A 3-phase solar inverter duty transformer is a specialized transformer designed to work efficiently in conjunction with solar inverters in a photovoltaic (solar power) system. It ensures safe, reliable, and optimal performance by stepping up or stepping down the voltage as needed between the solar inverter and the electrical grid or the load. Power Ratings Use the required MVA or kVA rating as well as the inverter output voltage for necessary calculations. The transformer must be suitable for the total inverter capacity and the grid-side voltage. Potential for future expansion as well as the load profile and site conditions should also be taken into account while deciding the ratings.