PV Fire Testing from the Front Lines
July 1, 2014
There’s been a lot of talk in the solar racking industry lately about fire testing to certify that mounting systems meet then new UL 1703-2013 standard. As SunLink works to ensure all of its RMS products are compliant, LinkUp sat down with Mechanical Design Engineer Sara to learn more about her recent trip to the UL testing lab in Northridge, IL to supervise the testing of Precision-Modular RMS and to find out exactly what’s involved in the testing process.
“UL is testing three different configurations for every racking system – fire approaching the north edge, the south edge and east/west,” explained Sara. “The test assumes that the roof ignites first, and that the flames move toward the solar array from one of those three directions. The goal is to ensure the flames don’t advance more rapidly than a given distance in a set amount of time.”
Racking systems are required to demonstrate passing results twice for each configuration.
“It was fascinating to watch because flames are so unpredictable, and at this stage, there is still so much that we all have to learn about how solar systems affect fire’s behavior. In this test, it was easier to predict outcomes for the north and south edge configurations because Precision-Modular’s north edge features deflectors and the south edge is very close to the roof – both factors that restrict air flow and slow fire. We weren’t 100% sure what to expect with the east/west test, but as we expected, the fact that Precision-Modular’s ballast are placed underneath the modules proved to be a huge advantage, as that slowed the flames very effectively. We passed on our first attempt.”
Because the guidelines were already available during the product development process, Precision-Modular was specifically designed with UL 1703-2013 in mind. The system is among the first to have passed with Type 1 modules, and testing of Type 2 modules is underway.
“You can’t think about solar mounting system design from a purely structural and mechanical perspective. You have to take into account real world environmental factors like fire as well. By thinking more holistically about everything that a commercial roof might be subjected to during its lifetime, we’re able to design solar racking that installers and building owners can trust.”