This article returns to the topic of my December 2013 column, which dealt with some of the changes that occurred to 210.12 for arc-fault circuit interrupters (AFCI) in the 2014 National Electrical Code (NEC), such as the expansion of AFCI devices to include circuits for kitchens and laundry equipment.


The December article also explained that the first three subsections were modified to provide coverage of 210.12(A)(1) with the entire branch circuit protected by a combination AFCI device (circuit breaker); 210.12(A)(2) with a listed branch/feeder AFCI device installed at the origin of the branch circuit and a listed outlet branch circuit at the first outlet box on the branch circuit (this provides both series and parallel ground-fault protection for the circuit); and 210.12(A)(3) where “a listed supplemental arc protection circuit breaker [is] installed at the origin of the branch circuit in combination with a listed outlet branch-circuit type arc-fault circuit interrupter installed at the first outlet box on the branch circuit where all of the following conditions are met: 


Section 210.12(A)(4) covers similar installation requirements as (A)(3); however, the AFCI overcurrent device is not a supplemental AFCI. The new text reads: “A listed outlet branch-circuit type arc-fault circuit interrupter installed at the first outlet on the branch circuit in combination with a listed branch-circuit overcurrent protective device where all of the following conditions are met: 


Again, this requires a system installation but using a listed outlet branch-circuit type AFCI and a listed branch circuit overcurrent protective device—not an AFCI breaker as was required in (3).


The text in 210.12(A)(5), 210.12(A)(6), and the exception for 210.12(A)(6) is relatively unchanged from the 2011 NEC. Section 210.12(A)(5) covers AFCI protection at the first outlet “if RMC, IMC, EMT, Type MC, or steel-armored Type AC cables meeting the requirements of 250.118, metal wireways, metal auxiliary gutters, metal outlet, and junction boxes are installed for the portion of the branch circuit between the branch-circuit overcurrent device and the first outlet, a listed outlet branch circuit type AFCI is permitted at the first outlet to provide protection for the remaining portion of the branch circuit.” Section 210.12(A)(6) still states, “where a listed metal or nonmetallic conduit or tubing or Type MC cable is encased in not less than 50 mm (2 inches) of concrete for the portion of the branch circuit between the branch-circuit overcurrent device and the first outlet, it shall be permitted to install a listed outlet branch-circuit type AFCI at the first outlet to provide protection for the remaining portion of the branch circuit.”


Informational Note 1 provides a reference for information on combination-type and branch/feeder-type AFCIs in UL 1699 2011, Standard for Arc-Fault Circuit Interrupters; on outlet branch-circuit-type AFCIs in UL Subject 1699A, Outline of Investigation for Outlet Branch Circuit Arc-Fault Circuit-Interrupters; and on system combination AFCIs in UL Subject 1699C, Outline of Investigation for System Combination Arc-Fault Circuit Interrupters. Informational Notes 2 and 3 
provide a reference to NFPA 72 for fire alarms and 760.41(B) and 760.121(B) for power supply requirements.


Since these changes are fairly extensive and complex, a thorough study may be necessary to understand them.