Since Underwriter’s Laboratory (UL) first published “Subject 2703 for Rack Mounting Systems and Clamping Devices for Flat-Plate Photovoltaic Modules and Panels” in October 2010, industry experts have been working on an ANSI consensus version of the standard to address “Rack Mounting Systems and Clamping Devices.” That work is nearing completion, and LinkUp is lucky to have SunLink’s very own Director of Electrical Products, Daniel, on hand to give us the full scoop. Daniel serves as chair of the UL standards technical panel task force responsible for developing an updated proposal for the standard.
“For the UL subject standard to become an ANSI standard it needs to go through a consensus process. UL forms a standards technical panel with representatives from the solar industry, testing laboratories and AHJ’s from around the country. This panel of experts then needs to achieve consensus on the final language of the standard through an official balloting process. This process of getting a room full of diverse experts to agree on the final language takes time.”
In 2012 the UL STP voted down a proposal to advance the original 2010 2703 language to an ANSI standard. Daniel explains: “The STP created our task group to address concerns and revise the 2703 language accordingly. We’ve been meeting once every three weeks via conference call to move the process along, it took a lot longer than we would have liked, but we finally were able to submit a revised version of the language for a new ballot this month. The process requires a 45 day comment review period before we actually perform the ballot process.”
In responding to industry comments, the task force has clarified definitions, significantly revised the mechanical loading requirements, provided guidelines on retesting and representative samples and tied the standard to the new fire testing standard language that allows for racking to achieve a system level fire classification rating.
“In all the work we’ve done, establishing re-testing guidelines has been the most controversial,” Daniel says. “Given the cost and time involved in the testing process, we certainly didn’t take the issue lightly. I think the industry will appreciate the exceptions we’ve now made for changes to racking hardware that fall within certain limits. Not every change to a racking system will require a retest.”
A 45-day comment period is underway, and a formal ballot will be issued in July. Once passed, the new and improved standard should be approved by ANSI and guide the industry for many years to come.