What it is: A solar combiner box (also called a PV combiner box or DC combiner box) is an electrical enclosure that collects DC output from multiple solar panel strings, combines them onto a common busbar, and routes the combined power to the inverter — while providing overcurrent. What it is: A solar combiner box (also called a PV combiner box or DC combiner box) is an electrical enclosure that collects DC output from multiple solar panel strings, combines them onto a common busbar, and routes the combined power to the inverter — while providing overcurrent. A PV combiner box is an electrical enclosure that brings multiple solar string circuits together before the inverter or charge controller. In a typical solar PV system, each string produces DC power. The combiner box collects those string outputs, provides protection and switching functions, and. power and the technical characteristics of the modules. It simplifies the wiring going to the inverter, which can reduce material and labor costs.
