In many conversations with electrical inspectors on the subject of arc-fault circuit-interrupters (AFCIs), I find them variously questioning, doubtful, confused, bewildered and puzzled concerning the application of 210.12. The most often expressed concern is that there have been many reports of AFCI failures.
The next concern is statistical: how many fires will be prevented, and at what cost? Fire reporting identifying arcing as the cause is collected from report forms on which “arcing” is essentially the only choice for the fire investigator. There are other fire causes than arcing. Also, there are forms of arcing, which the present generation of AFCI devices is not able to detect.
By requiring the entire branch circuit to be protected, the protection of flexible cords has been compromised, whereas cords are the most likely source of arcing faults. It appears that the Code and the public are being asked to conduct and finance the research on this new product that should have been done before it was introduced into the Code.
The NEC is not retroactive, and therefore the AFCI applications will largely be done on branch circuits that are new. The older wiring that is more likely to fail will receive AFCI protection only gradually, as remodeling, additions and re-wiring are done on older structures.
This brings up some of the concerns of the electrical inspector. In a new dwelling there is no question—210.12 must be followed, adding relatively little to the overall cost of the construction. Why the smoke detector on a bedroom branch circuit is subject to disconnection by the AFCI is a mystery. Battery backup has been cited as making this of no concern, but it is well known that batteries in smoke detectors are frequently missing.
210.8(A)(5) Exception No. 3 says that GFCI protection is not required where smoke detectors are on the circuit. Why not except such circuits from AFCI protection as well?
Where an addition to an existing dwelling is made, including a new bedroom, there is no question that the branch circuit(s) to the new bedroom must be AFCI protected. Even where the existing lighting and appliance branch circuit panelboard is adequate for the new addition, if the panelboard does not accept AFCI breakers then the panelboard will have to be replaced. This is one of the major concerns of the inspector—a great many existing panelboards do not accept AFCI circuit breakers, and to replace the panelboard is a major undertaking and a major expense for the owner.
Where alterations are undertaken involving an existing bedroom, it may be reasonable to require that AFCI breakers be installed, also providing the panelboard will accept them.
Where a dwelling is being completely rewired to meet a housing code requirement, then the AFCI breakers will be required.
In the case of a major remodel, such as a bathroom or a kitchen, but not involving the bedroom(s), it would depend on the make of panelboard. If the existing, or new, panelboard will accept AFCI breakers, then the bedroom circuits could reasonably be picked up.
On the occasion of a truck pulling down the drop, or vandalism, it is sometimes necessary to change the service consisting of a meter and a main, but nothing else. In this case, when the lighting and appliance branch circuit panelboard is not being touched, it would not be reasonable to require the bedroom circuits to be AFCI protected.
Where there is a service change and the main is part of a combination panelboard it would be reasonable to require that the new panelboard be one that accommodates AFCI breakers, and that the bedroom circuits be protected.
There are a great many existing panelboards in dwellings of a make, which will not accept an AFCI circuit breaker.
The results of these concerns is that in new construction, including remodeling, the new wiring that is the least likely to fail and arc is being protected, while the vast amount of old wiring is left without AFCI protection, good or bad. The fire statistics on which the requirement for the AFCI is based had to include existing dwellings of 30, 40 and more years old, so that AFCIs installed today will not start preventing fires for several years. Maybe that is to the good, but in the meantime look at the cost.
The inspectors’ reluctance to impose a requirement that adds a relatively large amount to the cost of a remodel project with a questionable degree of added safety is understandable. EC
SCHWAN is an electrical Code consultant in Hayward, Calif. He can be reached at firstname.lastname@example.org.