Solar photovoltaic array combiners (solar panel combiner boxes) are commonly used to combine several solar panels (or strings of panels) into a common bus. They are basically junction boxes that are specially designed for the types of wiring used in PV systems. Array combiners are usually needed for larger systems, but even in small PV systems it can make wiring, monitoring, and future troubleshooting much easier. We recommend using breakers instead of fuses for 12 to 48 volt array combiners. In most cases fuses are required for higher voltage systems over 48 volts for either battery or grid tie.