UL Extends Low-Voltage Ceilings Standard - National Electrical Code is Next

March 21, 2013 by Jeff Shepard

Recognizing that DC power distribution would also be desirable in Canada and seeing no conflicts within the Canadian Electrical Code (CEC), the EMerge Alliance requested that UL partner with its Canadian affiliate (ULC, an accredited standards development organization in Canada) to pursue a harmonized US.-Canadian Standard. UL agreed, and in February 2013, upon completion of successful balloting from the bi-national technical committee, UL published the Standard for Suspended Ceiling Grid Low Voltage Systems and Equipment, ANSI UL 2577 / CAN ULC-S2577. This document now serves as the national standard for both the U.S. and Canada, with virtually no technical differences. This common platform establishes a North American safety certification system that promotes trade, creates expanded market opportunities, and maintains a uniform understanding of best practices for deployment of the next generation of suspended ceiling grid low voltage products.

As of 2008, the only provisions in the U.S. National Electrical Code (NEC) for low voltage systems (excluding the class 2 wiring methods addressed by Article 725) were for lighting, in Article 411. While this facilitated deployment and inspection authority acceptance of the suspended ceiling grid low-voltage lighting systems, the EMerge Alliance had a larger vision. The Alliance thus assembled task groups to develop proposals for the 2014 NEC, and seeing value in the effort, UL collaborated on several of these task groups. One result was the drafting of a new Article 393, for Low Voltage Suspended Ceiling Power Distribution Systems. That article has been successfully balloted and is awaiting publication in the 2014 NEC.

In anticipation of the new NEC Article, UL expanded the scope of UL 2577 to allow for other low voltage peripheral equipment (besides lighting) to be certified for use with the grid systems. Understanding the value of national standards where the equipment is subject to Code approvals, UL then proposed publication of UL 2577 as a U.S. national (ANSI) standard.

In late 2008, UL was asked to certify a Suspended Ceiling Grid Low Voltage Lighting System. The system consisted of grid rails that support suspended ceiling tiles but also carry low voltage current for use by luminaires and other ceiling (or above ceiling) mounted equipment such as audio speakers, ventilation controls, and security system devices. In June 2009, UL published UL 2577, the Outline of Investigation for Suspended Ceiling Grid Low Voltage Lighting Systems, to document the requirements developed to verify that these systems met the expected level of safety. In September, UL issued the first certification to Armstrong World Industries.

It is anticipated that UL will continue working with the EMerge Alliance on developing additional standards for DC power distribution, and developing certification programs to facilitate their acceptance and use throughout North America.