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…
Short-circuits and faults
Archive
Category: Sizing Breakers
Three kinds of protective devices
There are three common types of protective devices you’ll encounter in the nuclear power industry. Here I summarize their functionality . . . .
Short-circuits and faults
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…
Sizing Breakers
Coordination curves
Sometimes you’ll need to use more exact methods for sizing your breakers than the rules given by the NEC . . . .
Sizing Breakers
Circuit breaker withstand ratings and overload conditions
These are two elementary characteristics inherent to any circuit breaker. If you get the trip rating right, but neglect one of these, you’ll be…
Sizing Breakers
A breaker’s primary function and electromagnetic forces
There’s a crucial link between circuit breakers and electromagnetics. There is good and bad . . . .
Sizing Breakers
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…
Sizing Breakers
Breaker sizing and short-circuits
Breaker sizing is another basic skill required for electrical engineers in the nuclear power industry. Here’s the short of it . . . .
Sizing Breakers