Last week, I introduced you to the GFCI outlet. I talked about how they function, why they are necessary, and where they should be located. To summarize, they are safety devices designed to prevent fatal electrocution accidents and should be located in all wet areas and areas with good potential for ground contact (think exterior). This week I will go into the different types of GFCI devices, common installation practices, and how to test them.
Types of GFCI Devices
Two types of GFCI devices commonly seen in a home inspection are outlets and circuit breakers. GFCI circuit breakers are located at, you guessed it, the main breaker panel. These protect all of the outlets on the circuit and don’t require any GFCI outlets to be installed in the circuit. GFCI beakers are often used to protect jacuzzi tubs where the outlet for the pump is concealed inside the tub enclosure. This prevents having to disassemble the tub enclosure to reset the outlet in the event of it tripping. These devices have a test button just like the outlets; to reset them you simply turn the breaker back on.
The other type of GFCI device, which I have already talked a little about, is the GFCI outlet. You’ve probably already seen them around your house. A distinguishing feature of a GFCI outlet is the presence of two buttons, one which says “TEST” and another labeled “RESET.” We will discuss these buttons and their functions in a bit. Similar to the GFCI breakers, a single GFCI outlet can protect other non- GFCI outlets on the circuit as well. If you look on the back of a GFCI outlet you will see terminal screws labeled line and load. Power coming into the outlet should be wired to the “line” side of the outlet. Any outlets to be protected “downstream” of the GFCI outlet should be wired to the “load” side of the outlet. Many homes use a GFCI outlet located in the garage to control or protect all of the exterior outlets. They may also install a GFCI in one bathroom that protects all of the other bathroom outlets. Each house is different, but a thorough home inspector will note GFCI outlet locations and the outlets they may or may not protect.
Testing GFCI Devices
Just like smoke detectors and other home safety devices, GFCI outlets should be tested regularly to ensure they are functioning properly. As part of a your home maintenance plan, you should test GFCI outlets monthly. Luckily, it is a very simple process. All you have to do is push the test button. When you push the test button, you can have a few possible outcomes:
Now, suppose you want to find out which non-GFCI outlets in your house are protected by an upstream GFCI outlet. A simple way to test them, the way I test them during an inspection, is to use a GFCI outlet tester. The tester can be found at your local home improvement store for under 10 dollars. You simply insert the tester into the Non-GFCI outlet and press the test button. If the power goes out, you know the outlet is protected. The trick can be figuring out which GFCI outlet is protecting it. I recommend making sure the house is nice and quiet so you can listen for the GFCI outlet to trip so you can determine its location. There’s almost nothing more frustrating than a tripped GFCI that you can’t find.
I hope I’ve answered any questions you may have had about GFCI outlets. If not, drop me a comment below and I’ll answer it or make it a future blog post!
For this week and next week’s blogs, I will be looking at GFCI outlets. I will discuss how they work, why they are needed, where they are needed, and how you can test GFCI outlets in your home.
Before we jump into GFCI outlets, we need to talk a little bit about wiring. In an electrical system, there are 2 wires that normally carry current. One of the wires makes the connection to the earth. This wire is considered a grounded conductor (not to be confused with the ground wire) and the other wire is considered an non-grounded conductor. The grounded conductor is (usually) the white wire and is referred to as the “neutral” wire. The non-grounded conductor can be any color other than white or green, although it is usually black. It is referred to as the “hot” wire.
Electricity’s goal always has been and always will be to find its way back to the earth. This is what causes lights to illuminate and other electrical devices to function. Electricity travels from the “hot” wire through a light or other electrical device and back to earth through the “neutral” wire. This inherent property of electricity is also what makes it a safety hazard.
Electricity can’t differentiate between a light bulb and a human being. If you provide electricity a path to ground through your body, it will pass through it just the same as a light bulb. When electricity finds its way to ground in a manner that it wasn’t supposed to, such as through your body, this is known as a ground fault. Wet areas in the home such as the kitchen and bathroom are prime locations for shocking experiences. A wet hand holding on to a faucet while another part of the body comes into contact with faulty wiring could spell disaster. This is where the GFCI outlet proves its worth.
A Ground Fault Circuit Interrupter, GFCI for short, is an electrical safety device designed to prevent fatal electrical shocks due to ground faults. A GFCI device monitors the electricity coming in and compares it to the electricity going back out through the grounded conductor. When the GFCI outlet senses a difference of as low as 5 milliamps (.005 amps), it shuts down or “interrupts” the circuit within milliseconds as a ground fault is most likely occurring. It’s not so fast that you won’t feel a shock at all, but it will prevent a fatal electrocution.
GFCI outlets requirements in the residential setting first appeared in 1971. They were first required to be installed near swimming pool equipment. Fast forward to today, and GFCI outlets are required to be installed in the areas of the home where shocks are most likely to occur, wet areas and areas where ground contact opportunities are best. This includes garages, exterior outlets, bathrooms, kitchen countertops/islands, basements, crawlspaces, and outlets within 6 feet of plumbing fixtures. Click here to see a great chart that illustrates when GFCI outlets became required in each respective area of the home.
That's a good stopping point. Next week I will talk about different types of GFCI devices, common installation practices, and how you can test the GFCI outlets in your home.
Colin is a Certified Professional Home Inspector as well as a licensed MS Residential Builder. He has been remodeling homes since he was 14 and even built his own house by hand from the ground up. Colin is also the owner of Wilson Home Inspections.