There were 3,688 proposals for changes to the National Electrical Code (NEC) and 2,349 comments processed by the National Fire Protection Association (NFPA) staff at NFPA headquarters in Quincy, Mass. The following are significant changes for the 2008 NEC, but remember, the NFPA NEC process is not yet complete. Based on any appeals that may be processed through the NFPA Standards Council meeting on July 23 and 24 in Las Vegas, the text may change before the issuance of the 2008 NEC.

The following are some of the most important changes. Strikethrough text shows deletions, and underlined text shows additions. Commentary denoted by red text also follows each change for explanation.

2008 NEC—Article 100

Clothes Closet. A non-habitable room or space intended primarily for storage garments and apparel.

A new definition has been added to clarify what constitutes a “clothes closet.”

2008 NEC—Article 100

Equipment. A general term including material, fittings, devices, appliances, luminaires (fixtures), apparatus, machinery, and the like used as a part of, or connection with, an electrical installation.

“Machinery” has been added to the definition to ensure electrical machinery is included in the definition for electrical equipment. Section 110.2 states conductors and electrical equipment required or permitted by the NEC to be acceptable only if approved. Adding “machinery” will now make it clear that the NEC covers industrial equipment installations.

2008 NEC—Article 100

Neutral Conductor. The conductor connected to the neutral point of a system that is intended to carry current under normal conditions.

Neutral Point. The common point on a wye-connection in a polyphase system or midpoint on a single-phase, 3-wire system, or midpoint of a single-phase portion of a 3-phase delta system, or a midpoint of a 3-wire, direct current system.

FPN: At the neutral point of the system, the vectorial sum of the nominal voltages from all other phases within the system that utilize the neutral, with respect to the neutral point, is zero potential.

Two new definitions provide information on what constitutes a neutral and a neutral point.

2008 NEC—Article 100

Qualified Person. One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved.

Adding the phrase “to recognize and avoid” to the definition of qualified person provides a reason for the safety training.

2008 NEC—Article 100

Short-Circuit Current Rating. The prospective symmetrical fault current at a nominal voltage to which an apparatus or system is able to be connected without sustaining damage exceeding defined acceptance criteria.

Adding this definition provides a definition for the phrase used in 110.10 and various other locations in the Code.

2008 NEC—110.20

Enclosure Types. Enclosures (other than surrounding fences or walls of switchboards, panelboards, industrial control panels, motor control centers, meter sockets, and motor controllers, rated not over 600 volts nominal and intended for such locations) shall be marked with an Enclosure Type number as shown in Table 110.20.

Table 110.20 shall be used for selecting enclosures for use in specific locations, other than hazardous (classified) locations. The enclosures are not intended to protect against conditions, such as condensation, icing, corrosion, or contamination that may occur within the enclosure or enter via the conduit or unsealed openings.

Table 430.91, covering motor controller enclosure types, has been used by many NEC users for enclosures for numerous kinds of equipment, even though 430.91 states it applies only to motor controller enclosures. Moving the requirements of 430.91 and Table 430.91 into a general application area of the NEC and specifically stating the kinds of equipment to which they apply will add clarity.

2005 NEC—110.26

(C) Entrance to Working Space

(2) Large Equipment. For equipment rated 1,200 amperes or more that contains overcurrent devices, switching devices, or control devices, there shall be one entrance to the required working space not less than 610 mm (24 in.) wide and 2.0 m (6½ ft.) high at each end of the working space. Where the entrance has a personnel door(s), the door(s) shall open in the direction of egress and be equipped with panic bars, pressure plates, or other devices that are normally latched but open under simple pressure.

A single entrance to the required working space shall be permitted where either of the conditions in 110.26(C)(2)(a) or (C)(2)(b) is met.

2008 NEC—110.26

(C) Entrance to Working Space

(2) Large Equipment. For equipment rated 1,200 amperes or more and over 1.8 m (6 ft.) wide that contains overcurrent devices, switching devices, or control devices, there shall be one entrance to the required working space not less than 610 mm (24 in.) wide and 2.0 m (6½ ft.) high at each end of the working space.

(3) Personnel Doors. Where equipment rated 1200 A or more that contains overcurrent devices, switching devices, or control devices is installed and there is a personnel door(s) intended for entrance to and egress from the working space less than 7.6 m (25 ft) from the nearest edge of the working space, the door(s) shall open in the direction of egress and be equipped with panic bars, pressure plates, or other devices that are normally latched but open under simple pressure.

This change effectively returns the requirement for large equipment to be over 6 feet in width, which was deleted for the 2005 NEC, and 1,200 amperes or more.

The requirements covering personnel doors intended for entrance and egress from large equipment has been relocated into new Section 110.26(C)(3). New (3) will now require any door within 25 feet from large equipment must have panic hardware and open in the direction of egress.

2005 NEC—210.12

Arc-Fault Circuit-Interrupter Protection.

(B) Dwelling Unit Bedrooms. All 120-volt, single phase, 15- and 20-ampere branch circuits supplying outlets installed in dwelling unit bedrooms shall be protected by a listed arc-fault circuit interrupter, combination type installed to provide protection of the branch circuit.

Branch/feeder AFCIs shall be permitted to be used to meet the requirements of 210.12(B) until January 1, 2008.

FPN: For information on types of arc-fault circuit interrupters, see UL 1699-1999, Standard for Arc-Fault Circuit Interrupters.

Exception: The location of the arc-fault circuit interrupter shall be permitted to be at other than the origination of the branch circuit in compliance with (a) and (b):

(a) The arc-fault circuit interrupter installed within 1.8 m (6 ft) of the branch circuit overcurrent device as measured along the branch circuit conductors.

(b) The circuit conductors between the branch circuit overcurrent device and the arc-fault circuit interrupter shall be installed in a metal raceway or a cable with a metallic sheath.

2008 NEC—210.12

Arc-Fault Circuit-Interrupter Protection.

(B) Dwelling Units. All 120-volt, single phase, 15- and 20-ampere branch circuits supplying outlets installed in dwelling unit in family rooms, dining rooms, living rooms, parlors, libraries, dens, sun rooms, recreation rooms, closets, hallways, or similar rooms or areas shall be protected by a listed arc-fault circuit interrupter, combination type installed to provide protection of the branch circuit.

FPN: For information on types of arc-fault circuit interrupters, see UL 1699-1999, Standard for Arc-Fault Circuit Interrupters.

Exception No. 1: Where RMC. IMC, EMT or steel armored cable, Type AC, meeting the requirements of 250.118 using metal outlet and junction boxes is installed for the portion of the branch circuit between the branch circuit overcurrent device and the first outlet, it shall be permitted to install a combination AFCI at the first outlet to provide protection for the remaining portion of the branch circuit.

The action in these proposals deleted the phrase “supplying outlets” and the word “bedrooms” now requiring AFCI protection for all 120-volt, single-phase, 15- and 20-ampere branch circuits in family rooms, dining rooms, living rooms, parlors, libraries, dens, sun rooms, recreation rooms, closets, hallways, or similar rooms or areas. In addition, the last sentence, permitting branch/feeder AFCI devices until January 1, 2008, has been deleted, and the effect is to now require only listed combination AFCI branch circuit protection.

A new exception has been added permitting RMC, IMC, EMT or steel AC cable to protect the branch circuit to the first outlet with the 6-foot length deleted.

The NEC is an ever-changing, ever-improving document, and these are only some of the most important changes for the 2008 version. For more information, see “Stallcup’s Illustrated Code Changes, 2008 edition”. EC

ODE is a staff engineering associate at Underwriters Laboratories Inc., in Research Triangle Park, N.C. He can be reached at 919.549.1726 or at mark.c.ode@us.ul.com. James G. STALLCUP is the CEO of Grayboy Inc., which develops and authors publications for the electrical industry and specializes in classroom training on the NEC and OSHA, as well as other standards. Contact him at 817.581.2206. James W. STALLCUP is vice president and senior editor at Grayboy.