Dual Function Circuit Breakers and Home Run Circuit Safety
Over 30% of circuits in the average home are “home run” circuits. That’s the distance from the load center to the first outlet. Wiring device manufacturers try and convince you that outlet AFCI/GFCI devices are just as safe as using dual function circuit breakers. Fact is, they’re not. Their outlet based AFCI/GFCI protection can’t always protect a home upstream (for parallel arcing conditions). Dual Function circuit breakers are recommended to protect the entire system from the load center.
What Device Manufacturers Forget to Tell You
Here's what device manufacturers who sell AFCI/GFCI combinations outlets forget to tell you and electricians:
- 1. The 2017 National Electrical Code does not allow AFCI outlets on the home run of any circuit in new construction that is not shielded by electrical conduit protecting the wire inside. You cannot use a standard circuit breaker and an AFCI outlet (or AFCI/GFCI outlet) in that first position and wire it with flexible cable. That’s a code violation.
- 2. ACBMA testing showed that standard thermal magnetic circuit breakers cannot protect the home run in all cases against parallel arcing faults. The arcing current needs to exceed the magnetic trip level of the circuit breaker. If this is not the case, the circuit breaker will not trip and a fire can result.
- 3. AFCI/GFCI combinations do not meet the UL1699 Test requirements for “worst case” testing. Basically, they need to be able to stop the arcing condition at 500 amps of available fault current. That can happen in load centers located far from a supporting transformer, such as in a neighborhood, in rural areas, or high rise buildings.
True or False:
Wiring devices, such as AFCI/GFCI outlets that are in the first outlet box of a new home can provide 100% protection against parallel arc faults that can cause a fire in the wiring that precedes it?
The answer is FALSE.
The outlet manufacturers want you to believe that, but their equipment is unable to protect almost 33% of a home because it is not in the load center, where the power flows from.
The current supplied by utilities can vary. When it approaches 500 Amps of “fault current” or the amount of current to cause harm if there is an electrical fault (such as a short circuit or arcing condition), you need approved products that will interrupt that current 100% of the time. Those are circuit breakers. They’re designed to handle that responsibility. Square D™ has been manufacturing Arc Fault Circuit Interruptors (AFCI) since 1999. We have almost 20 years of experience and can detect these dangerous faults to safeguard a home. Why leave 30% or more of your house at risk?
Our Dual Function circuit breakers, with built-in AFCI and GFCI protection, save space and eliminate the need for AFCI/GFCI outlets on the circuits they protect. Imagine only having to go to one location to discover where you’ve “tripped” a circuit. No more hunting around for GFCI outlets. When installed in our Plug-on Neutral load centers, the overall cost is actually less than using AFCI/GFCI outlets.