What prompted your testing/cost comparison of AFCI/Dual Function breakers and AFCI/Dual Function receptacles?
- We want electrical contractors, inspectors and others involved in new home building and renovation to fully understand the differences between AFCI circuit breakers and AFCI outlet receptacles.
- The best way to help educate electrical professionals on the facts and differences and to eliminate any confusion was by testing AFCI breakers and receptacles using UL 1699 standards.
- Some have claimed AFCI receptacles are cheaper and provide the same level of safety as an AFCI circuit breaker. Our testing, based on current technology and National Electrical Code® (NEC®) safety requirements, proved this is not true. In fact, when it comes to parallel arcing and protection in the home run of wiring throughout the home (the wiring from the circuit breaker to the first outlet in the branch circuit), the AFCI circuit breakers were far superior to AFCI receptacles. AFCI circuit breakers provided greater whole-house wiring protection. The breakers detected one of the most dangerous forms of arcing, stopping it before electrical fires could start.
How were the tests conducted?
- Our tests were based on UL 1699 standards and conducted by manufacturing experts with decades of experience in AFCI technology. All testing was videotaped in a controlled environment for complete transparency and the video can be accessed on this website.
- Our testing revealed that while an AFCI receptacle certainly offers electrical protection at an outlet, it cannot protect against parallel arcing in the wiring throughout the home. In fact, if you look very closely, receptacle manufacturers never claim to protect the home run portion of the branch circuit from parallel arcing. Electrical professionals realize that is important because the home run represents more than 30% of the wiring in a new home. Parallel arcing is also one of the most dangerous forms of arcing that can cause electrical fires.
- AFCI circuit breakers however, do protect against parallel arcing in wiring throughout the home, not just at the outlet. The tests prove that electrical fire prevention and safety is at a much higher level throughout a home with AFCI circuit breakers versus receptacles. That’s one of many reasons why AFCI circuit breakers have been a NEC® requirement since 1999.
What is one major thing electrical contractors and others might not realize about AFCI receptacles?
- AFCI receptacles cost much more than some claim. Per the 2017 NEC requirements, the wiring used with AFCI receptacles must be encased in metal conduit or two inches of cement to physically protect the home run circuit. If that is not done by a contractor, it violates the NEC®. The materials and labor costs to do this are significant. Installing an AFCI circuit breaker is relatively simple in comparison and more thoroughly protects the electrical system in the home.
What are the main differences between the AFCI/Dual Function breakers versus AFCI/Dual Function outlet receptacles?
- Both AFCI circuit breakers and receptacles work well, but in different ways. Circuit breakers provide more whole-house wiring coverage throughout the home run, while receptacles are outlet-based. As manufacturers, we share a common goal of preventing electrical fires, but these devices have significant and important differences and that’s why we want electrical contractors and inspectors to be fully educated on their use.
- AFCI circuit breakers, a NEC requirement in all new home construction since 1999, protect the entire branch circuit by detecting dangerous series and parallel arcing. They are installed at the beginning of the branch circuit and protect through the home run of the home’s wiring. AFCI receptacles installed in outlets cannot protect against parallel (line-to-neutral) arcing on the home run wiring, which is the wiring from the circuit breaker to the first outlet in the branch circuit. This is why AFCI receptacle manufacturers avoid claiming this protection.
- To protect the home run wiring using an AFCI receptacle, a contractor would have to physically protect the wiring by encasing it in metal conduit or two inches of concrete for protection. That requirement is a difficult installation that requires additional cost for the encasement materials and labor, ultimately making AFCI receptacles more costly than AFCI circuit breakers. In contrast, AFCI circuit breakers are simple to install and provide greater whole house coverage.
Is this a safety concern and are people in danger?
- Any installation that uses AFCI receptacles without also physically protecting the home run circuit, encasing it in metal conduit or two inches of cement, is not only in violation of the NEC®, but also creates a situation where the homeowner may be completely unaware that a portion of the circuit has no parallel arc fault protection. That can mean up to 30% of the home’s electrical system is unprotected against arcing conditions.
- Electrical professionals know that in many cases, the home run wiring is a significant percentage of the branch circuit, so that is a critical detail, depending on each home’s construction. The effects of parallel arcing can be devastating. Electrical contractors need to make clear to their customers that with AFCI receptacles they will only be “partially” protected, or they can opt for whole-house protection with AFCI circuit breakers.
Some builders have indicated that AFCI circuit breakers are just too costly.
- Sadly, these critics have greatly exaggerated these costs. In fact, using average pricing from hardware stores, anyone can easily see the cost for AFCI circuit breakers are $30-$40 a piece or typically around $300 to fully protect the average 2,000-square-foot home in the United States. That is based on using twice the allowable minimum number of circuits. On a typical 30-year mortgage, this may amount to less than $1 per month to the homeowner. This is approximately a 0.1% increase for the average U.S. home over having no AFCIs at all. That’s a small price for protecting your family from electrical fires over the life of your home.
What should a homeowner do if they have concerns their house is not “fully” protected against parallel arcing?
Contractor AFCI Handout