Calculating short-circuit currents by hand

You won’t do many short-circuit hand calculations, but it’s useful to go through the exercise to develop an understanding of the fault behavior of typical electrical equipment. There are five you should get to know . . . . Continue reading “Calculating short-circuit currents by hand”

Three fault regions of a time-current plot

In a previous article I discussed the importance of coordination curves. Here I provide some home-made examples. Yep, you got it. Fashioned in the fires of Microsoft Powerpoint . . . . Continue reading “Three fault regions of a time-current plot”

Some basic protective-device principles

When you hear “protective device,” think “breakers” and “fuses.” It’s one thing to know how to size them correctly. It’s another thing to know why. But it can be expensive to learn the “why” . . . . Continue reading “Some basic protective-device principles”