Estimate the ideal inverter size for your grid-tied solar system based on solar array capacity, system losses, and inverter loading ratio (ILR). 3 for balanced performance. TWhen sizing a solar combiner box, it is important to consider the open-circuit voltage (Voc) of each module. While our previous article — How to Calculate PV Combiner Box Specifications? — provided a hands-on example, this article dives deeper into How to Match Your Solar Panels with. Here are some valuable system sizing and interconnection tips shared by our engineering team. This guide dives deep into the real-world do's and don'ts of solar inverter installation, helping homeowners.