Charting a Course for Safety
NFPA Journal®, May/June 2012
Next year, the NFPA membership will vote on the 2014 edition of NFPA 70®, National Electrical Code®, at the NFPA Conference & Expo, which will be held in Chicago. Between now and then, there will be task group meetings, the Report on Comments meeting of the entire NEC® committee, a meeting of the NEC Technical Correlating Committee, and many hours of work on the part of NFPA’s technical, production, and editorial staff. Our volunteer committee members and the public will spend countless hours moving the NEC’s electrical safety mission forward.
The 2014 NEC will be the 53rd edition of the code, and some of the changes that have been initially accepted through the proposal phase of the revision process indicate that these are indeed interesting times in the electrical industry. Those changes emphasize the importance of providing jurisdictions with a code that is up to date with the latest innovations in the way electricity is used and controlled.
Proposals to include five new articles in the 2014 NEC were accepted at the ROP meeting held in January in South Carolina. The new articles are representative of the current expansion of innovation and technology in the electrical industry and address topics that have not been covered in earlier editions of the code, or topics that have been covered but for which new technology has necessitated a more focused set of performance and installation safety requirements.
One proposal is Article 302–Low-Voltage Suspended Ceiling Power Distribution Systems, the result of work prepared by members of the NEC dc Task Group. Look up at the ceiling in your office: it probably consists of a metal grid system with drop-in tiles that is suspended from the structure of the building. This type of ceiling system has been in use for years in residential, commercial, and institutional applications, and the NEC has covered the installation of electrical equipment supported by this type of ceiling system. The vast network of metal grid work in buildings can now be used not only to accommodate a means to drop in the ceiling tiles but also has an electrical distribution system. Article 302 provides installation requirements for ceiling systems that include busbars and their support systems for the distribution of Class 2 (Article 725 in the 2014 NEC) power systems. The article limits these systems to 30 volts ac or 60 volts dc and permits their installation inside residential, commercial, and industrial buildings. Lighting, control, and signaling equipment supplied by a suspended ceiling power distribution system must be a listed component of those systems.
The substantiation supporting inclusion of Article 302 cited that direct current derived from alternative energy sources such as photovoltaic arrays and wind turbines is increasingly being used to supply power directly to lighting and control equipment. The use of the extensive grid work of a suspended ceiling system to support an electrical distribution system is an efficient means of delivering power to electrical equipment installed in these ceiling systems, which are commonly used in many types of building construction.
I’ll look at the other proposed articles in the next issue of NFPA Journal. For more on proposed Article 302 and the 2014 NEC, visit nfpa.org/70. The closing date for comments on the NEC proposals is October 17, 2012.
Jeffrey Sargent is a regional electrical code specialist for NFPA.