The full chain — utility service, transformer, main switchboard, distribution, panelboards, feeders, branch circuits, equipment — and why voltage, current, and protection choices change at every stage on the way down.
Every building sits at the end of the same chain, and this module walks it stage by stage: why the utility service voltage you negotiate up front constrains everything below it, what a transformer's percent impedance does to downstream fault current and equipment ratings, why the main switchboard's coordination study matters even on a fully code-compliant design, and how feeder and branch-circuit sizing compound ampacity, continuous-load, and voltage-drop requirements together rather than one at a time.
It closes at the equipment end of the chain, where every upstream decision — voltage, fault current, protection coordination — shows up as a real, measurable condition at the last foot of wire, which is exactly where Module 10's troubleshooting work and Module 8's motor-starting discussion both pick this chain back up.