Have you ever wondered why the square root of three shows up in so many three-phase power calculations?

Where does this number come from, and why is it so special?

While the long answer to these questions comes from trigonometry, the good news is that we can use phasor diagrams to make explaining it very simple to understand.

Understanding phasor diagrams is an important skill for relay testing and working through the examples in this article will give you a much deeper understanding of and appreciation for the phasor quantities in phasor diagrams. Regardless of which part of the industry you work in, this will greatly benefit your career in electrical power and relay testing.