2011 Changes to the NEC – 210.12

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There are some important features in this text which help to highlight the changes that you should be aware of:

• Each Code section which contains a change includes a summary of the change, followed by a paraphrase of the NEC text affected by the change. Any specific change is denoted by underlined text and in the corresponding chapter color
• Graphics with green borders and 2011 CC icons next to the heading are graphics that contain a 2011 change; graphics without a green border or icon are graphics that support the concept being discussed, but nothing in the graphic was affected by a 2011 Code change.

210.12 Arc-Fault Circuit-Interrupter Protection for Dwelling Units

Changes have been made to this section to address fire alarm circuiting, Type MC Cables, concrete-encased raceways, and branch circuit extensions or modifications.

210.12 Arc-Fault Circuit-Interrupter Protection for Dwelling Units.

Author’s Comment: The combination AFCI is a circuit breaker that protects downstream branch-circuit wiring as well as cord sets and power-supply cords; an outlet branch circuit AFCI (receptacle) is installed as the first outlet in a branch circuit to protect downstream branch-circuit wiring, cord sets, and power-supply cords.

(A) Where Required. All 15A or 20A, 120V branch circuits in dwelling units supplying outlets in family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, or similar rooms or areas must be protected by a listed AFCI device of the combination type.

Figure 210-15 (Click on image to enlarge)

Author’s Comment: The 120V circuit limitation means AFCI protection isn’t required for equipment rated 230V, such as a baseboard heater or room air conditioner. For more information, visit www.MikeHolt.com, click on the “Search” link, and search for “AFCI.”

Note 3: See 760.41(B) and 760.121(B) for power-supply requirements for fire alarm systems.

Author’s Comment: Smoke alarms connected to a 15A or 20A circuit of a dwelling unit must be AFCI protected if the smoke alarm is located in one of the areas specified in 210.12(A). The exemption from AFCI protection for the “fire alarm circuit” contained in 760.41(B) and 760.121(B) doesn’t apply to the single- or multiple-station smoke alarm circuit typically installed in dwelling unit bedroom areas. This is because a smoke alarm circuit isn’t a fire alarm circuit as defined in NFPA 72, National Fire Alarm Code. Unlike single- or multiple-station smoke alarms, fire alarm systems are managed by a fire alarm control panel.

Figure 210-16 (Click on image to enlarge)

Ex 1: AFCI protection can be of the branch-circuit type located at the first outlet if the circuit conductors are installed in RMC, IMC, EMT, or Type MC or steel armored Type AC cable meeting the requirements of 250.118, and the AFCI device is contained in a metal outlet or junction box.

Ex 2: Where a listed metal or nonmetallic conduit or tubing is encased in not less than 2 in. of concrete for the portion of the branch circuit between the branch-circuit overcurrent device and the first outlet, an outlet branch-circuit AFCI at the first outlet is permitted to provide protection for the remaining portion of the branch circuit.

Ex 3: AFCI protection can be omitted for an individual branch circuit to a fire alarm system in accordance with 760.41(B) and 760.121(B), if the circuit con-ductors are installed in RMC, IMC, EMT, or steel sheath Type AC or MC cable that qualifies as an equipment grounding conductor in accordance with 250.118, with metal outlet and junction boxes.

(B) Branch-Circuit Extensions or Modifications—Dwelling Units. Where branch-circuit wiring is modified, replaced, or extended in any of the areas specified in 210.12(A), the branch circuit must be protected by:

(1) A listed combination AFCI located at the origin of the branch circuit; or

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

 

ANALYSIS: Fire alarm systems covered by Article 760 have been exempted from the requirements of AFCI protection, but the circuiting of the those systems was previously not addressed. This inadvertently left a loophole for installers to incorporate other outlets in areas specified by 210.12 on the same circuit as the fire alarm system and omit the AFCI protection required for circuits in those areas. This change also includes MC cable as a permitted wiring method when employing this exception. Section 210.12 Ex 1 has been revised to allow MC cables as one of the allowable wiring methods in the exception. MC cable meeting the requirements of 250.118 has been proven safe, so this allowance seems fair enough. New to the NEC is 210.12(A) Ex 2. Concrete encased raceways obviously provide an increased level of protection for circuit conductors, so a new exception was added to allow such raceways to be installed without AFCI protection at the source, provided that there’s an outlet type AFCI installed at the first outlet of the circuit. Also new to the NEC is subsection (B), dealing with branch-circuit extensions or modifications in existing buildings. The question of what to do with existing buildings in regard to AFCI protection has been prevalent ever since AFCI requirements were added to the Code in 1999. With this change it’s clear that when branch-circuit wiring is extended or modified, some level of AFCI protection will be required.

 

Don't let the scale of the code changes intimidate you, this package will get you up to speed on the most essential 2011 NEC changes quickly. The book is well-organized, easy to follow, and the full-color illustrations bring the material to life. The DVDs bring together a group of experts from the field to discuss the changes and how they apply in the real-world. This program includes the following items: Changes to the NEC 2011 Textbook Changes to the NEC 2011 DVD 1 & 2 includes Articles 90 - 810 Product Code: 11CCDVD Price: $198.00