Top 10 Changes in NEC-2008

[jtedesco1]

Top 10 Changes in NEC-2008

by Michael J. Johnston

Because new technologies are entering the market continually and code rules must be developed or revised to address electrical safety concerns related to these emerging products, systems, methods, and equipment, the NEC development process is dynamic—a vital, ever-moving force.
The 2008 process demonstrated that revisions are inevitable and very necessary. Here are ten of the most important changes.
1. Article 100 and Entire Code: Definitions

Throughout the entire NEC-2008, revisions have been made to numerous Code rules where grounding and bonding terms are used. Several terms have been redefined and simplified for accuracy. Effectively grounded has been deleted and a new definition of ungrounded has been added. The terms affected by this revision are as follows:

• bonding (bonded) – revised
• grounding electrode conductor – revised
• grounding conductor, equipment – revised
• grounding electrode – revise
• ground – revised
• grounding (grounded) – revised
• grounded, effectively – deleted
• ungrounded – new

Appropriate Code-wide usage has been ensured, and grounding and bonding terms are used more consistently with their defined meaning. Rules throughout Article 250 and the NEC have been revised to be more specific and prescriptive where rules related to grounding and bonding requirements were inconsistent with what is intended to be accomplished from a performance perspective and what is required by the actual text used in the Code.

2. 110.26(C)(3) Personnel Doors

The second sentence in 110.26(C)(2) was relocated to become item (3) and revised to address specific requirements relating to personnel doors. Personnel access doors less than 25 feet from the working space are to open outward with simple pressure. Similar revisions were made in 110.33 to the personnel door requirements for equipment rated over 600 volts.

Egress doors less than 25 feet from the working space (from page 47)
3. 210.4(B) Multiwire Branch Circuits
Information about conductors of multiwire branch circuits originating from the same panelboard or distribution equipment has been relocated to 210.4(A). Now 210.4(B) addresses disconnecting means for simultaneously disconnecting all ungrounded conductors of all multiwire branch circuits. Simultaneously disconnecting all conductors of multiwire branch circuits is now expanded to all multiwire branch circuits, not just those that supply more than one device mounted on the same yoke or mounting strap.

Multiwire branch circuits (from page 54)
4. 210.8(A)(2) and (A)(5) Dwelling Units
The GFCI protection requirements for receptacles in basements, garages, and accessory buildings have been expanded to all 125-volt, single-phase, 15- and 20-ampere receptacles regardless of accessibility or movability of an appliance from one location to another.
Four exceptions were deleted: the two from 210.8(A)(2) and Nos. 1 and 2 to (A)(5). Additional text added to 210.8(A)(5) indicates that any receptacles installed under the exception to 210.8(A)(5) shall not be considered as meeting the requirements of 210.52(G). A new FPN refers users to 760.41(B) and 760.121(B) for fire alarm system supply-circuit requirements.

GFCI protection is required for receptacles in basements, accessory buildings, and garages of dwellings unless exempted by remaining exceptions. (from page 57)
5. 210.12(B) Dwelling Units
Combination-type AFCI-protective devices are now required in all dwelling unit rooms, except for kitchens, bathroom, garages, basements, and rooms or areas not specified in this section. This continues the incremental migration to provide whole-house AFCI protection for dwelling units that was the objective of the original proposals in the 1999 NEC development cycle.
This section was revised to include a list of rooms and areas where the serving branch circuits are to be protected by arc-fault circuit-interrupter protection. Essentially, the requirements for this protection are expanded to most areas and rooms in the dwelling unit with the exception of those named above and other areas or rooms not specifically identified in this section. The AFCI-protective devices must be listed combination types.

Locations of AFCI protection in a typical dwelling (from page 64)
6. 250.32(B) and Exception, Grounded Systems
Equipment grounding conductors are required to be installed with all branch circuits and feeders supplying separate buildings or structures. The exception applies to existing premises wiring systems only.
This change should help reduce the number of designs that purposely invite the possibilities of inappropriate neutral-to-ground connections that can and often do happen in later renovations, which is uncontrollable by any NEC rule. Existing installations meeting the requirements of 250.32(B)(2) in previous editions of the NEC would be allowed to remain operational. The restrictive conditions of the new exception [former 250.32(B)(2)] still have to be met and are subject to approval of the applicable authority having jurisdiction.

Equipment grounding conductors in branch circuits and feeders supplying separate buildings (from page 114)
7. 310.15(B)(2)(c) and Table 310.15(B)(2)(c) Conduits Exposed to Sunlight on Rooftops
Conductors and cables installed in conduit or tubing exposed to direct sunlight on rooftops are subject to temperature adjustment factors in accordance with the values in Table 310.15(B)(2)(c) based on distance above the roof surface. The temperature values in the table shall be added to the ambient temperature and applied to the temperature correction factors provided in Table 310.15 and Table 310.18.
A new requirement in subdivision (c) has been added to 310.15(B)(2). In addition to the new text in subdivision (c), a new companion Table 310.15(B)(2)(c) has been added. To correlate with this change, the existing FPN to 310.10 has been deleted.

Conduits exposed to sunlight on rooftops (from page 154)

Conduits exposed to sunlight on rooftops (from page 155)
8. 406.11 Tamper-Resistant Receptacles in Dwelling Units
Listed tamper-resistant receptacles are required for 125-volt, 15- and 20-ampere receptacles in dwelling units in areas specified in 210.52.
Substantiation provided by The U.S. Consumer Product Safety Commission’s National Electronic Injury Surveillance System indicated that during a 10-year period, from 1991 to 2001, over 24,000 children in the United States were injured when they inserted foreign objects into electrical receptacles. Every year, at least 2,400 children, on average, are injured when tampering with electrical receptacles. The number of injuries is significant and demonstrates the need for more protection.

Tamper-resistant receptacles in dwelling units (from page 227)

Tamper-resistant receptacle (from page 227)
9. New Article 626 Electrified Truck Parking Space
Article 626 provides installation requirements for truck stops that will supply electrical and communications services so that truck engines will be shut off for a time to lessen carbon emissions and to reduce fuel consumption.
Over the past several years, the attention of regulatory agencies and environmental groups has focused on means to reducing truck idling, thereby reducing emissions and fuel consumption. More than twenty states and cities have already adopted legislation to reduce the number of hours a truck idles. This article includes provisions similar to those already existing in Articles 550 and 551 that also include requirements for permanent power facilities. Requirements for standardized wiring methods, materials and configurations will result in uniform electrified truck parking spaces throughout the country. It will also ensure that all truck fleets will have the ability to connect to “shore power” to run cab amenities (hotel loads) and the heating, ventilation and air-conditioning systems.

Electrified truck parking space (from page 327)
10. New Article 708 Critical Operations Power Systems
Critical operations power systems (COPS) provide requirements for facilities that are designated as mission critical and vital for national security such as 911 operations center, hospitals, telecommunications centers, air traffic control, water pumping stations, some fueling facilities and petrochemical plants. This list is not exhaustive.
The requirements in this article target electrical power continuity for systems and circuits that are vital to national security, the economy, or public health and safety. Some of the rules call for hardened electrical circuit wiring, specific power sources and source location designs, overcurrent protection operational characteristics and locations, and system performance and analysis.

Critical operations power system (from page 36

Entrance to a critical operations power system (from page 369)
Summary
There were 3688 proposals and 2349 comments resulting in many significant and interesting revisions in NEC-2008. Four new articles and two new annexes have been added for this cycle along with rules that address electrified truck parking space equipment and critical operations facilities. Each edition of the NEC experiences revisions necessary to keep up with the dynamics of the electrical field. NEC-2008 has been revised to enhance protection against arcing faults in dwellings, thus increasing electrical safety for dwellings and occupants. The expansion of ground-fault circuit-interrupter protection requirements in dwellings and other occupancies increases protection against electric shock and electrocution for persons.
This article provides only a small review of some of the more significant changes in NEC-2008, but many more revisions resulted in improved code-wide clarity and usability. The International Association of Electrical Inspectors is actively involved in the Code development process and provides detailed coverage of over 400 of the 2008 Code revisions in IAEI’s Analysis of Changes NEC-2008. Contact IAEI at 1-800-786-4234 for your copy today.
The 2011 NEC development process is already underway with over 200 proposals already submitted. Get involved in the process. After all, it is our Code, publicly developed and improved each cycle through open consensus, resulting in enhanced electrical safety for persons and property, the bottom line.


Michael J. Johnston is IAEI’s director of education, codes and standards, technical editor, and an IAEI principal member on CMP-5. Johnston was formerly employed as an electrical field inspections supervisor for the city of Phoenix, Arizona. He is fully certified in many areas. He is a member of the IBEW. He achieved both journeyman E-2 and master electrician E-1 licenses in the state of Connecticut. Additionally, he holds all IAEI certifications. He also holds ICC Electrical Inspections Certification. He is a member of the UL Electrical Council.

http://www.electricalassociation.com...8NECTop10.aspx

http://www.electrician2.com/2008nec_...rvframehol.htm

[Troy Farmer]

Thanks Joe good stuff