With 63 strings needed total, using 16-input combiners gives us 4 boxes (63 ÷ 16 = 3. Here's where installers often trip up. Say we're designing a 500kW commercial array using 400W modules. 9375 isn't leftover pizza! You'll need to round up to 4. A solar combiner box is a crucial component in solar energy systems, designed to consolidate the outputs of multiple solar panel strings into a single output that connects to an inverter. Hidden behind the scenes is a critical piece of equipment: the PV combiner box. Its main purpose is to simplify the wiring structure, enhance system security and simplify maintenance procedures.