The Voltacon BFS-S4 is a solar pv combiner box built for rooftop fire safety, combining six PV string inputs with rapid shutdown functionality. It gives installers a manual DC isolation point that firefighters can operate to cut string-level power in a fault or fire, reducing DC shock risk on the roof.

Solar pv combiner box with rapid shutdown

When the property's AC supply is switched off, the BFS-S4 disconnects all six DC strings at the same time, so the whole array is de-energised rather than just the AC side. Each of the 6 string inputs is paired with a matching output, rated at 50A per string, with paralleling permitted up to that current at 1500V DC.

Key features

• String-level shutdown, each of the 6 PV strings is isolated independently.
• Rating, 1500V DC, 50A per string.
• Simultaneous DC disconnect, triggered automatically when AC supply is removed.
• Thermal protection, automatic shutdown if the enclosure overheats.
• Installation, plug and play, with no interference to the inverter or Wi-Fi signal.
• Compatibility, works with most string inverters and solar panels.

Applications

Suited to residential and commercial rooftop solar PV systems, particularly installations that need to meet fire safety rapid shutdown requirements, or where firefighters need a dedicated DC isolation point.

Installation notes

Fit in line with the manufacturer's wiring guide and current electrical regulations. Position rapid shutdown devices so firefighters can access and operate them safely. All DC connections should be made by a qualified solar installer.