The NEC 2014 section 690.12 requires new photovoltaic systems to have a rapid shutdown functionality, which de-energizes the array to less than 30 V within 10 seconds in order to enhance rooftop and firefighter safety. This code requirement has caused challenges throughout the solar industry, since many products are not able to accommodate such functionality. The Fronius Rapid Shutdown Box-Multi, shipping in May 2016, is a larger version of the previously released Fronius Rapid Shutdown Box-Single already available on the market.
When installed with Fronius SnapINverters, which include the Fronius Galvo, Fronius Primo and Fronius Symo inverter families, Fronius is able to offer a reliable, flexible and simple-to-install solution for SnapINverters ranging from 1.5 kW to 24.0 kW for 600 V DC applications. Installers benefit from reduced labor, quicker installation and reduced system costs since The Fronius Rapid Shutdown Boxes eliminate the need for external power supplies and any additional ground-level hardware. Additionally, the Fronius Rapid Shutdown Box eliminates the need for any extra conduit since it is directly connected to the inverter through the same DC conduit as the DC homeruns. The rapid shutdown function is initiated whenever AC is not present. Once triggered the DC lines are rapidly discharged by the Fronius SnapINverter.
The Fronius Rapid Shutdown Box can be mounted on the roof within 10 feet from the array, on the array or in the attic within 5 feet of the array. This flexibility affords the installer to choose the best option needed for safety compliance and limits the needs for extra hardware on the roof. Fronius is now accepting orders of both the Fronius Rapid Shutdown Box-Single and Multi versions.
News item from Fronius USA