Datum precedence is a fundamental principle in the design and manufacture of mechanical parts and assemblies.
It refers to the order of importance assigned to different datums, which are specific points, lines, or planes on a part, which are used as references for measurement and geometric tolerances.
Phase Relationships Between Line-Neutral and Line-Line Voltages
Learners view a demonstration showing that line-neutral voltages and line-line voltages are not in-phase with each other, but have a definite 30-degree relationship.