Per unit fault calculations is a method whereby system impedances and quantities are normalised across different voltage levels to a common base.  By removing...

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...

Visitors who like to type web address rather then click menus may be interested in how our URL structure works.

Cable insulation is used to provide electrical separation between conductors of  a cable.  During the historical development of cables, numerous types...

Following on from my post on railway electrification voltages, I thought an introduction to traction substations would be a good idea. Traction substations...

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...

If you want to check a circuit is dead (not live), you should always use the three point method. First check a known live circuit, then check the dead...

These lifts were first built in 1884 by J. E. Hall and called a paternoster ("Our Father", the first two words of the Lord's Prayer in Latin) due to its...

There are a lot of interesting two page type notes on various medium voltage topics – switchgear, circuit breakers, bus systems etc. It is on the Siemens...