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. Modern solar power stations—from residential rooftops to 1500V industrial arrays—depend heavily on high-quality electrical enclosures, advanced protection components, and intelligent data systems to maintain long-term reliability. But as the number of strings, cable runs and outdoor installation points. If you're wondering what is a combiner box as used in PV system, it's a device that connects multiple solar panel strings into a single output for your solar setup. As system scale increases, more strings need to be managed within a structured electrical layout.