In a previous article I looked at the dc resistance of conductors and in this article we turn our attention to ac resistance. If you have not read the...

This article gives an introduction to IEEE 485 method for the selection and calculation of battery capacity.

In three phase systems, the use of transformers with three windings (or legs) per side is common.  These three windings are often connected in delta or...

Depending where in the world you work, you are likely following one of two standards International Electrotechnical Commission (IEC) National...

Over the past year or so I've been involved in on going discussions related to referring fault levels from the secondary of a transformer to the primary...

Over recent years the Lithium Ion battery has become popular in applications requiring high power densities with small weight and footprint.  Today Lithium...

A UPS is an uninterruptible power supply.  It is a device which maintains a continuous supply of electrical power, even in the event of failure of the...

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

I think this post is going to be helpful to several of our readers. While the IEC low voltage circuit breaker Standard [IEC 60947-2, Low voltage switchgear...

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 ...