08 Sep Why GFCIs Make Homes Safe
In 1971, the National Electrical Code added an important requirement that would save thousands of lives and help reduce the amount of home electrocutions by 50%. What was the key addition? Ground fault circuit interrupters (or GFCI) are inexpensive electrical devices designed to protect people from severe or fatal electric shocks.
- GFCI’s shut off electric power in the event of a ground fault within 1/40 of a second.
- 26% of respondents who tested GFCI receptacles discovered one that was not working.
- In the United States, arcing faults cause about 30,000 home fires each year, resulting in hundreds of deaths and injuries and more than $862 million in property damage.
GFCIs have played a key role in reducing electrocutions and greater use of GFCIs would help mitigate thousands of electrical burns and shock injuries that continue to occur in homes every year.
To help homeowners understand GFCIs and how they work to reduce serious injuries, please find some common questions to explain these inexpensive, yet important devices.
What is a GFCI?
A ground fault circuit interrupter (GFCI) is a device that shuts off an electric power circuit when it detects that current is flowing along an unintended path, such as through water or a person.
Ground fault protection is integrated into GFCI receptacles and GFCI circuit breakers for installation into an electrical system. Ground fault protection is particularly important for circuit outlets in areas where electrical equipment is near water (such as bathroom or kitchen sinks).
What Does Ground Fault Mean?
A ground fault is an unintentional electrical path between a power source and a grounded surface. Ground faults most often occur when equipment is damaged or defective, such that live electrical parts are no longer adequately protected from unintended contact.
Many home electrocutions, burns and shocks occur when a ground fault is not in place. If your body provides a path to the ground for this current, you could be burned, severely shocked or electrocuted.
How Does a GFCI Prevent Electrocutions?
A GFCI constantly monitors the current flowing through a circuit by measuring the current flowing into the circuit compared to the returning current.
GFCIs are most frequently used in wet locations, construction sites or other high-risk areas to interrupt the flow of electricity within as little as 1/40 of a second to prevent electrocution.
How Do GFCIs Work?
In the US, most homes have 120-volt outlets, where there are two vertical slots (with the left slot slightly larger than the right slot) and then a round hole centered below them.
- The left slot is called “neutral”
- The right slot is called “hot”
- The center hole is “ground”
In properly working appliances, the electricity flows from from hot to neutral and the GFCI monitors the amount of current flowing from hot to neutral. If there is any imbalance, it trips the circuit to stop the flow of electricity.
For example, if you are outside with a power drill completing a project as it starts raining, you are standing on the ground. Since the drill is wet, there is a path from the hot wire inside the drill through you to ground. If electricity flows from hot to ground through you, it could be fatal. The GFCI can sense the current flowing through you because not all of the current is flowing from hot to neutral as it expects…some of it is flowing through you to ground. As soon as the GFCI senses that, it trips the circuit and cuts off the electricity.
How to Test GFCIs?
Homeowners should test all GFCIs every month. The best way to test a GFCI is based on the manufacturer’s instructions. However, if the instructions are not readily available, here is a commonly accepted procedure.
- Plug a lamp into the outlet and turn the lamp on.
- Press the GFCI’s test button.
Did the light go out? If not, the GFCI is not working or has not been correctly installed and you should contact a qualified electrician to correct the wiring and/or replace the defective GFCI.
If the light went out, press the reset button. Did the light come back on? If not, replace the GFCI. If the light came back on, then the GFCI is working appropriately.
Here is a video of GFCI testing instructions from the ESFI.
Where Should GFCIs Be Installed?
A GFCI should be used in any indoor or outdoor area where water may come into contact with electrical products. For reference, the National Electrical Code GFCI requirements (and effective date):
- Underwater pool lighting (since 1968)
- Outdoors (since 1973)
- Bathrooms (since 1975)
- Garages (since 1978)
- Kitchens (since 1987)
- Crawl spaces and unfinished basements (since 1990)
- Wet bar sinks (since 1993)
- Laundry and utility sinks (since 2005)
Consider portable GFCI protection whenever operating electrically-powered garden equipment (mower, hedge trimmer, edger, etc.). Additionally, portable GFCI protection works with electric tools (drills, saws, sanders, etc.) for do-it-yourself work in and around the house.
Can I install GFCIs Myself?
The ESFI advises that GFCIs should only be installed by a licensed, qualified electrician.
However, portable GFCIs require no tools for installation. Plus, they provide flexibility for using receptacles, which are not GFCI-protected. These typically offer great options for outside use.
If you have any questions or would like to install any GFCIs, please don’t hesitate to contact Snappy today.