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

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 ...

Our IEE cable sizing was wrote a few years ago and had become rough around the edges. I thought it was time to give the tool a service. Unfortunately when...

HTML supports a variety of entity symbols which can be entered using either numbers or an entity name.  The number or name is preceded by the ‘&’ sign...

Electromechanical relays have been the traditional backbone of electrical protection systems.  While over recent years these have been replaced by microprocessor...

This is the second post in a series of two on periodic electrical inspections. In the first post, I discussed how often inspections should be carried out...

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

The other day I came across an article in Technology Review on the development of a smart transformer. A professor at North Carolina State University is...

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...

Dielectrics (insulating materials for example) when subjected to a varying electric field, will have some energy loss.   The varying electric field causes...