Combination Arc-Fault Circuit-Breaker VS. Dual Function: Arc-Fault/GFCI Circuit-Breaker

By: Wes Gubitz | Feb 05, 2019

A “COMBINATION” Arc-Fault Circuit Breaker is NOT equivalent to a “DUAL-FUNCTION” Circuit Breaker.

With ever changing electrical Code requirements, a circuit breaker with the ability to provide both Arc-Fault protection as well as Ground Fault (GFCI) protection was long overdue. But beware, the “combination” function that is identified on recently manufactured AFCI circuit breakers DOES NOT provide this AFCI/GFCI protection.

COMBINATION AFCI Circuit-Breaker: Provides protection against both parallel arcing conditions (which is a hot to ground arcing condition), and series arcing conditions (which is arcing that occurs along a single conductor where a portion of that conductor is broken, frayed, or otherwise partially disassembled, causing the current to leap an air-gap to continue on its path).

DUAL-FUNCTION AFCI/GFCI Circuit-Breaker: Combines both AFCI and GFCI branch-circuit protection into one OCPD.

The Combination Type Arc-Fault Circuit Interrupter

Branch circuit protection has steadily evolved over the decades concerning electrical safety for Family Dwelling Units. The Fuse being one of the first advances, then the circuit breaker, the GFCI, and most recently the AFCI. All of these devices are, by action, circuit interrupters; they de-energize the circuit being protected. The fuse interrupts the circuit when there is an overcurrent condition (short circuit or overload), but unlike the other devices, it is a one and done; when a fuse interrupts a circuit, when it blows, it must be replaced. The circuit breaker is also a circuit interrupter. It opens when there is an overcurrent condition in the branch circuit it protects, and it is resettable. Both the fuse and the circuit breaker are designed to protect the circuit against short circuit current and overloads.

The GFCI, the ground-fault circuit interrupter, and the AFCI, the arc-fault circuit interrupter, are devices designed to meet specific electrical safety issues. The GFCI is designed to protect personnel against electrocution while operating tools or equipment on a GFCI protected circuit. It is designed to interrupt and de-energize the circuit if there is an imbalance in current of 6 mA or greater between the line conductors (NEC 100IN). The GFCI is resettable. The AFCI is resettable and designed to interrupt and de-energize a circuit to protect life and property should anomalies that mimic arcing faults occur in an AFCI protected circuit.

Arc-fault circuit protection was first introduced as a requirement for bedrooms in the 1999 NEC that was to take effect in the 2002 NEC cycle. The Code requiring Arc-Fault Circuit-Interrupter Protection, 210.12, has evolved with the technology. The AFCI shall be installed in a readily accessible location, and protect all 120-volt, single phase, 15- and 20-ampere branch circuits supplying outlets or devices installed in dwelling unit kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, laundry areas, or similar rooms or areas shall be protected…, 210.12(A).

Several Code cycles through and including the 2017 NEC have amended the ACFI requirements such that the rooms or areas shall be protected by any of the means described in 210.12(A)(1) through (6). The means described in (A)(1) is a listed combination-type arc-fault circuit interrupter, installed to provide protection of the entire branch circuit.

According to Siemens, a supplier of combination-type arc-fault interrupter circuit breakers, “Combination Type Arc Fault Circuit Interrupters (AFCI) detects arcing faults (an unintentional arcing condition in a circuit) that standard circuit breakers are unable to detect. The device is intended to mitigate the effects of arcing faults by functioning to de-energize the circuit when an arc-fault is detected. A Combination Type AFCI detects all three types of arcing: line-to-neutral, line-to-ground, and series arcing.”

The most probable and convenient “means” to meet the AFCI Protection requirement for new construction dwelling units is through use of a Combination Type AFCI Breaker, 210.12(A)(1). This will allow the use of GFCI receptacles for those circuits where GFCI protection is required. Another possible and the next probable device to be used in new construction that would also meet the AFCI Protection requirements of 210.12(A) is the Combination Type ACFCI Breaker that also has GFCI Protection, a Dual-Function AFCI/GFCI Breaker. The remaining means described in 210.12(A)(2) through (6) requires a thorough understanding of the related Code and specific input at the local level from the Authority Having Jurisdiction.

What about when an existing circuit that is required to be AFCI Protected has to be repaired or modified?

The Code covers this in 210.12(D)(1) and (2), Branch-Circuit Extensions or Modifications – Dwelling Units and Dormitory Units. In any of the areas specified in 210.12(A) or (B), where branch-circuit wiring is modified, replaced, or extended, the branch-circuit shall be protected by one of the following:

(1) A listed combination type AFCI located at the origin of the branch-circuit

(2) A listed outlet branch-circuit-type AFCI located at the first receptacle outlet of the existing branch circuit.

The electrician could replace the standard circuit breaker with the Combination Type AFCI Breaker to provide the required AFCI Protection, but…. this may not be the best option on older homes. Circuit neutrals must remain separated for AFCI devices to operate correctly. Neutral maintenance is required on new construction, meaning that all neutrals are separated when leaving the panel and do not tie in with any other neutral outside the panel. The Combination Type AFCI Outlet Receptacle may be the better choice when existing branch circuit wiring is modified, replaced, or extended. Check out our electrical license exam prep courses now.


29 thoughts on “Combination Arc-Fault Circuit-Breaker VS. Dual Function: Arc-Fault/GFCI Circuit-Breaker

  1. I firmly support a requirement that all circuits in a new home construction should be dual function. The statistics on death by short circuit or arc fault are overwhelming and a few dollars more to save innocent lives especially thru fire is a minimal amount to incur. This could be you or one of your family members.
    Figure an additional 500.00 and make your home safe as best we now how right now.

  2. Well, Jim, that would be swell if the things actually worked correctly. But with the thousands of documented cases of nuisance tripping caused by the AFCI’s inability to differentiate between an actual arc fault and the normal arcing of motor brushes, perhaps it’s an idea whose time has not quite come yet. Alas, the NEC is forcing it on us, nevertheless.

  3. Ditto on David’s comment.
    Jim… you speak like a true investor…
    I doubt anyone can find much fault in the GFCI, but the AFCI posses it’s own saftey hazards.
    Words like fire and electrocution always get tossed in first… but the plans never talk about the thousands
    of home owners tripping AFCI’s unplugginf a phone, vacuuming, turning on an iron.. Now they’re in the dark?
    Now thy’re in the panel… resetting a possible bad issue.. multiple times …
    I a not talking about inconvenience nor cost issues.. This is about a National Mandate on a product that is flawed.
    True prove my point, lets fix the real issues about arching, or overloading. STOP with the waggles or stab in versus the wire nut. twist it and cap it or wrap it around a screw. #14 cu is a joke stick to #12 minimum.
    Arguably the same cost increase as a home full of AFCI’s but now there is an actual inherent value added (material wise and workmanship). Someone is getting rich on these ideas on paper but in the field?
    Let us know Jim, the countless number of lives saved that the industry has dreamed up.

  4. AFCI/GFCI breakers are Flawed in design and need to be Re-designed So they don’t trip just Because a fan picks of speed in a computer. I replaced two of them and it still would trip. went back to a normal 15 amp breaker and no issues.. I would like to add that the AFCI/GFCI 15 amp circuit was not even to half Capacity when it would trip. Just a gaming computer and a monitor and a led light bulb lighting room.

  5. AFCI/GFCI is a Very Flawed design. It trips off the circuit just by computer fan running high. I had a 15 amp GFCI /AFCI on my computer room circuit and it would trip when my fans would pick up RPM ‘s . The 15 amp circuit was nowhere its 15amp limit. Just a computer a monitor and a led room light. Replace with a standard 15amp breaker and issue was fix. Hopefully they re design and flawed AFCI breakers

  6. I recently purchased a new home and the builder stated that he as installed dual function ARC/GFI’s in the panel. Do I still NEED GFCI’s in the kitchen and bathrooms?

  7. I’d like to replace a 20amp single pole AFCI/GFCI which feeds 4 kitchen counter outlets solely with a 20 amp single pole GFCI breaker due to new coffee maker tripping issue. I’ve checked and tightened all 4 outlets for any loose wire conditions without improved success. My home is 1&1/2 yrs old. I don’t know what else to do. Any other suggestions? try a different AFCI/GFCI breaker?

  8. Get a different coffee maker. New codes require AFCI/GFCI. Electrical contractors are bound by the code. Plug coffee pot into different kitchen counter AFCI/GFCI circuit. If this circuit trips too, it’s the coffee maker.

    Had same problem with new mini refrigerator. Customer had to replace.

  9. My daughter Dual GE circuit breaker GFCI and combination AFCI Type THQLDF breaker went off. She reset the circuit by pressing the test button and and turning the circuit to on.The items on that circuit started to work but two yellow light came on. The light and garage opener are working. Is this normal and the yellow light suppose to be on?

  10. I wired a duel function breaker with neutral wire on the bottom and the hot wire on the top of the breaker. my gage should that the wores were reversed. so I switched the wires on the breaker and gage should correct Why?

  11. AFCI/GFCI breakers are Flawed in design and need to be Re-designed So they don’t trip just Because a fan picks of speed in a computer. I replaced two of them and it still would trip. went back to a normal 15 amp breaker and no issues.. I would like to add that the AFCI/GFCI 15 amp circuit was not even to half Capacity when it would trip. Just a gaming computer and a monitor and a led light bulb lighting room.

  12. Power your computer with an UPS battery backup device. <$100. This will insulate your computer fan from the AFCI circuit breaker and eliminate tripping.

  13. Circuit neutrals must remain separated for AFCI, CFCI, DFCI devices to operate correctly. Neutral maintenance is required on new construction, meaning that all neutrals remain separated when leaving distribution panel and do not tie in with any other neutral outside the panel. Combination type AFCI Outlet Receptacle in your first drop box might be a better choice when existing branch circuit wiring is modified, replaced, or extended. Even so arc from motor brushes and various other minor arc sources may trip contemporary AFCI, CFCI, DFCI devices (the technology is what it is, in some cases it could save your house burning down, in others some may consider it a not quite ready for ‘prime-time’ play. Hopefully technology gets better and perfected and less annoying in some applications so it saves lives, property, and insurance and legal costs. Until then you live with the local jurisdiction you’re under, until you can persuade them requirements need to be readdressed until technology changes and any related costs are swallowed.)

  14. if you have afci / gfci comb installed. you can install regular receptacle in the kitchen and put a sticker on each “gfci protected receptacle”

  15. Pool motors are cap start and likely will not trip the AFCI breaker. The modern inverter based types should be even less likely to trip the AFCI/GFCI breaker. Every pool we do gets these combo breakers as standard.

  16. What is flawed with this logic? Separate AFCI breakers and GFCI receptacles enables troubleshooting the nature of a fault (arcing or ground short) depending upon which device trips. How do you identify the nature of a fault when a duel function (AFCI/GFCI) breaker trips. Device tripping due to OCP is a different troubleshooting task.

  17. Excellent question! Your logic is sound. Unless the combination unit has special indicating lights that differentiate type of fault triggering the trip event, your left with no other troubleshooting strategy other than the laborious process of repeatedly disconnecting sections of your wiring system and keep re-testing until fault clears. Even then, when you find the culprit, it’s not always obvious whether the wiring (or appliance) was producing an “arc signature” or just leaking a little current to ground. If you must know what kind of fault it was, you would end up having to take the combination device “out of the circuit”, replace it with a single function unit (GFCI or AFCI), and then, re-test. Too much work! So, your idea about using AFCI’s at the panel and GFCI’s at the wall outlets may be the best option electrician’s presently have at this time. Besides, doing it that way still gives us the building wiring fire protection we are looking for with AFCI technology while also giving us electrical shock protection at the wall outlet from the GFCI technology. We get the best of both worlds! Now if we could just get an AFCI that’s better at distinguishing a true “arc signature” from mere “electrical noise”. We need a better algorithm! LOL.

  18. The dual function breakers (Eaton’s newest generation) just installed in my home flash an LED from one to 6 times when reset, indicating the reason that power was interrupted. They flash this code 30 times so it can be validated.
    Those codes are:
    1 flash: Series Arc
    2 flashes: Parallel Arc
    3 flashes: Short delay
    4 flashes: Overvoltage
    5 flashes: Ground Fault
    6 flashes: Self Test failure

    I found the online version of the breaker manual that includes this chart, along with explanations of each condition, printed it on half-page label stock and placed it on the inside of the panel door for reference.
    I’ve had experience with several iterations of AFCI and GFCI breakers. I am not an electrician but have designed and implemented power systems for carrier-grade data centers and broadcast video regional hubs over the past 30 years.
    This latest generation of breakers really does seem to have eliminated the nuisance trips the first few generations suffered from. As with GFCI technology, equipment manufacturers are having to tighten up arc fault tolerances in their devices to avoid customer returns as “defective” because they trip a breaker. This is a good thing.

    The biggest issue is that these ‘smart’ breakers, due to their circuitry, are just nowhere near as durable as basic TM(thermo-magnetic) breakers. They wear out. A homeowner-replacable design within the breaker, like screw-in fuses were, is called for but perhaps not practical. However, PON(plug on neutral) designs are certainly a step in that direction.

  19. Anyone K, for a “Multiwire Branch Circuit”, such as 2 circuits wired with a single run of 12/3 sharing the neutral, you would want to either run a dedicated neutral wire for one of the circuits, or locate a 2 pole 20 amp AFCI breaker made for that application. Murray is one manufacturer of such a breaker that has test buttons for each leg. Be aware a fault on either circuit will put both circuits out of service.
    One benefit of this specialty breaker is that it enforces 2 key safety conditions of multiwire branch circuits. It ensures that they are not rearranged to be on the same phase(potentially overloading the neutral) and it has the common trip built in.
    The 1949 house I moved into 3 years ago, besides having been ‘upgraded’ to a Zinnsco panel, included 4 multiwire branch circuits in a later addition. While these were clearly marked at a junction box under the house, it wasn’t marked at the main panel and a common trip 2 pole breaker/trip bar was not installed for these circuits. That’s not required but is a good safety practice.
    One included a shop/garage circuit where I’d definitely be using power tools. In the unlikely event I’d de-energize one of those circuits while using the other, the neutral for the de-energized circuit would still be carrying power.

  20. I’ve been having trouble with two particular circuit breakers tripping since we moved into this house several years ago.
    I thought they might have worn out and were tripping at too low a current.
    Today I took close look at the circuit breakers in the panel and saw that they are labeled
    “combination arc fault breaker type cl”. They were added to the panel just before we bought the house in 2016.
    They have also tripped twice this month due to utility power outages.
    So, not a GFCI problem, a possibility I suspected earlier.
    It’s really a nuisance that I have to go outside to the panel once in a while
    to reset these circuit breakers for no good reason. Grrrr!

  21. Try using an door bell on an arc fault breakers circuit. It will trip every time the button is pushed. Breaker will sense the button push and trip off.

  22. Totally agree with the flaws of the current AFCI products. Most people in my experience, both electricians and homeowners, will replace the breaker or receptacle after their inspection final anyway. I also agree with you on the quick connects and stabs. Too many times I’ve answered service calls where either the feed or neutral have come loose with a stabbed device.

  23. My 24 yo house has an old GE PowerMark Gold Load Center panel hanging on the outside. When I search for modern AFCI/GFCI/Dual ckt breakers either they don’t exist or cost an arm and leg, and even if they are available seem sketch.

    Any possibility one of the new Eaton Breakers could be made to fit my panel, or any other manufacturers?

  24. So..I’ve replaced the panel and meter base, added isolated neutral to nm disconnects, 4 wire where needed, so hopefully totally isolated ….. will my 19 combination and 1 dual trip like that

  25. There are various opinions on here but the main idea is Safety and Fire Prevention. That being said an ARC/GFCI outlet that has met all the UL,CSA, and two tons of other certification requirements is okay for my people and myself to install according to the NEC. This combination (d) is simply not made and the Code Book should take more caution in creating these articles to insure the product is available first instead of just writing it in a section and hope it comes about by manufactures. There are alot of great items coming out but they are simply no hear yet and in some parts of the code they have how it is to be used, ridiculously written. Cart before the Horse. This just gives those that have nothing important to enforce or do an excuse to create problems in the field for those of us who have been their installing longer than most of you have been alive. l My personal opinion and I am sticking to it.

  26. I am a professional licensed electrician since 1982. Over this time there have been many continuous revisions of the NEC, requiring increased use of GFCI, AFCI, intrinsic grounding and many more codes that Will make your eyes glaze over.
    All of these improvements in circuit protection are good when properly applied by a competent professional installer.
    However, I will go on the record to tell you that when electrical work is installed by someone who is incompetent, people will still die of electrocution or fires.
    My hope is that the electrical community will stand up to the ‘real’ problem. When you need electrical work hire a licensed and insured professional. This needs to be legislated and in place to insure this nationwide.

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