Electrical Design Calculator Bundle (3 workbooks)

If your work covers distribution boards, cables and solar, this bundle gives you our three IEC / metric design workbooks in one download. They are built to be used in order: balance the board and get its main breaker and feeder, size that feeder and every final circuit for current and voltage drop, then plan an off-grid or hybrid solar system for the same loads. The cable workbook handles up to 50 circuits, the panel schedule up to 60, and the solar workbook runs from a daily load table to PV strings, battery bank, controller and inverter. Each file has a Start Here sheet, a worked example and a printable PDF of that example. Scripts compared the formulas with a separate Python calculation across 34 test cases. These are estimation aids: check every result against the rules where you work.