Fault calculations are one of the most common types of calculation carried out during the design and analysis of electrical systems. These calculations...

Variable frequency drives are widely used to control the speed of ac motors.  This note looks at the mechanisms which enable drive units to control the...

Many questions sent in to the site are in connection with motor starting and in particular star-delta.  For all but the simplest application, there is...

For the past few years I have reading eBooks on my HTC touch phone. On and off I have debated buying an eReader and recently purchased a Sony PRS-300 ...

If two dissimilar metals are touching and an external conducting path exists, corrosion of one the metals can take place.  Moisture or other materials...

This post is quick introduction and overview to different railway electrification voltages used in answer to a question sent in via email. While there...

I was having a conversation the other day about voltage levels.  While everyone was in agreement that low voltage was 1000 V and less, there was more confusion...

The image (reproduced from IEC 60909) shows a typical fault in an ac system.  From the illustration it can seen that there is an initial dc component ...

Electrical notes are a collaborative collection of electrical engineering information and educational material. Any registered user can add content. ...

When selecting a cable, the performance of the cable under fault conditions is an important consideration. It is important that calculations be carried...