And 2 Plus 2 = 4

So how exactly does one earn a "P.E." and a "DEE" (not to mention a 6-figure salary as Public Works Director) where you can't explain basic, grade-school level electricity off-the-cuff?

Now, of course, we presume that the request was for the difference (the measure of distinction) between single and 3-phase power, and not the deference (showing respect or regard) between single and 3-phase power. But with this bunch, you never know.

(click on image to enlarge)