NFPA Journal®, July/August 2012
In the last issue of NFPA Journal, I began a two-part review of the proposed articles for the 2014 edition of NFPA 70®, National Electrical Code®, that resulted from actions taken by several code-making panels (CMPs) at the January 2012 Report on Proposals (ROP) meeting. After the meeting and before the ROP was issued, the NEC Correlating Committee reviewed the actions taken by the CMPs. The committee directed that Article 302, Low Voltage Suspended Ceiling Power Distribution Systems, be renumbered as Article 393 and rejected a proposed Article 696, Energy Storage Systems.
The committee also directed the chairs of CMP 4, CMP 13, Direct Current Task Group, and the Smart Grid Task Group to form another task group to review the requirements in the proposed Article 696, to determine if they can be incorporated into existing articles or are better suited for a stand-alone article.
The committee accepted three other new articles proposed for the 2014 NEC. Article 646, Modular Data Centers, covers an emerging trend in data center architecture. It defines a modular data center as a “prefabricated unit rated 600 volts or less, consisting of an outer enclosure housing information technology equipment (ITE) and various support equipment such as electrical service and distribution equipment, HVAC systems and the like.”
The concept of a modular data center is no different than other off-site structures or equipment in that the electrical infrastructure is installed in a manufacturing facility, then sent to the end-user for installation. The on-site wiring involves installing supply circuits from the premises’ electrical supply to the pre-wired unit. All the other wiring is installed during manufacture. This is what distinguishes a modular data center from field-installed information technology equipment wired in accordance with the provisions of Article 645, Information Technology Equipment. The new article requires modular data centers to be listed and labeled by a qualified testing laboratory.
Article 728, Fire Resistive Cable Systems, centralizes installation requirements for this type of fire protective system, which provides survivability to critical power and signaling circuits in the event of a fire. Currently, fire-resistive cable systems are addressed in a number of NEC articles, including 695, Fire Pumps; 700, Emergency Systems; 725, Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power-Limited Circuits; 760, Fire Alarms Systems; 770, Optical Fiber Cables and Raceways; and 800, Communications Circuits. Fire-resistive cable systems have specific installation requirements that cover the type of wiring method, the support of the wiring method, the type of enclosures that can be used for splicing, and the splicing method. This article also provides other installation requirements unique to this type of wiring system.
The last article proposed is 750, Energy Management Systems. A correlating committee task group was convened to study how the “smart grid” idea may affect premises wiring systems and what requirements the NEC should include to allow for implementation in the electrical infrastructure the code covers. Energy management systems are used to control and manage electrical power use in a building. At some point, these systems are likely to “talk” to the smart grid to control electrical loads during peak power usage and as part of managing on-site electrical power production sources that interact with the power grid. The new article provides requirements to ensure that critical safety equipment is not disabled by off-site control.
The closing date for public comment on the 2014 NEC is October 17.
Jeffrey Sargent is a regional electrical code specialist for NFPA.