GFCI and AFCI outlets offer more and better protection for devices plugged into them. They can still be mysterious, though. This guide explains fault circuit interrupters, and what GFCI status lights are trying to tell you.
Ground Fault Circuit Interrupter
GFCI stands for “ground-fault circuit interrupter." This technology has become an integral part of specialized outlets and devices such as circuit breakers, designed specifically to detect problems related to ground fault electrical circuitry.
As such devices are designed to protect individuals from getting an electrical shock from environmental hazards, they're often legally required in areas subject to moisture. These include bathrooms, kitchens, laundry rooms, utility rooms, garages, wet bars, spas, and pool areas, unfinished basements, crawlspaces, and building exteriors.
These fast-acting circuit breakers are designed to monitor and detect imbalances of current between the live wire and the neutral lines as small as five milliamps or 0.005 amps within a circuit and shut off the current flow within 1/40th of a second.
Note: GFCI outlets should not be used for refrigerators, freezers, or other appliances that you don’t want to shut off without your knowledge.
Ground Fault Interrupter
GFI or “ground fault interrupter” is simply another name for “ground fault circuit interrupters” (GFCIs), and both are exactly the same device.
Arc Fault Circuit Interrupter
AFCI is for “arc-fault circuit interrupter.” These devices protect homes in a different way, as they detect electrical hazards from the heat generated by electrical arcing within a circuit.
This allows them to protect against overheating electrical wires and receptacles, thus preventing fires and wire deterioration (especially inside walls).
Such hazards can be caused by damaged wire jackets from rodents, a misplaced nail, or an overheating device. The AFCI circuitry within the outlet or the breaker can detect this arcing and shut down the outlet before any damage can occur.
Although such outlets are commonly available, AFCI circuit breakers installed at the main service panel present a more commonly used and popular alternative.
AFCI protection is usually required in areas such as bedrooms, dens, kitchens, and laundry areas.
Selection and Installation
Specialized outlets should be selected according to their intended location as a wrong choice could lead to limited or inadequate protection.
There are, however, combined versions of specialized outlets that incorporates both circuitries into one.
Those devices would be identified as such on their packaging and labeling as GFCI/AFCI outlets or similar markings.
For any of these devices to be trustworthy, the installation and wiring must be done properly and according to the instructions. This is especially crucial if one GFCI outlet feeds other outlets downstream, as one such device, properly wired, can protect several standard outlets.
Older wiring jobs can often present you with deteriorated ground wires that might give a higher resistance within the conductor, thus making the human body an easier path for the current to return to the ground.
The GFCI might then only trip should that path be provided, giving the person a brief and probably harmless electric shock before quickly tripping.
GFCIs mostly just protect against ground faults, though, and therefore would not protect you if you were to hold both a hot wire and a neutral wire or two hot wires, one in each hand.
GFCI Outlet Status Indicator Lights
Status indicator lights are not an integral part of all outlets as many will not have any at all.
Some outlets have one light, others have two or more, making it easier to monitor by providing a constant view of the outlet’s ground-fault protection status.
The lights are coded in such a way that they can have a steady, flickering, or blinking glow, and are normally color-coded in two or more colors, including green, red, orange, or yellow, to provide you with a more accurate diagnosis.
Not every brand of those outlets, however, follow the same ruling for coding or color, so it is wise to keep the instruction sheet accessible for proper troubleshooting, should the need arise.
The following behaviors would relate to the most popular models.
The Green Status Light
When the outlet is properly wired and installed, the green indicator light should glow solid and steady.
A Solid Green Glow
indicates that the circuit has passed the self-test and is currently powered under normal operation with full ground fault protection.
The Green Light Is on but No Power at the Outlets
Just try to reset the GFCI, as in some rare cases, you’ll come across a GFCI that uses a green light to show a tripped circuit instead of a red light.
If that doesn’t work, however, you might want to check the wiring of the outlet as it is likely to be the cause of the problem or replace the GFCI as it may very well be defective.
No Green Light
A GFCI outlet is only powered when the green light is glowing and is usually off when the outlet has tripped, in which case another color of light should’ve come on if it has one.
A complete absence of any light glowing would indicate that the circuit doesn’t have power which can be confirmed by pressing the reset button, restoring its normal operation status.
A Flickering Green Light
A green light should never flicker, but if it does, it’s probably due to a faulty indicator light or a defective GFCI circuit unless this outlet is unconventionally coded, in which case you’ll need the product’s datasheet to find out what it means, which you might be able to find online.
The Red Indicator Light
When a GFCI comes on, it usually carries out a self-test while a red status light “flashes” red until the process is complete and a green light replaces it, and the power comes on.
A “blinking” red status should be present when the GFCI has tripped or has failed the internal self-test.
Common causes of a red status light are due to bad wiring, a ground fault, an overload, or even other various factors.
If the red light glows steadily, although some models could show flashing red, it could mean that the GFCI has encountered a problem or that it failed an internal self-test.
It does not, however, tell you what is wrong with the circuit, just that there is something wrong with the circuit that needs to be investigated.
Note: If the status light is red and the outlet is working normally, you should read the datasheets to find out the exact purpose of the red light and what it means when it’s on.
In your case, you might be surprised to realize that the red light indicates normal operation and that there is, in fact, no green light status. With these devices, you can always expect exceptions to the rules and never dismiss any possibilities.
Modern GFCI outlets have a feature that carries out a regular internal test to confirm that the power supplied to the outlet is duly protected by ensuring that all protective mechanisms are properly operating.
In most cases, the self-test starts with the light momentarily flashing red. Eventually, if the test proves to be successful, it will turn green.
If the device fails the test, a red light will come on, either steady or flashing, to indicate the failure. In the case of such failure, the device has disabled itself by triggering a failsafe mechanism.
Once you get the cause of the fault corrected, you should be able to return the device to its normal operation by pressing the reset button, thus returning the outlet to a green light status (for most GFCIs).
With the receptacle without any power and the red light on, you can start by checking the “RESET” button on the receptacle to see if it’s protruding above the “TEST” button.
If it isn’t, press the “TEST” button to intentionally create a ground fault and trigger it out. With the “RESET” button sticking out, push it back in to create a reset where the button will remain inside and flush with the front of the device and resume power to the outlets.
If, despite your attempts to reset the GFCI, the red light remains on, you should consider that one or more other outlets might be connected to the same circuit downstream and that perhaps one of those is causing the GFCI to trip.
On the other hand, never dismiss the possibility that your GFCI receptacle could be defective. A GFCI receptacle is rated with a lifespan of 15 to 25 years.
Although possible for devices submitted to normal use under dry conditions, this life span can be greatly reduced by outside adverse weather conditions and humidity and also in humid and wet environments such as crawlspaces and unfinished basements, offering conditions that can cause an outlet to fail within five years. When GFCI and AFCI devices get compromised, they sometimes have to be replaced.
Warning: These observations are based on general observations made from the more popular makes of those specialty devices. None of it is dictated by code and the colors of lights chosen, and their lighting sequences are simply a matter of choice for any manufacturers involved.
It is best, therefore, to get the datasheets prior to assessing such items. Some of those datasheets are also made available online.
Yellow Status Light
A yellow light “flickering” will let you know that your GFCI has reached the end of its lifespan and should be replaced. It can also be used instead of a red light to indicate possible tripping of the outlet, turning it off.
As with the red indicator light, the GFCI needs to be reset to return to normal operation by pressing the “RESET” button.
The GFCI has tripped because it has detected a problem within the circuit or the outlet. If you can’t reset it, it is probably because the problem remains and needs fixing.
It could be from the wiring, a faulty GFCI, a ground fault, or a short circuit at that outlet or any other outlet or fixture downstream.
The Orange Light
This color of status light varies in its meaning from outlet to outlet, depending on its manufacturer.
It is far less common than the yellow and the red light but still used by some companies, although its meaning is less obvious than for the other color warnings.
Its meaning can therefore be varied to the point of indicating a properly functioning GFCI outlet to a tripped outlet. The datasheet will be needed in such cases and might also be available online.
The 3 Types of GFCIs
The GFCIs are readily available in several forms to be used for several different needs. The GFCI outlet commonly used around the homes is the cheapest and most popular used in construction and renovations.
More costly is the circuit breaker, where ground faults are detected right at the main panel for dedicated circuits around the house, and the portable GFCIs that are exactly as they’re called, portable so you can plug them anywhere to be used to power any appliance or tool anywhere around the house, inside or outside, the outside versions being weatherproof.
1. GFCI Outlet
The GFCI outlet is basically the type of GFCIs that were covered thus far. It is like a standard electrical outlet and protects any appliance plugged into it. The GFCI outlet can also be wired to protect other outlets that are connected to it.
It is commonly used as a replacement for common outlets to provide better protection against electrical shock and is installed in the same manner, except for its wiring that requires special instructions, especially when used to protect another few outlets downstream.
The unit itself replaces the regular receptacle, so it is screwed into the same electrical box and uses the same cover plate.
2. GFCI Circuit Breaker
The GFCI circuit breaker is used as a replacement also, but for the breakers inside the main panel.
This type of protection initiated from the panel will profit all of its dedicated circuit and what’s in it but makes it a lot of going back and forth to the panel when you need to do some troubleshooting within a circuit.
It controls and protects an entire circuit, and is installed as a replacement for a standard circuit breaker in a home’s main circuit board.
Compared to multiple GFCI outlets, one GFCI circuit breaker can protect the entire circuit, which may include all bathrooms or all outdoor fixtures.
Precautions to take: The GFCI circuit breaker should match the requirements of the main electrical panel. For an older panel that utilizes fuses, GFCI outlets must be used instead of a GFCI circuit breaker.
3. Portable GFCI
The portable GFCI is the only type that can be simply unplugged from a regular unprotected receptacle and taken to another location without requiring any tools. They are used for portable applications and provide the same protection as any of the other two types.
It is used for mobile applications and can work as well as the ones installed in a house. Portable GFCIs are frequently used by contractors on worksites.
But Portable GFCI protection could also be put to use whenever electrically-powered equipment is used in garden-related works and when using electric tools in and around the house.
An outlet box with the male prongs that plug into a regular unprotected receptacle provides you with one outlet plus the “TEST” button, the “RESET” button, and an internal GFCI circuitry to activate ground fault protection to an otherwise unprotected receptacle.
A similar device can also be found on some exterior extension cords to also provide ground fault protection to exterior receptacles while being weatherproof, in order to give an alternative means to using electrical tools and appliances in humid and wet weather.
This cord-connected type has a GFCI module incorporated into it to protect any equipment attached to the extension cord and the person using it and is also equipped with the “TEST” and “RESET” buttons.
If you’d like extra information on the technical aspect of GCFIs and how to choose and troubleshoot those types of circuits, check out 5 Ground Fault Circuit Interrupter Facts and Troubleshooting 3 Common GFCI Outlet Problems.