, a GFI also minimizes the risk of fire.
5. AFCI Protects Against Fire
The majority of electrical fires are caused by an arc fault. An arc fault happens when a loose, damaged, or deteriorating wire causes electric current to spark. Not only can electric sparks ignite flammable material, but they also create heat that causes fires.
An AFCI outlet looks like a GFI outlet. But it’s not the same thing. An arc fault circuit interrupter (AFCI) is a switch that protects against fires caused by arc faults. An AFCI outlet is installed…at the outlet. An AFCI breaker is installed at the electrical panel. Similar to a GFCI, an AFCI breaker will cut power to all the circuits that it’s protecting if it detects an arc fault.
An AFCI is not a substitute for a GFI!
Remember, a GFI protects against potentially fatal electric shock from ground faults whereas an AFCI protects against fires caused by arc faults. However, an AFCI can be used in combination with a GFI. A dual functioning GFI/AFCI can be installed at the outlet. Or you can install one switch at the breaker and the other at the outlet. Electric code requires a combination of AFCI and GFI for new homes and remodeling.
What to Do if Your GFI or AFCI Outlet Is Tripped
While a GFI or AFCI can be reset at the outlet, it’s important to understand why it trips before you go on your merry way. Overloaded circuits trip breakers. A ground fault trips a GFI; an arc fault trips an AFCI. This means there is a ground fault or arc fault in one of your appliances or in your electrical wiring. Unplugging appliances and resetting the switch only temporarily solves the problem.
If a GFCI or AFCI breaker is tripped at the electric panel, the fault could be in any appliance, outlet, or electric wiring on that circuit. To find out which, you need to test the appliances one-by-one.
- Unplug all your appliances from the outlet. If a breaker tripped, unplug all appliances on that circuit.
- Press the RESET button to restore power to your outlet. To restore power to a tripped GFCI or AFCI breaker, press the RESET button, then firmly press the breaker to the off position, then firmly press the breaker to the ON position.
- Plug in and power on each appliance one-at-a-time.
- An appliance that trips the outlet or breaker should be repaired or replaced.
- A GFI or AFCI outlet that won’t reset is a sign of an issue with the wiring to that outlet or an issue with the outlet itself.
- A GFCI or AFCI breaker that won’t reset is a sign of an issue with any outlet or electrical wiring on that circuit.
- Call a licensed electrician to troubleshoot any GFI, GFCI, or AFCI that won’t reset.
How to Know Your GFI or AFCI Is Working
You should test your GFI and AFCI outlets and breakers every month. Testing is a simple process of pressing the TEST button and making sure the power has been cut.
You can check that the power is off with a GFCI tester, which is a handheld device that can identify wiring issues. While a GFCI tester is a cheap and handy tool, it’s not critical for testing an outlet or breaker.
You can check that the flow of power has been stopped by plugging in a radio or lamp. You should check each outlet on each switch or circuit. You should not be able to turn on the appliance after the TEST button has been pressed. Replace any outlet or breaker that continues to provide power after the TEST button has been pressed.
Restore power to the outlet by pressing the RESET button. Restore power to the circuit by pressing the breaker RESET button, then firmly pressing the breaker OFF, then firmly pressing the breaker ON.
Malfunctioning or improperly wired GFI and AFCI switches and breakers will not protect you, your family, your staff, or customers from electric shock. Call a licensed electrician to replace or install a GFI or AFCI.
Need a GFI or AFCI replaced or installed? Call Redline Electric & Solar: 480-430-1939.
NABCEP certified Redline Electric & Solar is the best choice for your electrical and solar needs in Arizona. We are a family owned and operated electrical contracting business, with over 60 years of combined experience. We pride ourselves in our honesty, integrity and high quality work, with 100% satisfaction guaranteed to our customers. When you choose Redline Electric and Solar, you can have peace of mind and be confident that you made the right decision.