Category Archives: Sizing cable

Articles here are about how to size cables.

Power cable sizing tips video

power-cable-sizing-tips

You might be surprised at what you can learn in under three minutes. . . .  Continue reading

Cable ampacity – insulation temperature rating vs. equipment terminal ratings

210H

This can be a confusing topic. The issue usually arises in nuclear power plants because most cable is rated at 90 degrees C, but equipment terminals are rated for 60 or 75 degrees C. Getting this wrong leads to costly rework down the line. Continue reading

Some non-electrical concerns to take into account when installing new cables

Installing new cables? There is a standard set of problems you need to be aware of. They aren’t necessarily electrical problems . . . . Continue reading

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

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 . . . .

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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

If your voltage-drop calculation fails

What do you do if, after sizing your cable and calculating voltage drop, your voltage drop exceeds what’s allowable? Continue reading

The importance of limiting voltage drop

You may not know that the National Electric Code doesn’t make complying with its voltage drop criteria mandatory. But there are still some important design factors that you need to keep in mind . . . . Continue reading