What is CAFCI & Why it’s the Future of Circuit Protection? 

Electrical devices have come a long way since electricity was first invented in the late 1800s. The type of lights, outlets, and other household devices that we don’t give a second thought would seem unfathomable to the great Thomas Edison. One of the biggest advancements in electrical devices has been how they make your house a safer place. 

CAFCI devices are an excellent example of electrical devices making your home a safer place. CAFCI protection is, without doubt, the future of circuit protection in the electrical industry. These devices are an updated version of the original AFCI circuit breakers and have more protection capabilities than their predecessors. 

If your interest is piqued about CAFCI devices and you want to know what all the rage is about, you’ve come to the right place. This article will go over everything that CAFCI devices do and why they’re so important to the modern home. We’ll also look at how they stack up against AFCI and GFCI devices. 

What is CAFCI Protection? 

CAFCI stands for Combination Arc Fault Circuit Interrupter and is an updated and more comprehensive version of AFCI devices. Where AFCI devices protect against parallel arcing, CAFCI devices protect against both parallel and series arcs. We’ll go into more detail about the difference between the two types of arcing later. 

Suffice to say, however, that both forms of arcing are extremely dangerous and can result in sparking, leading to a house fire. According to the NEC, because of the new and improved abilities of CAFCI devices, they are quickly becoming the preferred and required form of circuit protection. 

The main goal of CAFCI protection is to prevent sparks that could result in a fire. CAFCI is the most comprehensive form of circuit protection as it guards against all types of arcing, whereas AFCI devices only protect against parallel arcing. 

What is Parallel Arcing? 

Parallel arcing, which AFCI devices protect against, is when there’s an arc between a hot wire and a nearby neutral or ground. Parallel arcing is usually the result of when a foreign metallic object of any sort touches a hot wire. Here are a few examples. 

  • When you accidentally drive a nail or screw into a hot electrical wire. 
  • The bare hot wire on an outlet touches the ground or neutral wire on the same circuit. 
  • Suppose your electrician installed an electrical wire with metal staples and pounded one too hard. The result is that the cable could pierce through the outer protective sheath and touch the wires inside. 
  • If the hot wire on one electrical circuit comes into contact with a hot wire from another electrical circuit. 
  • A hot wire makes contact with an electrical appliance causing inadvertent sparking or arcing. 

Essentially, any time electricity from a hot wire makes contact and transfers electricity to anything other than what it’s supposed to. A parallel arc fault can result. Parallel arcs are often more dangerous than series arcs, but both of them can cause fires to start. Parallel arcing is more common than series arcing, which is likely why it’s considered more dangerous. 

What is Series Arcing? 

Where parallel arcing is when electricity jumps from one circuit to another, series arcing is when arcing occurs along the same line of electricity. Series arcing happens when electricity jumps from one section of an electrical wire to another or from one hot wire to another in the same circuit. 

The most common example of a series arc is as follows. 

  1. The hot phase on an electrical wire didn’t get properly connected to the hot screw on a wall outlet. 
  2. Because the wire isn’t tight on the screw, there’s a slight gap between the screw and the electrical wire. 
  3. The two components may make contact periodically, but the gap is enough that arcing or sparking might occur. 
  4. Depending on the circuit the series arc happens in, the resulting voltage will be the same as the circuit. 

Because of this, series arcs vary in danger according to the circuit that causes them. However, no matter the voltage, any type of series arcing can cause sparking, which could start a fire. 

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What Can It Do That AFCI Cannot?

The biggest difference that CAFCI devices have over AFCI devices is that they protect against both parallel and series arcs. Both forms of arcing cause sparks that could start a fire, so dual protection is necessary. 

Where is CAFCI Protection Required? 

CAFCI protection gets required in nearly every part of your home or property. Originally, AFCI devices were only necessary for bedrooms since they were the most prone to undetected arcing resulting in fires. However, as the apparent need for increased protection has become more obvious, AFCI or CAFCI devices are necessary for all parts of your home. 

The only exception to this rule is where you install a GFCI device rather than a CAFCI one. GFCI devices usually get installed in areas prone to moisture, such as bathrooms, kitchens, outdoor circuits, and laundry rooms. Advancements continue with CAFCI technology, however, with the goal being that they will replace GFCI devices. 

How do CAFCI Devices Work? 

Essentially, CAFCI devices work the same way AFCI and GFCI devices do. When they detect electrical anomalies that can cause arcing, it terminates the flow of electricity to the device in question. CAFCI devices usually get installed at the breaker box in the form of a circuit breaker and protect whatever outlets and lights they’re powering. 

CAFCI devices do their work in the blink of an eye. However, they have to because electrical arcs happen just as quickly and without warning. Everything will be working fine until suddenly, it isn’t. Here’s how it works. 

  1. You install a CAFCI circuit breaker at the main panel box.  
  2. If the CAFCI device detects abnormal electrical behavior that could result in arcing, the breaker flips and terminates the flow of electricity. 
  3. Because electricity stops flowing immediately, the threat of arcing gets cut off before it can fully begin. 
  4. If electricity would continue to flow, it would likely be enough to cause arcing, which would then cause a spark and possibly an ensuing fire. 
  5. CAFCI devices have built-in technology that helps them differentiate between false arcs and actual ones. 

AFCI Outlets Vs. CAFCI Breakers 

Because CAFCI devices protect against both series and parallel arcing, they’re more comprehensive and superior to AFCI devices. In most cases, CAFCI devices get installed at the breaker box and protect every outlet and light on its circuit. However, you also can install an AFCI outlet rather than a CAFCI breaker in select circumstances. 

The downside of AFCI outlets is that they only protect all outlets downstream from the AFCI device. Anything between the outlet and the breaker box won’t receive the benefit of AFCI protection. However, if you don’t need protection for an entire circuit and only for several breakers within the circuit, AFCI outlets are cheaper and easier to install than circuit breakers. 

They’re also less dangerous than circuit breakers and are ideal for DIY jobs or remodeling projects where you want to alter the electrical work. 

How to Install a CAFCI Outlet or Breaker 

AFCI Outlet 

If you want to replace an existing GFCI or ordinary breaker with an AFCI one, here’s how you do it. 

  1. Always start by turning off the power to the outlet you want to replace. Electrical shock is possible if you work with live electricity, regardless of your electrical experience. 
  2. Next, remove the existing outlet by removing the cover plate. 
  3. With the cover plate removed, you can access the terminal screws and loosen them. 
  4. Remove the outlet once the screws are loosened and take the new AFCI outlet from its package. 
  5. Connect the black (hot) wire to the golden terminal screws, the white (neutral) wire or wires to the silver screw terminals, and the bare or green ground wire to the green screw terminal. 
  6. With all the terminal screws tightened and the wires in place, push the new outlet back into the outlet box. 
  7. Place the new outlet faceplate atop the outlet and ensure it’s level with the wall for aesthetics. 
  8. Turn the power back on the outlet and perform a test run with an electrical device. 

CAFCI Breaker 

CAFCI breakers are more dangerous than outlets, and you shouldn’t attempt to install one without electrical experience. 

  1. Locate the main panel box in your home or the building in question. 
  2. Turn off the breaker at the top of the panel and terminate electricity to the entire building. 
  3. With the power terminated, you can start work on removing the old circuit breaker. 
  4. Loosen the terminal screws on the circuit breaker and pull them away from the device. 
  5. Use a needlenose plier to pull the device out of the breaker box. Depending on the breaker type in question, you may need to do different things to remove the device. 
  6. Ensure that the new breaker you’re installing is the same brand and size as the old one. Different makers put different twists and designs on their circuit breakers so that they’re not one size fits all. 
  7. Push the new breaker on the panel box exactly as the old one came off. 
  8. Typically, you’ll have to push the outer part of the breaker into place and then push the inner part of the breaker into place. 
  9. You should both hear and feel an audible click as the breaker slides into place. 
  10. With the breaker properly installed, you can reattach the black and white wires to the terminal screws. 
  11. It doesn’t matter which wire you attach to either screw, as long as they’re tight and in place. 
  12. If it’s easier, you can also attach the terminal screws to the wires before pushing the outlet into the breaker box. The area you’ll have to work with is cramped, and it could prove too difficult for an inexperienced electrician. 
  13. Flip the breaker to ON and test an electrical device or outlet in the circuit. 

What About GFCI? 

Another massive benefit of CAFCI devices is that they protect against the same things that GFCI breakers do. GFCI stands for ground fault circuit interruption, most commonly caused by moisture coming into contact with a hot electrical wire. It can cause an electrical shock to anyone who touches the outlet, or something plugged into the outlet, sparking and possibly even starting a fire. 

GFCI protection is required by the NEC in bathrooms, laundry rooms, kitchens, and anywhere subject to potential moisture. However, thanks to the advancement in CAFCI technology, you can now install a CAFCI breaker anywhere that GFCI or AFCI protection gets required.  

Circuits that once required an AFCI breaker and GFCI receptacles, now only require combination arc fault protection for the branch circuit.

CAFCI dual function breakers protect against all types of electric faults and dangerous arcs.

Advantages of CAFCI vs. AFCI 

If you’re on the fence about which type of device to install, here are a few advantages that CAFCI breakers have over AFCI outlets and breakers. 

  1. CAFCI circuit breakers are similar in price to AFCI circuit breakers and are easy to install. 
  2. CAFCI devices feature parallel and series arc protection and ground fault protection. Meaning any circuit that the NEC requires both AFCI and GFCI protection can use a CAFCI breaker.
  3. There are certain restrictions on installing AFCI devices, whereas CAFCI devices don’t have any restrictions. You can install them wherever you want, and you’re encouraged to do so. 
  4. CAFCI devices are the best way to meet all NEC requirements regarding protection against arcing and ground faults. 
  5. They provide the maximum amount of protection that you can have against fires, arcing, and electrical shocks. 
  6. You can install CAFCI breakers on old wiring. The protected circuits can be a mean time saver diagnostics and troubleshooting when problems arise.

Related Questions 

Are CAFCI devices better than AFCI ones? 

Because CAFCI devices guard against both parallel and series arcing and AFCI only protects against parallel arcs, CAFCI devices are the better option. 

Is CAFCI the same as GFCI? 

CAFCI stands for Combination Arc Fault Circuit Interrupter, and they protect against all types of arc faults. GFCI stands for ground fault circuit interrupter, protecting against ground faults. Modern CAFCI devices can protect against arc and ground faults and are therefore the preferred option. However, you can opt to install a GFCI outlet if you don’t want CAFCI protection for the entire circuit. 

When would you use a CAFCI breaker? 

AFCI or CAFCI protection gets required by the NEC in nearly every part of your home outside of where you use GFCI devices instead. Because you have to choose one or the other, CAFCI devices are preferred because they protect against more dangers. 

Are breakers with blue test buttons recalled?

If you have a Square D panel with older AFCI breakers with blue test buttons, they’re likely on the Square D recall list. These breakers were recalled because of a high rate of failure. Look for a recall notice. It’s highly likely you have a recalled breaker. Note that some other AFCIs like those from Seimens that are not on the recall list.

Final Thoughts 

While CAFCI devices are still relatively new to the world of electricity, there’s no doubt that they’re the future. CAFCI devices meet the ever-growing NEC requirements regarding electrical devices that protect your home from fires and electrical shock. Because they protect against virtually all types of electrical faults, they’re quickly becoming the preferred choice for electricians and homeowners everywhere. 

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Hubert Miles

I've been conducting home inspections for 17 years. I'm a licensed Home Inspector, Certified Master Inspector (CMI), and FHA 203k Consultant. I started HomeInspectionInsider.com to help people better understand the home inspection process and answer questions about homeownership and home maintenance.
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