Various techniques exist to enable the correct selection of batteries for UPS applications.  The procedure described below is one of the more common. ...

The other day I was reading 'Night of the New Magicians' by Mary Pope Osborn with my son.  The story is about a young boy and girl who travel back in time...

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

The following tables provide quick order of magnitude fault levels for a a range of typical low voltage situations.

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...

I was reminded of Occam's Razor while reading a book. It's quite a simple principal of logic which has stood the test of time and is accepted as central...

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

In electrical engineering, Network Theory is the study of how to solve circuit problems. By analyzing circuits, the engineer looks to determine the various...

The IEC publishes a series of documents and rules governing the preparation of documents, drawings and the referencing of equipment.   Depending on country...