Are you wondering about the number of GFCI outlets on your circuit? Or maybe you're worried they'll overheat or overload if you run several appliances at once? You’ve come to the right place! We've researched this topic and have come up with the answers to help you out.
Following the 80% circuit load of the National Electrical Code (NEC), you can have a maximum of 8 and 10 GFCI outlets for 15 amp and 20 amp circuits, respectively. These are ideal for daily power consumption safety.
It can be confusing how many GFCI outlets should be used in a specific amperage circuit, but it is easy to determine once you know. Continue reading—we're confident that you'll be able to figure it out as we elaborate on the topic.
What is GFCI?
The GFCI (Ground Fault Circuit Interrupter) balances the electrical current moving through a circuit. When it detects a ground fault, it turns off the power to protect people from being electrocuted. For your family's safety, all sockets, breakers, and circuits in your house should be GFCI-protected. Be aware that a GFCI will not stop fires caused by an electrical overload.
There are types of GFCI devices as mentioned below:
- GFCI receptacles or outlets. It is the most common type of GFCI in residential homes. This device works with any standard outlet and can protect other outlets receiving power from the GFCI outlet. GFCI outlets are typically bigger than standard outlets, taking up more space in a single gang or double gang electrical box.
- GFCI circuit breaker. It is more popular among professionals because they allow builders and electricians to use standard (low-cost) outlets. Therefore, only a single GFCI circuit breaker is installed in the panel box. It has the advantage of protecting all of the circuit's fixtures, including lights, outlets, and fans. They also protect overloads and simple short-circuits.
- Portable GFCI. This is a portable GFCI outlet strip or device. It safeguards the cord and any equipment connected to it. The attachment plug has a unique design that includes test and reset buttons. It has a no-voltage release device that disconnects power to the load if there's an open supply of conductors.
The Difference between 15 amp and 20 amp GFCI outlets
GFCIs of 15 amp and 20 amp are not the same. They have a couple of differences that influence the work they do, such as the following:
Both 15A and 20A GFCIs have three slots designed to accommodate 3-prong plugs. The 15A outlet does not have a T-shaped neutral while the 20A outlet has.
Location of Installation
The 15A outlets are frequently used for lighting. The 15A GFCIs should be installed in locations where 15A outlets are required.
In comparison to 15A outlets, 20A outlets can transmit more power. As a result, 20A outlets must be installed where heavy-duty items like washing machines, hairdryers, and microwave ovens are normally found, such as in the kitchen, bathroom, and laundry room. These areas contain appliances that consume a lot of power.
The 15A GFCI outlets are less expensive than 20A, so they are commonly used in many homes. However, the cost difference is minor.
A 14-gauge wire is required for 15A circuits. Circuits requiring 20A should be wired with 12-gauge wire. If the wires must travel a long distance, use a 10-gauge wire or even higher.
Maximum GFCI outlets for 15 amp and 20 amp circuits
When it comes to outlets or receptacles, it is preferable to have multiple outlets to distribute power evenly. But the power draw of all those outlets, on the other hand, could cause the wires to overheat, resulting in a tripped breaker or a fire hazard. That is why your house should have well-designed electricity load management.
Nowadays, U.S. commercial house outlets run on 120 volts, and according to the NEC, which is referred by EC&M, your circuit should not exceed 80% of the rated load. They also require each outlet must be measured at 180 volts per ampere, or VA.
If you want to determine how many GFCI outlets can be installed on your circuit, it's simple. For 15 amp, 80% of it is 12 amps, then multiplied by a 120 volts system, then divided by 180 VA, you can only have a limit of 8 outlets. The exact process is for 20 amp, and you will have a maximum of 10 outlets.
Check out our chart below that shows the above calculations:
Can you have a 15 amp GFCI outlet on a 20 amp circuit?
It's perfectly okay to use a 15 amp GFCI outlet on a 20 amp circuit. It is legal under NEC because a 20 amp circuit is designed to work with a 15 amp outlet. But if you use a 15 amp receptacle to power an appliance that draws 20 amp or more, you risk overloading it. As such, a 20 amp plug will not fit in a 15 amp outlet.
Specifically, the NEC states that a single receptacle's amperage rating cannot be less than the ampere rating of the branch circuit on which it is installed, with some exceptions.
Some people believe you put too much power into the outlet, causing it to overheat and catch fire. You can't ignore this issue entirely. A malfunction can cause an appliance that should only draw 15 amp but draw more current than is safe. Such occurrences, however, are uncommon.
What happens when you put a 20 amp receptacle on a 15 amp circuit?
The breaker will trip as a result of installing a 20 amp outlet on a 15 amp circuit. You risk starting a fire if the breaker fails, especially when using a 20A GFCI to power a 20A appliance.
The National Electric Code establishes strict guidelines for outlet usage. While it permits electricians to install 15 and 20 amp outlets on 20 amp circuits, it forbids them from installing receptacles that draw more than 15 amp on 15 amp circuits.
Can you have 2 GFCI outlets on the same circuit?
You can use two or more GFCI outlets on the same circuit if you want. This is a common practice. However, if one trips or fails, it will affect all the outlets/GFCIs downstream.
Multiple GFCIs usually share load output from the original GFCI on the same circuit. When the GFCI outlet to which the other outlets are wired loses power, the other outlets will usually shut down. This usually means that all of the outlets in that particular area of the house will stop working, which can be a significant problem.
How to reset a GFCI outlet
If the problem occurs in GFCI outlets having shared in the same circuit, you have to reset the GFCI outlets by following these basic steps:
Check your outlets
If you have several GFCI outlets on the same circuit, they're almost certainly all dead. Even so, you should double-check each of your outlets that share a circuit to be sure. If it is not working, unplug all appliances.
Locate the circuit breaker
It would be best to locate your circuit breaker after all essential electrical appliances have been unplugged. Check the inside of the circuit breaker to see if any of the circuits have been tripped. It has been tripped if one of the circuit switches in the breaker faces the opposite direction as the others.
Reset the breaker
Turn off the breaker before proceeding. To make sure it sticks, move the handle to the "off" position and hold it there for a few seconds. When you push your breaker switch, it should be firm and hard; otherwise, the handle may be defective.
To reset the breaker, wait a minute and then firmly push it back into the "on" position. If your breaker handle is no longer aligned with the other switches, you have a more serious electrical problem. Have your breaker rewired or replaced by an electrician if this is the case.
Reset GFCI button
Press the reset button, which is usually in red. See if your outlet begins to work again. Plug a lamp into it to ensure that the GFCI outlet is working properly. If that doesn’t work, you may need help already from a professional electrician.
Wrapping things up
Keep in mind that there is a limit of outlets you can install on a circuit to avoid overheating and electrical hazards. You also have to make sure your circuit, wire sizes, and outlets are compatible.
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