Fronius launches a new generation of its Rapid Shutdown Box, offering the most convenient solution for NEC 2014 (690.12) and NEC 2017 (Array Disconnect) compliance, while enhancing overall rooftop and firefighter safety. The new generation includes two versions: the Fronius Rapid Shutdown Box Duo and Quattro.
NEC 2014 requires PV system conductors away from the array to be brought down to a safe level so that firefighters can have assurance that they will not be exposed to potentially lethal voltage during firefighting operations. The National Electrical Code instructs us that the DC “homerun” conductors must be at no more than 30V and within 30 seconds of rapid shutdown initiation. The same requirement is in effect for NEC 2017 (Array Disconnect, until January 1st of 2019).
The second generation of the Fronius Rapid Shutdown Box provides installers with an even more convenient solution for this code requirement. “Based on customer feedback, we implemented many improvements into this new generation of our Rapid Shutdown Box”, says Michael Mendik, Head of Solutions Management at Fronius USA. “The low-profile design, as well as installer-friendly mounting and wiring options, make this solution the most convenient and cost effective one on the market”.
Directly connected to the inverter through the same conduit as the DC homeruns and powered by the array, the Fronius solution minimizes the number of components and eliminates the need for an external power supply. The low-profile design and the multiple mounting options allow for installation underneath the modules, ensuring a clean system look. In addition, the NEMA 4X rating ensures the box is built for severe outdoor conditions. MC4 connectors, spring loaded terminals and generous wiring space make the wiring a breeze. The Rapid Shutdown Box can also act as a combiner box, replacing a standard junction box, keeping the number of components low.
The new generation consists of two version. The smaller Fronius Rapid Shutdown Box DUO, for up to two strings, and the bigger Fronius Rapid Shutdown Box QUATTRO, for up to 4 strings. Both versions are compatible with all Fronius SnapINverters in systems up to 600 V (excluding the Fronius Symo 15.0 208 V).
Shipping of the Fronius Rapid Shutdown Box Duo (for up to 2 strings) starts as of now. The Fronius Rapid Shutdown Box Quattro (for up to 4 strings) starts shipping in November. Fronius continues to offer the existing Rapid Shutdown Box Multi (also for up to 4 strings) until the new Quattro version is available.
— Solar Builder magazine