Updates to 2014 NEC
NFPA 70, the National Electrical Code, will next be updated in 2014. Here's a look at what to expect.
By Justin Schultz, PE, LEED AP ID+C, Metro CD Engineering, Dublin, Ohio
In 2011, 3745 proposals were submitted to NFPA to be considered for incorporation into the upcoming 2014 National Electrical Code (NEC). Technical committees reviewed these proposals, commented on them, and gave a recommended action (e.g., accept or reject) in a document called the report on proposals (ROP). The ROP was published and open for comments, which will be considered and addressed in the report on comments (ROC) to be presented for action at the NFPA Technical Meeting in 2013. The 2014 edition of the National Electrical Code will be available in the fall of 2013.
Some of the new NEC articles and changes are indicative of the code progressing to address new and evolving technologies. Proposals currently listed as accepted include four new articles, which are representative of technology advances that are either not currently covered in the NEC or require a more detailed set of requirements. The articles and changes serve the NEC’s mission to provide practical safeguards from the hazards that arise from using electricity.
In addition to changes addressing new technologies, there are also proposed changes to existing articles that will impact the status quo for electrical design. Electrical engineers and designers should take note, for example, of the additional locations requiring GFCI and AFCI protection (Article 210), the additional requirements for installations involving generators (Article 445), and the increased minimum number of receptacles required for patient bed locations and operating rooms (Article 517).
393 Low-voltage Suspended Ceiling Power Distribution Systems A proposed new article would cover installations of low-voltage suspended ceiling power distribution systems. These systems have similar characteristics to track lighting, where the ceiling grid is used as an electrical system for distributing power to lighting fixtures and other powered devices. The substantiation for adding this article states that alternative and renewable energy sources (e.g., photovoltaics, wind turbines, batteries, fuel cells, etc.) are increasingly being installed and, “this coupled with the reality that many of the loads installed ultimately use electricity in its dc form has renewed an interest in dc power and its distribution in buildings.” Proponents of these types of systems state that they enable lighting (and other device) reconfigurations without rewiring and require no ac/dc conversion (when directly connected to alternative energy sources).
Consider that most commercial buildings as well as many residential buildings today have suspended ceilings. The prevalent metal grid work can not only be used as support for acoustical ceiling tile and lighting fixtures, but also as a power distribution system. Details of the article include installation requirements, and uses permitted are limited to indoor dry locations for residential, commercial, and industrial installations. The system must be listed or an assembly of listed parts. The article limits systems to a maximum of 30 Vac or 60 Vdc Class 2 power.
646 Modular Data Centers This new article would define and list applicable requirements for a developing trend in data center architecture called modular data centers (MDCs). The unique customization and scalability of MDCs can vary their sizes from a large enclosure to a prefabricated building, while the equipment is typically not permanently installed. Details of the article include requirements for nameplate data, supply conductors and overcurrent protection, short-circuit current rating, field wiring compartments, and flexible power cable. Also listed are provisions for equipment, lighting, and work space requirements.
728 Fire Resistive Cable Systems A new article would list all requirements in one place for fire-resistive cable, conductor, and other system components used for survivability of critical circuits in fire conditions. Some of the installation requirements listed include mounting, supports, splices, raceways, and pulling lubricants.
750 Energy Management Systems A task group was appointed to focus on interconnection and energy management systems. The task group drafted this proposed article to address safety requirements for implementing infrastructure to allow the Smart Grid to actively manage energy management systems as a means to reduce energy costs or reduce peak power needs.
New or revised sections and subdivisions
100 Retrofit Kit A definition for “retrofit kit” is proposed to be added to Article 100. Retrofit kit would be defined as, “a general term for a complete listed subassembly of parts and devices for field conversion of utilization equipment.” New requirements for luminaire retrofit kits are also proposed to Section 410.6 (see below).
110.17 Working Space Marking This proposed new section in Article 110 (Requirements for Electrical Installations) would require that equipment working space be identified on or adjacent to the equipment. The marking shall include the words, “CAUTION! AREA IN FRONT OF ELECTRICAL PANELS EQUIPMENT SHALL BE KEPT CLEAR FOR DEPTH: WIDTH: HEIGHT” with the required dimensions listed.
110.21(B) Field-Applied Markings This proposed new subdivision lists specific requirements for the content, color, durability, and suitability for field-applied markings and labels.
110.25 Lockable Disconnecting Means This new section would consolidate requirements for lockable disconnecting means into one section. The new text requires that where a disconnecting means is required to be lockable open, it shall be capable of being locked in the open position. It also ensures that the means for placing the lock remain in place.
110.26 Ground-Fault and Arc-Fault Circuit Interrupter Receptacles A new section would require that all ground-fault circuit-interrupter (GFCI) and outlet branch circuit type arc-fault circuit-interrupter (AFCI) receptacles be installed in a readily accessible location. The intent is to help facilitate the required periodic testing of these devices.
110.27(C)(2) and (3) Entrance to and Egress from Working Space, Personnel Doors These subdivisions currently list the requirements for two personnel doors where equipment rated 1200 A or more is installed containing overcurrent devices, switching devices, or control devices. The proposed amendment would reduce the requirement threshold to equipment rated 800 A or more. Another change would require that the egress doors have listed panic hardware (rather than allowing the use of other devices that are normally latched but open under simple pressure).
210.8(A)(9) GFCI Protection for Personnel, Dwelling Units This subdivision would add laundry areas to the current list of locations in dwelling units which currently require that all 125 V, single-phase, 15 A and 20 A receptacles have GFCI protection. The current list of locations includes bathrooms, garages, outdoors, crawl spaces, unfinished basements, kitchens, sinks, and boathouses.
210.12(A) Arc-Fault Circuit-Interrupter Protection, Dwelling Units Kitchens would be added to the list of rooms and areas in dwelling units that require AFCI protection for all 120 V, single-phase, 15 A and 20 A branch circuits supplying outlets. AFCIs were first introduced in the NEC in 1999 and were required in bedrooms. Their primary purpose is to protect the building from a fire. Newer releases of the NEC have added additional requirements and spaces where AFCIs are required. This proposed change is the next incremental step toward AFCI protection of all 120 V, 15 A and 20 A branch circuits in dwelling units.
Another revision would recognize use of a listed outlet branch circuit type AFCI installed at the first outlet on the branch circuit. In order to use AFCI outlet devices, the following four specific conditions must be met:
(a) The branch circuit overcurrent protection device shall be a listed circuit breaker having an instantaneous trip not exceeding 300 A.
(b) The branch circuit wiring shall be continuous from the branch circuit overcurrent device to the outlet branch circuit arc-fault circuit interrupter.
(c) The maximum length of the branch circuit wiring from the branch circuit overcurrent device to the first outlet shall not exceed 50 ft for a 14 AWG or 70 ft for a 12 AWG conductor.
(d) The first outlet box in the branch circuit shall be identified.
210.17 Electric Vehicle Branch Circuit The proposed new section to Article 210 (Branch Circuits) would require that outlet(s) intended for the purpose of charging electric vehicles be supplied by a separate, dedicated branch circuit.
210.64 Electrical Service Areas A new section would require that at least one 15 A or 20 A receptacle outlet be installed within 50 ft of the electrical service equipment (except for in one- and two-family dwellings). The new receptacle requirement is intended to facilitate use of portable electrical equipment for testing and servicing purposes.
240.11 Oversized Ungrounded Conductors The proposed new section to Article 240 (Overcurrent Protection) would require marking or tagging of ungrounded conductors that are increased in size for voltage drop or derating purposes. The mark or tag shall be located at the point where the conductors receive their supply. An exception would be provided for conditions where maintenance and engineering supervision ensure that only qualified personnel document, monitor, and service the equipment.
250.122(F) Conductors in Parallel This section would be amended to clarify that where conductors are run in parallel, the equipment grounding conductors shall not be required to be larger than the largest ungrounded conductor.
250.194 Grounding and Bonding of Fences and Other Metal Structures This proposed new section would provide new rules for bonding and grounding metal fences and metal structures, including guy wires. The requirements are intended to limit step, touch, and transfer voltages.
310.15(B)(7) 120/240 V, Single-Phase Dwelling Services and Feeders The proposed change would replace the existing Table 310.15(B)(7) with text stating that 83% of the 230.79 service ampere rating shall be permitted to be used as the minimum ampacity to determine the size of the ungrounded conductors. Although the reduction in minimum ampacity is the same as permitted in the existing table, the intent is to present the requirements in a user-friendly format. An example would be referenced in Annex D to provide more information on how to apply the new language.
330.30(D) Unsupported Cables The new subdivision would allow metal-clad cable (type MC) to be unsupported in lengths up to 3 ft for equipment flexibility reasons or to minimize transmission of vibration.
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